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)
623 st->retries=st->setup_retries;
624 BUF_ALLOC(&st->buffer,what);
625 buffer_init(&st->buffer,0);
626 buf_append_uint32(&st->buffer,
627 (type==LABEL_MSG1?0:st->setup_session_id));
628 buf_append_uint32(&st->buffer,st->index);
629 buf_append_uint32(&st->buffer,type);
632 append_string_xinfo_start(&st->buffer,&xia,st->localname);
633 if ((st->local_capabilities & st->early_capabilities) ||
634 (type != LABEL_MSG1)) {
635 buf_append_uint32(&st->buffer,st->local_capabilities);
637 if (type_is_msg34(type)) {
638 buf_append_uint16(&st->buffer,st->mtu_target);
640 append_string_xinfo_done(&st->buffer,&xia);
642 buf_append_string(&st->buffer,st->remotename);
643 BUF_ADD_OBJ(append,&st->buffer,st->localN);
644 if (type==LABEL_MSG1) return True;
645 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
646 if (type==LABEL_MSG2) return True;
648 if (hacky_par_mid_failnow()) return False;
650 if (MSGMAJOR(type) == 3) do {
651 minor = MSGMINOR(type);
652 if (minor < 1) break;
653 buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
656 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
657 buf_append_string(&st->buffer,dhpub);
660 bool_t ok=st->privkey->sign(st->privkey->st,
671 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
674 nm->len=buf_unprepend_uint16(msg);
675 CHECK_AVAIL(msg,nm->len);
676 nm->name=buf_unprepend(msg,nm->len);
677 uint8_t *nul=memchr(nm->name,0,nm->len);
679 buffer_readonly_view(&nm->extrainfo,0,0);
681 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
682 nm->len=nul-nm->name;
687 static bool_t unpick_msg(struct site *st, uint32_t type,
688 struct buffer_if *msg, struct msg *m)
692 m->capab_transformnum=-1;
693 m->hashstart=msg->start;
695 m->dest=buf_unprepend_uint32(msg);
697 m->source=buf_unprepend_uint32(msg);
698 CHECK_TYPE(msg,type);
699 if (!unpick_name(msg,&m->remote)) return False;
700 m->remote_capabilities=0;
702 if (m->remote.extrainfo.size) {
703 CHECK_AVAIL(&m->remote.extrainfo,4);
704 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
706 if (type_is_msg34(type) && m->remote.extrainfo.size) {
707 CHECK_AVAIL(&m->remote.extrainfo,2);
708 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
710 if (!unpick_name(msg,&m->local)) return False;
711 if (type==LABEL_PROD) {
715 CHECK_AVAIL(msg,NONCELEN);
716 m->nR=buf_unprepend(msg,NONCELEN);
717 if (type==LABEL_MSG1) {
721 CHECK_AVAIL(msg,NONCELEN);
722 m->nL=buf_unprepend(msg,NONCELEN);
723 if (type==LABEL_MSG2) {
727 if (MSGMAJOR(type) == 3) do {
728 minor = MSGMINOR(type);
729 #define MAYBE_READ_CAP(minminor, kind, dflt) do { \
730 if (minor < (minminor)) \
731 m->capab_##kind##num = (dflt); \
733 CHECK_AVAIL(msg, 1); \
734 m->capab_##kind##num = buf_unprepend_uint8(msg); \
737 MAYBE_READ_CAP(1, transform, CAPAB_BIT_ANCIENTTRANSFORM);
738 #undef MAYBE_READ_CAP
741 m->pklen=buf_unprepend_uint16(msg);
742 CHECK_AVAIL(msg,m->pklen);
743 m->pk=buf_unprepend(msg,m->pklen);
744 m->hashlen=msg->start-m->hashstart;
746 if (!st->pubkey->unpick(st->pubkey->st,msg,&m->sig)) {
755 static bool_t name_matches(const struct parsedname *nm, const char *expected)
757 int expected_len=strlen(expected);
759 nm->len == expected_len &&
760 !memcmp(nm->name, expected, expected_len);
763 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
766 if (type==LABEL_MSG1) return True;
768 /* Check that the site names and our nonce have been sent
769 back correctly, and then store our peer's nonce. */
770 if (!name_matches(&m->remote,st->remotename)) {
771 *error="wrong remote site name";
774 if (!name_matches(&m->local,st->localname)) {
775 *error="wrong local site name";
778 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
779 *error="wrong locally-generated nonce";
782 if (type==LABEL_MSG2) return True;
783 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
784 *error="wrong remotely-generated nonce";
787 /* MSG3 has complicated rules about capabilities, which are
788 * handled in process_msg3. */
789 if (MSGMAJOR(type) == 3) return True;
790 if (m->remote_capabilities!=st->remote_capabilities) {
791 *error="remote capabilities changed";
794 if (type==LABEL_MSG4) return True;
795 *error="unknown message type";
799 static bool_t generate_msg1(struct site *st)
801 st->random->generate(st->random->st,NONCELEN,st->localN);
802 return generate_msg(st,LABEL_MSG1,"site:MSG1");
805 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
806 const struct comm_addr *src,
809 /* We've already determined we're in an appropriate state to
810 process an incoming MSG1, and that the MSG1 has correct values
813 st->setup_session_id=m->source;
814 st->remote_capabilities=m->remote_capabilities;
815 memcpy(st->remoteN,m->nR,NONCELEN);
819 static bool_t generate_msg2(struct site *st)
821 st->random->generate(st->random->st,NONCELEN,st->localN);
822 return generate_msg(st,LABEL_MSG2,"site:MSG2");
825 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
826 const struct comm_addr *src,
827 struct msg *m /* returned */)
831 if (!unpick_msg(st,LABEL_MSG2,msg2,m)) return False;
832 if (!check_msg(st,LABEL_MSG2,m,&err)) {
833 slog(st,LOG_SEC,"msg2: %s",err);
836 st->setup_session_id=m->source;
837 st->remote_capabilities=m->remote_capabilities;
839 /* Select the transform to use */
841 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
842 if (!remote_crypto_caps)
843 /* old secnets only had this one transform */
844 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
846 #define CHOOSE_CRYPTO(kind, whats) do { \
847 struct kind##_if *iface; \
848 uint32_t bit, ours = 0; \
850 for (i= 0; i < st->n##kind##s; i++) { \
851 iface=st->kind##s[i]; \
852 bit = 1UL << iface->capab_bit; \
853 if (bit & remote_crypto_caps) goto kind##_found; \
856 slog(st,LOG_ERROR,"no " whats " in common" \
857 " (us %#"PRIx32"; them: %#"PRIx32")", \
858 st->local_capabilities & ours, remote_crypto_caps); \
861 st->chosen_##kind = iface; \
864 CHOOSE_CRYPTO(transform, "transforms");
868 memcpy(st->remoteN,m->nR,NONCELEN);
872 static bool_t generate_msg3(struct site *st)
874 /* Now we have our nonce and their nonce. Think of a secret key,
875 and create message number 3. */
876 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
877 return generate_msg(st,
878 (st->remote_capabilities & CAPAB_TRANSFORM_MASK)
884 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
886 /* Check signature and store g^x mod m */
887 if (!st->pubkey->check(st->pubkey->st,
