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 int32_t site_max_start_pad = 4*4;
112 static cstring_t state_name(uint32_t state)
115 case 0: return "STOP";
116 case 1: return "RUN";
117 case 2: return "RESOLVE";
118 case 3: return "SENTMSG1";
119 case 4: return "SENTMSG2";
120 case 5: return "SENTMSG3";
121 case 6: return "SENTMSG4";
122 case 7: return "SENTMSG5";
123 case 8: return "WAIT";
124 default: return "*bad state*";
130 #define LOG_UNEXPECTED 0x00000001
131 #define LOG_SETUP_INIT 0x00000002
132 #define LOG_SETUP_TIMEOUT 0x00000004
133 #define LOG_ACTIVATE_KEY 0x00000008
134 #define LOG_TIMEOUT_KEY 0x00000010
135 #define LOG_SEC 0x00000020
136 #define LOG_STATE 0x00000040
137 #define LOG_DROP 0x00000080
138 #define LOG_DUMP 0x00000100
139 #define LOG_ERROR 0x00000400
140 #define LOG_PEER_ADDRS 0x00000800
142 static struct flagstr log_event_table[]={
143 { "unexpected", LOG_UNEXPECTED },
144 { "setup-init", LOG_SETUP_INIT },
145 { "setup-timeout", LOG_SETUP_TIMEOUT },
146 { "activate-key", LOG_ACTIVATE_KEY },
147 { "timeout-key", LOG_TIMEOUT_KEY },
148 { "security", LOG_SEC },
149 { "state-change", LOG_STATE },
150 { "packet-drop", LOG_DROP },
151 { "dump-packets", LOG_DUMP },
152 { "errors", LOG_ERROR },
153 { "peer-addrs", LOG_PEER_ADDRS },
154 { "default", LOG_SETUP_INIT|LOG_SETUP_TIMEOUT|
155 LOG_ACTIVATE_KEY|LOG_TIMEOUT_KEY|LOG_SEC|LOG_ERROR },
156 { "all", 0xffffffff },
161 /***** TRANSPORT PEERS declarations *****/
163 /* Details of "mobile peer" semantics:
165 - We use the same data structure for the different configurations,
166 but manage it with different algorithms.
168 - We record up to mobile_peers_max peer address/port numbers
169 ("peers") for key setup, and separately up to mobile_peers_max
172 - In general, we make a new set of addrs (see below) when we start
173 a new key exchange; the key setup addrs become the data transport
174 addrs when key setup complets.
176 If our peer is mobile:
178 - We send to all recent addresses of incoming packets, plus
179 initially all configured addresses (which we also expire).
181 - So, we record addrs of good incoming packets, as follows:
182 1. expire any peers last seen >120s ("mobile-peer-expiry") ago
183 2. add the peer of the just received packet to the applicable list
184 (possibly evicting the oldest entries to make room)
185 NB that we do not expire peers until an incoming packet arrives.
187 - If the peer has a configured address or name, we record them the
188 same way, but only as a result of our own initiation of key
189 setup. (We might evict some incoming packet addrs to make room.)
191 - The default number of addrs to keep is 3, or 4 if we have a
192 configured name or address. That's space for two configured
193 addresses (one IPv6 and one IPv4), plus two received addresses.
195 - Outgoing packets are sent to every recorded address in the
196 applicable list. Any unsupported[1] addresses are deleted from
197 the list right away. (This should only happen to configured
198 addresses, of course, but there is no need to check that.)
200 - When we successfully complete a key setup, we merge the key setup
201 peers into the data transfer peers.
203 [1] An unsupported address is one for whose AF we don't have a
204 socket (perhaps because we got EAFNOSUPPORT or some such) or for
205 which sendto gives ENETUNREACH.
207 If neither end is mobile:
209 - When peer initiated the key exchange, we use the incoming packet
212 - When we initiate the key exchange, we try configured addresses
213 until we get one which isn't unsupported then fixate on that.
215 - When we complete a key setup, we replace the data transport peers
216 with those from the key setup.
220 - We can't tell when local network setup changes so we can't cache
221 the unsupported addrs and completely remove the spurious calls to
222 sendto, but we can optimise things a bit by deprioritising addrs
223 which seem to be unsupported.
225 - Use only configured addresses. (Except, that if our peer
226 initiated a key exchange we use the incoming packet address until
227 our name resolution completes.)
229 - When we send a packet, try each address in turn; if addr
230 supported, put that address to the end of the list for future
231 packets, and go onto the next address.
233 - When we complete a key setup, we replace the data transport peers
234 with those from the key setup.
240 struct comm_addr addr;
244 /* configuration information */
245 /* runtime information */
247 transport_peer peers[MAX_PEER_ADDRS];
250 /* Basic operations on transport peer address sets */
251 static void transport_peers_clear(struct site *st, transport_peers *peers);
252 static int transport_peers_valid(transport_peers *peers);
253 static void transport_peers_copy(struct site *st, transport_peers *dst,
254 const transport_peers *src);
256 /* Record address of incoming setup packet; resp. data packet. */
257 static void transport_setup_msgok(struct site *st, const struct comm_addr *a);
258 static void transport_data_msgok(struct site *st, const struct comm_addr *a);
260 /* Initialise the setup addresses. Called before we send the first
261 * packet in a key exchange. If we are the initiator, as a result of
262 * resolve completing (or being determined not to be relevant) or an
263 * incoming PROD; if we are the responder, as a result of the MSG1. */
264 static bool_t transport_compute_setupinit_peers(struct site *st,
265 const struct comm_addr *configured_addrs /* 0 if none or not found */,
266 int n_configured_addrs /* 0 if none or not found */,
267 const struct comm_addr *incoming_packet_addr /* 0 if none */);
269 /* Called if we are the responder in a key setup, when the resolve
270 * completes. transport_compute_setupinit_peers will hvae been called
271 * earlier. If _complete is called, we are still doing the key setup
272 * (and we should use the new values for both the rest of the key
273 * setup and the ongoing data exchange); if _tardy is called, the key
274 * setup is done (either completed or not) and only the data peers are
276 static void transport_resolve_complete(struct site *st,
277 const struct comm_addr *addrs, int naddrs);
278 static void transport_resolve_complete_tardy(struct site *st,
279 const struct comm_addr *addrs, int naddrs);
281 static void transport_xmit(struct site *st, transport_peers *peers,
282 struct buffer_if *buf, bool_t candebug);
284 /***** END of transport peers declarations *****/
288 struct transform_inst_if *transform;
289 uint64_t key_timeout; /* End of life of current key */
290 uint32_t remote_session_id;
296 /* configuration information */
300 bool_t local_mobile, peer_mobile; /* Mobile client support */
301 int32_t transport_peers_max;
302 string_t tunname; /* localname<->remotename by default, used in logs */
303 cstring_t *addresses; /* DNS name or address(es) for bootstrapping, optional */
304 int remoteport; /* Port for bootstrapping, optional */
306 struct netlink_if *netlink;
307 struct comm_if **comms;
308 struct comm_clientinfo **commclientinfos;
310 struct resolver_if *resolver;
312 struct random_if *random;
313 struct rsaprivkey_if *privkey;
314 struct rsapubkey_if *pubkey;
315 struct transform_if **transforms;
318 struct hash_if *hash;
320 uint32_t index; /* Index of this site */
321 uint32_t early_capabilities;
322 uint32_t local_capabilities;
323 int32_t setup_retries; /* How many times to send setup packets */
324 int32_t setup_retry_interval; /* Initial timeout for setup packets */
325 int32_t wait_timeout_mean; /* How long to wait if setup unsuccessful */
326 int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
327 int32_t key_lifetime; /* How long a key lasts once set up */
328 int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
329 after this time, initiate a new
332 bool_t our_name_later; /* our name > peer name */
335 /* runtime information */
337 uint64_t now; /* Most recently seen time */
338 bool_t allow_send_prod;
339 bool_t msg1_crossed_logged;
341 int resolving_n_results_all;
342 int resolving_n_results_stored;
343 struct comm_addr resolving_results[MAX_PEER_ADDRS];
345 /* The currently established session */
346 struct data_key current;
347 struct data_key auxiliary_key;
348 bool_t auxiliary_is_new;
349 uint64_t renegotiate_key_time; /* When we can negotiate a new key */
350 uint64_t auxiliary_renegotiate_key_time;
351 transport_peers peers; /* Current address(es) of peer for data traffic */
353 /* The current key setup protocol exchange. We can only be
354 involved in one of these at a time. There's a potential for
355 denial of service here (the attacker keeps sending a setup
356 packet; we keep trying to continue the exchange, and have to
357 timeout before we can listen for another setup packet); perhaps
358 we should keep a list of 'bad' sources for setup packets. */
359 uint32_t remote_capabilities;
360 uint16_t remote_adv_mtu;
361 struct transform_if *chosen_transform;
362 uint32_t setup_session_id;
363 transport_peers setup_peers;
364 uint8_t localN[NONCELEN]; /* Nonces for key exchange */
365 uint8_t remoteN[NONCELEN];
366 struct buffer_if buffer; /* Current outgoing key exchange packet */
367 struct buffer_if scratch;
368 int32_t retries; /* Number of retries remaining */
369 uint64_t timeout; /* Timeout for current state */
371 uint8_t *sharedsecret;
372 uint32_t sharedsecretlen, sharedsecretallocd;
373 struct transform_inst_if *new_transform; /* For key setup/verify */
376 static uint32_t event_log_priority(struct site *st, uint32_t event)
378 if (!(event&st->log_events))
381 case LOG_UNEXPECTED: return M_INFO;
382 case LOG_SETUP_INIT: return M_INFO;
383 case LOG_SETUP_TIMEOUT: return M_NOTICE;
384 case LOG_ACTIVATE_KEY: return M_INFO;
385 case LOG_TIMEOUT_KEY: return M_INFO;
386 case LOG_SEC: return M_SECURITY;
387 case LOG_STATE: return M_DEBUG;
388 case LOG_DROP: return M_DEBUG;
389 case LOG_DUMP: return M_DEBUG;
390 case LOG_ERROR: return M_ERR;
391 case LOG_PEER_ADDRS: return M_DEBUG;
392 default: return M_ERR;
396 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
398 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
402 class=event_log_priority(st, event);
404 slilog_part(st->log,class,"%s: ",st->tunname);
405 vslilog_part(st->log,class,msg,ap);
406 slilog_part(st->log,class,"\n");
410 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
412 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
416 vslog(st,event,msg,ap);
420 static void logtimeout(struct site *st, const char *fmt, ...)
