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 local_capabilities;
322 int32_t setup_retries; /* How many times to send setup packets */
323 int32_t setup_retry_interval; /* Initial timeout for setup packets */
324 int32_t wait_timeout_mean; /* How long to wait if setup unsuccessful */
325 int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
326 int32_t key_lifetime; /* How long a key lasts once set up */
327 int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
328 after this time, initiate a new
331 bool_t our_name_later; /* our name > peer name */
334 /* runtime information */
336 uint64_t now; /* Most recently seen time */
337 bool_t allow_send_prod;
338 bool_t msg1_crossed_logged;
340 int resolving_n_results_all;
341 int resolving_n_results_stored;
342 struct comm_addr resolving_results[MAX_PEER_ADDRS];
344 /* The currently established session */
345 struct data_key current;
346 struct data_key auxiliary_key;
347 bool_t auxiliary_is_new;
348 uint64_t renegotiate_key_time; /* When we can negotiate a new key */
349 uint64_t auxiliary_renegotiate_key_time;
350 transport_peers peers; /* Current address(es) of peer for data traffic */
352 /* The current key setup protocol exchange. We can only be
353 involved in one of these at a time. There's a potential for
354 denial of service here (the attacker keeps sending a setup
355 packet; we keep trying to continue the exchange, and have to
356 timeout before we can listen for another setup packet); perhaps
357 we should keep a list of 'bad' sources for setup packets. */
358 uint32_t remote_capabilities;
359 uint16_t remote_adv_mtu;
360 struct transform_if *chosen_transform;
361 uint32_t setup_session_id;
362 transport_peers setup_peers;
363 uint8_t localN[NONCELEN]; /* Nonces for key exchange */
364 uint8_t remoteN[NONCELEN];
365 struct buffer_if buffer; /* Current outgoing key exchange packet */
366 struct buffer_if scratch;
367 int32_t retries; /* Number of retries remaining */
368 uint64_t timeout; /* Timeout for current state */
370 uint8_t *sharedsecret;
371 uint32_t sharedsecretlen, sharedsecretallocd;
372 struct transform_inst_if *new_transform; /* For key setup/verify */
375 static uint32_t event_log_priority(struct site *st, uint32_t event)
377 if (!(event&st->log_events))
380 case LOG_UNEXPECTED: return M_INFO;
381 case LOG_SETUP_INIT: return M_INFO;
382 case LOG_SETUP_TIMEOUT: return M_NOTICE;
383 case LOG_ACTIVATE_KEY: return M_INFO;
384 case LOG_TIMEOUT_KEY: return M_INFO;
385 case LOG_SEC: return M_SECURITY;
386 case LOG_STATE: return M_DEBUG;
387 case LOG_DROP: return M_DEBUG;
388 case LOG_DUMP: return M_DEBUG;
389 case LOG_ERROR: return M_ERR;
390 case LOG_PEER_ADDRS: return M_DEBUG;
391 default: return M_ERR;
395 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
397 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
401 class=event_log_priority(st, event);
403 slilog_part(st->log,class,"%s: ",st->tunname);
404 vslilog_part(st->log,class,msg,ap);
405 slilog_part(st->log,class,"\n");
409 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
411 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
415 vslog(st,event,msg,ap);
419 static void logtimeout(struct site *st, const char *fmt, ...)
421 static void logtimeout(struct site *st, const char *fmt, ...)
423 uint32_t class=event_log_priority(st,LOG_SETUP_TIMEOUT);
430 slilog_part(st->log,class,"%s: ",st->tunname);
431 vslilog_part(st->log,class,fmt,ap);
435 for (i=0, delim=" (tried ";
436 i<st->setup_peers.npeers;
438 transport_peer *peer=&st->setup_peers.peers[i];
439 const char *s=comm_addr_to_string(&peer->addr);
440 slilog_part(st->log,class,"%s%s",delim,s);
443 slilog_part(st->log,class,")\n");
447 static void set_link_quality(struct site *st);
448 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
449 static void delete_one_key(struct site *st, struct data_key *key,
450 const char *reason /* may be 0 meaning don't log*/,
451 const char *which /* ignored if !reasonn */,
452 uint32_t loglevel /* ignored if !reasonn */);
453 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
454 const struct comm_addr *prod_hint);
455 static void enter_state_run(struct site *st);
456 static bool_t enter_state_resolve(struct site *st);
457 static void decrement_resolving_count(struct site *st, int by);
458 static bool_t enter_new_state(struct site *st,uint32_t next);
459 static void enter_state_wait(struct site *st);
460 static void activate_new_key(struct site *st);
462 static bool_t is_transform_valid(struct transform_inst_if *transform)
464 return transform && transform->valid(transform->st);
467 static bool_t current_valid(struct site *st)
469 return is_transform_valid(st->current.transform);
472 #define DEFINE_CALL_TRANSFORM(fwdrev) \
473 static transform_apply_return \
474 call_transform_##fwdrev(struct site *st, \
475 struct transform_inst_if *transform, \
476 struct buffer_if *buf, \
477 const char **errmsg) \
479 if (!is_transform_valid(transform)) { \
480 *errmsg="transform not set up"; \
481 return transform_apply_err; \
483 return transform->fwdrev(transform->st,buf,errmsg); \
486 DEFINE_CALL_TRANSFORM(forwards)
487 DEFINE_CALL_TRANSFORM(reverse)
489 static void dispose_transform(struct transform_inst_if **transform_var)
491 struct transform_inst_if *transform=*transform_var;
493 transform->delkey(transform->st);
494 transform->destroy(transform->st);
499 #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
500 #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
501 #define CHECK_TYPE(b,t) do { uint32_t type; \
502 CHECK_AVAIL((b),4); \
503 type=buf_unprepend_uint32((b)); \
504 if (type!=(t)) return False; } while(0)
506 static _Bool type_is_msg34(uint32_t type)
509 type == LABEL_MSG3 ||
510 type == LABEL_MSG3BIS ||
517 struct buffer_if extrainfo;
524 struct parsedname remote;
525 struct parsedname local;
526 uint32_t remote_capabilities;
528 int capab_transformnum;
538 static int32_t wait_timeout(struct site *st) {
539 int32_t t = st->wait_timeout_mean;
542 st->random->generate(st->random->st,sizeof(factor),&factor);
543 t += (t / 256) * factor;
548 static _Bool set_new_transform(struct site *st, char *pk)
552 /* Make room for the shared key */
553 st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
554 assert(st->sharedsecretlen);
555 if (st->sharedsecretlen > st->sharedsecretallocd) {
556 st->sharedsecretallocd=st->sharedsecretlen;
557 st->sharedsecret=safe_realloc_ary(st->sharedsecret,1,
558 st->sharedsecretallocd,
559 "site:sharedsecret");
562 /* Generate the shared key */
563 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,pk,
564 st->sharedsecret,st->sharedsecretlen);
566 /* Set up the transform */
567 struct transform_if *generator=st->chosen_transform;
568 struct transform_inst_if *generated=generator->create(generator->st);
569 ok = generated->setkey(generated->st,st->sharedsecret,
570 st->sharedsecretlen,st->our_name_later);
572 dispose_transform(&st->new_transform);
573 if (!ok) return False;
574 st->new_transform=generated;
576 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
577 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
578 st->chosen_transform->capab_transformnum,
579 st->local_capabilities, st->remote_capabilities);
584 int32_t lenpos, afternul;
586 static void append_string_xinfo_start(struct buffer_if *buf,
587 struct xinfoadd *xia,
589 /* Helps construct one of the names with additional info as found
590 * in MSG1..4. Call this function first, then append all the
591 * desired extra info (not including the nul byte) to the buffer,