888 m->hashstart,m->hashlen,
890 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
894 st->remote_adv_mtu=m->remote_mtu;
899 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
900 const struct comm_addr *src, uint32_t msgtype,
901 struct msg *m /* returned */)
906 case CASES_MSG3_KNOWN: break;
910 if (!unpick_msg(st,msgtype,msg3,m)) return False;
911 if (!check_msg(st,msgtype,m,&err)) {
912 slog(st,LOG_SEC,"msg3: %s",err);
915 uint32_t capab_adv_late = m->remote_capabilities
916 & ~st->remote_capabilities & st->early_capabilities;
917 if (capab_adv_late) {
918 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
919 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
920 capab_adv_late, st->remote_capabilities, m->remote_capabilities);
924 #define CHOSE_CRYPTO(kind, what) do { \
925 struct kind##_if *iface; \
927 for (i=0; i<st->n##kind##s; i++) { \
928 iface=st->kind##s[i]; \
929 if (iface->capab_bit == m->capab_##kind##num) \
932 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
933 m->capab_##kind##num); \
936 st->chosen_##kind=iface; \
939 CHOSE_CRYPTO(transform, "transform");
943 if (!process_msg3_msg4(st,m))
946 /* Update our idea of the remote site's capabilities, now that we've
947 * verified that its message was authentic.
949 * Our previous idea of the remote site's capabilities came from the
950 * unauthenticated MSG1. We've already checked that this new message
951 * doesn't change any of the bits we relied upon in the past, but it may
952 * also have set additional capability bits. We simply throw those away
953 * now, and use the authentic capabilities from this MSG3. */
954 st->remote_capabilities=m->remote_capabilities;
956 /* Terminate their DH public key with a '0' */
958 /* Invent our DH secret key */
959 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
961 /* Generate the shared key and set up the transform */
962 if (!set_new_transform(st,m->pk)) return False;
967 static bool_t generate_msg4(struct site *st)
969 /* We have both nonces, their public key and our private key. Generate
970 our public key, sign it and send it to them. */
971 return generate_msg(st,LABEL_MSG4,"site:MSG4");
974 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
975 const struct comm_addr *src,
976 struct msg *m /* returned */)
980 if (!unpick_msg(st,LABEL_MSG4,msg4,m)) return False;
981 if (!check_msg(st,LABEL_MSG4,m,&err)) {
982 slog(st,LOG_SEC,"msg4: %s",err);
986 if (!process_msg3_msg4(st,m))
989 /* Terminate their DH public key with a '0' */
992 /* Generate the shared key and set up the transform */
993 if (!set_new_transform(st,m->pk)) return False;
1004 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1007 CHECK_AVAIL(msg0,4);
1008 m->dest=buf_unprepend_uint32(msg0);
1009 CHECK_AVAIL(msg0,4);
1010 m->source=buf_unprepend_uint32(msg0);
1011 CHECK_AVAIL(msg0,4);
1012 m->type=buf_unprepend_uint32(msg0);
1014 /* Leaves transformed part of buffer untouched */
1017 static bool_t generate_msg5(struct site *st)
1019 cstring_t transform_err;
1021 BUF_ALLOC(&st->buffer,"site:MSG5");
1022 /* We are going to add four words to the message */
1023 buffer_init(&st->buffer,calculate_max_start_pad());
1024 /* Give the netlink code an opportunity to put its own stuff in the
1025 message (configuration information, etc.) */
1026 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1027 if (call_transform_forwards(st,st->new_transform,
1028 &st->buffer,&transform_err))
1030 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1031 buf_prepend_uint32(&st->buffer,st->index);
1032 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1034 st->retries=st->setup_retries;
1038 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1039 const struct comm_addr *src,
1040 struct transform_inst_if *transform)
1043 cstring_t transform_err;
1045 if (!unpick_msg0(st,msg5,&m)) return False;
1047 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1048 /* There's a problem */
1049 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1052 /* Buffer should now contain untransformed PING packet data */
1053 CHECK_AVAIL(msg5,4);
1054 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1055 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1058 /* Older versions of secnet used to write some config data here
1059 * which we ignore. So we don't CHECK_EMPTY */
1063 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1064 uint32_t session_id)
1066 cstring_t transform_err;
1068 BUF_ALLOC(&st->buffer,"site:MSG6");
1069 /* We are going to add four words to the message */
1070 buffer_init(&st->buffer,calculate_max_start_pad());
1071 /* Give the netlink code an opportunity to put its own stuff in the
1072 message (configuration information, etc.) */
1073 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1074 transform_apply_return problem =
1075 call_transform_forwards(st,transform,
1076 &st->buffer,&transform_err);
1078 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1079 buf_prepend_uint32(&st->buffer,st->index);
1080 buf_prepend_uint32(&st->buffer,session_id);
1083 static bool_t generate_msg6(struct site *st)
1085 if (!is_transform_valid(st->new_transform))
1087 create_msg6(st,st->new_transform,st->setup_session_id);
1088 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1092 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1093 const struct comm_addr *src)
1096 cstring_t transform_err;
1098 if (!unpick_msg0(st,msg6,&m)) return False;
1100 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1101 /* There's a problem */
1102 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1105 /* Buffer should now contain untransformed PING packet data */
1106 CHECK_AVAIL(msg6,4);
1107 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1108 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1111 /* Older versions of secnet used to write some config data here
1112 * which we ignore. So we don't CHECK_EMPTY */
1116 static transform_apply_return
1117 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1118 const struct comm_addr *src)
1120 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1122 transform_apply_return problem;
1124 if (!unpick_msg0(st,msg0,&m)) return False;
1126 /* Keep a copy so we can try decrypting it with multiple keys */
1127 buffer_copy(&st->scratch, msg0);
1129 problem = call_transform_reverse(st,st->current.transform,
1130 msg0,&transform_err);
1132 if (!st->auxiliary_is_new)
1133 delete_one_key(st,&st->auxiliary_key,
