1 /* site.c - manage communication with a remote network site */
4 * This file is part of secnet.
5 * See README for full list of copyright holders.
7 * secnet is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 3 of the License, or
10 * (at your option) any later version.
12 * secnet is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * version 3 along with secnet; if not, see
19 * https://www.gnu.org/licenses/gpl.html.
22 /* The 'site' code doesn't know anything about the structure of the
23 packets it's transmitting. In fact, under the new netlink
24 configuration scheme it doesn't need to know anything at all about
25 IP addresses, except how to contact its peer. This means it could
26 potentially be used to tunnel other protocols too (IPv6, IPX, plain
27 old Ethernet frames) if appropriate netlink code can be written
28 (and that ought not to be too hard, eg. using the TUN/TAP device to
29 pretend to be an Ethernet interface). */
31 /* At some point in the future the netlink code will be asked for
32 configuration information to go in the PING/PONG packets at the end
33 of the key exchange. */
40 #include <sys/socket.h>
44 #include "unaligned.h"
47 #define SETUP_BUFFER_LEN 2048
49 #define DEFAULT_KEY_LIFETIME (3600*1000) /* [ms] */
50 #define DEFAULT_KEY_RENEGOTIATE_GAP (5*60*1000) /* [ms] */
51 #define DEFAULT_SETUP_RETRIES 5
52 #define DEFAULT_SETUP_RETRY_INTERVAL (2*1000) /* [ms] */
53 #define DEFAULT_WAIT_TIME (20*1000) /* [ms] */
55 #define DEFAULT_MOBILE_KEY_LIFETIME (2*24*3600*1000) /* [ms] */
56 #define DEFAULT_MOBILE_KEY_RENEGOTIATE_GAP (12*3600*1000) /* [ms] */
57 #define DEFAULT_MOBILE_SETUP_RETRIES 30
58 #define DEFAULT_MOBILE_SETUP_RETRY_INTERVAL (1*1000) /* [ms] */
59 #define DEFAULT_MOBILE_WAIT_TIME (10*1000) /* [ms] */
61 #define DEFAULT_MOBILE_PEER_EXPIRY (2*60) /* [s] */
63 /* Each site can be in one of several possible states. */
66 SITE_STOP - nothing is allowed to happen; tunnel is down;
67 all session keys have been erased
68 -> SITE_RUN upon external instruction
69 SITE_RUN - site up, maybe with valid key
70 -> SITE_RESOLVE upon outgoing packet and no valid key
71 we start name resolution for the other end of the tunnel
72 -> SITE_SENTMSG2 upon valid incoming message 1 and suitable time
73 we send an appropriate message 2
74 SITE_RESOLVE - waiting for name resolution
75 -> SITE_SENTMSG1 upon successful resolution
76 we send an appropriate message 1
77 -> SITE_SENTMSG2 upon valid incoming message 1 (then abort resolution)
78 we abort resolution and
79 -> SITE_WAIT on timeout or resolution failure
81 -> SITE_SENTMSG2 upon valid incoming message 1 from higher priority end
82 -> SITE_SENTMSG3 upon valid incoming message 2
83 -> SITE_WAIT on timeout
85 -> SITE_SENTMSG4 upon valid incoming message 3
86 -> SITE_WAIT on timeout
88 -> SITE_SENTMSG5 upon valid incoming message 4
89 -> SITE_WAIT on timeout
91 -> SITE_RUN upon valid incoming message 5
92 -> SITE_WAIT on timeout
94 -> SITE_RUN upon valid incoming message 6
95 -> SITE_WAIT on timeout
96 SITE_WAIT - failed to establish key; do nothing for a while
97 -> SITE_RUN on timeout
102 #define SITE_RESOLVE 2
103 #define SITE_SENTMSG1 3
104 #define SITE_SENTMSG2 4
105 #define SITE_SENTMSG3 5
106 #define SITE_SENTMSG4 6
107 #define SITE_SENTMSG5 7
110 #define CASES_MSG3_KNOWN LABEL_MSG3: case LABEL_MSG3BIS
114 int32_t site_max_start_pad = 4*4;
116 static cstring_t state_name(uint32_t state)
119 case 0: return "STOP";
120 case 1: return "RUN";
121 case 2: return "RESOLVE";
122 case 3: return "SENTMSG1";
123 case 4: return "SENTMSG2";
124 case 5: return "SENTMSG3";
125 case 6: return "SENTMSG4";
126 case 7: return "SENTMSG5";
127 case 8: return "WAIT";
128 default: return "*bad state*";
134 #define LOG_UNEXPECTED 0x00000001
135 #define LOG_SETUP_INIT 0x00000002
136 #define LOG_SETUP_TIMEOUT 0x00000004
137 #define LOG_ACTIVATE_KEY 0x00000008
138 #define LOG_TIMEOUT_KEY 0x00000010
139 #define LOG_SEC 0x00000020
140 #define LOG_STATE 0x00000040
141 #define LOG_DROP 0x00000080
142 #define LOG_DUMP 0x00000100
143 #define LOG_ERROR 0x00000400
144 #define LOG_PEER_ADDRS 0x00000800
146 static struct flagstr log_event_table[]={
147 { "unexpected", LOG_UNEXPECTED },
148 { "setup-init", LOG_SETUP_INIT },
149 { "setup-timeout", LOG_SETUP_TIMEOUT },
150 { "activate-key", LOG_ACTIVATE_KEY },
151 { "timeout-key", LOG_TIMEOUT_KEY },
152 { "security", LOG_SEC },
153 { "state-change", LOG_STATE },
154 { "packet-drop", LOG_DROP },
155 { "dump-packets", LOG_DUMP },
156 { "errors", LOG_ERROR },
157 { "peer-addrs", LOG_PEER_ADDRS },
158 { "default", LOG_SETUP_INIT|LOG_SETUP_TIMEOUT|
159 LOG_ACTIVATE_KEY|LOG_TIMEOUT_KEY|LOG_SEC|LOG_ERROR },
160 { "all", 0xffffffff },
165 /***** TRANSPORT PEERS declarations *****/
167 /* Details of "mobile peer" semantics:
169 - We use the same data structure for the different configurations,
170 but manage it with different algorithms.
172 - We record up to mobile_peers_max peer address/port numbers
173 ("peers") for key setup, and separately up to mobile_peers_max
176 - In general, we make a new set of addrs (see below) when we start
177 a new key exchange; the key setup addrs become the data transport
178 addrs when key setup complets.
180 If our peer is mobile:
182 - We send to all recent addresses of incoming packets, plus
183 initially all configured addresses (which we also expire).
185 - So, we record addrs of good incoming packets, as follows:
186 1. expire any peers last seen >120s ("mobile-peer-expiry") ago
187 2. add the peer of the just received packet to the applicable list
188 (possibly evicting the oldest entries to make room)
189 NB that we do not expire peers until an incoming packet arrives.
191 - If the peer has a configured address or name, we record them the
192 same way, but only as a result of our own initiation of key
193 setup. (We might evict some incoming packet addrs to make room.)
195 - The default number of addrs to keep is 3, or 4 if we have a
196 configured name or address. That's space for two configured
197 addresses (one IPv6 and one IPv4), plus two received addresses.
199 - Outgoing packets are sent to every recorded address in the
200 applicable list. Any unsupported[1] addresses are deleted from
201 the list right away. (This should only happen to configured
202 addresses, of course, but there is no need to check that.)
204 - When we successfully complete a key setup, we merge the key setup
205 peers into the data transfer peers.
207 [1] An unsupported address is one for whose AF we don't have a
208 socket (perhaps because we got EAFNOSUPPORT or some such) or for
209 which sendto gives ENETUNREACH.
211 If neither end is mobile:
213 - When peer initiated the key exchange, we use the incoming packet
216 - When we initiate the key exchange, we try configured addresses
217 until we get one which isn't unsupported then fixate on that.
219 - When we complete a key setup, we replace the data transport peers
220 with those from the key setup.
224 - We can't tell when local network setup changes so we can't cache
225 the unsupported addrs and completely remove the spurious calls to
226 sendto, but we can optimise things a bit by deprioritising addrs
227 which seem to be unsupported.
229 - Use only configured addresses. (Except, that if our peer
230 initiated a key exchange we use the incoming packet address until
231 our name resolution completes.)
233 - When we send a packet, try each address in turn; if addr
234 supported, put that address to the end of the list for future
235 packets, and go onto the next address.
237 - When we complete a key setup, we replace the data transport peers
238 with those from the key setup.