422 static void logtimeout(struct site *st, const char *fmt, ...)
424 uint32_t class=event_log_priority(st,LOG_SETUP_TIMEOUT);
431 slilog_part(st->log,class,"%s: ",st->tunname);
432 vslilog_part(st->log,class,fmt,ap);
436 for (i=0, delim=" (tried ";
437 i<st->setup_peers.npeers;
439 transport_peer *peer=&st->setup_peers.peers[i];
440 const char *s=comm_addr_to_string(&peer->addr);
441 slilog_part(st->log,class,"%s%s",delim,s);
444 slilog_part(st->log,class,")\n");
448 static void set_link_quality(struct site *st);
449 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
450 static void delete_one_key(struct site *st, struct data_key *key,
451 const char *reason /* may be 0 meaning don't log*/,
452 const char *which /* ignored if !reasonn */,
453 uint32_t loglevel /* ignored if !reasonn */);
454 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
455 const struct comm_addr *prod_hint);
456 static void enter_state_run(struct site *st);
457 static bool_t enter_state_resolve(struct site *st);
458 static void decrement_resolving_count(struct site *st, int by);
459 static bool_t enter_new_state(struct site *st,uint32_t next);
460 static void enter_state_wait(struct site *st);
461 static void activate_new_key(struct site *st);
463 static bool_t is_transform_valid(struct transform_inst_if *transform)
465 return transform && transform->valid(transform->st);
468 static bool_t current_valid(struct site *st)
470 return is_transform_valid(st->current.transform);
473 #define DEFINE_CALL_TRANSFORM(fwdrev) \
474 static transform_apply_return \
475 call_transform_##fwdrev(struct site *st, \
476 struct transform_inst_if *transform, \
477 struct buffer_if *buf, \
478 const char **errmsg) \
480 if (!is_transform_valid(transform)) { \
481 *errmsg="transform not set up"; \
482 return transform_apply_err; \
484 return transform->fwdrev(transform->st,buf,errmsg); \
487 DEFINE_CALL_TRANSFORM(forwards)
488 DEFINE_CALL_TRANSFORM(reverse)
490 static void dispose_transform(struct transform_inst_if **transform_var)
492 struct transform_inst_if *transform=*transform_var;
494 transform->delkey(transform->st);
495 transform->destroy(transform->st);
500 #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
501 #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
502 #define CHECK_TYPE(b,t) do { uint32_t type; \
503 CHECK_AVAIL((b),4); \
504 type=buf_unprepend_uint32((b)); \
505 if (type!=(t)) return False; } while(0)
507 static _Bool type_is_msg34(uint32_t type)
510 type == LABEL_MSG3 ||
511 type == LABEL_MSG3BIS ||
518 struct buffer_if extrainfo;
525 struct parsedname remote;
526 struct parsedname local;
527 uint32_t remote_capabilities;
529 int capab_transformnum;
539 static int32_t wait_timeout(struct site *st) {
540 int32_t t = st->wait_timeout_mean;
543 st->random->generate(st->random->st,sizeof(factor),&factor);
544 t += (t / 256) * factor;
549 static _Bool set_new_transform(struct site *st, char *pk)
553 /* Make room for the shared key */
554 st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
555 assert(st->sharedsecretlen);
556 if (st->sharedsecretlen > st->sharedsecretallocd) {
557 st->sharedsecretallocd=st->sharedsecretlen;
558 st->sharedsecret=safe_realloc_ary(st->sharedsecret,1,
559 st->sharedsecretallocd,
560 "site:sharedsecret");
563 /* Generate the shared key */
564 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,pk,
565 st->sharedsecret,st->sharedsecretlen);
567 /* Set up the transform */
568 struct transform_if *generator=st->chosen_transform;
569 struct transform_inst_if *generated=generator->create(generator->st);
570 ok = generated->setkey(generated->st,st->sharedsecret,
571 st->sharedsecretlen,st->our_name_later);
573 dispose_transform(&st->new_transform);
574 if (!ok) return False;
575 st->new_transform=generated;
577 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
578 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
579 st->chosen_transform->capab_bit,
580 st->local_capabilities, st->remote_capabilities);
585 int32_t lenpos, afternul;
587 static void append_string_xinfo_start(struct buffer_if *buf,
588 struct xinfoadd *xia,
590 /* Helps construct one of the names with additional info as found
591 * in MSG1..4. Call this function first, then append all the
592 * desired extra info (not including the nul byte) to the buffer,
593 * then call append_string_xinfo_done. */
595 xia->lenpos = buf->size;
596 buf_append_string(buf,str);
597 buf_append_uint8(buf,0);
598 xia->afternul = buf->size;
600 static void append_string_xinfo_done(struct buffer_if *buf,
601 struct xinfoadd *xia)
603 /* we just need to adjust the string length */
604 if (buf->size == xia->afternul) {
605 /* no extra info, strip the nul too */
606 buf_unappend_uint8(buf);
608 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
612 /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
613 out using a transform of config data supplied by netlink */
614 static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what)
620 st->retries=st->setup_retries;
621 BUF_ALLOC(&st->buffer,what);
622 buffer_init(&st->buffer,0);
623 buf_append_uint32(&st->buffer,
624 (type==LABEL_MSG1?0:st->setup_session_id));
625 buf_append_uint32(&st->buffer,st->index);
626 buf_append_uint32(&st->buffer,type);
629 append_string_xinfo_start(&st->buffer,&xia,st->localname);
630 if ((st->local_capabilities & st->early_capabilities) ||
631 (type != LABEL_MSG1)) {
632 buf_append_uint32(&st->buffer,st->local_capabilities);
634 if (type_is_msg34(type)) {
635 buf_append_uint16(&st->buffer,st->mtu_target);
637 append_string_xinfo_done(&st->buffer,&xia);
639 buf_append_string(&st->buffer,st->remotename);
640 BUF_ADD_OBJ(append,&st->buffer,st->localN);
641 if (type==LABEL_MSG1) return True;
642 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
643 if (type==LABEL_MSG2) return True;
645 if (hacky_par_mid_failnow()) return False;
647 if (type==LABEL_MSG3BIS)
648 buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
650 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
651 buf_append_string(&st->buffer,dhpub);
653 hash=safe_malloc(st->hash->len, "generate_msg");
654 hst=st->hash->init();
655 st->hash->update(hst,st->buffer.start,st->buffer.size);
656 st->hash->final(hst,hash);
657 sig=st->privkey->sign(st->privkey->st,hash,st->hash->len);
658 buf_append_string(&st->buffer,sig);
664 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
667 nm->len=buf_unprepend_uint16(msg);
668 CHECK_AVAIL(msg,nm->len);
669 nm->name=buf_unprepend(msg,nm->len);
670 uint8_t *nul=memchr(nm->name,0,nm->len);