1134 "peer has used new key","auxiliary key",LOG_SEC);
1137 if (transform_apply_return_badseq(problem))
1140 buffer_copy(msg0, &st->scratch);
1141 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1144 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1145 if (st->auxiliary_is_new) {
1146 /* We previously timed out in state SENTMSG5 but it turns
1147 * out that our peer did in fact get our MSG5 and is
1148 * using the new key. So we should switch to it too. */
1149 /* This is a bit like activate_new_key. */
1152 st->current=st->auxiliary_key;
1153 st->auxiliary_key=t;
1155 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1156 "previous key",LOG_SEC);
1157 st->auxiliary_is_new=0;
1158 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1162 if (transform_apply_return_badseq(problem))
1165 if (st->state==SITE_SENTMSG5) {
1166 buffer_copy(msg0, &st->scratch);
1167 problem = call_transform_reverse(st,st->new_transform,
1170 /* It looks like we didn't get the peer's MSG6 */
1171 /* This is like a cut-down enter_new_state(SITE_RUN) */
1172 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1173 BUF_FREE(&st->buffer);
1175 activate_new_key(st);
1176 return 0; /* do process the data in this packet */
1178 if (transform_apply_return_badseq(problem))
1182 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1183 transform_err,auxkey_err,newkey_err);
1184 initiate_key_setup(st,"incoming message would not decrypt",0);
1185 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1190 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1195 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1196 const struct comm_addr *src)
1199 transform_apply_return problem;
1201 problem = decrypt_msg0(st,msg0,src);
1202 if (problem==transform_apply_seqdupe) {
1203 /* We recently received another copy of this packet, maybe due
1204 * to polypath. That's not a problem; indeed, for the
1205 * purposes of transport address management it is a success.
1206 * But we don't want to process the packet. */
1207 transport_data_msgok(st,src);
1213 CHECK_AVAIL(msg0,4);
1214 type=buf_unprepend_uint32(msg0);
1217 /* We must forget about the current session. */
1218 delete_keys(st,"request from peer",LOG_SEC);
1219 /* probably, the peer is shutting down, and this is going to fail,
1220 * but we need to be trying to bring the link up again */
1222 initiate_key_setup(st,"peer requested key teardown",0);
1225 /* Deliver to netlink layer */
1226 st->netlink->deliver(st->netlink->st,msg0);
1227 transport_data_msgok(st,src);
1228 /* See whether we should start negotiating a new key */
1229 if (st->now > st->renegotiate_key_time)
1230 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1233 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1240 static void dump_packet(struct site *st, struct buffer_if *buf,
1241 const struct comm_addr *addr, bool_t incoming,
1244 uint32_t dest=get_uint32(buf->start);
1245 uint32_t source=get_uint32(buf->start+4);
1246 uint32_t msgtype=get_uint32(buf->start+8);
1248 if (st->log_events & LOG_DUMP)
1249 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1250 st->tunname,incoming?"incoming":"outgoing",
1251 dest,source,msgtype,comm_addr_to_string(addr),
1255 static bool_t comm_addr_sendmsg(struct site *st,
1256 const struct comm_addr *dest,
1257 struct buffer_if *buf)
1260 struct comm_clientinfo *commclientinfo = 0;
1262 for (i=0; i < st->ncomms; i++) {
1263 if (st->comms[i] == dest->comm) {
1264 commclientinfo = st->commclientinfos[i];
1268 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1271 static uint32_t site_status(void *st)
1276 static bool_t send_msg(struct site *st)
1278 if (st->retries>0) {
1279 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1280 st->timeout=st->now+st->setup_retry_interval;
1283 } else if (st->state==SITE_SENTMSG5) {
1284 logtimeout(st,"timed out sending MSG5, stashing new key");
1285 /* We stash the key we have produced, in case it turns out that
1286 * our peer did see our MSG5 after all and starts using it. */
1287 /* This is a bit like some of activate_new_key */
1288 struct transform_inst_if *t;
1289 t=st->auxiliary_key.transform;
1290 st->auxiliary_key.transform=st->new_transform;
1291 st->new_transform=t;
1292 dispose_transform(&st->new_transform);
1294 st->auxiliary_is_new=1;
1295 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1296 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1297 st->auxiliary_key.remote_session_id=st->setup_session_id;
1299 enter_state_wait(st);
1302 logtimeout(st,"timed out sending key setup packet "
1303 "(in state %s)",state_name(st->state));
1304 enter_state_wait(st);
1309 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1310 int stored_naddrs, int all_naddrs,
1311 const char *address, const char *failwhy)
1313 struct site *st=sst;
1315 if (!stored_naddrs) {
1316 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1318 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1319 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1321 int space=st->transport_peers_max-st->resolving_n_results_stored;
1322 int n_tocopy=MIN(stored_naddrs,space);
1323 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1326 st->resolving_n_results_stored += n_tocopy;
1327 st->resolving_n_results_all += all_naddrs;
1330 decrement_resolving_count(st,1);
1333 static void decrement_resolving_count(struct site *st, int by)
1335 assert(st->resolving_count>0);
1336 st->resolving_count-=by;
1338 if (st->resolving_count)
1341 /* OK, we are done with them all. Handle combined results. */
1343 const struct comm_addr *addrs=st->resolving_results;
1344 int naddrs=st->resolving_n_results_stored;
1345 assert(naddrs<=st->transport_peers_max);
1348 if (naddrs != st->resolving_n_results_all) {
1349 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1350 " yielded too many results (%d > %d), some ignored",
1351 st->resolving_n_results_all, naddrs);
1353 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1354 naddrs, iaddr_to_string(&addrs[0].ia));;
1357 switch (st->state) {
1359 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1360 enter_new_state(st,SITE_SENTMSG1,0);
1362 /* Can't figure out who to try to to talk to */
1363 slog(st,LOG_SETUP_INIT,
1364 "key exchange failed: cannot find peer address");
1365 enter_state_run(st);
1368 case SITE_SENTMSG1: case SITE_SENTMSG2:
1369 case SITE_SENTMSG3: case SITE_SENTMSG4:
1372 /* We start using the address immediately for data too.