244 struct comm_addr addr;
248 /* configuration information */
249 /* runtime information */
251 transport_peer peers[MAX_PEER_ADDRS];
254 /* Basic operations on transport peer address sets */
255 static void transport_peers_clear(struct site *st, transport_peers *peers);
256 static int transport_peers_valid(transport_peers *peers);
257 static void transport_peers_copy(struct site *st, transport_peers *dst,
258 const transport_peers *src);
260 /* Record address of incoming setup packet; resp. data packet. */
261 static void transport_setup_msgok(struct site *st, const struct comm_addr *a);
262 static void transport_data_msgok(struct site *st, const struct comm_addr *a);
264 /* Initialise the setup addresses. Called before we send the first
265 * packet in a key exchange. If we are the initiator, as a result of
266 * resolve completing (or being determined not to be relevant) or an
267 * incoming PROD; if we are the responder, as a result of the MSG1. */
268 static bool_t transport_compute_setupinit_peers(struct site *st,
269 const struct comm_addr *configured_addrs /* 0 if none or not found */,
270 int n_configured_addrs /* 0 if none or not found */,
271 const struct comm_addr *incoming_packet_addr /* 0 if none */);
273 /* Called if we are the responder in a key setup, when the resolve
274 * completes. transport_compute_setupinit_peers will hvae been called
275 * earlier. If _complete is called, we are still doing the key setup
276 * (and we should use the new values for both the rest of the key
277 * setup and the ongoing data exchange); if _tardy is called, the key
278 * setup is done (either completed or not) and only the data peers are
280 static void transport_resolve_complete(struct site *st,
281 const struct comm_addr *addrs, int naddrs);
282 static void transport_resolve_complete_tardy(struct site *st,
283 const struct comm_addr *addrs, int naddrs);
285 static void transport_xmit(struct site *st, transport_peers *peers,
286 struct buffer_if *buf, bool_t candebug);
288 /***** END of transport peers declarations *****/
292 struct transform_inst_if *transform;
293 uint64_t key_timeout; /* End of life of current key */
294 uint32_t remote_session_id;
300 /* configuration information */
304 bool_t local_mobile, peer_mobile; /* Mobile client support */
305 int32_t transport_peers_max;
306 string_t tunname; /* localname<->remotename by default, used in logs */
307 cstring_t *addresses; /* DNS name or address(es) for bootstrapping, optional */
308 int remoteport; /* Port for bootstrapping, optional */
310 struct netlink_if *netlink;
311 struct comm_if **comms;
312 struct comm_clientinfo **commclientinfos;
314 struct resolver_if *resolver;
316 struct random_if *random;
317 struct sigprivkey_if *privkey;
318 struct sigpubkey_if *pubkey;
319 struct transform_if **transforms;
323 uint32_t index; /* Index of this site */
324 uint32_t early_capabilities;
325 uint32_t local_capabilities;
326 int32_t setup_retries; /* How many times to send setup packets */
327 int32_t setup_retry_interval; /* Initial timeout for setup packets */
328 int32_t wait_timeout_mean; /* How long to wait if setup unsuccessful */
329 int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
330 int32_t key_lifetime; /* How long a key lasts once set up */
331 int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
332 after this time, initiate a new
335 bool_t our_name_later; /* our name > peer name */
338 /* runtime information */
340 uint64_t now; /* Most recently seen time */
341 bool_t allow_send_prod;
342 bool_t msg1_crossed_logged;
344 int resolving_n_results_all;
345 int resolving_n_results_stored;
346 struct comm_addr resolving_results[MAX_PEER_ADDRS];
348 /* The currently established session */
349 struct data_key current;
350 struct data_key auxiliary_key;
351 bool_t auxiliary_is_new;
352 uint64_t renegotiate_key_time; /* When we can negotiate a new key */
353 uint64_t auxiliary_renegotiate_key_time;
354 transport_peers peers; /* Current address(es) of peer for data traffic */
356 /* The current key setup protocol exchange. We can only be
357 involved in one of these at a time. There's a potential for
358 denial of service here (the attacker keeps sending a setup
359 packet; we keep trying to continue the exchange, and have to
360 timeout before we can listen for another setup packet); perhaps
361 we should keep a list of 'bad' sources for setup packets. */
362 uint32_t remote_capabilities;
363 uint16_t remote_adv_mtu;
364 struct transform_if *chosen_transform;
365 uint32_t setup_session_id;
366 transport_peers setup_peers;
367 uint8_t localN[NONCELEN]; /* Nonces for key exchange */
368 uint8_t remoteN[NONCELEN];
369 struct buffer_if buffer; /* Current outgoing key exchange packet */
370 struct buffer_if scratch;
371 int32_t retries; /* Number of retries remaining */
372 uint64_t timeout; /* Timeout for current state */
374 uint8_t *sharedsecret;
375 uint32_t sharedsecretlen, sharedsecretallocd;
376 struct transform_inst_if *new_transform; /* For key setup/verify */
379 static uint32_t event_log_priority(struct site *st, uint32_t event)
381 if (!(event&st->log_events))
384 case LOG_UNEXPECTED: return M_INFO;
385 case LOG_SETUP_INIT: return M_INFO;
386 case LOG_SETUP_TIMEOUT: return M_NOTICE;
387 case LOG_ACTIVATE_KEY: return M_INFO;
388 case LOG_TIMEOUT_KEY: return M_INFO;
389 case LOG_SEC: return M_SECURITY;
390 case LOG_STATE: return M_DEBUG;
391 case LOG_DROP: return M_DEBUG;
392 case LOG_DUMP: return M_DEBUG;
393 case LOG_ERROR: return M_ERR;
394 case LOG_PEER_ADDRS: return M_DEBUG;
395 default: return M_ERR;
399 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
401 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
405 class=event_log_priority(st, event);
407 slilog_part(st->log,class,"%s: ",st->tunname);
408 vslilog_part(st->log,class,msg,ap);
409 slilog_part(st->log,class,"\n");
413 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
415 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
419 vslog(st,event,msg,ap);
423 static void logtimeout(struct site *st, const char *fmt, ...)
425 static void logtimeout(struct site *st, const char *fmt, ...)
427 uint32_t class=event_log_priority(st,LOG_SETUP_TIMEOUT);
434 slilog_part(st->log,class,"%s: ",st->tunname);
435 vslilog_part(st->log,class,fmt,ap);
439 for (i=0, delim=" (tried ";
440 i<st->setup_peers.npeers;
442 transport_peer *peer=&st->setup_peers.peers[i];
443 const char *s=comm_addr_to_string(&peer->addr);
444 slilog_part(st->log,class,"%s%s",delim,s);
447 slilog_part(st->log,class,")\n");
451 static void set_link_quality(struct site *st);
452 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
453 static void delete_one_key(struct site *st, struct data_key *key,
454 const char *reason /* may be 0 meaning don't log*/,
455 const char *which /* ignored if !reasonn */,
456 uint32_t loglevel /* ignored if !reasonn */);
457 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
458 const struct comm_addr *prod_hint);
459 static void enter_state_run(struct site *st);
460 static bool_t enter_state_resolve(struct site *st);
461 static void decrement_resolving_count(struct site *st, int by);
462 static bool_t enter_new_state(struct site *st,uint32_t next,
463 const struct msg *prompt
464 /* may be 0 for SENTMSG1 */);
465 static void enter_state_wait(struct site *st);
466 static void activate_new_key(struct site *st);
468 static bool_t is_transform_valid(struct transform_inst_if *transform)
470 return transform && transform->valid(transform->st);
473 static bool_t current_valid(struct site *st)
475 return is_transform_valid(st->current.transform);
478 #define DEFINE_CALL_TRANSFORM(fwdrev) \
479 static transform_apply_return \
480 call_transform_##fwdrev(struct site *st, \
481 struct transform_inst_if *transform, \
482 struct buffer_if *buf, \
483 const char **errmsg) \
485 if (!is_transform_valid(transform)) { \
486 *errmsg="transform not set up"; \
487 return transform_apply_err; \
489 return transform->fwdrev(transform->st,buf,errmsg); \
492 DEFINE_CALL_TRANSFORM(forwards)
493 DEFINE_CALL_TRANSFORM(reverse)
495 static void dispose_transform(struct transform_inst_if **transform_var)
497 struct transform_inst_if *transform=*transform_var;
499 transform->delkey(transform->st);
500 transform->destroy(transform->st);
505 #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
506 #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
507 #define CHECK_TYPE(b,t) do { uint32_t type; \
508 CHECK_AVAIL((b),4); \
509 type=buf_unprepend_uint32((b)); \
510 if (type!=(t)) return False; } while(0)
512 static _Bool type_is_msg34(uint32_t type)
515 case CASES_MSG3_KNOWN: case LABEL_MSG4: return True;
516 default: return False;
523 struct buffer_if extrainfo;
530 struct parsedname remote;
531 struct parsedname local;
532 uint32_t remote_capabilities;
534 int capab_transformnum;
540 struct alg_msg_data sig;
543 static int32_t wait_timeout(struct site *st) {
544 int32_t t = st->wait_timeout_mean;
547 st->random->generate(st->random->st,sizeof(factor),&factor);
548 t += (t / 256) * factor;
553 static _Bool set_new_transform(struct site *st, char *pk)
557 /* Make room for the shared key */
558 st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
559 assert(st->sharedsecretlen);
560 if (st->sharedsecretlen > st->sharedsecretallocd) {
561 st->sharedsecretallocd=st->sharedsecretlen;
562 st->sharedsecret=safe_realloc_ary(st->sharedsecret,1,
563 st->sharedsecretallocd,
564 "site:sharedsecret");
567 /* Generate the shared key */