672 buffer_readonly_view(&nm->extrainfo,0,0);
674 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
675 nm->len=nul-nm->name;
680 static bool_t unpick_msg(struct site *st, uint32_t type,
681 struct buffer_if *msg, struct msg *m)
683 m->capab_transformnum=-1;
684 m->hashstart=msg->start;
686 m->dest=buf_unprepend_uint32(msg);
688 m->source=buf_unprepend_uint32(msg);
689 CHECK_TYPE(msg,type);
690 if (!unpick_name(msg,&m->remote)) return False;
691 m->remote_capabilities=0;
693 if (m->remote.extrainfo.size) {
694 CHECK_AVAIL(&m->remote.extrainfo,4);
695 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
697 if (type_is_msg34(type) && m->remote.extrainfo.size) {
698 CHECK_AVAIL(&m->remote.extrainfo,2);
699 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
701 if (!unpick_name(msg,&m->local)) return False;
702 if (type==LABEL_PROD) {
706 CHECK_AVAIL(msg,NONCELEN);
707 m->nR=buf_unprepend(msg,NONCELEN);
708 if (type==LABEL_MSG1) {
712 CHECK_AVAIL(msg,NONCELEN);
713 m->nL=buf_unprepend(msg,NONCELEN);
714 if (type==LABEL_MSG2) {
718 if (type==LABEL_MSG3BIS) {
720 m->capab_transformnum = buf_unprepend_uint8(msg);
722 m->capab_transformnum = CAPAB_BIT_ANCIENTTRANSFORM;
725 m->pklen=buf_unprepend_uint16(msg);
726 CHECK_AVAIL(msg,m->pklen);
727 m->pk=buf_unprepend(msg,m->pklen);
728 m->hashlen=msg->start-m->hashstart;
730 m->siglen=buf_unprepend_uint16(msg);
731 CHECK_AVAIL(msg,m->siglen);
732 m->sig=buf_unprepend(msg,m->siglen);
735 /* In `process_msg3_msg4' below, we assume that we can write a nul
736 * terminator following the signature. Make sure there's enough space.
738 if (msg->start >= msg->base + msg->alloclen)
744 static bool_t name_matches(const struct parsedname *nm, const char *expected)
746 int expected_len=strlen(expected);
748 nm->len == expected_len &&
749 !memcmp(nm->name, expected, expected_len);
752 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
755 if (type==LABEL_MSG1) return True;
757 /* Check that the site names and our nonce have been sent
758 back correctly, and then store our peer's nonce. */
759 if (!name_matches(&m->remote,st->remotename)) {
760 *error="wrong remote site name";
763 if (!name_matches(&m->local,st->localname)) {
764 *error="wrong local site name";
767 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
768 *error="wrong locally-generated nonce";
771 if (type==LABEL_MSG2) return True;
772 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
773 *error="wrong remotely-generated nonce";
776 /* MSG3 has complicated rules about capabilities, which are
777 * handled in process_msg3. */
778 if (type==LABEL_MSG3 || type==LABEL_MSG3BIS) return True;
779 if (m->remote_capabilities!=st->remote_capabilities) {
780 *error="remote capabilities changed";
783 if (type==LABEL_MSG4) return True;
784 *error="unknown message type";
788 static bool_t generate_msg1(struct site *st)
790 st->random->generate(st->random->st,NONCELEN,st->localN);
791 return generate_msg(st,LABEL_MSG1,"site:MSG1");
794 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
795 const struct comm_addr *src, struct msg *m)
797 /* We've already determined we're in an appropriate state to
798 process an incoming MSG1, and that the MSG1 has correct values
801 st->setup_session_id=m->source;
802 st->remote_capabilities=m->remote_capabilities;
803 memcpy(st->remoteN,m->nR,NONCELEN);
807 static bool_t generate_msg2(struct site *st)
809 st->random->generate(st->random->st,NONCELEN,st->localN);
810 return generate_msg(st,LABEL_MSG2,"site:MSG2");
813 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
814 const struct comm_addr *src)
819 if (!unpick_msg(st,LABEL_MSG2,msg2,&m)) return False;
820 if (!check_msg(st,LABEL_MSG2,&m,&err)) {
821 slog(st,LOG_SEC,"msg2: %s",err);
824 st->setup_session_id=m.source;
825 st->remote_capabilities=m.remote_capabilities;
827 /* Select the transform to use */
829 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
830 if (!remote_crypto_caps)
831 /* old secnets only had this one transform */
832 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
834 #define CHOOSE_CRYPTO(kind, whats) do { \
835 struct kind##_if *iface; \
836 uint32_t bit, ours = 0; \
838 for (i= 0; i < st->n##kind##s; i++) { \
839 iface=st->kind##s[i]; \
840 bit = 1UL << iface->capab_bit; \
841 if (bit & remote_crypto_caps) goto kind##_found; \
844 slog(st,LOG_ERROR,"no " whats " in common" \
845 " (us %#"PRIx32"; them: %#"PRIx32")", \
846 st->local_capabilities & ours, remote_crypto_caps); \
849 st->chosen_##kind = iface; \
852 CHOOSE_CRYPTO(transform, "transforms");
856 memcpy(st->remoteN,m.nR,NONCELEN);
860 static bool_t generate_msg3(struct site *st)
862 /* Now we have our nonce and their nonce. Think of a secret key,
863 and create message number 3. */
864 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
865 return generate_msg(st,
866 (st->remote_capabilities & CAPAB_TRANSFORM_MASK
867 ? LABEL_MSG3BIS : LABEL_MSG3),
871 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
876 /* Check signature and store g^x mod m */
877 hash=safe_malloc(st->hash->len, "process_msg3_msg4");
878 hst=st->hash->init();
879 st->hash->update(hst,m->hashstart,m->hashlen);
880 st->hash->final(hst,hash);
881 /* Terminate signature with a '0' - already checked that this will fit */
883 if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m->sig)) {
884 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
890 st->remote_adv_mtu=m->remote_mtu;
895 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
896 const struct comm_addr *src, uint32_t msgtype)
901 assert(msgtype==LABEL_MSG3 || msgtype==LABEL_MSG3BIS);
903 if (!unpick_msg(st,msgtype,msg3,&m)) return False;
904 if (!check_msg(st,msgtype,&m,&err)) {
905 slog(st,LOG_SEC,"msg3: %s",err);
908 uint32_t capab_adv_late = m.remote_capabilities
909 & ~st->remote_capabilities & st->early_capabilities;
910 if (capab_adv_late) {
911 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
912 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
913 capab_adv_late, st->remote_capabilities, m.remote_capabilities);
917 #define CHOSE_CRYPTO(kind, what) do { \
918 struct kind##_if *iface; \
920 for (i=0; i<st->n##kind##s; i++) { \
921 iface=st->kind##s[i]; \
922 if (iface->capab_bit == m.capab_##kind##num) \
925 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
926 m.capab_##kind##num); \
929 st->chosen_##kind=iface; \
932 CHOSE_CRYPTO(transform, "transform");
936 if (!process_msg3_msg4(st,&m))
939 /* Update our idea of the remote site's capabilities, now that we've
940 * verified that its message was authentic.