1373 * It's best to store it in st->peers now because we might
1374 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1375 * the new key (without updating the data peer addrs). */
1376 transport_resolve_complete(st,addrs,naddrs);
1377 } else if (st->local_mobile) {
1378 /* We can't let this rest because we may have a peer
1379 * address which will break in the future. */
1380 slog(st,LOG_SETUP_INIT,"resolution failed: "
1381 "abandoning key exchange");
1382 enter_state_wait(st);
1384 slog(st,LOG_SETUP_INIT,"resolution failed: "
1385 " continuing to use source address of peer's packets"
1386 " for key exchange and ultimately data");
1391 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1392 " updating peer address(es)");
1393 transport_resolve_complete_tardy(st,addrs,naddrs);
1394 } else if (st->local_mobile) {
1395 /* Not very good. We should queue (another) renegotiation
1396 * so that we can update the peer address. */
1397 st->key_renegotiate_time=st->now+wait_timeout(st);
1399 slog(st,LOG_SETUP_INIT,"resolution failed: "
1400 " continuing to use source address of peer's packets");
1410 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1411 const struct comm_addr *prod_hint)
1413 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1414 if (st->state!=SITE_RUN) return False;
1415 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1416 if (st->addresses) {
1417 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1418 return enter_state_resolve(st);
1419 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1420 return enter_new_state(st,SITE_SENTMSG1,0);
1422 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1426 static void activate_new_key(struct site *st)
1428 struct transform_inst_if *t;
1430 /* We have three transform instances, which we swap between old,
1432 t=st->auxiliary_key.transform;
1433 st->auxiliary_key.transform=st->current.transform;
1434 st->current.transform=st->new_transform;
1435 st->new_transform=t;
1436 dispose_transform(&st->new_transform);
1439 st->auxiliary_is_new=0;
1440 st->auxiliary_key.key_timeout=st->current.key_timeout;
1441 st->current.key_timeout=st->now+st->key_lifetime;
1442 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1443 transport_peers_copy(st,&st->peers,&st->setup_peers);
1444 st->current.remote_session_id=st->setup_session_id;
1446 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1447 * But their mtu be unspecified, in which case we just use ours. */
1448 uint32_t intersite_mtu=
1449 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1450 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1452 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1453 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1454 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1455 enter_state_run(st);
1458 static void delete_one_key(struct site *st, struct data_key *key,
1459 cstring_t reason, cstring_t which, uint32_t loglevel)
1461 if (!is_transform_valid(key->transform)) return;
1462 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1463 dispose_transform(&key->transform);
1467 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1469 if (current_valid(st)) {
1470 slog(st,loglevel,"session closed (%s)",reason);
1472 delete_one_key(st,&st->current,0,0,0);
1473 set_link_quality(st);
1475 delete_one_key(st,&st->auxiliary_key,0,0,0);
1478 static void state_assert(struct site *st, bool_t ok)
1480 if (!ok) fatal("site:state_assert");
1483 static void enter_state_stop(struct site *st)
1485 st->state=SITE_STOP;
1487 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1488 dispose_transform(&st->new_transform);
1491 static void set_link_quality(struct site *st)
1494 if (current_valid(st))
1495 quality=LINK_QUALITY_UP;
1496 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1497 quality=LINK_QUALITY_DOWN;
1498 else if (st->addresses)
1499 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1500 else if (transport_peers_valid(&st->peers))
1501 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1503 quality=LINK_QUALITY_DOWN;
1505 st->netlink->set_quality(st->netlink->st,quality);
1508 static void enter_state_run(struct site *st)
1510 slog(st,LOG_STATE,"entering state RUN%s",
1511 current_valid(st) ? " (keyed)" : " (unkeyed)");
1515 st->setup_session_id=0;
1516 transport_peers_clear(st,&st->setup_peers);
1517 FILLZERO(st->localN);
1518 FILLZERO(st->remoteN);
1519 dispose_transform(&st->new_transform);
1520 memset(st->dhsecret,0,st->dh->len);
1521 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1522 set_link_quality(st);
1524 if (st->keepalive && !current_valid(st))
1525 initiate_key_setup(st, "keepalive", 0);
1528 static bool_t ensure_resolving(struct site *st)
1530 /* Reentrancy hazard: may call site_resolve_callback and hence
1531 * enter_new_state, enter_state_* and generate_msg*. */
1532 if (st->resolving_count)
1535 assert(st->addresses);
1537 /* resolver->request might reentrantly call site_resolve_callback
1538 * which will decrement st->resolving, so we need to increment it
1539 * twice beforehand to prevent decrement from thinking we're
1540 * finished, and decrement it ourselves. Alternatively if
1541 * everything fails then there are no callbacks due and we simply
1542 * set it to 0 and return false.. */
1543 st->resolving_n_results_stored=0;
1544 st->resolving_n_results_all=0;
1545 st->resolving_count+=2;
1546 const char **addrp=st->addresses;
1547 const char *address;
1549 for (; (address=*addrp++); ) {
1550 bool_t ok = st->resolver->request(st->resolver->st,address,
1551 st->remoteport,st->comms[0],
1552 site_resolve_callback,st);
1554 st->resolving_count++;
1558 st->resolving_count=0;
1561 decrement_resolving_count(st,2);
1565 static bool_t enter_state_resolve(struct site *st)
1567 /* Reentrancy hazard! See ensure_resolving. */
1568 state_assert(st,st->state==SITE_RUN);
1569 slog(st,LOG_STATE,"entering state RESOLVE");
1570 st->state=SITE_RESOLVE;
1571 return ensure_resolving(st);
1574 static bool_t enter_new_state(struct site *st, uint32_t next,
1575 const struct msg *prompt
1576 /* may be 0 for SENTMSG1 */)
1578 bool_t (*gen)(struct site *st, struct msg *prompt);
1581 slog(st,LOG_STATE,"entering state %s",state_name(next));
1584 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1586 st->msg1_crossed_logged = False;
1589 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1590 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1594 state_assert(st,st->state==SITE_SENTMSG1);
1595 BUF_FREE(&st->buffer);
1599 state_assert(st,st->state==SITE_SENTMSG2);
1600 BUF_FREE(&st->buffer);