592 * then call append_string_xinfo_done. */
594 xia->lenpos = buf->size;
595 buf_append_string(buf,str);
596 buf_append_uint8(buf,0);
597 xia->afternul = buf->size;
599 static void append_string_xinfo_done(struct buffer_if *buf,
600 struct xinfoadd *xia)
602 /* we just need to adjust the string length */
603 if (buf->size == xia->afternul) {
604 /* no extra info, strip the nul too */
605 buf_unappend_uint8(buf);
607 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
611 /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
612 out using a transform of config data supplied by netlink */
613 static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what)
619 st->retries=st->setup_retries;
620 BUF_ALLOC(&st->buffer,what);
621 buffer_init(&st->buffer,0);
622 buf_append_uint32(&st->buffer,
623 (type==LABEL_MSG1?0:st->setup_session_id));
624 buf_append_uint32(&st->buffer,st->index);
625 buf_append_uint32(&st->buffer,type);
628 append_string_xinfo_start(&st->buffer,&xia,st->localname);
629 if ((st->local_capabilities & CAPAB_EARLY) || (type != LABEL_MSG1)) {
630 buf_append_uint32(&st->buffer,st->local_capabilities);
632 if (type_is_msg34(type)) {
633 buf_append_uint16(&st->buffer,st->mtu_target);
635 append_string_xinfo_done(&st->buffer,&xia);
637 buf_append_string(&st->buffer,st->remotename);
638 BUF_ADD_OBJ(append,&st->buffer,st->localN);
639 if (type==LABEL_MSG1) return True;
640 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
641 if (type==LABEL_MSG2) return True;
643 if (hacky_par_mid_failnow()) return False;
645 if (type==LABEL_MSG3BIS)
646 buf_append_uint8(&st->buffer,st->chosen_transform->capab_transformnum);
648 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
649 buf_append_string(&st->buffer,dhpub);
651 hash=safe_malloc(st->hash->len, "generate_msg");
652 hst=st->hash->init();
653 st->hash->update(hst,st->buffer.start,st->buffer.size);
654 st->hash->final(hst,hash);
655 sig=st->privkey->sign(st->privkey->st,hash,st->hash->len);
656 buf_append_string(&st->buffer,sig);
662 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
665 nm->len=buf_unprepend_uint16(msg);
666 CHECK_AVAIL(msg,nm->len);
667 nm->name=buf_unprepend(msg,nm->len);
668 uint8_t *nul=memchr(nm->name,0,nm->len);
670 buffer_readonly_view(&nm->extrainfo,0,0);
672 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
673 nm->len=nul-nm->name;
678 static bool_t unpick_msg(struct site *st, uint32_t type,
679 struct buffer_if *msg, struct msg *m)
681 m->capab_transformnum=-1;
682 m->hashstart=msg->start;
684 m->dest=buf_unprepend_uint32(msg);
686 m->source=buf_unprepend_uint32(msg);
687 CHECK_TYPE(msg,type);
688 if (!unpick_name(msg,&m->remote)) return False;
689 m->remote_capabilities=0;
691 if (m->remote.extrainfo.size) {
692 CHECK_AVAIL(&m->remote.extrainfo,4);
693 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
695 if (type_is_msg34(type) && m->remote.extrainfo.size) {
696 CHECK_AVAIL(&m->remote.extrainfo,2);
697 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
699 if (!unpick_name(msg,&m->local)) return False;
700 if (type==LABEL_PROD) {
704 CHECK_AVAIL(msg,NONCELEN);
705 m->nR=buf_unprepend(msg,NONCELEN);
706 if (type==LABEL_MSG1) {
710 CHECK_AVAIL(msg,NONCELEN);
711 m->nL=buf_unprepend(msg,NONCELEN);
712 if (type==LABEL_MSG2) {
716 if (type==LABEL_MSG3BIS) {
718 m->capab_transformnum = buf_unprepend_uint8(msg);
720 m->capab_transformnum = CAPAB_TRANSFORMNUM_ANCIENT;
723 m->pklen=buf_unprepend_uint16(msg);
724 CHECK_AVAIL(msg,m->pklen);
725 m->pk=buf_unprepend(msg,m->pklen);
726 m->hashlen=msg->start-m->hashstart;
728 m->siglen=buf_unprepend_uint16(msg);
729 CHECK_AVAIL(msg,m->siglen);
730 m->sig=buf_unprepend(msg,m->siglen);
733 /* In `process_msg3_msg4' below, we assume that we can write a nul
734 * terminator following the signature. Make sure there's enough space.
736 if (msg->start >= msg->base + msg->alloclen)
742 static bool_t name_matches(const struct parsedname *nm, const char *expected)
744 int expected_len=strlen(expected);
746 nm->len == expected_len &&
747 !memcmp(nm->name, expected, expected_len);
750 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
753 if (type==LABEL_MSG1) return True;
755 /* Check that the site names and our nonce have been sent
756 back correctly, and then store our peer's nonce. */
757 if (!name_matches(&m->remote,st->remotename)) {
758 *error="wrong remote site name";
761 if (!name_matches(&m->local,st->localname)) {
762 *error="wrong local site name";
765 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
766 *error="wrong locally-generated nonce";
769 if (type==LABEL_MSG2) return True;
770 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)!=0) {
771 *error="wrong remotely-generated nonce";
774 /* MSG3 has complicated rules about capabilities, which are
775 * handled in process_msg3. */
776 if (type==LABEL_MSG3 || type==LABEL_MSG3BIS) return True;
777 if (m->remote_capabilities!=st->remote_capabilities) {
778 *error="remote capabilities changed";
781 if (type==LABEL_MSG4) return True;
782 *error="unknown message type";
786 static bool_t generate_msg1(struct site *st)
788 st->random->generate(st->random->st,NONCELEN,st->localN);
789 return generate_msg(st,LABEL_MSG1,"site:MSG1");
792 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
793 const struct comm_addr *src, struct msg *m)
795 /* We've already determined we're in an appropriate state to
796 process an incoming MSG1, and that the MSG1 has correct values
799 st->setup_session_id=m->source;
800 st->remote_capabilities=m->remote_capabilities;
801 memcpy(st->remoteN,m->nR,NONCELEN);
805 static bool_t generate_msg2(struct site *st)
807 st->random->generate(st->random->st,NONCELEN,st->localN);
808 return generate_msg(st,LABEL_MSG2,"site:MSG2");
811 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
812 const struct comm_addr *src)
817 if (!unpick_msg(st,LABEL_MSG2,msg2,&m)) return False;
818 if (!check_msg(st,LABEL_MSG2,&m,&err)) {
819 slog(st,LOG_SEC,"msg2: %s",err);
822 st->setup_session_id=m.source;
823 st->remote_capabilities=m.remote_capabilities;
825 /* Select the transform to use */
827 uint32_t remote_transforms = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
828 if (!remote_transforms)
829 /* old secnets only had this one transform */
830 remote_transforms = 1UL << CAPAB_TRANSFORMNUM_ANCIENT;
832 struct transform_if *ti;
834 for (i=0; i<st->ntransforms; i++) {
835 ti=st->transforms[i];
836 if ((1UL << ti->capab_transformnum) & remote_transforms)
837 goto transform_found;
839 slog(st,LOG_ERROR,"no transforms in common"
840 " (us %#"PRIx32"; them: %#"PRIx32")",
841 st->local_capabilities & CAPAB_TRANSFORM_MASK,
845 st->chosen_transform=ti;
847 memcpy(st->remoteN,m.nR,NONCELEN);
851 static bool_t generate_msg3(struct site *st)
853 /* Now we have our nonce and their nonce. Think of a secret key,
854 and create message number 3. */
855 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
856 return generate_msg(st,
857 (st->remote_capabilities & CAPAB_TRANSFORM_MASK
858 ? LABEL_MSG3BIS : LABEL_MSG3),
862 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
867 /* Check signature and store g^x mod m */
868 hash=safe_malloc(st->hash->len, "process_msg3_msg4");
869 hst=st->hash->init();
870 st->hash->update(hst,m->hashstart,m->hashlen);
871 st->hash->final(hst,hash);
872 /* Terminate signature with a '0' - already checked that this will fit */
874 if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m->sig)) {
875 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
881 st->remote_adv_mtu=m->remote_mtu;
886 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