942 * Our previous idea of the remote site's capabilities came from the
943 * unauthenticated MSG1. We've already checked that this new message
944 * doesn't change any of the bits we relied upon in the past, but it may
945 * also have set additional capability bits. We simply throw those away
946 * now, and use the authentic capabilities from this MSG3. */
947 st->remote_capabilities=m.remote_capabilities;
949 /* Terminate their DH public key with a '0' */
951 /* Invent our DH secret key */
952 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
954 /* Generate the shared key and set up the transform */
955 if (!set_new_transform(st,m.pk)) return False;
960 static bool_t generate_msg4(struct site *st)
962 /* We have both nonces, their public key and our private key. Generate
963 our public key, sign it and send it to them. */
964 return generate_msg(st,LABEL_MSG4,"site:MSG4");
967 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
968 const struct comm_addr *src)
973 if (!unpick_msg(st,LABEL_MSG4,msg4,&m)) return False;
974 if (!check_msg(st,LABEL_MSG4,&m,&err)) {
975 slog(st,LOG_SEC,"msg4: %s",err);
979 if (!process_msg3_msg4(st,&m))
982 /* Terminate their DH public key with a '0' */
985 /* Generate the shared key and set up the transform */
986 if (!set_new_transform(st,m.pk)) return False;
997 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1000 CHECK_AVAIL(msg0,4);
1001 m->dest=buf_unprepend_uint32(msg0);
1002 CHECK_AVAIL(msg0,4);
1003 m->source=buf_unprepend_uint32(msg0);
1004 CHECK_AVAIL(msg0,4);
1005 m->type=buf_unprepend_uint32(msg0);
1007 /* Leaves transformed part of buffer untouched */
1010 static bool_t generate_msg5(struct site *st)
1012 cstring_t transform_err;
1014 BUF_ALLOC(&st->buffer,"site:MSG5");
1015 /* We are going to add four words to the message */
1016 buffer_init(&st->buffer,calculate_max_start_pad());
1017 /* Give the netlink code an opportunity to put its own stuff in the
1018 message (configuration information, etc.) */
1019 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1020 if (call_transform_forwards(st,st->new_transform,
1021 &st->buffer,&transform_err))
1023 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1024 buf_prepend_uint32(&st->buffer,st->index);
1025 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1027 st->retries=st->setup_retries;
1031 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1032 const struct comm_addr *src,
1033 struct transform_inst_if *transform)
1036 cstring_t transform_err;
1038 if (!unpick_msg0(st,msg5,&m)) return False;
1040 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1041 /* There's a problem */
1042 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1045 /* Buffer should now contain untransformed PING packet data */
1046 CHECK_AVAIL(msg5,4);
1047 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1048 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1051 /* Older versions of secnet used to write some config data here
1052 * which we ignore. So we don't CHECK_EMPTY */
1056 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1057 uint32_t session_id)
1059 cstring_t transform_err;
1061 BUF_ALLOC(&st->buffer,"site:MSG6");
1062 /* We are going to add four words to the message */
1063 buffer_init(&st->buffer,calculate_max_start_pad());
1064 /* Give the netlink code an opportunity to put its own stuff in the
1065 message (configuration information, etc.) */
1066 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1067 transform_apply_return problem =
1068 call_transform_forwards(st,transform,
1069 &st->buffer,&transform_err);
1071 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1072 buf_prepend_uint32(&st->buffer,st->index);
1073 buf_prepend_uint32(&st->buffer,session_id);
1076 static bool_t generate_msg6(struct site *st)
1078 if (!is_transform_valid(st->new_transform))
1080 create_msg6(st,st->new_transform,st->setup_session_id);
1081 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1085 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1086 const struct comm_addr *src)
1089 cstring_t transform_err;
1091 if (!unpick_msg0(st,msg6,&m)) return False;
1093 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1094 /* There's a problem */
1095 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1098 /* Buffer should now contain untransformed PING packet data */
1099 CHECK_AVAIL(msg6,4);
1100 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1101 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1104 /* Older versions of secnet used to write some config data here
1105 * which we ignore. So we don't CHECK_EMPTY */
1109 static transform_apply_return
1110 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1111 const struct comm_addr *src)
1113 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1115 transform_apply_return problem;
1117 if (!unpick_msg0(st,msg0,&m)) return False;
1119 /* Keep a copy so we can try decrypting it with multiple keys */
1120 buffer_copy(&st->scratch, msg0);
1122 problem = call_transform_reverse(st,st->current.transform,
1123 msg0,&transform_err);
1125 if (!st->auxiliary_is_new)
1126 delete_one_key(st,&st->auxiliary_key,
1127 "peer has used new key","auxiliary key",LOG_SEC);
1130 if (transform_apply_return_badseq(problem))
1133 buffer_copy(msg0, &st->scratch);
1134 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1137 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1138 if (st->auxiliary_is_new) {
1139 /* We previously timed out in state SENTMSG5 but it turns
1140 * out that our peer did in fact get our MSG5 and is
1141 * using the new key. So we should switch to it too. */
1142 /* This is a bit like activate_new_key. */
1145 st->current=st->auxiliary_key;
1146 st->auxiliary_key=t;
1148 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1149 "previous key",LOG_SEC);
1150 st->auxiliary_is_new=0;
1151 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1155 if (transform_apply_return_badseq(problem))
1158 if (st->state==SITE_SENTMSG5) {
1159 buffer_copy(msg0, &st->scratch);
1160 problem = call_transform_reverse(st,st->new_transform,
1163 /* It looks like we didn't get the peer's MSG6 */
1164 /* This is like a cut-down enter_new_state(SITE_RUN) */
1165 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1166 BUF_FREE(&st->buffer);
1168 activate_new_key(st);
1169 return 0; /* do process the data in this packet */
1171 if (transform_apply_return_badseq(problem))
1175 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1176 transform_err,auxkey_err,newkey_err);
1177 initiate_key_setup(st,"incoming message would not decrypt",0);
1178 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1183 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1188 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1189 const struct comm_addr *src)
1192 transform_apply_return problem;
1194 problem = decrypt_msg0(st,msg0,src);
1195 if (problem==transform_apply_seqdupe) {
1196 /* We recently received another copy of this packet, maybe due
1197 * to polypath. That's not a problem; indeed, for the
1198 * purposes of transport address management it is a success.
1199 * But we don't want to process the packet. */
1200 transport_data_msgok(st,src);
1206 CHECK_AVAIL(msg0,4);
1207 type=buf_unprepend_uint32(msg0);
1210 /* We must forget about the current session. */
1211 delete_keys(st,"request from peer",LOG_SEC);
1212 /* probably, the peer is shutting down, and this is going to fail,
1213 * but we need to be trying to bring the link up again */
1215 initiate_key_setup(st,"peer requested key teardown",0);
1218 /* Deliver to netlink layer */
1219 st->netlink->deliver(st->netlink->st,msg0);
1220 transport_data_msgok(st,src);
1221 /* See whether we should start negotiating a new key */
1222 if (st->now > st->renegotiate_key_time)
1223 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1226 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1233 static void dump_packet(struct site *st, struct buffer_if *buf,
1234 const struct comm_addr *addr, bool_t incoming,
1237 uint32_t dest=get_uint32(buf->start);
1238 uint32_t source=get_uint32(buf->start+4);
1239 uint32_t msgtype=get_uint32(buf->start+8);
1241 if (st->log_events & LOG_DUMP)
1242 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1243 st->tunname,incoming?"incoming":"outgoing",
1244 dest,source,msgtype,comm_addr_to_string(addr),
1248 static bool_t comm_addr_sendmsg(struct site *st,
1249 const struct comm_addr *dest,
1250 struct buffer_if *buf)
1253 struct comm_clientinfo *commclientinfo = 0;
1255 for (i=0; i < st->ncomms; i++) {
1256 if (st->comms[i] == dest->comm) {
1257 commclientinfo = st->commclientinfos[i];
1261 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1264 static uint32_t site_status(void *st)
1269 static bool_t send_msg(struct site *st)
1271 if (st->retries>0) {
1272 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1273 st->timeout=st->now+st->setup_retry_interval;
1276 } else if (st->state==SITE_SENTMSG5) {
1277 logtimeout(st,"timed out sending MSG5, stashing new key");
1278 /* We stash the key we have produced, in case it turns out that
1279 * our peer did see our MSG5 after all and starts using it. */
1280 /* This is a bit like some of activate_new_key */
1281 struct transform_inst_if *t;
1282 t=st->auxiliary_key.transform;
1283 st->auxiliary_key.transform=st->new_transform;
1284 st->new_transform=t;
1285 dispose_transform(&st->new_transform);
1287 st->auxiliary_is_new=1;
1288 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1289 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1290 st->auxiliary_key.remote_session_id=st->setup_session_id;
1292 enter_state_wait(st);
1295 logtimeout(st,"timed out sending key setup packet "
1296 "(in state %s)",state_name(st->state));
1297 enter_state_wait(st);
1302 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1303 int stored_naddrs, int all_naddrs,
1304 const char *address, const char *failwhy)
1306 struct site *st=sst;
1308 if (!stored_naddrs) {
1309 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1311 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1312 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1314 int space=st->transport_peers_max-st->resolving_n_results_stored;
1315 int n_tocopy=MIN(stored_naddrs,space);
1316 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1319 st->resolving_n_results_stored += n_tocopy;
1320 st->resolving_n_results_all += all_naddrs;
1323 decrement_resolving_count(st,1);
1326 static void decrement_resolving_count(struct site *st, int by)
1328 assert(st->resolving_count>0);
1329 st->resolving_count-=by;
1331 if (st->resolving_count)
1334 /* OK, we are done with them all. Handle combined results. */
1336 const struct comm_addr *addrs=st->resolving_results;
1337 int naddrs=st->resolving_n_results_stored;
1338 assert(naddrs<=st->transport_peers_max);
1341 if (naddrs != st->resolving_n_results_all) {
1342 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1343 " yielded too many results (%d > %d), some ignored",
1344 st->resolving_n_results_all, naddrs);
1346 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1347 naddrs, iaddr_to_string(&addrs[0].ia));;
1350 switch (st->state) {
1352 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1353 enter_new_state(st,SITE_SENTMSG1);
1355 /* Can't figure out who to try to to talk to */
1356 slog(st,LOG_SETUP_INIT,
1357 "key exchange failed: cannot find peer address");
1358 enter_state_run(st);
1361 case SITE_SENTMSG1: case SITE_SENTMSG2:
1362 case SITE_SENTMSG3: case SITE_SENTMSG4:
1365 /* We start using the address immediately for data too.