1604 state_assert(st,st->state==SITE_SENTMSG3);
1605 BUF_FREE(&st->buffer);
1609 state_assert(st,st->state==SITE_SENTMSG4);
1610 BUF_FREE(&st->buffer);
1615 fatal("enter_new_state(%s): invalid new state",state_name(next));
1619 if (hacky_par_start_failnow()) return False;
1621 r= gen(st) && send_msg(st);
1624 st->setup_retries, st->setup_retry_interval,
1629 if (next==SITE_RUN) {
1630 BUF_FREE(&st->buffer); /* Never reused */
1631 st->timeout=0; /* Never retransmit */
1632 activate_new_key(st);
1636 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1637 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1638 in either state, and enter_state_wait() will
1640 enter_state_wait(st);
1644 /* msg7 tells our peer that we're about to forget our key */
1645 static bool_t send_msg7(struct site *st, cstring_t reason)
1647 cstring_t transform_err;
1649 if (current_valid(st) && st->buffer.free
1650 && transport_peers_valid(&st->peers)) {
1651 BUF_ALLOC(&st->buffer,"site:MSG7");
1652 buffer_init(&st->buffer,calculate_max_start_pad());
1653 buf_append_uint32(&st->buffer,LABEL_MSG7);
1654 buf_append_string(&st->buffer,reason);
1655 if (call_transform_forwards(st, st->current.transform,
1656 &st->buffer, &transform_err))
1658 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1659 buf_prepend_uint32(&st->buffer,st->index);
1660 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1661 transport_xmit(st,&st->peers,&st->buffer,True);
1662 BUF_FREE(&st->buffer);
1669 /* We go into this state if our peer becomes uncommunicative. Similar to
1670 the "stop" state, we forget all session keys for a while, before
1671 re-entering the "run" state. */
1672 static void enter_state_wait(struct site *st)
1674 slog(st,LOG_STATE,"entering state WAIT");
1675 st->timeout=st->now+wait_timeout(st);
1676 st->state=SITE_WAIT;
1677 set_link_quality(st);
1678 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1679 /* XXX Erase keys etc. */
1682 static void generate_prod(struct site *st, struct buffer_if *buf)
1685 buf_append_uint32(buf,0);
1686 buf_append_uint32(buf,0);
1687 buf_append_uint32(buf,LABEL_PROD);
1688 buf_append_string(buf,st->localname);
1689 buf_append_string(buf,st->remotename);
1692 static void generate_send_prod(struct site *st,
1693 const struct comm_addr *source)
1695 if (!st->allow_send_prod) return; /* too soon */
1696 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1697 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1699 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1700 st->allow_send_prod=0;
1701 generate_prod(st,&st->scratch);
1702 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1703 dump_packet(st,&st->scratch,source,False,ok);
1706 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1709 int64_t offset=timeout-*now;
1710 if (offset<0) offset=0;
1711 if (offset>INT_MAX) offset=INT_MAX;
1712 if (*timeout_io<0 || offset<*timeout_io)
1717 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1720 struct site *st=sst;
1722 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1725 /* Work out when our next timeout is. The earlier of 'timeout' or
1726 'current.key_timeout'. A stored value of '0' indicates no timeout
1728 site_settimeout(st->timeout, timeout_io);
1729 site_settimeout(st->current.key_timeout, timeout_io);
1730 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1732 return 0; /* success */
1735 static void check_expiry(struct site *st, struct data_key *key,
1738 if (key->key_timeout && *now>key->key_timeout) {
1739 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1743 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1744 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1746 struct site *st=sst;
1749 if (st->timeout && *now>st->timeout) {
1751 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1752 if (!hacky_par_start_failnow())
1754 } else if (st->state==SITE_WAIT) {
1755 enter_state_run(st);
1757 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1761 check_expiry(st,&st->current,"current key");
1762 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1765 /* This function is called by the netlink device to deliver packets
1766 intended for the remote network. The packet is in "raw" wire
1767 format, but is guaranteed to be word-aligned. */
1768 static void site_outgoing(void *sst, struct buffer_if *buf)
1770 struct site *st=sst;
1771 cstring_t transform_err;
1773 if (st->state==SITE_STOP) {
1778 st->allow_send_prod=1;
1780 /* In all other states we consider delivering the packet if we have
1781 a valid key and a valid address to send it to. */
1782 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1783 /* Transform it and send it */
1785 buf_prepend_uint32(buf,LABEL_MSG9);
1786 if (call_transform_forwards(st, st->current.transform,
1787 buf, &transform_err))
1789 buf_prepend_uint32(buf,LABEL_MSG0);
1790 buf_prepend_uint32(buf,st->index);
1791 buf_prepend_uint32(buf,st->current.remote_session_id);
1792 transport_xmit(st,&st->peers,buf,False);
1799 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1801 initiate_key_setup(st,"outgoing packet",0);
1804 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1805 uint32_t type, struct msg *m)
1806 /* For packets which are identified by the local and remote names.
1807 * If it has our name and our peer's name in it it's for us. */
1809 struct buffer_if buf[1];
1810 buffer_readonly_clone(buf,buf_in);
1811 return unpick_msg(st,type,buf,m)
1812 && name_matches(&m->remote,st->remotename)
1813 && name_matches(&m->local,st->localname);
1816 static bool_t we_have_priority(struct site *st, const struct msg *m) {
1817 if (st->local_capabilities & m->remote_capabilities &
1818 CAPAB_PRIORITY_MOBILE) {
1819 if (st->local_mobile) return True;
1820 if (st-> peer_mobile) return False;
1822 return st->our_name_later;
1825 static bool_t setup_late_msg_ok(struct site *st,
1826 const struct buffer_if *buf_in,
1828 const struct comm_addr *source,
1829 struct msg *m /* returned */) {
1830 /* For setup packets which seem from their type like they are
1831 * late. Maybe they came via a different path. All we do is make
1832 * a note of the sending address, iff they look like they are part
1833 * of the current key setup attempt. */
1834 if (!named_for_us(st,buf_in,msgtype,m))
1835 /* named_for_us calls unpick_msg which gets the nonces */
1837 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN) ||
1838 !consttime_memeq(m->nL,st->localN, NONCELEN))
1839 /* spoof ? from stale run ? who knows */
1841 transport_setup_msgok(st,source);
1845 /* This function is called by the communication device to deliver
1846 packets from our peers.