887 const struct comm_addr *src, uint32_t msgtype)
892 assert(msgtype==LABEL_MSG3 || msgtype==LABEL_MSG3BIS);
894 if (!unpick_msg(st,msgtype,msg3,&m)) return False;
895 if (!check_msg(st,msgtype,&m,&err)) {
896 slog(st,LOG_SEC,"msg3: %s",err);
899 uint32_t capab_adv_late = m.remote_capabilities
900 & ~st->remote_capabilities & CAPAB_EARLY;
901 if (capab_adv_late) {
902 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
903 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
904 capab_adv_late, st->remote_capabilities, m.remote_capabilities);
907 st->remote_capabilities|=m.remote_capabilities;
909 struct transform_if *ti;
911 for (i=0; i<st->ntransforms; i++) {
912 ti=st->transforms[i];
913 if (ti->capab_transformnum == m.capab_transformnum)
914 goto transform_found;
916 slog(st,LOG_SEC,"peer chose unknown-to-us transform %d!",
917 m.capab_transformnum);
920 st->chosen_transform=ti;
922 if (!process_msg3_msg4(st,&m))
925 /* Terminate their DH public key with a '0' */
927 /* Invent our DH secret key */
928 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
930 /* Generate the shared key and set up the transform */
931 if (!set_new_transform(st,m.pk)) return False;
936 static bool_t generate_msg4(struct site *st)
938 /* We have both nonces, their public key and our private key. Generate
939 our public key, sign it and send it to them. */
940 return generate_msg(st,LABEL_MSG4,"site:MSG4");
943 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
944 const struct comm_addr *src)
949 if (!unpick_msg(st,LABEL_MSG4,msg4,&m)) return False;
950 if (!check_msg(st,LABEL_MSG4,&m,&err)) {
951 slog(st,LOG_SEC,"msg4: %s",err);
955 if (!process_msg3_msg4(st,&m))
958 /* Terminate their DH public key with a '0' */
961 /* Generate the shared key and set up the transform */
962 if (!set_new_transform(st,m.pk)) return False;
973 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
977 m->dest=buf_unprepend_uint32(msg0);
979 m->source=buf_unprepend_uint32(msg0);
981 m->type=buf_unprepend_uint32(msg0);
983 /* Leaves transformed part of buffer untouched */
986 static bool_t generate_msg5(struct site *st)
988 cstring_t transform_err;
990 BUF_ALLOC(&st->buffer,"site:MSG5");
991 /* We are going to add four words to the message */
992 buffer_init(&st->buffer,calculate_max_start_pad());
993 /* Give the netlink code an opportunity to put its own stuff in the
994 message (configuration information, etc.) */
995 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
996 if (call_transform_forwards(st,st->new_transform,
997 &st->buffer,&transform_err))
999 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1000 buf_prepend_uint32(&st->buffer,st->index);
1001 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1003 st->retries=st->setup_retries;
1007 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1008 const struct comm_addr *src,
1009 struct transform_inst_if *transform)
1012 cstring_t transform_err;
1014 if (!unpick_msg0(st,msg5,&m)) return False;
1016 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1017 /* There's a problem */
1018 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1021 /* Buffer should now contain untransformed PING packet data */
1022 CHECK_AVAIL(msg5,4);
1023 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1024 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1027 /* Older versions of secnet used to write some config data here
1028 * which we ignore. So we don't CHECK_EMPTY */
1032 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1033 uint32_t session_id)
1035 cstring_t transform_err;
1037 BUF_ALLOC(&st->buffer,"site:MSG6");
1038 /* We are going to add four words to the message */
1039 buffer_init(&st->buffer,calculate_max_start_pad());
1040 /* Give the netlink code an opportunity to put its own stuff in the
1041 message (configuration information, etc.) */
1042 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1043 transform_apply_return problem =
1044 call_transform_forwards(st,transform,
1045 &st->buffer,&transform_err);
1047 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1048 buf_prepend_uint32(&st->buffer,st->index);
1049 buf_prepend_uint32(&st->buffer,session_id);
1052 static bool_t generate_msg6(struct site *st)
1054 if (!is_transform_valid(st->new_transform))
1056 create_msg6(st,st->new_transform,st->setup_session_id);
1057 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1061 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1062 const struct comm_addr *src)
1065 cstring_t transform_err;
1067 if (!unpick_msg0(st,msg6,&m)) return False;
1069 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1070 /* There's a problem */
1071 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1074 /* Buffer should now contain untransformed PING packet data */
1075 CHECK_AVAIL(msg6,4);
1076 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1077 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1080 /* Older versions of secnet used to write some config data here
1081 * which we ignore. So we don't CHECK_EMPTY */
1085 static transform_apply_return
1086 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1087 const struct comm_addr *src)
1089 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1091 transform_apply_return problem;
1093 if (!unpick_msg0(st,msg0,&m)) return False;
1095 /* Keep a copy so we can try decrypting it with multiple keys */
1096 buffer_copy(&st->scratch, msg0);
1098 problem = call_transform_reverse(st,st->current.transform,
1099 msg0,&transform_err);
1101 if (!st->auxiliary_is_new)
1102 delete_one_key(st,&st->auxiliary_key,
1103 "peer has used new key","auxiliary key",LOG_SEC);
1106 if (transform_apply_return_badseq(problem))
1109 buffer_copy(msg0, &st->scratch);
1110 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1113 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1114 if (st->auxiliary_is_new) {
1115 /* We previously timed out in state SENTMSG5 but it turns
1116 * out that our peer did in fact get our MSG5 and is
1117 * using the new key. So we should switch to it too. */
1118 /* This is a bit like activate_new_key. */
1121 st->current=st->auxiliary_key;
1122 st->auxiliary_key=t;
1124 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1125 "previous key",LOG_SEC);
1126 st->auxiliary_is_new=0;
1127 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1131 if (transform_apply_return_badseq(problem))
1134 if (st->state==SITE_SENTMSG5) {
1135 buffer_copy(msg0, &st->scratch);
1136 problem = call_transform_reverse(st,st->new_transform,
1139 /* It looks like we didn't get the peer's MSG6 */
1140 /* This is like a cut-down enter_new_state(SITE_RUN) */
1141 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1142 BUF_FREE(&st->buffer);
1144 activate_new_key(st);
1145 return 0; /* do process the data in this packet */
1147 if (transform_apply_return_badseq(problem))
1151 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1152 transform_err,auxkey_err,newkey_err);
1153 initiate_key_setup(st,"incoming message would not decrypt",0);
1154 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1159 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1164 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1165 const struct comm_addr *src)
1168 transform_apply_return problem;
1170 problem = decrypt_msg0(st,msg0,src);
1171 if (problem==transform_apply_seqdupe) {
1172 /* We recently received another copy of this packet, maybe due
1173 * to polypath. That's not a problem; indeed, for the
1174 * purposes of transport address management it is a success.