1366 * It's best to store it in st->peers now because we might
1367 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1368 * the new key (without updating the data peer addrs). */
1369 transport_resolve_complete(st,addrs,naddrs);
1370 } else if (st->local_mobile) {
1371 /* We can't let this rest because we may have a peer
1372 * address which will break in the future. */
1373 slog(st,LOG_SETUP_INIT,"resolution failed: "
1374 "abandoning key exchange");
1375 enter_state_wait(st);
1377 slog(st,LOG_SETUP_INIT,"resolution failed: "
1378 " continuing to use source address of peer's packets"
1379 " for key exchange and ultimately data");
1384 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1385 " updating peer address(es)");
1386 transport_resolve_complete_tardy(st,addrs,naddrs);
1387 } else if (st->local_mobile) {
1388 /* Not very good. We should queue (another) renegotiation
1389 * so that we can update the peer address. */
1390 st->key_renegotiate_time=st->now+wait_timeout(st);
1392 slog(st,LOG_SETUP_INIT,"resolution failed: "
1393 " continuing to use source address of peer's packets");
1403 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1404 const struct comm_addr *prod_hint)
1406 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1407 if (st->state!=SITE_RUN) return False;
1408 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1409 if (st->addresses) {
1410 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1411 return enter_state_resolve(st);
1412 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1413 return enter_new_state(st,SITE_SENTMSG1);
1415 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1419 static void activate_new_key(struct site *st)
1421 struct transform_inst_if *t;
1423 /* We have three transform instances, which we swap between old,
1425 t=st->auxiliary_key.transform;
1426 st->auxiliary_key.transform=st->current.transform;
1427 st->current.transform=st->new_transform;
1428 st->new_transform=t;
1429 dispose_transform(&st->new_transform);
1432 st->auxiliary_is_new=0;
1433 st->auxiliary_key.key_timeout=st->current.key_timeout;
1434 st->current.key_timeout=st->now+st->key_lifetime;
1435 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1436 transport_peers_copy(st,&st->peers,&st->setup_peers);
1437 st->current.remote_session_id=st->setup_session_id;
1439 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1440 * But their mtu be unspecified, in which case we just use ours. */
1441 uint32_t intersite_mtu=
1442 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1443 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1445 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1446 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1447 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1448 enter_state_run(st);
1451 static void delete_one_key(struct site *st, struct data_key *key,
1452 cstring_t reason, cstring_t which, uint32_t loglevel)
1454 if (!is_transform_valid(key->transform)) return;
1455 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1456 dispose_transform(&key->transform);
1460 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1462 if (current_valid(st)) {
1463 slog(st,loglevel,"session closed (%s)",reason);
1465 delete_one_key(st,&st->current,0,0,0);
1466 set_link_quality(st);
1468 delete_one_key(st,&st->auxiliary_key,0,0,0);
1471 static void state_assert(struct site *st, bool_t ok)
1473 if (!ok) fatal("site:state_assert");
1476 static void enter_state_stop(struct site *st)
1478 st->state=SITE_STOP;
1480 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1481 dispose_transform(&st->new_transform);
1484 static void set_link_quality(struct site *st)
1487 if (current_valid(st))
1488 quality=LINK_QUALITY_UP;
1489 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1490 quality=LINK_QUALITY_DOWN;
1491 else if (st->addresses)
1492 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1493 else if (transport_peers_valid(&st->peers))
1494 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1496 quality=LINK_QUALITY_DOWN;
1498 st->netlink->set_quality(st->netlink->st,quality);
1501 static void enter_state_run(struct site *st)
1503 slog(st,LOG_STATE,"entering state RUN%s",
1504 current_valid(st) ? " (keyed)" : " (unkeyed)");
1508 st->setup_session_id=0;
1509 transport_peers_clear(st,&st->setup_peers);
1510 FILLZERO(st->localN);
1511 FILLZERO(st->remoteN);
1512 dispose_transform(&st->new_transform);
1513 memset(st->dhsecret,0,st->dh->len);
1514 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1515 set_link_quality(st);
1517 if (st->keepalive && !current_valid(st))
1518 initiate_key_setup(st, "keepalive", 0);
1521 static bool_t ensure_resolving(struct site *st)
1523 /* Reentrancy hazard: may call site_resolve_callback and hence
1524 * enter_new_state, enter_state_* and generate_msg*. */
1525 if (st->resolving_count)
1528 assert(st->addresses);
1530 /* resolver->request might reentrantly call site_resolve_callback
1531 * which will decrement st->resolving, so we need to increment it
1532 * twice beforehand to prevent decrement from thinking we're
1533 * finished, and decrement it ourselves. Alternatively if
1534 * everything fails then there are no callbacks due and we simply
1535 * set it to 0 and return false.. */
1536 st->resolving_n_results_stored=0;
1537 st->resolving_n_results_all=0;
1538 st->resolving_count+=2;
1539 const char **addrp=st->addresses;
1540 const char *address;
1542 for (; (address=*addrp++); ) {
1543 bool_t ok = st->resolver->request(st->resolver->st,address,
1544 st->remoteport,st->comms[0],
1545 site_resolve_callback,st);
1547 st->resolving_count++;
1551 st->resolving_count=0;
1554 decrement_resolving_count(st,2);
1558 static bool_t enter_state_resolve(struct site *st)
1560 /* Reentrancy hazard! See ensure_resolving. */
1561 state_assert(st,st->state==SITE_RUN);
1562 slog(st,LOG_STATE,"entering state RESOLVE");
1563 st->state=SITE_RESOLVE;
1564 return ensure_resolving(st);
1567 static bool_t enter_new_state(struct site *st, uint32_t next)
1569 bool_t (*gen)(struct site *st);
1572 slog(st,LOG_STATE,"entering state %s",state_name(next));
1575 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1577 st->msg1_crossed_logged = False;
1580 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1581 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1585 state_assert(st,st->state==SITE_SENTMSG1);
1586 BUF_FREE(&st->buffer);
1590 state_assert(st,st->state==SITE_SENTMSG2);
1591 BUF_FREE(&st->buffer);
1595 state_assert(st,st->state==SITE_SENTMSG3);
1596 BUF_FREE(&st->buffer);
1600 state_assert(st,st->state==SITE_SENTMSG4);
1601 BUF_FREE(&st->buffer);
1606 fatal("enter_new_state(%s): invalid new state",state_name(next));
1610 if (hacky_par_start_failnow()) return False;
1612 r= gen(st) && send_msg(st);
1615 st->setup_retries, st->setup_retry_interval,
1620 if (next==SITE_RUN) {
1621 BUF_FREE(&st->buffer); /* Never reused */
1622 st->timeout=0; /* Never retransmit */
1623 activate_new_key(st);
1627 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1628 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1629 in either state, and enter_state_wait() will
1631 enter_state_wait(st);
1635 /* msg7 tells our peer that we're about to forget our key */
1636 static bool_t send_msg7(struct site *st, cstring_t reason)
1638 cstring_t transform_err;
1640 if (current_valid(st) && st->buffer.free
1641 && transport_peers_valid(&st->peers)) {
1642 BUF_ALLOC(&st->buffer,"site:MSG7");
1643 buffer_init(&st->buffer,calculate_max_start_pad());
1644 buf_append_uint32(&st->buffer,LABEL_MSG7);
1645 buf_append_string(&st->buffer,reason);
1646 if (call_transform_forwards(st, st->current.transform,
1647 &st->buffer, &transform_err))
1649 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1650 buf_prepend_uint32(&st->buffer,st->index);
1651 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1652 transport_xmit(st,&st->peers,&st->buffer,True);
1653 BUF_FREE(&st->buffer);
1660 /* We go into this state if our peer becomes uncommunicative. Similar to
1661 the "stop" state, we forget all session keys for a while, before
1662 re-entering the "run" state. */