1847 It should return True if the packet is recognised as being for
1848 this current site instance (and should therefore not be processed
1849 by other sites), even if the packet was otherwise ignored. */
1850 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1851 const struct comm_addr *source)
1853 struct site *st=sst;
1855 if (buf->size < 12) return False;
1857 uint32_t dest=get_uint32(buf->start);
1858 uint32_t msgtype=get_uint32(buf->start+8);
1860 /* initialised by named_for_us, or process_msgN for N!=1 */
1862 if (msgtype==LABEL_MSG1) {
1863 if (!named_for_us(st,buf,msgtype,&msg))
1865 /* It's a MSG1 addressed to us. Decide what to do about it. */
1866 dump_packet(st,buf,source,True,True);
1867 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1868 st->state==SITE_WAIT) {
1869 /* We should definitely process it */
1870 transport_compute_setupinit_peers(st,0,0,source);
1871 if (process_msg1(st,buf,source,&msg)) {
1872 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1873 bool_t entered=enter_new_state(st,SITE_SENTMSG2,&msg);
1874 if (entered && st->addresses && st->local_mobile)
1875 /* We must do this as the very last thing, because
1876 the resolver callback might reenter us. */
1877 ensure_resolving(st);
1879 slog(st,LOG_ERROR,"failed to process incoming msg1");
1883 } else if (st->state==SITE_SENTMSG1) {
1884 /* We've just sent a message 1! They may have crossed on
1885 the wire. If we have priority then we ignore the
1886 incoming one, otherwise we process it as usual. */
1887 if (we_have_priority(st,&msg)) {
1889 if (!st->msg1_crossed_logged++)
1890 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
1891 "priority => ignore incoming msg1");
1894 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
1895 "priority => use incoming msg1");
1896 if (process_msg1(st,buf,source,&msg)) {
1897 BUF_FREE(&st->buffer); /* Free our old message 1 */
1898 transport_setup_msgok(st,source);
1899 enter_new_state(st,SITE_SENTMSG2,&msg);
1901 slog(st,LOG_ERROR,"failed to process an incoming "
1902 "crossed msg1 (we have low priority)");
1907 } else if (st->state==SITE_SENTMSG2 ||
1908 st->state==SITE_SENTMSG4) {
1909 if (consttime_memeq(msg.nR,st->remoteN,NONCELEN)) {
1910 /* We are ahead in the protocol, but that msg1 had the
1911 * peer's nonce so presumably it is from this key
1912 * exchange run, via a slower route */
1913 transport_setup_msgok(st,source);
1915 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
1920 /* The message 1 was received at an unexpected stage of the
1921 key setup. Well, they lost the race. */
1922 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1926 if (msgtype==LABEL_PROD) {
1927 if (!named_for_us(st,buf,msgtype,&msg))
1929 dump_packet(st,buf,source,True,True);
1930 if (st->state!=SITE_RUN) {
1931 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1932 } else if (current_valid(st)) {
1933 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1935 initiate_key_setup(st,"peer sent PROD packet",source);
1940 if (dest==st->index) {
1941 /* Explicitly addressed to us */
1942 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
1945 /* If the source is our current peer then initiate a key setup,
1946 because our peer's forgotten the key */
1947 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
1949 initiated = initiate_key_setup(st,"received a NAK",source);
1950 if (!initiated) generate_send_prod(st,source);
1952 slog(st,LOG_SEC,"bad incoming NAK");
1956 process_msg0(st,buf,source);
1959 /* Setup packet: should not have been explicitly addressed
1961 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
1964 /* Setup packet: expected only in state SENTMSG1 */
1965 if (st->state!=SITE_SENTMSG1) {
1966 if ((st->state==SITE_SENTMSG3 ||
1967 st->state==SITE_SENTMSG5) &&
1968 setup_late_msg_ok(st,buf,msgtype,source,&msg))
1970 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
1971 } else if (process_msg2(st,buf,source,&msg)) {
1972 transport_setup_msgok(st,source);
1973 enter_new_state(st,SITE_SENTMSG3,&msg);
1975 slog(st,LOG_SEC,"invalid MSG2");
1978 case CASES_MSG3_KNOWN:
1979 /* Setup packet: expected only in state SENTMSG2 */
1980 if (st->state!=SITE_SENTMSG2) {
1981 if ((st->state==SITE_SENTMSG4) &&
1982 setup_late_msg_ok(st,buf,msgtype,source,&msg))
1984 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
1985 } else if (process_msg3(st,buf,source,msgtype,&msg)) {
1986 transport_setup_msgok(st,source);
1987 enter_new_state(st,SITE_SENTMSG4,&msg);
1989 slog(st,LOG_SEC,"invalid MSG3");
1993 /* Setup packet: expected only in state SENTMSG3 */
1994 if (st->state!=SITE_SENTMSG3) {
1995 if ((st->state==SITE_SENTMSG5) &&
1996 setup_late_msg_ok(st,buf,msgtype,source,&msg))
1998 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
1999 } else if (process_msg4(st,buf,source,&msg)) {
2000 transport_setup_msgok(st,source);
2001 enter_new_state(st,SITE_SENTMSG5,&msg);
2003 slog(st,LOG_SEC,"invalid MSG4");
2007 /* Setup packet: expected only in state SENTMSG4 */
2008 /* (may turn up in state RUN if our return MSG6 was lost
2009 and the new key has already been activated. In that
2010 case we discard it. The peer will realise that we
2011 are using the new key when they see our data packets.