568 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,pk,
569 st->sharedsecret,st->sharedsecretlen);
571 /* Set up the transform */
572 struct transform_if *generator=st->chosen_transform;
573 struct transform_inst_if *generated=generator->create(generator->st);
574 ok = generated->setkey(generated->st,st->sharedsecret,
575 st->sharedsecretlen,st->our_name_later);
577 dispose_transform(&st->new_transform);
578 if (!ok) return False;
579 st->new_transform=generated;
581 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
582 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
583 st->chosen_transform->capab_bit,
584 st->local_capabilities, st->remote_capabilities);
589 int32_t lenpos, afternul;
591 static void append_string_xinfo_start(struct buffer_if *buf,
592 struct xinfoadd *xia,
594 /* Helps construct one of the names with additional info as found
595 * in MSG1..4. Call this function first, then append all the
596 * desired extra info (not including the nul byte) to the buffer,
597 * then call append_string_xinfo_done. */
599 xia->lenpos = buf->size;
600 buf_append_string(buf,str);
601 buf_append_uint8(buf,0);
602 xia->afternul = buf->size;
604 static void append_string_xinfo_done(struct buffer_if *buf,
605 struct xinfoadd *xia)
607 /* we just need to adjust the string length */
608 if (buf->size == xia->afternul) {
609 /* no extra info, strip the nul too */
610 buf_unappend_uint8(buf);
612 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
616 /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
617 out using a transform of config data supplied by netlink */
618 static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what,
619 const struct msg *prompt
620 /* may be 0 for MSG1 */)
625 st->retries=st->setup_retries;
626 BUF_ALLOC(&st->buffer,what);
627 buffer_init(&st->buffer,0);
628 buf_append_uint32(&st->buffer,
629 (type==LABEL_MSG1?0:st->setup_session_id));
630 buf_append_uint32(&st->buffer,st->index);
631 buf_append_uint32(&st->buffer,type);
634 append_string_xinfo_start(&st->buffer,&xia,st->localname);
635 if ((st->local_capabilities & st->early_capabilities) ||
636 (type != LABEL_MSG1)) {
637 buf_append_uint32(&st->buffer,st->local_capabilities);
639 if (type_is_msg34(type)) {
640 buf_append_uint16(&st->buffer,st->mtu_target);
642 append_string_xinfo_done(&st->buffer,&xia);
644 buf_append_string(&st->buffer,st->remotename);
645 BUF_ADD_OBJ(append,&st->buffer,st->localN);
646 if (type==LABEL_MSG1) return True;
647 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
648 if (type==LABEL_MSG2) return True;
650 if (hacky_par_mid_failnow()) return False;
652 if (MSGMAJOR(type) == 3) do {
653 minor = MSGMINOR(type);
654 if (minor < 1) break;
655 buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
658 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
659 buf_append_string(&st->buffer,dhpub);
662 bool_t ok=st->privkey->sign(st->privkey->st,
673 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
676 nm->len=buf_unprepend_uint16(msg);
677 CHECK_AVAIL(msg,nm->len);
678 nm->name=buf_unprepend(msg,nm->len);
679 uint8_t *nul=memchr(nm->name,0,nm->len);
681 buffer_readonly_view(&nm->extrainfo,0,0);
683 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
684 nm->len=nul-nm->name;
689 static bool_t unpick_msg(struct site *st, uint32_t type,
690 struct buffer_if *msg, struct msg *m)
694 m->capab_transformnum=-1;
695 m->hashstart=msg->start;
697 m->dest=buf_unprepend_uint32(msg);
699 m->source=buf_unprepend_uint32(msg);
700 CHECK_TYPE(msg,type);
701 if (!unpick_name(msg,&m->remote)) return False;
702 m->remote_capabilities=0;
704 if (m->remote.extrainfo.size) {
705 CHECK_AVAIL(&m->remote.extrainfo,4);
706 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
708 if (type_is_msg34(type) && m->remote.extrainfo.size) {
709 CHECK_AVAIL(&m->remote.extrainfo,2);
710 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
712 if (!unpick_name(msg,&m->local)) return False;
713 if (type==LABEL_PROD) {
717 CHECK_AVAIL(msg,NONCELEN);
718 m->nR=buf_unprepend(msg,NONCELEN);
719 if (type==LABEL_MSG1) {
723 CHECK_AVAIL(msg,NONCELEN);
724 m->nL=buf_unprepend(msg,NONCELEN);
725 if (type==LABEL_MSG2) {
729 if (MSGMAJOR(type) == 3) do {
730 minor = MSGMINOR(type);
731 #define MAYBE_READ_CAP(minminor, kind, dflt) do { \
732 if (minor < (minminor)) \
733 m->capab_##kind##num = (dflt); \
735 CHECK_AVAIL(msg, 1); \
736 m->capab_##kind##num = buf_unprepend_uint8(msg); \
739 MAYBE_READ_CAP(1, transform, CAPAB_BIT_ANCIENTTRANSFORM);
740 #undef MAYBE_READ_CAP
743 m->pklen=buf_unprepend_uint16(msg);
744 CHECK_AVAIL(msg,m->pklen);
745 m->pk=buf_unprepend(msg,m->pklen);
746 m->hashlen=msg->start-m->hashstart;
748 if (!st->pubkey->unpick(st->pubkey->st,msg,&m->sig)) {
757 static bool_t name_matches(const struct parsedname *nm, const char *expected)
759 int expected_len=strlen(expected);
761 nm->len == expected_len &&
762 !memcmp(nm->name, expected, expected_len);
765 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
768 if (type==LABEL_MSG1) return True;
770 /* Check that the site names and our nonce have been sent
771 back correctly, and then store our peer's nonce. */
772 if (!name_matches(&m->remote,st->remotename)) {
773 *error="wrong remote site name";
776 if (!name_matches(&m->local,st->localname)) {
777 *error="wrong local site name";
780 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
781 *error="wrong locally-generated nonce";
784 if (type==LABEL_MSG2) return True;
785 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
786 *error="wrong remotely-generated nonce";
789 /* MSG3 has complicated rules about capabilities, which are
790 * handled in process_msg3. */
791 if (MSGMAJOR(type) == 3) return True;
792 if (m->remote_capabilities!=st->remote_capabilities) {
793 *error="remote capabilities changed";
796 if (type==LABEL_MSG4) return True;
797 *error="unknown message type";
801 static bool_t generate_msg1(struct site *st, const struct msg *prompt_maybe_0)
803 st->random->generate(st->random->st,NONCELEN,st->localN);
804 return generate_msg(st,LABEL_MSG1,"site:MSG1",prompt_maybe_0);
807 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
808 const struct comm_addr *src,
811 /* We've already determined we're in an appropriate state to
812 process an incoming MSG1, and that the MSG1 has correct values
815 st->setup_session_id=m->source;
816 st->remote_capabilities=m->remote_capabilities;
817 memcpy(st->remoteN,m->nR,NONCELEN);
821 static bool_t generate_msg2(struct site *st,
822 const struct msg *prompt_may_be_null)
824 st->random->generate(st->random->st,NONCELEN,st->localN);
825 return generate_msg(st,LABEL_MSG2,"site:MSG2",prompt_may_be_null);
828 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
829 const struct comm_addr *src,
830 struct msg *m /* returned */)
834 if (!unpick_msg(st,LABEL_MSG2,msg2,m)) return False;
835 if (!check_msg(st,LABEL_MSG2,m,&err)) {
836 slog(st,LOG_SEC,"msg2: %s",err);
839 st->setup_session_id=m->source;
840 st->remote_capabilities=m->remote_capabilities;
842 /* Select the transform to use */
844 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
845 if (!remote_crypto_caps)
846 /* old secnets only had this one transform */
847 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
849 #define CHOOSE_CRYPTO(kind, whats) do { \
850 struct kind##_if *iface; \
851 uint32_t bit, ours = 0; \
853 for (i= 0; i < st->n##kind##s; i++) { \
854 iface=st->kind##s[i]; \
855 bit = 1UL << iface->capab_bit; \
856 if (bit & remote_crypto_caps) goto kind##_found; \
859 slog(st,LOG_ERROR,"no " whats " in common" \
860 " (us %#"PRIx32"; them: %#"PRIx32")", \
861 st->local_capabilities & ours, remote_crypto_caps); \
864 st->chosen_##kind = iface; \
867 CHOOSE_CRYPTO(transform, "transforms");
871 memcpy(st->remoteN,m->nR,NONCELEN);
875 static bool_t generate_msg3(struct site *st, const struct msg *prompt)
877 /* Now we have our nonce and their nonce. Think of a secret key,
878 and create message number 3. */
879 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
880 return generate_msg(st,
881 (st->remote_capabilities & CAPAB_TRANSFORM_MASK)
887 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
889 /* Check signature and store g^x mod m */
890 if (!st->pubkey->check(st->pubkey->st,
891 m->hashstart,m->hashlen,
893 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
897 st->remote_adv_mtu=m->remote_mtu;
902 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
903 const struct comm_addr *src, uint32_t msgtype,
904 struct msg *m /* returned */)
909 case CASES_MSG3_KNOWN: break;
913 if (!unpick_msg(st,msgtype,msg3,m)) return False;
914 if (!check_msg(st,msgtype,m,&err)) {
915 slog(st,LOG_SEC,"msg3: %s",err);
918 uint32_t capab_adv_late = m->remote_capabilities
919 & ~st->remote_capabilities & st->early_capabilities;
920 if (capab_adv_late) {
921 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
922 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
923 capab_adv_late, st->remote_capabilities, m->remote_capabilities);
927 #define CHOSE_CRYPTO(kind, what) do { \
928 struct kind##_if *iface; \
930 for (i=0; i<st->n##kind##s; i++) { \
931 iface=st->kind##s[i]; \
932 if (iface->capab_bit == m->capab_##kind##num) \
935 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
936 m->capab_##kind##num); \
939 st->chosen_##kind=iface; \
942 CHOSE_CRYPTO(transform, "transform");
946 if (!process_msg3_msg4(st,m))
949 /* Update our idea of the remote site's capabilities, now that we've
950 * verified that its message was authentic.