1663 static void enter_state_wait(struct site *st)
1665 slog(st,LOG_STATE,"entering state WAIT");
1666 st->timeout=st->now+wait_timeout(st);
1667 st->state=SITE_WAIT;
1668 set_link_quality(st);
1669 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1670 /* XXX Erase keys etc. */
1673 static void generate_prod(struct site *st, struct buffer_if *buf)
1676 buf_append_uint32(buf,0);
1677 buf_append_uint32(buf,0);
1678 buf_append_uint32(buf,LABEL_PROD);
1679 buf_append_string(buf,st->localname);
1680 buf_append_string(buf,st->remotename);
1683 static void generate_send_prod(struct site *st,
1684 const struct comm_addr *source)
1686 if (!st->allow_send_prod) return; /* too soon */
1687 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1688 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1690 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1691 st->allow_send_prod=0;
1692 generate_prod(st,&st->scratch);
1693 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1694 dump_packet(st,&st->scratch,source,False,ok);
1697 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1700 int64_t offset=timeout-*now;
1701 if (offset<0) offset=0;
1702 if (offset>INT_MAX) offset=INT_MAX;
1703 if (*timeout_io<0 || offset<*timeout_io)
1708 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1711 struct site *st=sst;
1713 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1716 /* Work out when our next timeout is. The earlier of 'timeout' or
1717 'current.key_timeout'. A stored value of '0' indicates no timeout
1719 site_settimeout(st->timeout, timeout_io);
1720 site_settimeout(st->current.key_timeout, timeout_io);
1721 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1723 return 0; /* success */
1726 static void check_expiry(struct site *st, struct data_key *key,
1729 if (key->key_timeout && *now>key->key_timeout) {
1730 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1734 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1735 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1737 struct site *st=sst;
1740 if (st->timeout && *now>st->timeout) {
1742 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1743 if (!hacky_par_start_failnow())
1745 } else if (st->state==SITE_WAIT) {
1746 enter_state_run(st);
1748 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1752 check_expiry(st,&st->current,"current key");
1753 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1756 /* This function is called by the netlink device to deliver packets
1757 intended for the remote network. The packet is in "raw" wire
1758 format, but is guaranteed to be word-aligned. */
1759 static void site_outgoing(void *sst, struct buffer_if *buf)
1761 struct site *st=sst;
1762 cstring_t transform_err;
1764 if (st->state==SITE_STOP) {
1769 st->allow_send_prod=1;
1771 /* In all other states we consider delivering the packet if we have
1772 a valid key and a valid address to send it to. */
1773 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1774 /* Transform it and send it */
1776 buf_prepend_uint32(buf,LABEL_MSG9);
1777 if (call_transform_forwards(st, st->current.transform,
1778 buf, &transform_err))
1780 buf_prepend_uint32(buf,LABEL_MSG0);
1781 buf_prepend_uint32(buf,st->index);
1782 buf_prepend_uint32(buf,st->current.remote_session_id);
1783 transport_xmit(st,&st->peers,buf,False);
1790 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1792 initiate_key_setup(st,"outgoing packet",0);
1795 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1796 uint32_t type, struct msg *m)
1797 /* For packets which are identified by the local and remote names.
1798 * If it has our name and our peer's name in it it's for us. */
1800 struct buffer_if buf[1];
1801 buffer_readonly_clone(buf,buf_in);
1802 return unpick_msg(st,type,buf,m)
1803 && name_matches(&m->remote,st->remotename)
1804 && name_matches(&m->local,st->localname);
1807 static bool_t we_have_priority(struct site *st, const struct msg *m) {
1808 if (st->local_capabilities & m->remote_capabilities &
1809 CAPAB_PRIORITY_MOBILE) {
1810 if (st->local_mobile) return True;
1811 if (st-> peer_mobile) return False;
1813 return st->our_name_later;
1816 static bool_t setup_late_msg_ok(struct site *st,
1817 const struct buffer_if *buf_in,
1819 const struct comm_addr *source) {
1820 /* For setup packets which seem from their type like they are
1821 * late. Maybe they came via a different path. All we do is make
1822 * a note of the sending address, iff they look like they are part
1823 * of the current key setup attempt. */
1825 if (!named_for_us(st,buf_in,msgtype,&m))
1826 /* named_for_us calls unpick_msg which gets the nonces */
1828 if (!consttime_memeq(m.nR,st->remoteN,NONCELEN) ||
1829 !consttime_memeq(m.nL,st->localN, NONCELEN))
1830 /* spoof ? from stale run ? who knows */
1832 transport_setup_msgok(st,source);
1836 /* This function is called by the communication device to deliver
1837 packets from our peers.
1838 It should return True if the packet is recognised as being for
1839 this current site instance (and should therefore not be processed
1840 by other sites), even if the packet was otherwise ignored. */
1841 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1842 const struct comm_addr *source)
1844 struct site *st=sst;
1846 if (buf->size < 12) return False;
1848 uint32_t dest=get_uint32(buf->start);
1849 uint32_t msgtype=get_uint32(buf->start+8);
1850 struct msg named_msg;
1852 if (msgtype==LABEL_MSG1) {
1853 if (!named_for_us(st,buf,msgtype,&named_msg))
1855 /* It's a MSG1 addressed to us. Decide what to do about it. */
1856 dump_packet(st,buf,source,True,True);
1857 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1858 st->state==SITE_WAIT) {
1859 /* We should definitely process it */
1860 transport_compute_setupinit_peers(st,0,0,source);
1861 if (process_msg1(st,buf,source,&named_msg)) {
1862 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1863 bool_t entered=enter_new_state(st,SITE_SENTMSG2);
1864 if (entered && st->addresses && st->local_mobile)
1865 /* We must do this as the very last thing, because
1866 the resolver callback might reenter us. */
1867 ensure_resolving(st);
1869 slog(st,LOG_ERROR,"failed to process incoming msg1");
1873 } else if (st->state==SITE_SENTMSG1) {
1874 /* We've just sent a message 1! They may have crossed on
1875 the wire. If we have priority then we ignore the
1876 incoming one, otherwise we process it as usual. */
1877 if (we_have_priority(st,&named_msg)) {
1879 if (!st->msg1_crossed_logged++)
1880 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
1881 "priority => ignore incoming msg1");
1884 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
1885 "priority => use incoming msg1");
1886 if (process_msg1(st,buf,source,&named_msg)) {
1887 BUF_FREE(&st->buffer); /* Free our old message 1 */
1888 transport_setup_msgok(st,source);
1889 enter_new_state(st,SITE_SENTMSG2);
1891 slog(st,LOG_ERROR,"failed to process an incoming "
1892 "crossed msg1 (we have low priority)");
1897 } else if (st->state==SITE_SENTMSG2 ||
1898 st->state==SITE_SENTMSG4) {
1899 if (consttime_memeq(named_msg.nR,st->remoteN,NONCELEN)) {
1900 /* We are ahead in the protocol, but that msg1 had the
1901 * peer's nonce so presumably it is from this key
1902 * exchange run, via a slower route */
1903 transport_setup_msgok(st,source);
1905 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
1910 /* The message 1 was received at an unexpected stage of the
1911 key setup. Well, they lost the race. */
1912 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1916 if (msgtype==LABEL_PROD) {
1917 if (!named_for_us(st,buf,msgtype,&named_msg))
1919 dump_packet(st,buf,source,True,True);
1920 if (st->state!=SITE_RUN) {
1921 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1922 } else if (current_valid(st)) {
1923 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1925 initiate_key_setup(st,"peer sent PROD packet",source);
1930 if (dest==st->index) {
1931 /* Explicitly addressed to us */
1932 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
1935 /* If the source is our current peer then initiate a key setup,
1936 because our peer's forgotten the key */
1937 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