2012 Until then the peer's data packets to us get discarded. */
2013 if (st->state==SITE_SENTMSG4) {
2014 if (process_msg5(st,buf,source,st->new_transform)) {
2015 transport_setup_msgok(st,source);
2016 enter_new_state(st,SITE_RUN,&msg);
2018 slog(st,LOG_SEC,"invalid MSG5");
2020 } else if (st->state==SITE_RUN) {
2021 if (process_msg5(st,buf,source,st->current.transform)) {
2022 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2023 transport_setup_msgok(st,source);
2024 create_msg6(st,st->current.transform,
2025 st->current.remote_session_id);
2026 transport_xmit(st,&st->peers,&st->buffer,True);
2027 BUF_FREE(&st->buffer);
2029 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2032 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2036 /* Setup packet: expected only in state SENTMSG5 */
2037 if (st->state!=SITE_SENTMSG5) {
2038 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2039 } else if (process_msg6(st,buf,source)) {
2040 BUF_FREE(&st->buffer); /* Free message 5 */
2041 transport_setup_msgok(st,source);
2042 activate_new_key(st);
2044 slog(st,LOG_SEC,"invalid MSG6");
2048 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2059 static void site_control(void *vst, bool_t run)
2061 struct site *st=vst;
2062 if (run) enter_state_run(st);
2063 else enter_state_stop(st);
2066 static void site_phase_hook(void *sst, uint32_t newphase)
2068 struct site *st=sst;
2070 /* The program is shutting down; tell our peer */
2071 send_msg7(st,"shutting down");
2074 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2076 struct site *st=sst;
2077 dispose_transform(&st->current.transform);
2078 dispose_transform(&st->auxiliary_key.transform);
2079 dispose_transform(&st->new_transform);
2080 /* Not much point overwiting the signing key, since we loaded it
2081 from disk, and it is only valid prospectively if at all,
2083 /* XXX it would be best to overwrite the DH state, because that
2084 _is_ relevant to forward secrecy. However we have no
2085 convenient interface for doing that and in practice gmp has
2086 probably dribbled droppings all over the malloc arena. A good
2087 way to fix this would be to have a privsep child for asymmetric
2088 crypto operations, but that's a task for another day. */
2091 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2094 static uint32_t index_sequence;
2102 st->cl.description="site";
2103 st->cl.type=CL_SITE;
2105 st->cl.interface=&st->ops;
2107 st->ops.control=site_control;
2108 st->ops.status=site_status;
2110 /* First parameter must be a dict */
2111 item=list_elem(args,0);
2112 if (!item || item->type!=t_dict)
2113 cfgfatal(loc,"site","parameter must be a dictionary\n");
2115 dict=item->data.dict;
2116 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2117 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2119 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2121 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2123 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2125 /* Sanity check (which also allows the 'sites' file to include
2126 site() closures for all sites including our own): refuse to
2127 talk to ourselves */
2128 if (strcmp(st->localname,st->remotename)==0) {
2129 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2131 if (st->peer_mobile != st->local_mobile)
2132 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2133 " but our local-mobile=%d\n",
2134 st->localname, st->peer_mobile, st->local_mobile);
2138 if (st->peer_mobile && st->local_mobile) {
2139 Message(M_WARNING,"site %s: site is mobile but so are we"
2140 " -> ignoring this site\n", st->remotename);
2145 assert(index_sequence < 0xffffffffUL);
2146 st->index = ++index_sequence;
2147 st->local_capabilities = 0;
2148 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2149 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2151 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2152 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2153 if (!things##_cfg) \
2154 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2155 st->nthings=list_length(things##_cfg); \
2156 NEW_ARY(st->things,st->nthings); \
2157 assert(st->nthings); \
2158 for (i=0; i<st->nthings; i++) { \
2159 item_t *item=list_elem(things##_cfg,i); \
2160 if (item->type!=t_closure) \
2161 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2162 closure_t *cl=item->data.closure; \
2163 if (cl->type!=CL_TYPE) \
2164 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2165 st->things[i]=cl->interface; \
2169 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2171 NEW_ARY(st->commclientinfos, st->ncomms);
2172 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2173 for (i=0; i<st->ncomms; i++) {
2174 st->commclientinfos[i] =
2176 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2179 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2180 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2181 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2183 st->privkey=find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2184 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2186 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2187 else st->remoteport=0;
2188 st->pubkey=find_cl_if(dict,"key",CL_SIGPUBKEY,True,"site",loc);
2190 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2192 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2194 if (st->privkey->sethash || st->pubkey->sethash) {
2195 struct hash_if *hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2196 if (st->privkey->sethash) st->privkey->sethash(st->privkey->st,hash);
2197 if (st->pubkey->sethash) st->pubkey->sethash(st->pubkey->st,hash);
2200 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2201 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2202 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2204 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2205 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2206 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2207 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2208 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2210 st->mobile_peer_expiry= dict_read_number(
2211 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2213 const char *peerskey= st->peer_mobile
2214 ? "mobile-peers-max" : "static-peers-max";
2215 st->transport_peers_max= dict_read_number(
2216 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2217 if (st->transport_peers_max<1 ||
2218 st->transport_peers_max>MAX_PEER_ADDRS) {
2219 cfgfatal(loc,"site", "%s must be in range 1.."
2220 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2223 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2224 st->key_renegotiate_time=st->key_lifetime/2;
2226 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2227 st->key_renegotiate_time=dict_read_number(
2228 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2229 if (st->key_renegotiate_time > st->key_lifetime) {
2230 cfgfatal(loc,"site",
2231 "renegotiate-time must be less than key-lifetime\n");
2234 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2235 log_event_table,"site");
2237 st->resolving_count=0;
2238 st->allow_send_prod=0;
2240 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2242 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2244 /* The information we expect to see in incoming messages of type 1 */
2245 /* fixme: lots of unchecked overflows here, but the results are only
2246 corrupted packets rather than undefined behaviour */
2247 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2249 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2251 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2252 BUF_ALLOC(&st->scratch,"site:scratch");
2254 /* We are interested in poll(), but only for timeouts. We don't have
2255 any fds of our own. */
2256 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2259 st->remote_capabilities=0;
2260 st->chosen_transform=0;
2261 st->current.key_timeout=0;
2262 st->auxiliary_key.key_timeout=0;
2263 transport_peers_clear(st,&st->peers);
2264 transport_peers_clear(st,&st->setup_peers);
2265 /* XXX mlock these */
2266 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2267 st->sharedsecretlen=st->sharedsecretallocd=0;
2270 #define SET_CAPBIT(bit) do { \
2271 uint32_t capflag = 1UL << (bit); \
2272 if (st->local_capabilities & capflag) \
2273 slog(st,LOG_ERROR,"capability bit" \
2274 " %d (%#"PRIx32") reused", (bit), capflag); \
2275 st->local_capabilities |= capflag; \
2278 for (i=0; i<st->ntransforms; i++)
2279 SET_CAPBIT(st->transforms[i]->capab_bit);
2283 if (st->local_mobile || st->peer_mobile)
2284 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2286 /* We need to register the remote networks with the netlink device */
2287 uint32_t netlink_mtu; /* local virtual interface mtu */
2288 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2289 if (!st->mtu_target)
2290 st->mtu_target=netlink_mtu;
2292 for (i=0; i<st->ncomms; i++)
2293 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2295 st->current.transform=0;
2296 st->auxiliary_key.transform=0;
2297 st->new_transform=0;
2298 st->auxiliary_is_new=0;
2300 enter_state_stop(st);
2302 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2303 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2305 return new_closure(&st->cl);
2308 void site_module(dict_t *dict)
2310 add_closure(dict,"site",site_apply);
2314 /***** TRANSPORT PEERS definitions *****/
2316 static void transport_peers_debug(struct site *st, transport_peers *dst,
2317 const char *didwhat,
2318 int nargs, const struct comm_addr *args,
2323 if (!(st->log_events & LOG_PEER_ADDRS))
2324 return; /* an optimisation */
2326 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2327 (dst==&st->peers ? "data" :
2328 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2329 didwhat, nargs, dst->npeers);
2331 for (i=0, argp=(void*)args;
2333 i++, (argp+=stride?stride:sizeof(*args))) {
2334 const struct comm_addr *ca=(void*)argp;
2335 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2336 i, comm_addr_to_string(ca));
2338 for (i=0; i<dst->npeers; i++) {
2339 struct timeval diff;
2340 timersub(tv_now,&dst->peers[i].last,&diff);
2341 const struct comm_addr *ca=&dst->peers[i].addr;
2342 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2343 i, comm_addr_to_string(ca),
2344 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2348 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2349 /* peers must be sorted first */
2350 int previous_peers=peers->npeers;
2351 struct timeval oldest;
2352 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2353 oldest.tv_usec = tv_now->tv_usec;
2354 while (peers->npeers>1 &&
2355 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2357 if (peers->npeers != previous_peers)
2358 transport_peers_debug(st,peers,"expire", 0,0,0);
2361 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2362 const struct comm_addr *ca,
2363 const struct timeval *tv) {
2364 /* returns false if output is full */
2367 if (peers->npeers >= st->transport_peers_max)
2370 for (search=0; search<peers->npeers; search++)
2371 if (comm_addr_equal(&peers->peers[search].addr, ca))
2374 peers->peers[peers->npeers].addr = *ca;
2375 peers->peers[peers->npeers].last = *tv;
2380 static void transport_record_peers(struct site *st, transport_peers *peers,
2381 const struct comm_addr *addrs, int naddrs,
2383 /* We add addrs into peers. The new entries end up at the front
2384 * and displace entries towards the end (perhaps even off the
2385 * end). Any existing matching entries are moved up to the front.