1175 * But we don't want to process the packet. */
1176 transport_data_msgok(st,src);
1182 CHECK_AVAIL(msg0,4);
1183 type=buf_unprepend_uint32(msg0);
1186 /* We must forget about the current session. */
1187 delete_keys(st,"request from peer",LOG_SEC);
1188 /* probably, the peer is shutting down, and this is going to fail,
1189 * but we need to be trying to bring the link up again */
1191 initiate_key_setup(st,"peer requested key teardown",0);
1194 /* Deliver to netlink layer */
1195 st->netlink->deliver(st->netlink->st,msg0);
1196 transport_data_msgok(st,src);
1197 /* See whether we should start negotiating a new key */
1198 if (st->now > st->renegotiate_key_time)
1199 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1202 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1209 static void dump_packet(struct site *st, struct buffer_if *buf,
1210 const struct comm_addr *addr, bool_t incoming,
1213 uint32_t dest=get_uint32(buf->start);
1214 uint32_t source=get_uint32(buf->start+4);
1215 uint32_t msgtype=get_uint32(buf->start+8);
1217 if (st->log_events & LOG_DUMP)
1218 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1219 st->tunname,incoming?"incoming":"outgoing",
1220 dest,source,msgtype,comm_addr_to_string(addr),
1224 static bool_t comm_addr_sendmsg(struct site *st,
1225 const struct comm_addr *dest,
1226 struct buffer_if *buf)
1229 struct comm_clientinfo *commclientinfo = 0;
1231 for (i=0; i < st->ncomms; i++) {
1232 if (st->comms[i] == dest->comm) {
1233 commclientinfo = st->commclientinfos[i];
1237 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1240 static uint32_t site_status(void *st)
1245 static bool_t send_msg(struct site *st)
1247 if (st->retries>0) {
1248 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1249 st->timeout=st->now+st->setup_retry_interval;
1252 } else if (st->state==SITE_SENTMSG5) {
1253 logtimeout(st,"timed out sending MSG5, stashing new key");
1254 /* We stash the key we have produced, in case it turns out that
1255 * our peer did see our MSG5 after all and starts using it. */
1256 /* This is a bit like some of activate_new_key */
1257 struct transform_inst_if *t;
1258 t=st->auxiliary_key.transform;
1259 st->auxiliary_key.transform=st->new_transform;
1260 st->new_transform=t;
1261 dispose_transform(&st->new_transform);
1263 st->auxiliary_is_new=1;
1264 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1265 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1266 st->auxiliary_key.remote_session_id=st->setup_session_id;
1268 enter_state_wait(st);
1271 logtimeout(st,"timed out sending key setup packet "
1272 "(in state %s)",state_name(st->state));
1273 enter_state_wait(st);
1278 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1279 int stored_naddrs, int all_naddrs,
1280 const char *address, const char *failwhy)
1282 struct site *st=sst;
1284 if (!stored_naddrs) {
1285 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1287 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1288 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1290 int space=st->transport_peers_max-st->resolving_n_results_stored;
1291 int n_tocopy=MIN(stored_naddrs,space);
1292 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1295 st->resolving_n_results_stored += n_tocopy;
1296 st->resolving_n_results_all += all_naddrs;
1299 decrement_resolving_count(st,1);
1302 static void decrement_resolving_count(struct site *st, int by)
1304 assert(st->resolving_count>0);
1305 st->resolving_count-=by;
1307 if (st->resolving_count)
1310 /* OK, we are done with them all. Handle combined results. */
1312 const struct comm_addr *addrs=st->resolving_results;
1313 int naddrs=st->resolving_n_results_stored;
1314 assert(naddrs<=st->transport_peers_max);
1317 if (naddrs != st->resolving_n_results_all) {
1318 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1319 " yielded too many results (%d > %d), some ignored",
1320 st->resolving_n_results_all, naddrs);
1322 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1323 naddrs, iaddr_to_string(&addrs[0].ia));;
1326 switch (st->state) {
1328 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1329 enter_new_state(st,SITE_SENTMSG1);
1331 /* Can't figure out who to try to to talk to */
1332 slog(st,LOG_SETUP_INIT,
1333 "key exchange failed: cannot find peer address");
1334 enter_state_run(st);
1337 case SITE_SENTMSG1: case SITE_SENTMSG2:
1338 case SITE_SENTMSG3: case SITE_SENTMSG4:
1341 /* We start using the address immediately for data too.
1342 * It's best to store it in st->peers now because we might
1343 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1344 * the new key (without updating the data peer addrs). */
1345 transport_resolve_complete(st,addrs,naddrs);
1346 } else if (st->local_mobile) {
1347 /* We can't let this rest because we may have a peer
1348 * address which will break in the future. */
1349 slog(st,LOG_SETUP_INIT,"resolution failed: "
1350 "abandoning key exchange");
1351 enter_state_wait(st);
1353 slog(st,LOG_SETUP_INIT,"resolution failed: "
1354 " continuing to use source address of peer's packets"
1355 " for key exchange and ultimately data");
1360 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1361 " updating peer address(es)");
1362 transport_resolve_complete_tardy(st,addrs,naddrs);
1363 } else if (st->local_mobile) {
1364 /* Not very good. We should queue (another) renegotiation
1365 * so that we can update the peer address. */
1366 st->key_renegotiate_time=st->now+wait_timeout(st);
1368 slog(st,LOG_SETUP_INIT,"resolution failed: "
1369 " continuing to use source address of peer's packets");
1379 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1380 const struct comm_addr *prod_hint)
1382 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1383 if (st->state!=SITE_RUN) return False;
1384 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1385 if (st->addresses) {
1386 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1387 return enter_state_resolve(st);
1388 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1389 return enter_new_state(st,SITE_SENTMSG1);
1391 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1395 static void activate_new_key(struct site *st)
1397 struct transform_inst_if *t;
1399 /* We have three transform instances, which we swap between old,
1401 t=st->auxiliary_key.transform;
1402 st->auxiliary_key.transform=st->current.transform;
1403 st->current.transform=st->new_transform;
1404 st->new_transform=t;
1405 dispose_transform(&st->new_transform);
1408 st->auxiliary_is_new=0;
1409 st->auxiliary_key.key_timeout=st->current.key_timeout;
1410 st->current.key_timeout=st->now+st->key_lifetime;
1411 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1412 transport_peers_copy(st,&st->peers,&st->setup_peers);
1413 st->current.remote_session_id=st->setup_session_id;
1415 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1416 * But their mtu be unspecified, in which case we just use ours. */
1417 uint32_t intersite_mtu=
1418 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1419 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1421 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1422 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1423 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1424 enter_state_run(st);
1427 static void delete_one_key(struct site *st, struct data_key *key,
1428 cstring_t reason, cstring_t which, uint32_t loglevel)
1430 if (!is_transform_valid(key->transform)) return;
1431 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1432 dispose_transform(&key->transform);
1436 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1438 if (current_valid(st)) {
1439 slog(st,loglevel,"session closed (%s)",reason);
1441 delete_one_key(st,&st->current,0,0,0);
1442 set_link_quality(st);
1444 delete_one_key(st,&st->auxiliary_key,0,0,0);
1447 static void state_assert(struct site *st, bool_t ok)
1449 if (!ok) fatal("site:state_assert");
1452 static void enter_state_stop(struct site *st)
1454 st->state=SITE_STOP;
1456 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1457 dispose_transform(&st->new_transform);