1939 initiated = initiate_key_setup(st,"received a NAK",source);
1940 if (!initiated) generate_send_prod(st,source);
1942 slog(st,LOG_SEC,"bad incoming NAK");
1946 process_msg0(st,buf,source);
1949 /* Setup packet: should not have been explicitly addressed
1951 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
1954 /* Setup packet: expected only in state SENTMSG1 */
1955 if (st->state!=SITE_SENTMSG1) {
1956 if ((st->state==SITE_SENTMSG3 ||
1957 st->state==SITE_SENTMSG5) &&
1958 setup_late_msg_ok(st,buf,msgtype,source))
1960 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
1961 } else if (process_msg2(st,buf,source)) {
1962 transport_setup_msgok(st,source);
1963 enter_new_state(st,SITE_SENTMSG3);
1965 slog(st,LOG_SEC,"invalid MSG2");
1970 /* Setup packet: expected only in state SENTMSG2 */
1971 if (st->state!=SITE_SENTMSG2) {
1972 if ((st->state==SITE_SENTMSG4) &&
1973 setup_late_msg_ok(st,buf,msgtype,source))
1975 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
1976 } else if (process_msg3(st,buf,source,msgtype)) {
1977 transport_setup_msgok(st,source);
1978 enter_new_state(st,SITE_SENTMSG4);
1980 slog(st,LOG_SEC,"invalid MSG3");
1984 /* Setup packet: expected only in state SENTMSG3 */
1985 if (st->state!=SITE_SENTMSG3) {
1986 if ((st->state==SITE_SENTMSG5) &&
1987 setup_late_msg_ok(st,buf,msgtype,source))
1989 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
1990 } else if (process_msg4(st,buf,source)) {
1991 transport_setup_msgok(st,source);
1992 enter_new_state(st,SITE_SENTMSG5);
1994 slog(st,LOG_SEC,"invalid MSG4");
1998 /* Setup packet: expected only in state SENTMSG4 */
1999 /* (may turn up in state RUN if our return MSG6 was lost
2000 and the new key has already been activated. In that
2001 case we discard it. The peer will realise that we
2002 are using the new key when they see our data packets.
2003 Until then the peer's data packets to us get discarded. */
2004 if (st->state==SITE_SENTMSG4) {
2005 if (process_msg5(st,buf,source,st->new_transform)) {
2006 transport_setup_msgok(st,source);
2007 enter_new_state(st,SITE_RUN);
2009 slog(st,LOG_SEC,"invalid MSG5");
2011 } else if (st->state==SITE_RUN) {
2012 if (process_msg5(st,buf,source,st->current.transform)) {
2013 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2014 transport_setup_msgok(st,source);
2015 create_msg6(st,st->current.transform,
2016 st->current.remote_session_id);
2017 transport_xmit(st,&st->peers,&st->buffer,True);
2018 BUF_FREE(&st->buffer);
2020 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2023 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2027 /* Setup packet: expected only in state SENTMSG5 */
2028 if (st->state!=SITE_SENTMSG5) {
2029 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2030 } else if (process_msg6(st,buf,source)) {
2031 BUF_FREE(&st->buffer); /* Free message 5 */
2032 transport_setup_msgok(st,source);
2033 activate_new_key(st);
2035 slog(st,LOG_SEC,"invalid MSG6");
2039 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2050 static void site_control(void *vst, bool_t run)
2052 struct site *st=vst;
2053 if (run) enter_state_run(st);
2054 else enter_state_stop(st);
2057 static void site_phase_hook(void *sst, uint32_t newphase)
2059 struct site *st=sst;
2061 /* The program is shutting down; tell our peer */
2062 send_msg7(st,"shutting down");
2065 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2067 struct site *st=sst;
2068 dispose_transform(&st->current.transform);
2069 dispose_transform(&st->auxiliary_key.transform);
2070 dispose_transform(&st->new_transform);
2071 /* Not much point overwiting the signing key, since we loaded it
2072 from disk, and it is only valid prospectively if at all,
2074 /* XXX it would be best to overwrite the DH state, because that
2075 _is_ relevant to forward secrecy. However we have no
2076 convenient interface for doing that and in practice gmp has
2077 probably dribbled droppings all over the malloc arena. A good
2078 way to fix this would be to have a privsep child for asymmetric
2079 crypto operations, but that's a task for another day. */
2082 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2085 static uint32_t index_sequence;
2093 st->cl.description="site";
2094 st->cl.type=CL_SITE;
2096 st->cl.interface=&st->ops;
2098 st->ops.control=site_control;
2099 st->ops.status=site_status;
2101 /* First parameter must be a dict */
2102 item=list_elem(args,0);
2103 if (!item || item->type!=t_dict)
2104 cfgfatal(loc,"site","parameter must be a dictionary\n");
2106 dict=item->data.dict;
2107 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2108 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2110 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2112 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2114 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2116 /* Sanity check (which also allows the 'sites' file to include
2117 site() closures for all sites including our own): refuse to
2118 talk to ourselves */
2119 if (strcmp(st->localname,st->remotename)==0) {
2120 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2122 if (st->peer_mobile != st->local_mobile)
2123 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2124 " but our local-mobile=%d\n",
2125 st->localname, st->peer_mobile, st->local_mobile);
2129 if (st->peer_mobile && st->local_mobile) {
2130 Message(M_WARNING,"site %s: site is mobile but so are we"
2131 " -> ignoring this site\n", st->remotename);
2136 assert(index_sequence < 0xffffffffUL);
2137 st->index = ++index_sequence;
2138 st->local_capabilities = 0;
2139 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2140 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2142 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2143 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2144 if (!things##_cfg) \
2145 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2146 st->nthings=list_length(things##_cfg); \
2147 NEW_ARY(st->things,st->nthings); \
2148 assert(st->nthings); \
2149 for (i=0; i<st->nthings; i++) { \
2150 item_t *item=list_elem(things##_cfg,i); \
2151 if (item->type!=t_closure) \
2152 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2153 closure_t *cl=item->data.closure; \
2154 if (cl->type!=CL_TYPE) \
2155 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2156 st->things[i]=cl->interface; \
2160 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2162 NEW_ARY(st->commclientinfos, st->ncomms);
2163 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2164 for (i=0; i<st->ncomms; i++) {
2165 st->commclientinfos[i] =
2167 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2170 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2171 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2172 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2174 st->privkey=find_cl_if(dict,"local-key",CL_RSAPRIVKEY,True,"site",loc);
2175 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2177 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2178 else st->remoteport=0;
2179 st->pubkey=find_cl_if(dict,"key",CL_RSAPUBKEY,True,"site",loc);
2181 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2183 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2184 st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2186 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2187 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2188 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2190 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2191 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2192 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2193 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2194 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2196 st->mobile_peer_expiry= dict_read_number(
2197 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2199 const char *peerskey= st->peer_mobile
2200 ? "mobile-peers-max" : "static-peers-max";
2201 st->transport_peers_max= dict_read_number(
2202 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2203 if (st->transport_peers_max<1 ||
2204 st->transport_peers_max>MAX_PEER_ADDRS) {
2205 cfgfatal(loc,"site", "%s must be in range 1.."