952 * Our previous idea of the remote site's capabilities came from the
953 * unauthenticated MSG1. We've already checked that this new message
954 * doesn't change any of the bits we relied upon in the past, but it may
955 * also have set additional capability bits. We simply throw those away
956 * now, and use the authentic capabilities from this MSG3. */
957 st->remote_capabilities=m->remote_capabilities;
959 /* Terminate their DH public key with a '0' */
961 /* Invent our DH secret key */
962 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
964 /* Generate the shared key and set up the transform */
965 if (!set_new_transform(st,m->pk)) return False;
970 static bool_t generate_msg4(struct site *st, const struct msg *prompt)
972 /* We have both nonces, their public key and our private key. Generate
973 our public key, sign it and send it to them. */
974 return generate_msg(st,LABEL_MSG4,"site:MSG4",prompt);
977 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
978 const struct comm_addr *src,
979 struct msg *m /* returned */)
983 if (!unpick_msg(st,LABEL_MSG4,msg4,m)) return False;
984 if (!check_msg(st,LABEL_MSG4,m,&err)) {
985 slog(st,LOG_SEC,"msg4: %s",err);
989 if (!process_msg3_msg4(st,m))
992 /* Terminate their DH public key with a '0' */
995 /* Generate the shared key and set up the transform */
996 if (!set_new_transform(st,m->pk)) return False;
1007 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1010 CHECK_AVAIL(msg0,4);
1011 m->dest=buf_unprepend_uint32(msg0);
1012 CHECK_AVAIL(msg0,4);
1013 m->source=buf_unprepend_uint32(msg0);
1014 CHECK_AVAIL(msg0,4);
1015 m->type=buf_unprepend_uint32(msg0);
1017 /* Leaves transformed part of buffer untouched */
1020 static bool_t generate_msg5(struct site *st, const struct msg *prompt)
1022 cstring_t transform_err;
1024 BUF_ALLOC(&st->buffer,"site:MSG5");
1025 /* We are going to add four words to the message */
1026 buffer_init(&st->buffer,calculate_max_start_pad());
1027 /* Give the netlink code an opportunity to put its own stuff in the
1028 message (configuration information, etc.) */
1029 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1030 if (call_transform_forwards(st,st->new_transform,
1031 &st->buffer,&transform_err))
1033 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1034 buf_prepend_uint32(&st->buffer,st->index);
1035 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1037 st->retries=st->setup_retries;
1041 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1042 const struct comm_addr *src,
1043 struct transform_inst_if *transform)
1046 cstring_t transform_err;
1048 if (!unpick_msg0(st,msg5,&m)) return False;
1050 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1051 /* There's a problem */
1052 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1055 /* Buffer should now contain untransformed PING packet data */
1056 CHECK_AVAIL(msg5,4);
1057 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1058 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1061 /* Older versions of secnet used to write some config data here
1062 * which we ignore. So we don't CHECK_EMPTY */
1066 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1067 uint32_t session_id)
1069 cstring_t transform_err;
1071 BUF_ALLOC(&st->buffer,"site:MSG6");
1072 /* We are going to add four words to the message */
1073 buffer_init(&st->buffer,calculate_max_start_pad());
1074 /* Give the netlink code an opportunity to put its own stuff in the
1075 message (configuration information, etc.) */
1076 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1077 transform_apply_return problem =
1078 call_transform_forwards(st,transform,
1079 &st->buffer,&transform_err);
1081 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1082 buf_prepend_uint32(&st->buffer,st->index);
1083 buf_prepend_uint32(&st->buffer,session_id);
1086 static bool_t generate_msg6(struct site *st, const struct msg *prompt)
1088 if (!is_transform_valid(st->new_transform))
1090 create_msg6(st,st->new_transform,st->setup_session_id);
1091 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1095 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1096 const struct comm_addr *src)
1099 cstring_t transform_err;
1101 if (!unpick_msg0(st,msg6,&m)) return False;
1103 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1104 /* There's a problem */
1105 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1108 /* Buffer should now contain untransformed PING packet data */
1109 CHECK_AVAIL(msg6,4);
1110 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1111 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1114 /* Older versions of secnet used to write some config data here
1115 * which we ignore. So we don't CHECK_EMPTY */
1119 static transform_apply_return
1120 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1121 const struct comm_addr *src)
1123 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1125 transform_apply_return problem;
1127 if (!unpick_msg0(st,msg0,&m)) return False;
1129 /* Keep a copy so we can try decrypting it with multiple keys */
1130 buffer_copy(&st->scratch, msg0);
1132 problem = call_transform_reverse(st,st->current.transform,
1133 msg0,&transform_err);
1135 if (!st->auxiliary_is_new)
1136 delete_one_key(st,&st->auxiliary_key,
1137 "peer has used new key","auxiliary key",LOG_SEC);
1140 if (transform_apply_return_badseq(problem))
1143 buffer_copy(msg0, &st->scratch);
1144 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1147 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1148 if (st->auxiliary_is_new) {
1149 /* We previously timed out in state SENTMSG5 but it turns
1150 * out that our peer did in fact get our MSG5 and is
1151 * using the new key. So we should switch to it too. */
1152 /* This is a bit like activate_new_key. */
1155 st->current=st->auxiliary_key;
1156 st->auxiliary_key=t;
1158 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1159 "previous key",LOG_SEC);
1160 st->auxiliary_is_new=0;
1161 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1165 if (transform_apply_return_badseq(problem))
1168 if (st->state==SITE_SENTMSG5) {
1169 buffer_copy(msg0, &st->scratch);
1170 problem = call_transform_reverse(st,st->new_transform,
1173 /* It looks like we didn't get the peer's MSG6 */
1174 /* This is like a cut-down enter_new_state(SITE_RUN) */
1175 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1176 BUF_FREE(&st->buffer);
1178 activate_new_key(st);
1179 return 0; /* do process the data in this packet */
1181 if (transform_apply_return_badseq(problem))
1185 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1186 transform_err,auxkey_err,newkey_err);
1187 initiate_key_setup(st,"incoming message would not decrypt",0);
1188 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1193 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1198 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1199 const struct comm_addr *src)
1202 transform_apply_return problem;
1204 problem = decrypt_msg0(st,msg0,src);
1205 if (problem==transform_apply_seqdupe) {
1206 /* We recently received another copy of this packet, maybe due
1207 * to polypath. That's not a problem; indeed, for the
1208 * purposes of transport address management it is a success.