1460 static void set_link_quality(struct site *st)
1463 if (current_valid(st))
1464 quality=LINK_QUALITY_UP;
1465 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1466 quality=LINK_QUALITY_DOWN;
1467 else if (st->addresses)
1468 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1469 else if (transport_peers_valid(&st->peers))
1470 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1472 quality=LINK_QUALITY_DOWN;
1474 st->netlink->set_quality(st->netlink->st,quality);
1477 static void enter_state_run(struct site *st)
1479 slog(st,LOG_STATE,"entering state RUN");
1483 st->setup_session_id=0;
1484 transport_peers_clear(st,&st->setup_peers);
1485 FILLZERO(st->localN);
1486 FILLZERO(st->remoteN);
1487 dispose_transform(&st->new_transform);
1488 memset(st->dhsecret,0,st->dh->len);
1489 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1490 set_link_quality(st);
1492 if (st->keepalive && !current_valid(st))
1493 initiate_key_setup(st, "keepalive", 0);
1496 static bool_t ensure_resolving(struct site *st)
1498 /* Reentrancy hazard: may call site_resolve_callback and hence
1499 * enter_new_state, enter_state_* and generate_msg*. */
1500 if (st->resolving_count)
1503 assert(st->addresses);
1505 /* resolver->request might reentrantly call site_resolve_callback
1506 * which will decrement st->resolving, so we need to increment it
1507 * twice beforehand to prevent decrement from thinking we're
1508 * finished, and decrement it ourselves. Alternatively if
1509 * everything fails then there are no callbacks due and we simply
1510 * set it to 0 and return false.. */
1511 st->resolving_n_results_stored=0;
1512 st->resolving_n_results_all=0;
1513 st->resolving_count+=2;
1514 const char **addrp=st->addresses;
1515 const char *address;
1517 for (; (address=*addrp++); ) {
1518 bool_t ok = st->resolver->request(st->resolver->st,address,
1519 st->remoteport,st->comms[0],
1520 site_resolve_callback,st);
1522 st->resolving_count++;
1526 st->resolving_count=0;
1529 decrement_resolving_count(st,2);
1533 static bool_t enter_state_resolve(struct site *st)
1535 /* Reentrancy hazard! See ensure_resolving. */
1536 state_assert(st,st->state==SITE_RUN);
1537 slog(st,LOG_STATE,"entering state RESOLVE");
1538 st->state=SITE_RESOLVE;
1539 return ensure_resolving(st);
1542 static bool_t enter_new_state(struct site *st, uint32_t next)
1544 bool_t (*gen)(struct site *st);
1547 slog(st,LOG_STATE,"entering state %s",state_name(next));
1550 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1552 st->msg1_crossed_logged = False;
1555 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1556 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1560 state_assert(st,st->state==SITE_SENTMSG1);
1561 BUF_FREE(&st->buffer);
1565 state_assert(st,st->state==SITE_SENTMSG2);
1566 BUF_FREE(&st->buffer);
1570 state_assert(st,st->state==SITE_SENTMSG3);
1571 BUF_FREE(&st->buffer);
1575 state_assert(st,st->state==SITE_SENTMSG4);
1576 BUF_FREE(&st->buffer);
1581 fatal("enter_new_state(%s): invalid new state",state_name(next));
1585 if (hacky_par_start_failnow()) return False;
1587 r= gen(st) && send_msg(st);
1590 st->setup_retries, st->setup_retry_interval,
1595 if (next==SITE_RUN) {
1596 BUF_FREE(&st->buffer); /* Never reused */
1597 st->timeout=0; /* Never retransmit */
1598 activate_new_key(st);
1602 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1603 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1604 in either state, and enter_state_wait() will
1606 enter_state_wait(st);
1610 /* msg7 tells our peer that we're about to forget our key */
1611 static bool_t send_msg7(struct site *st, cstring_t reason)
1613 cstring_t transform_err;
1615 if (current_valid(st) && st->buffer.free
1616 && transport_peers_valid(&st->peers)) {
1617 BUF_ALLOC(&st->buffer,"site:MSG7");
1618 buffer_init(&st->buffer,calculate_max_start_pad());
1619 buf_append_uint32(&st->buffer,LABEL_MSG7);
1620 buf_append_string(&st->buffer,reason);
1621 if (call_transform_forwards(st, st->current.transform,
1622 &st->buffer, &transform_err))
1624 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1625 buf_prepend_uint32(&st->buffer,st->index);
1626 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1627 transport_xmit(st,&st->peers,&st->buffer,True);
1628 BUF_FREE(&st->buffer);
1635 /* We go into this state if our peer becomes uncommunicative. Similar to
1636 the "stop" state, we forget all session keys for a while, before
1637 re-entering the "run" state. */
1638 static void enter_state_wait(struct site *st)
1640 slog(st,LOG_STATE,"entering state WAIT");
1641 st->timeout=st->now+wait_timeout(st);
1642 st->state=SITE_WAIT;
1643 set_link_quality(st);
1644 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1645 /* XXX Erase keys etc. */
1648 static void generate_prod(struct site *st, struct buffer_if *buf)
1651 buf_append_uint32(buf,0);
1652 buf_append_uint32(buf,0);
1653 buf_append_uint32(buf,LABEL_PROD);
1654 buf_append_string(buf,st->localname);
1655 buf_append_string(buf,st->remotename);
1658 static void generate_send_prod(struct site *st,
1659 const struct comm_addr *source)
1661 if (!st->allow_send_prod) return; /* too soon */
1662 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1663 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1665 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1666 st->allow_send_prod=0;
1667 generate_prod(st,&st->scratch);
1668 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1669 dump_packet(st,&st->scratch,source,False,ok);
1672 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1675 int64_t offset=timeout-*now;
1676 if (offset<0) offset=0;
1677 if (offset>INT_MAX) offset=INT_MAX;
1678 if (*timeout_io<0 || offset<*timeout_io)
1683 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1686 struct site *st=sst;
1688 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1691 /* Work out when our next timeout is. The earlier of 'timeout' or
1692 'current.key_timeout'. A stored value of '0' indicates no timeout
1694 site_settimeout(st->timeout, timeout_io);
1695 site_settimeout(st->current.key_timeout, timeout_io);
1696 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1698 return 0; /* success */
1701 static void check_expiry(struct site *st, struct data_key *key,
1704 if (key->key_timeout && *now>key->key_timeout) {
1705 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1709 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1710 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1712 struct site *st=sst;
1715 if (st->timeout && *now>st->timeout) {
1717 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1718 if (!hacky_par_start_failnow())
1720 } else if (st->state==SITE_WAIT) {
1721 enter_state_run(st);
1723 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1727 check_expiry(st,&st->current,"current key");
1728 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1731 /* This function is called by the netlink device to deliver packets
1732 intended for the remote network. The packet is in "raw" wire
1733 format, but is guaranteed to be word-aligned. */
1734 static void site_outgoing(void *sst, struct buffer_if *buf)
1736 struct site *st=sst;
1737 cstring_t transform_err;
1739 if (st->state==SITE_STOP) {
1744 st->allow_send_prod=1;
1746 /* In all other states we consider delivering the packet if we have
1747 a valid key and a valid address to send it to. */
1748 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1749 /* Transform it and send it */
1751 buf_prepend_uint32(buf,LABEL_MSG9);
1752 if (call_transform_forwards(st, st->current.transform,
1753 buf, &transform_err))
1755 buf_prepend_uint32(buf,LABEL_MSG0);
1756 buf_prepend_uint32(buf,st->index);
1757 buf_prepend_uint32(buf,st->current.remote_session_id);
1758 transport_xmit(st,&st->peers,buf,False);
1765 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1767 initiate_key_setup(st,"outgoing packet",0);
1770 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1771 uint32_t type, struct msg *m)
1772 /* For packets which are identified by the local and remote names.