2387 * Caller must first call transport_peers_expire. */
2390 /* avoids debug for uninteresting updates */
2392 for (i=0; i<peers->npeers; i++) {
2393 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2394 memmove(peers->peers+1, peers->peers,
2395 sizeof(peers->peers[0]) * i);
2396 peers->peers[0].addr = addrs[0];
2397 peers->peers[0].last = *tv_now;
2403 int old_npeers=peers->npeers;
2404 transport_peer old_peers[old_npeers];
2405 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2409 for (i=0; i<naddrs; i++) {
2410 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2413 for (i=0; i<old_npeers; i++) {
2414 const transport_peer *old=&old_peers[i];
2415 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2419 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2422 static void transport_expire_record_peers(struct site *st,
2423 transport_peers *peers,
2424 const struct comm_addr *addrs,
2425 int naddrs, const char *m) {
2426 /* Convenience function */
2427 transport_peers_expire(st,peers);
2428 transport_record_peers(st,peers,addrs,naddrs,m);
2431 static bool_t transport_compute_setupinit_peers(struct site *st,
2432 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2433 int n_configured_addrs /* 0 if none or not found */,
2434 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2435 if (!n_configured_addrs && !incoming_packet_addr &&
2436 !transport_peers_valid(&st->peers))
2439 slog(st,LOG_SETUP_INIT,
2440 "using: %d configured addr(s);%s %d old peer addrs(es)",
2442 incoming_packet_addr ? " incoming packet address;" : "",
2445 /* Non-mobile peers try addresses until one is plausible. The
2446 * effect is that this code always tries first the configured
2447 * address if supplied, or otherwise the address of the incoming
2448 * PROD, or finally the existing data peer if one exists; this is
2451 transport_peers_copy(st,&st->setup_peers,&st->peers);
2452 transport_peers_expire(st,&st->setup_peers);
2454 if (incoming_packet_addr)
2455 transport_record_peers(st,&st->setup_peers,
2456 incoming_packet_addr,1, "incoming");
2458 if (n_configured_addrs)
2459 transport_record_peers(st,&st->setup_peers,
2460 configured_addrs,n_configured_addrs, "setupinit");
2462 assert(transport_peers_valid(&st->setup_peers));
2466 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2467 if (st->peer_mobile)
2468 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2470 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2471 if (st->peer_mobile)
2472 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2475 static int transport_peers_valid(transport_peers *peers) {
2476 return peers->npeers;
2478 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2480 transport_peers_debug(st,peers,"clear",0,0,0);
2482 static void transport_peers_copy(struct site *st, transport_peers *dst,
2483 const transport_peers *src) {
2484 dst->npeers=src->npeers;
2485 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2486 transport_peers_debug(st,dst,"copy",
2487 src->npeers, &src->peers->addr, sizeof(*src->peers));
2490 static void transport_resolve_complete(struct site *st,
2491 const struct comm_addr *addrs,
2493 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2495 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2499 static void transport_resolve_complete_tardy(struct site *st,
2500 const struct comm_addr *addrs,
2502 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2503 "resolved tardily");
2506 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2508 const transport_peers *inp) {
2509 /* out and in->peers may be the same region, or nonoverlapping */
2510 const transport_peer *in=inp->peers;
2512 for (slot=0; slot<inp->npeers; slot++) {
2513 if (!(mask & (1U << slot)))
2515 if (!(out==in && slot==*nout_io))
2516 COPY_OBJ(out[*nout_io], in[slot]);
2521 void transport_xmit(struct site *st, transport_peers *peers,
2522 struct buffer_if *buf, bool_t candebug) {
2524 transport_peers_expire(st, peers);
2525 unsigned failed=0; /* bitmask */
2526 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2529 for (slot=0; slot<peers->npeers; slot++) {
2530 transport_peer *peer=&peers->peers[slot];
2531 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2533 dump_packet(st, buf, &peer->addr, False, ok);
2535 failed |= 1U << slot;
2538 if (ok && !st->peer_mobile)
2541 /* Now we need to demote/delete failing addrs: if we are mobile we
2542 * merely demote them; otherwise we delete them. */
2543 if (st->local_mobile) {
2544 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2545 /* `expected' has all the failures at the end already */
2546 if (failed != expected) {
2548 transport_peer failedpeers[nfailed];
2549 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2550 assert(fslot == nfailed);
2552 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2553 assert(wslot+nfailed == peers->npeers);
2554 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2555 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2558 if (failed && peers->npeers > 1) {
2560 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2561 peers->npeers=wslot;
2562 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2567 /***** END of transport peers declarations *****/