1209 * But we don't want to process the packet. */
1210 transport_data_msgok(st,src);
1216 CHECK_AVAIL(msg0,4);
1217 type=buf_unprepend_uint32(msg0);
1220 /* We must forget about the current session. */
1221 delete_keys(st,"request from peer",LOG_SEC);
1222 /* probably, the peer is shutting down, and this is going to fail,
1223 * but we need to be trying to bring the link up again */
1225 initiate_key_setup(st,"peer requested key teardown",0);
1228 /* Deliver to netlink layer */
1229 st->netlink->deliver(st->netlink->st,msg0);
1230 transport_data_msgok(st,src);
1231 /* See whether we should start negotiating a new key */
1232 if (st->now > st->renegotiate_key_time)
1233 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1236 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1243 static void dump_packet(struct site *st, struct buffer_if *buf,
1244 const struct comm_addr *addr, bool_t incoming,
1247 uint32_t dest=get_uint32(buf->start);
1248 uint32_t source=get_uint32(buf->start+4);
1249 uint32_t msgtype=get_uint32(buf->start+8);
1251 if (st->log_events & LOG_DUMP)
1252 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1253 st->tunname,incoming?"incoming":"outgoing",
1254 dest,source,msgtype,comm_addr_to_string(addr),
1258 static bool_t comm_addr_sendmsg(struct site *st,
1259 const struct comm_addr *dest,
1260 struct buffer_if *buf)
1263 struct comm_clientinfo *commclientinfo = 0;
1265 for (i=0; i < st->ncomms; i++) {
1266 if (st->comms[i] == dest->comm) {
1267 commclientinfo = st->commclientinfos[i];
1271 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1274 static uint32_t site_status(void *st)
1279 static bool_t send_msg(struct site *st)
1281 if (st->retries>0) {
1282 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1283 st->timeout=st->now+st->setup_retry_interval;
1286 } else if (st->state==SITE_SENTMSG5) {
1287 logtimeout(st,"timed out sending MSG5, stashing new key");
1288 /* We stash the key we have produced, in case it turns out that
1289 * our peer did see our MSG5 after all and starts using it. */
1290 /* This is a bit like some of activate_new_key */
1291 struct transform_inst_if *t;
1292 t=st->auxiliary_key.transform;
1293 st->auxiliary_key.transform=st->new_transform;
1294 st->new_transform=t;
1295 dispose_transform(&st->new_transform);
1297 st->auxiliary_is_new=1;
1298 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1299 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1300 st->auxiliary_key.remote_session_id=st->setup_session_id;
1302 enter_state_wait(st);
1305 logtimeout(st,"timed out sending key setup packet "
1306 "(in state %s)",state_name(st->state));
1307 enter_state_wait(st);
1312 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1313 int stored_naddrs, int all_naddrs,
1314 const char *address, const char *failwhy)
1316 struct site *st=sst;
1318 if (!stored_naddrs) {
1319 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1321 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1322 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1324 int space=st->transport_peers_max-st->resolving_n_results_stored;
1325 int n_tocopy=MIN(stored_naddrs,space);
1326 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1329 st->resolving_n_results_stored += n_tocopy;
1330 st->resolving_n_results_all += all_naddrs;
1333 decrement_resolving_count(st,1);
1336 static void decrement_resolving_count(struct site *st, int by)
1338 assert(st->resolving_count>0);
1339 st->resolving_count-=by;
1341 if (st->resolving_count)
1344 /* OK, we are done with them all. Handle combined results. */
1346 const struct comm_addr *addrs=st->resolving_results;
1347 int naddrs=st->resolving_n_results_stored;
1348 assert(naddrs<=st->transport_peers_max);
1351 if (naddrs != st->resolving_n_results_all) {
1352 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1353 " yielded too many results (%d > %d), some ignored",
1354 st->resolving_n_results_all, naddrs);
1356 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1357 naddrs, iaddr_to_string(&addrs[0].ia));;
1360 switch (st->state) {
1362 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1363 enter_new_state(st,SITE_SENTMSG1,0);
1365 /* Can't figure out who to try to to talk to */
1366 slog(st,LOG_SETUP_INIT,
1367 "key exchange failed: cannot find peer address");
1368 enter_state_run(st);
1371 case SITE_SENTMSG1: case SITE_SENTMSG2:
1372 case SITE_SENTMSG3: case SITE_SENTMSG4:
1375 /* We start using the address immediately for data too.
1376 * It's best to store it in st->peers now because we might
1377 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1378 * the new key (without updating the data peer addrs). */
1379 transport_resolve_complete(st,addrs,naddrs);
1380 } else if (st->local_mobile) {
1381 /* We can't let this rest because we may have a peer
1382 * address which will break in the future. */
1383 slog(st,LOG_SETUP_INIT,"resolution failed: "
1384 "abandoning key exchange");
1385 enter_state_wait(st);
1387 slog(st,LOG_SETUP_INIT,"resolution failed: "
1388 " continuing to use source address of peer's packets"
1389 " for key exchange and ultimately data");
1394 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1395 " updating peer address(es)");
1396 transport_resolve_complete_tardy(st,addrs,naddrs);
1397 } else if (st->local_mobile) {
1398 /* Not very good. We should queue (another) renegotiation
1399 * so that we can update the peer address. */
1400 st->key_renegotiate_time=st->now+wait_timeout(st);
1402 slog(st,LOG_SETUP_INIT,"resolution failed: "
1403 " continuing to use source address of peer's packets");
1413 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1414 const struct comm_addr *prod_hint)
1416 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1417 if (st->state!=SITE_RUN) return False;
1418 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1419 if (st->addresses) {
1420 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1421 return enter_state_resolve(st);
1422 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1423 return enter_new_state(st,SITE_SENTMSG1,0);
1425 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1429 static void activate_new_key(struct site *st)
1431 struct transform_inst_if *t;
1433 /* We have three transform instances, which we swap between old,
1435 t=st->auxiliary_key.transform;
1436 st->auxiliary_key.transform=st->current.transform;
1437 st->current.transform=st->new_transform;
1438 st->new_transform=t;
1439 dispose_transform(&st->new_transform);
1442 st->auxiliary_is_new=0;
1443 st->auxiliary_key.key_timeout=st->current.key_timeout;
1444 st->current.key_timeout=st->now+st->key_lifetime;
1445 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1446 transport_peers_copy(st,&st->peers,&st->setup_peers);
1447 st->current.remote_session_id=st->setup_session_id;
1449 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1450 * But their mtu be unspecified, in which case we just use ours. */
1451 uint32_t intersite_mtu=
1452 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1453 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1455 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1456 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1457 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1458 enter_state_run(st);
1461 static void delete_one_key(struct site *st, struct data_key *key,
1462 cstring_t reason, cstring_t which, uint32_t loglevel)
1464 if (!is_transform_valid(key->transform)) return;
1465 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1466 dispose_transform(&key->transform);
1470 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1472 if (current_valid(st)) {
1473 slog(st,loglevel,"session closed (%s)",reason);
1475 delete_one_key(st,&st->current,0,0,0);
1476 set_link_quality(st);
1478 delete_one_key(st,&st->auxiliary_key,0,0,0);
1481 static void state_assert(struct site *st, bool_t ok)
1483 if (!ok) fatal("site:state_assert");
1486 static void enter_state_stop(struct site *st)
1488 st->state=SITE_STOP;
1490 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1491 dispose_transform(&st->new_transform);
1494 static void set_link_quality(struct site *st)
1497 if (current_valid(st))
1498 quality=LINK_QUALITY_UP;
1499 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1500 quality=LINK_QUALITY_DOWN;
1501 else if (st->addresses)
1502 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1503 else if (transport_peers_valid(&st->peers))
1504 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1506 quality=LINK_QUALITY_DOWN;
1508 st->netlink->set_quality(st->netlink->st,quality);
1511 static void enter_state_run(struct site *st)
1513 slog(st,LOG_STATE,"entering state RUN%s",
1514 current_valid(st) ? " (keyed)" : " (unkeyed)");
1518 st->setup_session_id=0;
1519 transport_peers_clear(st,&st->setup_peers);
1520 FILLZERO(st->localN);