1773 * If it has our name and our peer's name in it it's for us. */
1775 struct buffer_if buf[1];
1776 buffer_readonly_clone(buf,buf_in);
1777 return unpick_msg(st,type,buf,m)
1778 && name_matches(&m->remote,st->remotename)
1779 && name_matches(&m->local,st->localname);
1782 static bool_t we_have_priority(struct site *st, const struct msg *m) {
1783 if ((st->local_capabilities & m->remote_capabilities)
1784 && CAPAB_PRIORITY_MOBILE) {
1785 if (st->local_mobile) return True;
1786 if (st-> peer_mobile) return False;
1788 return st->our_name_later;
1791 static bool_t setup_late_msg_ok(struct site *st,
1792 const struct buffer_if *buf_in,
1794 const struct comm_addr *source) {
1795 /* For setup packets which seem from their type like they are
1796 * late. Maybe they came via a different path. All we do is make
1797 * a note of the sending address, iff they look like they are part
1798 * of the current key setup attempt. */
1800 if (!named_for_us(st,buf_in,msgtype,&m))
1801 /* named_for_us calls unpick_msg which gets the nonces */
1803 if (!consttime_memeq(m.nR,st->remoteN,NONCELEN) ||
1804 !consttime_memeq(m.nL,st->localN, NONCELEN))
1805 /* spoof ? from stale run ? who knows */
1807 transport_setup_msgok(st,source);
1811 /* This function is called by the communication device to deliver
1812 packets from our peers.
1813 It should return True if the packet is recognised as being for
1814 this current site instance (and should therefore not be processed
1815 by other sites), even if the packet was otherwise ignored. */
1816 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1817 const struct comm_addr *source)
1819 struct site *st=sst;
1821 if (buf->size < 12) return False;
1823 uint32_t dest=get_uint32(buf->start);
1824 uint32_t msgtype=get_uint32(buf->start+8);
1825 struct msg named_msg;
1827 if (msgtype==LABEL_MSG1) {
1828 if (!named_for_us(st,buf,msgtype,&named_msg))
1830 /* It's a MSG1 addressed to us. Decide what to do about it. */
1831 dump_packet(st,buf,source,True,True);
1832 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1833 st->state==SITE_WAIT) {
1834 /* We should definitely process it */
1835 transport_compute_setupinit_peers(st,0,0,source);
1836 if (process_msg1(st,buf,source,&named_msg)) {
1837 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1838 bool_t entered=enter_new_state(st,SITE_SENTMSG2);
1839 if (entered && st->addresses && st->local_mobile)
1840 /* We must do this as the very last thing, because
1841 the resolver callback might reenter us. */
1842 ensure_resolving(st);
1844 slog(st,LOG_ERROR,"failed to process incoming msg1");
1848 } else if (st->state==SITE_SENTMSG1) {
1849 /* We've just sent a message 1! They may have crossed on
1850 the wire. If we have priority then we ignore the
1851 incoming one, otherwise we process it as usual. */
1852 if (we_have_priority(st,&named_msg)) {
1854 if (!st->msg1_crossed_logged++)
1855 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
1856 "priority => ignore incoming msg1");
1859 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
1860 "priority => use incoming msg1");
1861 if (process_msg1(st,buf,source,&named_msg)) {
1862 BUF_FREE(&st->buffer); /* Free our old message 1 */
1863 transport_setup_msgok(st,source);
1864 enter_new_state(st,SITE_SENTMSG2);
1866 slog(st,LOG_ERROR,"failed to process an incoming "
1867 "crossed msg1 (we have low priority)");
1872 } else if (st->state==SITE_SENTMSG2 ||
1873 st->state==SITE_SENTMSG4) {
1874 if (consttime_memeq(named_msg.nR,st->remoteN,NONCELEN)) {
1875 /* We are ahead in the protocol, but that msg1 had the
1876 * peer's nonce so presumably it is from this key
1877 * exchange run, via a slower route */
1878 transport_setup_msgok(st,source);
1880 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
1885 /* The message 1 was received at an unexpected stage of the
1886 key setup. Well, they lost the race. */
1887 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1891 if (msgtype==LABEL_PROD) {
1892 if (!named_for_us(st,buf,msgtype,&named_msg))
1894 dump_packet(st,buf,source,True,True);
1895 if (st->state!=SITE_RUN) {
1896 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1897 } else if (current_valid(st)) {
1898 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1900 initiate_key_setup(st,"peer sent PROD packet",source);
1905 if (dest==st->index) {
1906 /* Explicitly addressed to us */
1907 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
1910 /* If the source is our current peer then initiate a key setup,
1911 because our peer's forgotten the key */
1912 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
1914 initiated = initiate_key_setup(st,"received a NAK",source);
1915 if (!initiated) generate_send_prod(st,source);
1917 slog(st,LOG_SEC,"bad incoming NAK");
1921 process_msg0(st,buf,source);
1924 /* Setup packet: should not have been explicitly addressed
1926 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
1929 /* Setup packet: expected only in state SENTMSG1 */
1930 if (st->state!=SITE_SENTMSG1) {
1931 if ((st->state==SITE_SENTMSG3 ||
1932 st->state==SITE_SENTMSG5) &&
1933 setup_late_msg_ok(st,buf,msgtype,source))
1935 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
1936 } else if (process_msg2(st,buf,source)) {
1937 transport_setup_msgok(st,source);
1938 enter_new_state(st,SITE_SENTMSG3);
1940 slog(st,LOG_SEC,"invalid MSG2");
1945 /* Setup packet: expected only in state SENTMSG2 */
1946 if (st->state!=SITE_SENTMSG2) {
1947 if ((st->state==SITE_SENTMSG4) &&
1948 setup_late_msg_ok(st,buf,msgtype,source))
1950 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
1951 } else if (process_msg3(st,buf,source,msgtype)) {
1952 transport_setup_msgok(st,source);
1953 enter_new_state(st,SITE_SENTMSG4);
1955 slog(st,LOG_SEC,"invalid MSG3");
1959 /* Setup packet: expected only in state SENTMSG3 */
1960 if (st->state!=SITE_SENTMSG3) {
1961 if ((st->state==SITE_SENTMSG5) &&
1962 setup_late_msg_ok(st,buf,msgtype,source))
1964 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
1965 } else if (process_msg4(st,buf,source)) {
1966 transport_setup_msgok(st,source);
1967 enter_new_state(st,SITE_SENTMSG5);
1969 slog(st,LOG_SEC,"invalid MSG4");
1973 /* Setup packet: expected only in state SENTMSG4 */
1974 /* (may turn up in state RUN if our return MSG6 was lost
1975 and the new key has already been activated. In that
1976 case we discard it. The peer will realise that we
1977 are using the new key when they see our data packets.