2206 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2209 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2210 st->key_renegotiate_time=st->key_lifetime/2;
2212 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2213 st->key_renegotiate_time=dict_read_number(
2214 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2215 if (st->key_renegotiate_time > st->key_lifetime) {
2216 cfgfatal(loc,"site",
2217 "renegotiate-time must be less than key-lifetime\n");
2220 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2221 log_event_table,"site");
2223 st->resolving_count=0;
2224 st->allow_send_prod=0;
2226 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2228 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2230 /* The information we expect to see in incoming messages of type 1 */
2231 /* fixme: lots of unchecked overflows here, but the results are only
2232 corrupted packets rather than undefined behaviour */
2233 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2235 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2237 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2238 BUF_ALLOC(&st->scratch,"site:scratch");
2240 /* We are interested in poll(), but only for timeouts. We don't have
2241 any fds of our own. */
2242 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2245 st->remote_capabilities=0;
2246 st->chosen_transform=0;
2247 st->current.key_timeout=0;
2248 st->auxiliary_key.key_timeout=0;
2249 transport_peers_clear(st,&st->peers);
2250 transport_peers_clear(st,&st->setup_peers);
2251 /* XXX mlock these */
2252 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2253 st->sharedsecretlen=st->sharedsecretallocd=0;
2256 #define SET_CAPBIT(bit) do { \
2257 uint32_t capflag = 1UL << (bit); \
2258 if (st->local_capabilities & capflag) \
2259 slog(st,LOG_ERROR,"capability bit" \
2260 " %d (%#"PRIx32") reused", (bit), capflag); \
2261 st->local_capabilities |= capflag; \
2264 for (i=0; i<st->ntransforms; i++)
2265 SET_CAPBIT(st->transforms[i]->capab_bit);
2269 if (st->local_mobile || st->peer_mobile)
2270 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2272 /* We need to register the remote networks with the netlink device */
2273 uint32_t netlink_mtu; /* local virtual interface mtu */
2274 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2275 if (!st->mtu_target)
2276 st->mtu_target=netlink_mtu;
2278 for (i=0; i<st->ncomms; i++)
2279 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2281 st->current.transform=0;
2282 st->auxiliary_key.transform=0;
2283 st->new_transform=0;
2284 st->auxiliary_is_new=0;
2286 enter_state_stop(st);
2288 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2289 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2291 return new_closure(&st->cl);
2294 void site_module(dict_t *dict)
2296 add_closure(dict,"site",site_apply);
2300 /***** TRANSPORT PEERS definitions *****/
2302 static void transport_peers_debug(struct site *st, transport_peers *dst,
2303 const char *didwhat,
2304 int nargs, const struct comm_addr *args,
2309 if (!(st->log_events & LOG_PEER_ADDRS))
2310 return; /* an optimisation */
2312 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2313 (dst==&st->peers ? "data" :
2314 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2315 didwhat, nargs, dst->npeers);
2317 for (i=0, argp=(void*)args;
2319 i++, (argp+=stride?stride:sizeof(*args))) {
2320 const struct comm_addr *ca=(void*)argp;
2321 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2322 i, comm_addr_to_string(ca));
2324 for (i=0; i<dst->npeers; i++) {
2325 struct timeval diff;
2326 timersub(tv_now,&dst->peers[i].last,&diff);
2327 const struct comm_addr *ca=&dst->peers[i].addr;
2328 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2329 i, comm_addr_to_string(ca),
2330 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2334 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2335 /* peers must be sorted first */
2336 int previous_peers=peers->npeers;
2337 struct timeval oldest;
2338 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2339 oldest.tv_usec = tv_now->tv_usec;
2340 while (peers->npeers>1 &&
2341 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2343 if (peers->npeers != previous_peers)
2344 transport_peers_debug(st,peers,"expire", 0,0,0);
2347 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2348 const struct comm_addr *ca,
2349 const struct timeval *tv) {
2350 /* returns false if output is full */
2353 if (peers->npeers >= st->transport_peers_max)
2356 for (search=0; search<peers->npeers; search++)
2357 if (comm_addr_equal(&peers->peers[search].addr, ca))
2360 peers->peers[peers->npeers].addr = *ca;
2361 peers->peers[peers->npeers].last = *tv;
2366 static void transport_record_peers(struct site *st, transport_peers *peers,
2367 const struct comm_addr *addrs, int naddrs,
2369 /* We add addrs into peers. The new entries end up at the front
2370 * and displace entries towards the end (perhaps even off the
2371 * end). Any existing matching entries are moved up to the front.
2373 * Caller must first call transport_peers_expire. */
2376 /* avoids debug for uninteresting updates */
2378 for (i=0; i<peers->npeers; i++) {
2379 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2380 memmove(peers->peers+1, peers->peers,
2381 sizeof(peers->peers[0]) * i);
2382 peers->peers[0].addr = addrs[0];
2383 peers->peers[0].last = *tv_now;
2389 int old_npeers=peers->npeers;
2390 transport_peer old_peers[old_npeers];
2391 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2395 for (i=0; i<naddrs; i++) {
2396 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2399 for (i=0; i<old_npeers; i++) {
2400 const transport_peer *old=&old_peers[i];
2401 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2405 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2408 static void transport_expire_record_peers(struct site *st,
2409 transport_peers *peers,
2410 const struct comm_addr *addrs,
2411 int naddrs, const char *m) {
2412 /* Convenience function */
2413 transport_peers_expire(st,peers);
2414 transport_record_peers(st,peers,addrs,naddrs,m);
2417 static bool_t transport_compute_setupinit_peers(struct site *st,
2418 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2419 int n_configured_addrs /* 0 if none or not found */,
2420 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2421 if (!n_configured_addrs && !incoming_packet_addr &&
2422 !transport_peers_valid(&st->peers))
2425 slog(st,LOG_SETUP_INIT,
2426 "using: %d configured addr(s);%s %d old peer addrs(es)",
2428 incoming_packet_addr ? " incoming packet address;" : "",
2431 /* Non-mobile peers try addresses until one is plausible. The
2432 * effect is that this code always tries first the configured
2433 * address if supplied, or otherwise the address of the incoming
2434 * PROD, or finally the existing data peer if one exists; this is
2437 transport_peers_copy(st,&st->setup_peers,&st->peers);
2438 transport_peers_expire(st,&st->setup_peers);
2440 if (incoming_packet_addr)
2441 transport_record_peers(st,&st->setup_peers,
2442 incoming_packet_addr,1, "incoming");
2444 if (n_configured_addrs)
2445 transport_record_peers(st,&st->setup_peers,
2446 configured_addrs,n_configured_addrs, "setupinit");
2448 assert(transport_peers_valid(&st->setup_peers));
2452 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2453 if (st->peer_mobile)
2454 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2456 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2457 if (st->peer_mobile)
2458 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2461 static int transport_peers_valid(transport_peers *peers) {
2462 return peers->npeers;
2464 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2466 transport_peers_debug(st,peers,"clear",0,0,0);
2468 static void transport_peers_copy(struct site *st, transport_peers *dst,
2469 const transport_peers *src) {
2470 dst->npeers=src->npeers;
2471 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2472 transport_peers_debug(st,dst,"copy",
2473 src->npeers, &src->peers->addr, sizeof(*src->peers));
2476 static void transport_resolve_complete(struct site *st,
2477 const struct comm_addr *addrs,
2479 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2481 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2485 static void transport_resolve_complete_tardy(struct site *st,
2486 const struct comm_addr *addrs,
2488 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2489 "resolved tardily");
2492 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2494 const transport_peers *inp) {
2495 /* out and in->peers may be the same region, or nonoverlapping */
2496 const transport_peer *in=inp->peers;
2498 for (slot=0; slot<inp->npeers; slot++) {
2499 if (!(mask & (1U << slot)))
2501 if (!(out==in && slot==*nout_io))
2502 COPY_OBJ(out[*nout_io], in[slot]);
2507 void transport_xmit(struct site *st, transport_peers *peers,
2508 struct buffer_if *buf, bool_t candebug) {
2510 transport_peers_expire(st, peers);
2511 unsigned failed=0; /* bitmask */
2512 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2515 for (slot=0; slot<peers->npeers; slot++) {
2516 transport_peer *peer=&peers->peers[slot];
2517 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2519 dump_packet(st, buf, &peer->addr, False, ok);
2521 failed |= 1U << slot;
2524 if (ok && !st->peer_mobile)
2527 /* Now we need to demote/delete failing addrs: if we are mobile we
2528 * merely demote them; otherwise we delete them. */
2529 if (st->local_mobile) {
2530 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2531 /* `expected' has all the failures at the end already */
2532 if (failed != expected) {
2534 transport_peer failedpeers[nfailed];
2535 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2536 assert(fslot == nfailed);
2538 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2539 assert(wslot+nfailed == peers->npeers);
2540 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2541 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2544 if (failed && peers->npeers > 1) {
2546 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2547 peers->npeers=wslot;
2548 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2553 /***** END of transport peers declarations *****/