1521 FILLZERO(st->remoteN);
1522 dispose_transform(&st->new_transform);
1523 memset(st->dhsecret,0,st->dh->len);
1524 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1525 set_link_quality(st);
1527 if (st->keepalive && !current_valid(st))
1528 initiate_key_setup(st, "keepalive", 0);
1531 static bool_t ensure_resolving(struct site *st)
1533 /* Reentrancy hazard: may call site_resolve_callback and hence
1534 * enter_new_state, enter_state_* and generate_msg*. */
1535 if (st->resolving_count)
1538 assert(st->addresses);
1540 /* resolver->request might reentrantly call site_resolve_callback
1541 * which will decrement st->resolving, so we need to increment it
1542 * twice beforehand to prevent decrement from thinking we're
1543 * finished, and decrement it ourselves. Alternatively if
1544 * everything fails then there are no callbacks due and we simply
1545 * set it to 0 and return false.. */
1546 st->resolving_n_results_stored=0;
1547 st->resolving_n_results_all=0;
1548 st->resolving_count+=2;
1549 const char **addrp=st->addresses;
1550 const char *address;
1552 for (; (address=*addrp++); ) {
1553 bool_t ok = st->resolver->request(st->resolver->st,address,
1554 st->remoteport,st->comms[0],
1555 site_resolve_callback,st);
1557 st->resolving_count++;
1561 st->resolving_count=0;
1564 decrement_resolving_count(st,2);
1568 static bool_t enter_state_resolve(struct site *st)
1570 /* Reentrancy hazard! See ensure_resolving. */
1571 state_assert(st,st->state==SITE_RUN);
1572 slog(st,LOG_STATE,"entering state RESOLVE");
1573 st->state=SITE_RESOLVE;
1574 return ensure_resolving(st);
1577 static bool_t enter_new_state(struct site *st, uint32_t next,
1578 const struct msg *prompt
1579 /* may be 0 for SENTMSG1 */)
1581 bool_t (*gen)(struct site *st, const struct msg *prompt);
1584 slog(st,LOG_STATE,"entering state %s",state_name(next));
1587 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1589 st->msg1_crossed_logged = False;
1592 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1593 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1597 state_assert(st,st->state==SITE_SENTMSG1);
1598 BUF_FREE(&st->buffer);
1602 state_assert(st,st->state==SITE_SENTMSG2);
1603 BUF_FREE(&st->buffer);
1607 state_assert(st,st->state==SITE_SENTMSG3);
1608 BUF_FREE(&st->buffer);
1612 state_assert(st,st->state==SITE_SENTMSG4);
1613 BUF_FREE(&st->buffer);
1618 fatal("enter_new_state(%s): invalid new state",state_name(next));
1622 if (hacky_par_start_failnow()) return False;
1624 r= gen(st,prompt) && send_msg(st);
1627 st->setup_retries, st->setup_retry_interval,
1632 if (next==SITE_RUN) {
1633 BUF_FREE(&st->buffer); /* Never reused */
1634 st->timeout=0; /* Never retransmit */
1635 activate_new_key(st);
1639 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1640 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1641 in either state, and enter_state_wait() will
1643 enter_state_wait(st);
1647 /* msg7 tells our peer that we're about to forget our key */
1648 static bool_t send_msg7(struct site *st, cstring_t reason)
1650 cstring_t transform_err;
1652 if (current_valid(st) && st->buffer.free
1653 && transport_peers_valid(&st->peers)) {
1654 BUF_ALLOC(&st->buffer,"site:MSG7");
1655 buffer_init(&st->buffer,calculate_max_start_pad());
1656 buf_append_uint32(&st->buffer,LABEL_MSG7);
1657 buf_append_string(&st->buffer,reason);
1658 if (call_transform_forwards(st, st->current.transform,
1659 &st->buffer, &transform_err))
1661 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1662 buf_prepend_uint32(&st->buffer,st->index);
1663 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1664 transport_xmit(st,&st->peers,&st->buffer,True);
1665 BUF_FREE(&st->buffer);
1672 /* We go into this state if our peer becomes uncommunicative. Similar to
1673 the "stop" state, we forget all session keys for a while, before
1674 re-entering the "run" state. */
1675 static void enter_state_wait(struct site *st)
1677 slog(st,LOG_STATE,"entering state WAIT");
1678 st->timeout=st->now+wait_timeout(st);
1679 st->state=SITE_WAIT;
1680 set_link_quality(st);
1681 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1682 /* XXX Erase keys etc. */
1685 static void generate_prod(struct site *st, struct buffer_if *buf)
1688 buf_append_uint32(buf,0);
1689 buf_append_uint32(buf,0);
1690 buf_append_uint32(buf,LABEL_PROD);
1691 buf_append_string(buf,st->localname);
1692 buf_append_string(buf,st->remotename);
1695 static void generate_send_prod(struct site *st,
1696 const struct comm_addr *source)
1698 if (!st->allow_send_prod) return; /* too soon */
1699 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1700 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1702 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1703 st->allow_send_prod=0;
1704 generate_prod(st,&st->scratch);
1705 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1706 dump_packet(st,&st->scratch,source,False,ok);
1709 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1712 int64_t offset=timeout-*now;
1713 if (offset<0) offset=0;
1714 if (offset>INT_MAX) offset=INT_MAX;
1715 if (*timeout_io<0 || offset<*timeout_io)
1720 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1723 struct site *st=sst;
1725 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1728 /* Work out when our next timeout is. The earlier of 'timeout' or
1729 'current.key_timeout'. A stored value of '0' indicates no timeout
1731 site_settimeout(st->timeout, timeout_io);
1732 site_settimeout(st->current.key_timeout, timeout_io);
1733 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1735 return 0; /* success */
1738 static void check_expiry(struct site *st, struct data_key *key,
1741 if (key->key_timeout && *now>key->key_timeout) {
1742 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1746 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1747 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1749 struct site *st=sst;
1752 if (st->timeout && *now>st->timeout) {
1754 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1755 if (!hacky_par_start_failnow())
1757 } else if (st->state==SITE_WAIT) {
1758 enter_state_run(st);
1760 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1764 check_expiry(st,&st->current,"current key");
1765 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1768 /* This function is called by the netlink device to deliver packets
1769 intended for the remote network. The packet is in "raw" wire
1770 format, but is guaranteed to be word-aligned. */
1771 static void site_outgoing(void *sst, struct buffer_if *buf)
1773 struct site *st=sst;
1774 cstring_t transform_err;
1776 if (st->state==SITE_STOP) {
1781 st->allow_send_prod=1;
1783 /* In all other states we consider delivering the packet if we have
1784 a valid key and a valid address to send it to. */
1785 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1786 /* Transform it and send it */
1788 buf_prepend_uint32(buf,LABEL_MSG9);
1789 if (call_transform_forwards(st, st->current.transform,
1790 buf, &transform_err))
1792 buf_prepend_uint32(buf,LABEL_MSG0);
1793 buf_prepend_uint32(buf,st->index);
1794 buf_prepend_uint32(buf,st->current.remote_session_id);
1795 transport_xmit(st,&st->peers,buf,False);
1802 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1804 initiate_key_setup(st,"outgoing packet",0);
1807 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1808 uint32_t type, struct msg *m)
1809 /* For packets which are identified by the local and remote names.
1810 * If it has our name and our peer's name in it it's for us. */
1812 struct buffer_if buf[1];
1813 buffer_readonly_clone(buf,buf_in);
1814 return unpick_msg(st,type,buf,m)
1815 && name_matches(&m->remote,st->remotename)
1816 && name_matches(&m->local,st->localname);
1819 static bool_t we_have_priority(struct site *st, const struct msg *m) {
1820 if (st->local_capabilities & m->remote_capabilities &
1821 CAPAB_PRIORITY_MOBILE) {
1822 if (st->local_mobile) return True;
1823 if (st-> peer_mobile) return False;
1825 return st->our_name_later;
1828 static bool_t setup_late_msg_ok(struct site *st,
1829 const struct buffer_if *buf_in,
1831 const struct comm_addr *source,
1832 struct msg *m /* returned */) {
1833 /* For setup packets which seem from their type like they are
1834 * late. Maybe they came via a different path. All we do is make
1835 * a note of the sending address, iff they look like they are part
1836 * of the current key setup attempt. */
1837 if (!named_for_us(st,buf_in,msgtype,m))
1838 /* named_for_us calls unpick_msg which gets the nonces */
1840 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN) ||
1841 !consttime_memeq(m->nL,st->localN, NONCELEN))
1842 /* spoof ? from stale run ? who knows */
1844 transport_setup_msgok(st,source);
1848 /* This function is called by the communication device to deliver
1849 packets from our peers.