1978 Until then the peer's data packets to us get discarded. */
1979 if (st->state==SITE_SENTMSG4) {
1980 if (process_msg5(st,buf,source,st->new_transform)) {
1981 transport_setup_msgok(st,source);
1982 enter_new_state(st,SITE_RUN);
1984 slog(st,LOG_SEC,"invalid MSG5");
1986 } else if (st->state==SITE_RUN) {
1987 if (process_msg5(st,buf,source,st->current.transform)) {
1988 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
1989 transport_setup_msgok(st,source);
1990 create_msg6(st,st->current.transform,
1991 st->current.remote_session_id);
1992 transport_xmit(st,&st->peers,&st->buffer,True);
1993 BUF_FREE(&st->buffer);
1995 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
1998 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2002 /* Setup packet: expected only in state SENTMSG5 */
2003 if (st->state!=SITE_SENTMSG5) {
2004 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2005 } else if (process_msg6(st,buf,source)) {
2006 BUF_FREE(&st->buffer); /* Free message 5 */
2007 transport_setup_msgok(st,source);
2008 activate_new_key(st);
2010 slog(st,LOG_SEC,"invalid MSG6");
2014 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2025 static void site_control(void *vst, bool_t run)
2027 struct site *st=vst;
2028 if (run) enter_state_run(st);
2029 else enter_state_stop(st);
2032 static void site_phase_hook(void *sst, uint32_t newphase)
2034 struct site *st=sst;
2036 /* The program is shutting down; tell our peer */
2037 send_msg7(st,"shutting down");
2040 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2042 struct site *st=sst;
2043 dispose_transform(&st->current.transform);
2044 dispose_transform(&st->auxiliary_key.transform);
2045 dispose_transform(&st->new_transform);
2046 /* Not much point overwiting the signing key, since we loaded it
2047 from disk, and it is only valid prospectively if at all,
2049 /* XXX it would be best to overwrite the DH state, because that
2050 _is_ relevant to forward secrecy. However we have no
2051 convenient interface for doing that and in practice gmp has
2052 probably dribbled droppings all over the malloc arena. A good
2053 way to fix this would be to have a privsep child for asymmetric
2054 crypto operations, but that's a task for another day. */
2057 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2060 static uint32_t index_sequence;
2068 st->cl.description="site";
2069 st->cl.type=CL_SITE;
2071 st->cl.interface=&st->ops;
2073 st->ops.control=site_control;
2074 st->ops.status=site_status;
2076 /* First parameter must be a dict */
2077 item=list_elem(args,0);
2078 if (!item || item->type!=t_dict)
2079 cfgfatal(loc,"site","parameter must be a dictionary\n");
2081 dict=item->data.dict;
2082 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2083 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2085 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2087 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2089 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2091 /* Sanity check (which also allows the 'sites' file to include
2092 site() closures for all sites including our own): refuse to
2093 talk to ourselves */
2094 if (strcmp(st->localname,st->remotename)==0) {
2095 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2097 if (st->peer_mobile != st->local_mobile)
2098 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2099 " but our local-mobile=%d\n",
2100 st->localname, st->peer_mobile, st->local_mobile);
2104 if (st->peer_mobile && st->local_mobile) {
2105 Message(M_WARNING,"site %s: site is mobile but so are we"
2106 " -> ignoring this site\n", st->remotename);
2111 assert(index_sequence < 0xffffffffUL);
2112 st->index = ++index_sequence;
2113 st->local_capabilities = 0;
2114 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2116 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2117 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2118 if (!things##_cfg) \
2119 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2120 st->nthings=list_length(things##_cfg); \
2121 NEW_ARY(st->things,st->nthings); \
2122 assert(st->nthings); \
2123 for (i=0; i<st->nthings; i++) { \
2124 item_t *item=list_elem(things##_cfg,i); \
2125 if (item->type!=t_closure) \
2126 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2127 closure_t *cl=item->data.closure; \
2128 if (cl->type!=CL_TYPE) \
2129 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2130 st->things[i]=cl->interface; \
2134 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2136 NEW_ARY(st->commclientinfos, st->ncomms);
2137 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2138 for (i=0; i<st->ncomms; i++) {
2139 st->commclientinfos[i] =
2141 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2144 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2145 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2146 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2148 st->privkey=find_cl_if(dict,"local-key",CL_RSAPRIVKEY,True,"site",loc);
2149 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2151 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2152 else st->remoteport=0;
2153 st->pubkey=find_cl_if(dict,"key",CL_RSAPUBKEY,True,"site",loc);
2155 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2157 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2158 st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2160 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2161 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2162 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2164 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2165 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2166 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2167 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2168 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2170 st->mobile_peer_expiry= dict_read_number(
2171 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2173 const char *peerskey= st->peer_mobile
2174 ? "mobile-peers-max" : "static-peers-max";
2175 st->transport_peers_max= dict_read_number(
2176 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2177 if (st->transport_peers_max<1 ||
2178 st->transport_peers_max>MAX_PEER_ADDRS) {
2179 cfgfatal(loc,"site", "%s must be in range 1.."
2180 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2183 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2184 st->key_renegotiate_time=st->key_lifetime/2;
2186 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2187 st->key_renegotiate_time=dict_read_number(
2188 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2189 if (st->key_renegotiate_time > st->key_lifetime) {
2190 cfgfatal(loc,"site",
2191 "renegotiate-time must be less than key-lifetime\n");
2194 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2195 log_event_table,"site");
2197 st->resolving_count=0;
2198 st->allow_send_prod=0;
2200 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2202 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2204 /* The information we expect to see in incoming messages of type 1 */
2205 /* fixme: lots of unchecked overflows here, but the results are only
2206 corrupted packets rather than undefined behaviour */
2207 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2209 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2211 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2212 BUF_ALLOC(&st->scratch,"site:scratch");
2214 /* We are interested in poll(), but only for timeouts. We don't have
2215 any fds of our own. */
2216 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2219 st->remote_capabilities=0;
2220 st->chosen_transform=0;
2221 st->current.key_timeout=0;
2222 st->auxiliary_key.key_timeout=0;
2223 transport_peers_clear(st,&st->peers);
2224 transport_peers_clear(st,&st->setup_peers);
2225 /* XXX mlock these */
2226 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2227 st->sharedsecretlen=st->sharedsecretallocd=0;
2230 for (i=0; i<st->ntransforms; i++) {
2231 struct transform_if *ti=st->transforms[i];
2232 uint32_t capbit = 1UL << ti->capab_transformnum;
2233 if (st->local_capabilities & capbit)
2234 slog(st,LOG_ERROR,"transformnum capability bit"
2235 " %d (%#"PRIx32") reused", ti->capab_transformnum, capbit);
2236 st->local_capabilities |= capbit;
2239 if (st->local_mobile || st->peer_mobile)
2240 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2242 /* We need to register the remote networks with the netlink device */
2243 uint32_t netlink_mtu; /* local virtual interface mtu */
2244 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2245 if (!st->mtu_target)
2246 st->mtu_target=netlink_mtu;
2248 for (i=0; i<st->ncomms; i++)
2249 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2251 st->current.transform=0;
2252 st->auxiliary_key.transform=0;
2253 st->new_transform=0;
2254 st->auxiliary_is_new=0;
2256 enter_state_stop(st);
2258 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2259 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2261 return new_closure(&st->cl);
2264 void site_module(dict_t *dict)
2266 add_closure(dict,"site",site_apply);
2270 /***** TRANSPORT PEERS definitions *****/
2272 static void transport_peers_debug(struct site *st, transport_peers *dst,
2273 const char *didwhat,
2274 int nargs, const struct comm_addr *args,
2279 if (!(st->log_events & LOG_PEER_ADDRS))
2280 return; /* an optimisation */
2282 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2283 (dst==&st->peers ? "data" :
2284 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2285 didwhat, nargs, dst->npeers);
2287 for (i=0, argp=(void*)args;
2289 i++, (argp+=stride?stride:sizeof(*args))) {
2290 const struct comm_addr *ca=(void*)argp;
2291 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2292 i, comm_addr_to_string(ca));
2294 for (i=0; i<dst->npeers; i++) {
2295 struct timeval diff;
2296 timersub(tv_now,&dst->peers[i].last,&diff);
2297 const struct comm_addr *ca=&dst->peers[i].addr;
2298 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2299 i, comm_addr_to_string(ca),
2300 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2304 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2305 /* peers must be sorted first */
2306 int previous_peers=peers->npeers;
2307 struct timeval oldest;
2308 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2309 oldest.tv_usec = tv_now->tv_usec;
2310 while (peers->npeers>1 &&
2311 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2313 if (peers->npeers != previous_peers)
2314 transport_peers_debug(st,peers,"expire", 0,0,0);
2317 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2318 const struct comm_addr *ca,
2319 const struct timeval *tv) {
2320 /* returns false if output is full */
2323 if (peers->npeers >= st->transport_peers_max)
2326 for (search=0; search<peers->npeers; search++)
2327 if (comm_addr_equal(&peers->peers[search].addr, ca))
2330 peers->peers[peers->npeers].addr = *ca;
2331 peers->peers[peers->npeers].last = *tv;
2336 static void transport_record_peers(struct site *st, transport_peers *peers,
2337 const struct comm_addr *addrs, int naddrs,
2339 /* We add addrs into peers. The new entries end up at the front
2340 * and displace entries towards the end (perhaps even off the
2341 * end). Any existing matching entries are moved up to the front.
2343 * Caller must first call transport_peers_expire. */
2346 /* avoids debug for uninteresting updates */
2348 for (i=0; i<peers->npeers; i++) {
2349 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2350 memmove(peers->peers+1, peers->peers,
2351 sizeof(peers->peers[0]) * i);
2352 peers->peers[0].addr = addrs[0];
2353 peers->peers[0].last = *tv_now;
2359 int old_npeers=peers->npeers;
2360 transport_peer old_peers[old_npeers];
2361 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2365 for (i=0; i<naddrs; i++) {
2366 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2369 for (i=0; i<old_npeers; i++) {
2370 const transport_peer *old=&old_peers[i];
2371 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2375 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2378 static void transport_expire_record_peers(struct site *st,
2379 transport_peers *peers,
2380 const struct comm_addr *addrs,
2381 int naddrs, const char *m) {
2382 /* Convenience function */
2383 transport_peers_expire(st,peers);
2384 transport_record_peers(st,peers,addrs,naddrs,m);
2387 static bool_t transport_compute_setupinit_peers(struct site *st,
2388 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2389 int n_configured_addrs /* 0 if none or not found */,
2390 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2391 if (!n_configured_addrs && !incoming_packet_addr &&
2392 !transport_peers_valid(&st->peers))
2395 slog(st,LOG_SETUP_INIT,
2396 "using: %d configured addr(s);%s %d old peer addrs(es)",
2398 incoming_packet_addr ? " incoming packet address;" : "",
2401 /* Non-mobile peers try addresses until one is plausible. The
2402 * effect is that this code always tries first the configured
2403 * address if supplied, or otherwise the address of the incoming
2404 * PROD, or finally the existing data peer if one exists; this is
2407 transport_peers_copy(st,&st->setup_peers,&st->peers);
2408 transport_peers_expire(st,&st->setup_peers);
2410 if (incoming_packet_addr)
2411 transport_record_peers(st,&st->setup_peers,
2412 incoming_packet_addr,1, "incoming");
2414 if (n_configured_addrs)
2415 transport_record_peers(st,&st->setup_peers,
2416 configured_addrs,n_configured_addrs, "setupinit");
2418 assert(transport_peers_valid(&st->setup_peers));
2422 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2423 if (st->peer_mobile)
2424 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2426 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2427 if (st->peer_mobile)
2428 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2431 static int transport_peers_valid(transport_peers *peers) {
2432 return peers->npeers;
2434 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2436 transport_peers_debug(st,peers,"clear",0,0,0);
2438 static void transport_peers_copy(struct site *st, transport_peers *dst,
2439 const transport_peers *src) {
2440 dst->npeers=src->npeers;
2441 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2442 transport_peers_debug(st,dst,"copy",
2443 src->npeers, &src->peers->addr, sizeof(*src->peers));
2446 static void transport_resolve_complete(struct site *st,
2447 const struct comm_addr *addrs,
2449 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2451 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2455 static void transport_resolve_complete_tardy(struct site *st,
2456 const struct comm_addr *addrs,
2458 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2459 "resolved tardily");
2462 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2464 const transport_peers *inp) {
2465 /* out and in->peers may be the same region, or nonoverlapping */
2466 const transport_peer *in=inp->peers;
2468 for (slot=0; slot<inp->npeers; slot++) {
2469 if (!(mask & (1U << slot)))
2471 if (!(out==in && slot==*nout_io))
2472 COPY_OBJ(out[*nout_io], in[slot]);
2477 void transport_xmit(struct site *st, transport_peers *peers,
2478 struct buffer_if *buf, bool_t candebug) {
2480 transport_peers_expire(st, peers);
2481 unsigned failed=0; /* bitmask */
2482 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2485 for (slot=0; slot<peers->npeers; slot++) {
2486 transport_peer *peer=&peers->peers[slot];
2487 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2489 dump_packet(st, buf, &peer->addr, False, ok);
2491 failed |= 1U << slot;
2494 if (ok && !st->peer_mobile)
2497 /* Now we need to demote/delete failing addrs: if we are mobile we
2498 * merely demote them; otherwise we delete them. */
2499 if (st->local_mobile) {
2500 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2501 /* `expected' has all the failures at the end already */
2502 if (failed != expected) {
2504 transport_peer failedpeers[nfailed];
2505 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2506 assert(fslot == nfailed);
2508 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2509 assert(wslot+nfailed == peers->npeers);
2510 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2511 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2514 if (failed && peers->npeers > 1) {
2516 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2517 peers->npeers=wslot;
2518 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2523 /***** END of transport peers declarations *****/