1850 It should return True if the packet is recognised as being for
1851 this current site instance (and should therefore not be processed
1852 by other sites), even if the packet was otherwise ignored. */
1853 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1854 const struct comm_addr *source)
1856 struct site *st=sst;
1858 if (buf->size < 12) return False;
1860 uint32_t dest=get_uint32(buf->start);
1861 uint32_t msgtype=get_uint32(buf->start+8);
1863 /* initialised by named_for_us, or process_msgN for N!=1 */
1865 if (msgtype==LABEL_MSG1) {
1866 if (!named_for_us(st,buf,msgtype,&msg))
1868 /* It's a MSG1 addressed to us. Decide what to do about it. */
1869 dump_packet(st,buf,source,True,True);
1870 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1871 st->state==SITE_WAIT) {
1872 /* We should definitely process it */
1873 transport_compute_setupinit_peers(st,0,0,source);
1874 if (process_msg1(st,buf,source,&msg)) {
1875 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1876 bool_t entered=enter_new_state(st,SITE_SENTMSG2,&msg);
1877 if (entered && st->addresses && st->local_mobile)
1878 /* We must do this as the very last thing, because
1879 the resolver callback might reenter us. */
1880 ensure_resolving(st);
1882 slog(st,LOG_ERROR,"failed to process incoming msg1");
1886 } else if (st->state==SITE_SENTMSG1) {
1887 /* We've just sent a message 1! They may have crossed on
1888 the wire. If we have priority then we ignore the
1889 incoming one, otherwise we process it as usual. */
1890 if (we_have_priority(st,&msg)) {
1892 if (!st->msg1_crossed_logged++)
1893 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
1894 "priority => ignore incoming msg1");
1897 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
1898 "priority => use incoming msg1");
1899 if (process_msg1(st,buf,source,&msg)) {
1900 BUF_FREE(&st->buffer); /* Free our old message 1 */
1901 transport_setup_msgok(st,source);
1902 enter_new_state(st,SITE_SENTMSG2,&msg);
1904 slog(st,LOG_ERROR,"failed to process an incoming "
1905 "crossed msg1 (we have low priority)");
1910 } else if (st->state==SITE_SENTMSG2 ||
1911 st->state==SITE_SENTMSG4) {
1912 if (consttime_memeq(msg.nR,st->remoteN,NONCELEN)) {
1913 /* We are ahead in the protocol, but that msg1 had the
1914 * peer's nonce so presumably it is from this key
1915 * exchange run, via a slower route */
1916 transport_setup_msgok(st,source);
1918 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
1923 /* The message 1 was received at an unexpected stage of the
1924 key setup. Well, they lost the race. */
1925 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1929 if (msgtype==LABEL_PROD) {
1930 if (!named_for_us(st,buf,msgtype,&msg))
1932 dump_packet(st,buf,source,True,True);
1933 if (st->state!=SITE_RUN) {
1934 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1935 } else if (current_valid(st)) {
1936 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1938 initiate_key_setup(st,"peer sent PROD packet",source);
1943 if (dest==st->index) {
1944 /* Explicitly addressed to us */
1945 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
1948 /* If the source is our current peer then initiate a key setup,
1949 because our peer's forgotten the key */
1950 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
1952 initiated = initiate_key_setup(st,"received a NAK",source);
1953 if (!initiated) generate_send_prod(st,source);
1955 slog(st,LOG_SEC,"bad incoming NAK");
1959 process_msg0(st,buf,source);
1962 /* Setup packet: should not have been explicitly addressed
1964 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
1967 /* Setup packet: expected only in state SENTMSG1 */
1968 if (st->state!=SITE_SENTMSG1) {
1969 if ((st->state==SITE_SENTMSG3 ||
1970 st->state==SITE_SENTMSG5) &&
1971 setup_late_msg_ok(st,buf,msgtype,source,&msg))
1973 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
1974 } else if (process_msg2(st,buf,source,&msg)) {
1975 transport_setup_msgok(st,source);
1976 enter_new_state(st,SITE_SENTMSG3,&msg);
1978 slog(st,LOG_SEC,"invalid MSG2");
1981 case CASES_MSG3_KNOWN:
1982 /* Setup packet: expected only in state SENTMSG2 */
1983 if (st->state!=SITE_SENTMSG2) {
1984 if ((st->state==SITE_SENTMSG4) &&
1985 setup_late_msg_ok(st,buf,msgtype,source,&msg))
1987 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
1988 } else if (process_msg3(st,buf,source,msgtype,&msg)) {
1989 transport_setup_msgok(st,source);
1990 enter_new_state(st,SITE_SENTMSG4,&msg);
1992 slog(st,LOG_SEC,"invalid MSG3");
1996 /* Setup packet: expected only in state SENTMSG3 */
1997 if (st->state!=SITE_SENTMSG3) {
1998 if ((st->state==SITE_SENTMSG5) &&
1999 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2001 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
2002 } else if (process_msg4(st,buf,source,&msg)) {
2003 transport_setup_msgok(st,source);
2004 enter_new_state(st,SITE_SENTMSG5,&msg);
2006 slog(st,LOG_SEC,"invalid MSG4");
2010 /* Setup packet: expected only in state SENTMSG4 */
2011 /* (may turn up in state RUN if our return MSG6 was lost
2012 and the new key has already been activated. In that
2013 case we discard it. The peer will realise that we
2014 are using the new key when they see our data packets.
2015 Until then the peer's data packets to us get discarded. */
2016 if (st->state==SITE_SENTMSG4) {
2017 if (process_msg5(st,buf,source,st->new_transform)) {
2018 transport_setup_msgok(st,source);
2019 enter_new_state(st,SITE_RUN,&msg);
2021 slog(st,LOG_SEC,"invalid MSG5");
2023 } else if (st->state==SITE_RUN) {
2024 if (process_msg5(st,buf,source,st->current.transform)) {
2025 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2026 transport_setup_msgok(st,source);
2027 create_msg6(st,st->current.transform,
2028 st->current.remote_session_id);
2029 transport_xmit(st,&st->peers,&st->buffer,True);
2030 BUF_FREE(&st->buffer);
2032 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2035 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2039 /* Setup packet: expected only in state SENTMSG5 */
2040 if (st->state!=SITE_SENTMSG5) {
2041 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2042 } else if (process_msg6(st,buf,source)) {
2043 BUF_FREE(&st->buffer); /* Free message 5 */
2044 transport_setup_msgok(st,source);
2045 activate_new_key(st);
2047 slog(st,LOG_SEC,"invalid MSG6");
2051 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2062 static void site_control(void *vst, bool_t run)
2064 struct site *st=vst;
2065 if (run) enter_state_run(st);
2066 else enter_state_stop(st);
2069 static void site_phase_hook(void *sst, uint32_t newphase)
2071 struct site *st=sst;
2073 /* The program is shutting down; tell our peer */
2074 send_msg7(st,"shutting down");
2077 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2079 struct site *st=sst;
2080 dispose_transform(&st->current.transform);
2081 dispose_transform(&st->auxiliary_key.transform);
2082 dispose_transform(&st->new_transform);
2083 /* Not much point overwiting the signing key, since we loaded it
2084 from disk, and it is only valid prospectively if at all,
2086 /* XXX it would be best to overwrite the DH state, because that
2087 _is_ relevant to forward secrecy. However we have no
2088 convenient interface for doing that and in practice gmp has
2089 probably dribbled droppings all over the malloc arena. A good
2090 way to fix this would be to have a privsep child for asymmetric
2091 crypto operations, but that's a task for another day. */
2094 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2097 static uint32_t index_sequence;
2105 st->cl.description="site";
2106 st->cl.type=CL_SITE;
2108 st->cl.interface=&st->ops;
2110 st->ops.control=site_control;
2111 st->ops.status=site_status;
2113 /* First parameter must be a dict */
2114 item=list_elem(args,0);
2115 if (!item || item->type!=t_dict)
2116 cfgfatal(loc,"site","parameter must be a dictionary\n");
2118 dict=item->data.dict;
2119 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2120 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2122 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2124 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2126 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2128 /* Sanity check (which also allows the 'sites' file to include
2129 site() closures for all sites including our own): refuse to
2130 talk to ourselves */
2131 if (strcmp(st->localname,st->remotename)==0) {
2132 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2134 if (st->peer_mobile != st->local_mobile)
2135 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2136 " but our local-mobile=%d\n",
2137 st->localname, st->peer_mobile, st->local_mobile);
2141 if (st->peer_mobile && st->local_mobile) {
2142 Message(M_WARNING,"site %s: site is mobile but so are we"
2143 " -> ignoring this site\n", st->remotename);
2148 assert(index_sequence < 0xffffffffUL);
2149 st->index = ++index_sequence;
2150 st->local_capabilities = 0;
2151 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2152 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2154 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2155 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2156 if (!things##_cfg) \
2157 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2158 st->nthings=list_length(things##_cfg); \
2159 NEW_ARY(st->things,st->nthings); \
2160 assert(st->nthings); \
2161 for (i=0; i<st->nthings; i++) { \
2162 item_t *item=list_elem(things##_cfg,i); \
2163 if (item->type!=t_closure) \
2164 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2165 closure_t *cl=item->data.closure; \
2166 if (cl->type!=CL_TYPE) \
2167 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2168 st->things[i]=cl->interface; \
2172 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2174 NEW_ARY(st->commclientinfos, st->ncomms);
2175 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2176 for (i=0; i<st->ncomms; i++) {
2177 st->commclientinfos[i] =
2179 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2182 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2183 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2184 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2186 st->privkey=find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2187 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2189 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2190 else st->remoteport=0;
2191 st->pubkey=find_cl_if(dict,"key",CL_SIGPUBKEY,True,"site",loc);
2193 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2195 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2197 if (st->privkey->sethash || st->pubkey->sethash) {
2198 struct hash_if *hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2199 if (st->privkey->sethash) st->privkey->sethash(st->privkey->st,hash);
2200 if (st->pubkey->sethash) st->pubkey->sethash(st->pubkey->st,hash);
2203 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2204 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2205 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2207 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2208 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2209 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2210 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2211 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2213 st->mobile_peer_expiry= dict_read_number(
2214 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2216 const char *peerskey= st->peer_mobile
2217 ? "mobile-peers-max" : "static-peers-max";
2218 st->transport_peers_max= dict_read_number(
2219 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2220 if (st->transport_peers_max<1 ||
2221 st->transport_peers_max>MAX_PEER_ADDRS) {
2222 cfgfatal(loc,"site", "%s must be in range 1.."
2223 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2226 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2227 st->key_renegotiate_time=st->key_lifetime/2;
2229 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2230 st->key_renegotiate_time=dict_read_number(
2231 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2232 if (st->key_renegotiate_time > st->key_lifetime) {
2233 cfgfatal(loc,"site",
2234 "renegotiate-time must be less than key-lifetime\n");
2237 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2238 log_event_table,"site");
2240 st->resolving_count=0;
2241 st->allow_send_prod=0;
2243 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2245 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2247 /* The information we expect to see in incoming messages of type 1 */
2248 /* fixme: lots of unchecked overflows here, but the results are only
2249 corrupted packets rather than undefined behaviour */
2250 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2252 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2254 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2255 BUF_ALLOC(&st->scratch,"site:scratch");
2257 /* We are interested in poll(), but only for timeouts. We don't have
2258 any fds of our own. */
2259 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2262 st->remote_capabilities=0;
2263 st->chosen_transform=0;
2264 st->current.key_timeout=0;
2265 st->auxiliary_key.key_timeout=0;
2266 transport_peers_clear(st,&st->peers);
2267 transport_peers_clear(st,&st->setup_peers);
2268 /* XXX mlock these */
2269 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2270 st->sharedsecretlen=st->sharedsecretallocd=0;
2273 #define SET_CAPBIT(bit) do { \
2274 uint32_t capflag = 1UL << (bit); \
2275 if (st->local_capabilities & capflag) \
2276 slog(st,LOG_ERROR,"capability bit" \
2277 " %d (%#"PRIx32") reused", (bit), capflag); \
2278 st->local_capabilities |= capflag; \
2281 for (i=0; i<st->ntransforms; i++)
2282 SET_CAPBIT(st->transforms[i]->capab_bit);
2286 if (st->local_mobile || st->peer_mobile)
2287 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2289 /* We need to register the remote networks with the netlink device */
2290 uint32_t netlink_mtu; /* local virtual interface mtu */
2291 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2292 if (!st->mtu_target)
2293 st->mtu_target=netlink_mtu;
2295 for (i=0; i<st->ncomms; i++)
2296 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2298 st->current.transform=0;
2299 st->auxiliary_key.transform=0;
2300 st->new_transform=0;
2301 st->auxiliary_is_new=0;
2303 enter_state_stop(st);
2305 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2306 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2308 return new_closure(&st->cl);
2311 void site_module(dict_t *dict)
2313 add_closure(dict,"site",site_apply);
2317 /***** TRANSPORT PEERS definitions *****/
2319 static void transport_peers_debug(struct site *st, transport_peers *dst,
2320 const char *didwhat,
2321 int nargs, const struct comm_addr *args,
2326 if (!(st->log_events & LOG_PEER_ADDRS))
2327 return; /* an optimisation */
2329 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2330 (dst==&st->peers ? "data" :
2331 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2332 didwhat, nargs, dst->npeers);
2334 for (i=0, argp=(void*)args;
2336 i++, (argp+=stride?stride:sizeof(*args))) {
2337 const struct comm_addr *ca=(void*)argp;
2338 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2339 i, comm_addr_to_string(ca));
2341 for (i=0; i<dst->npeers; i++) {
2342 struct timeval diff;
2343 timersub(tv_now,&dst->peers[i].last,&diff);
2344 const struct comm_addr *ca=&dst->peers[i].addr;
2345 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2346 i, comm_addr_to_string(ca),
2347 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2351 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2352 /* peers must be sorted first */
2353 int previous_peers=peers->npeers;
2354 struct timeval oldest;
2355 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2356 oldest.tv_usec = tv_now->tv_usec;
2357 while (peers->npeers>1 &&
2358 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2360 if (peers->npeers != previous_peers)
2361 transport_peers_debug(st,peers,"expire", 0,0,0);
2364 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2365 const struct comm_addr *ca,
2366 const struct timeval *tv) {
2367 /* returns false if output is full */
2370 if (peers->npeers >= st->transport_peers_max)
2373 for (search=0; search<peers->npeers; search++)
2374 if (comm_addr_equal(&peers->peers[search].addr, ca))
2377 peers->peers[peers->npeers].addr = *ca;
2378 peers->peers[peers->npeers].last = *tv;
2383 static void transport_record_peers(struct site *st, transport_peers *peers,
2384 const struct comm_addr *addrs, int naddrs,
2386 /* We add addrs into peers. The new entries end up at the front
2387 * and displace entries towards the end (perhaps even off the
2388 * end). Any existing matching entries are moved up to the front.
2390 * Caller must first call transport_peers_expire. */
2393 /* avoids debug for uninteresting updates */
2395 for (i=0; i<peers->npeers; i++) {
2396 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2397 memmove(peers->peers+1, peers->peers,
2398 sizeof(peers->peers[0]) * i);
2399 peers->peers[0].addr = addrs[0];
2400 peers->peers[0].last = *tv_now;
2406 int old_npeers=peers->npeers;
2407 transport_peer old_peers[old_npeers];
2408 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2412 for (i=0; i<naddrs; i++) {
2413 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2416 for (i=0; i<old_npeers; i++) {
2417 const transport_peer *old=&old_peers[i];
2418 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2422 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2425 static void transport_expire_record_peers(struct site *st,
2426 transport_peers *peers,
2427 const struct comm_addr *addrs,
2428 int naddrs, const char *m) {
2429 /* Convenience function */
2430 transport_peers_expire(st,peers);
2431 transport_record_peers(st,peers,addrs,naddrs,m);
2434 static bool_t transport_compute_setupinit_peers(struct site *st,
2435 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2436 int n_configured_addrs /* 0 if none or not found */,
2437 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2438 if (!n_configured_addrs && !incoming_packet_addr &&
2439 !transport_peers_valid(&st->peers))
2442 slog(st,LOG_SETUP_INIT,
2443 "using: %d configured addr(s);%s %d old peer addrs(es)",
2445 incoming_packet_addr ? " incoming packet address;" : "",
2448 /* Non-mobile peers try addresses until one is plausible. The
2449 * effect is that this code always tries first the configured
2450 * address if supplied, or otherwise the address of the incoming
2451 * PROD, or finally the existing data peer if one exists; this is
2454 transport_peers_copy(st,&st->setup_peers,&st->peers);
2455 transport_peers_expire(st,&st->setup_peers);
2457 if (incoming_packet_addr)
2458 transport_record_peers(st,&st->setup_peers,
2459 incoming_packet_addr,1, "incoming");
2461 if (n_configured_addrs)
2462 transport_record_peers(st,&st->setup_peers,
2463 configured_addrs,n_configured_addrs, "setupinit");
2465 assert(transport_peers_valid(&st->setup_peers));
2469 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2470 if (st->peer_mobile)
2471 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2473 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2474 if (st->peer_mobile)
2475 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2478 static int transport_peers_valid(transport_peers *peers) {
2479 return peers->npeers;
2481 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2483 transport_peers_debug(st,peers,"clear",0,0,0);
2485 static void transport_peers_copy(struct site *st, transport_peers *dst,
2486 const transport_peers *src) {
2487 dst->npeers=src->npeers;
2488 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2489 transport_peers_debug(st,dst,"copy",
2490 src->npeers, &src->peers->addr, sizeof(*src->peers));
2493 static void transport_resolve_complete(struct site *st,
2494 const struct comm_addr *addrs,
2496 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2498 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2502 static void transport_resolve_complete_tardy(struct site *st,
2503 const struct comm_addr *addrs,
2505 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2506 "resolved tardily");
2509 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2511 const transport_peers *inp) {
2512 /* out and in->peers may be the same region, or nonoverlapping */
2513 const transport_peer *in=inp->peers;
2515 for (slot=0; slot<inp->npeers; slot++) {
2516 if (!(mask & (1U << slot)))
2518 if (!(out==in && slot==*nout_io))
2519 COPY_OBJ(out[*nout_io], in[slot]);
2524 void transport_xmit(struct site *st, transport_peers *peers,
2525 struct buffer_if *buf, bool_t candebug) {
2527 transport_peers_expire(st, peers);
2528 unsigned failed=0; /* bitmask */
2529 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2532 for (slot=0; slot<peers->npeers; slot++) {
2533 transport_peer *peer=&peers->peers[slot];
2534 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2536 dump_packet(st, buf, &peer->addr, False, ok);
2538 failed |= 1U << slot;
2541 if (ok && !st->peer_mobile)
2544 /* Now we need to demote/delete failing addrs: if we are mobile we
2545 * merely demote them; otherwise we delete them. */
2546 if (st->local_mobile) {
2547 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2548 /* `expected' has all the failures at the end already */
2549 if (failed != expected) {
2551 transport_peer failedpeers[nfailed];
2552 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2553 assert(fslot == nfailed);
2555 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2556 assert(wslot+nfailed == peers->npeers);
2557 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2558 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2561 if (failed && peers->npeers > 1) {
2563 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2564 peers->npeers=wslot;
2565 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2570 /***** END of transport peers declarations *****/