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 uint32_t slog_start(struct site *st, uint32_t event)
401 uint32_t class=event_log_priority(st, event);
403 slilog_part(st->log,class,"%s: ",st->tunname);
408 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
410 static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
414 class=slog_start(st,event);
416 vslilog_part(st->log,class,msg,ap);
417 slilog_part(st->log,class,"\n");
421 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
423 static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
427 vslog(st,event,msg,ap);
431 static void logtimeout(struct site *st, const char *fmt, ...)
433 static void logtimeout(struct site *st, const char *fmt, ...)
435 uint32_t class=event_log_priority(st,LOG_SETUP_TIMEOUT);
442 slilog_part(st->log,class,"%s: ",st->tunname);
443 vslilog_part(st->log,class,fmt,ap);
447 for (i=0, delim=" (tried ";
448 i<st->setup_peers.npeers;
450 transport_peer *peer=&st->setup_peers.peers[i];
451 const char *s=comm_addr_to_string(&peer->addr);
452 slilog_part(st->log,class,"%s%s",delim,s);
455 slilog_part(st->log,class,")\n");
459 static void set_link_quality(struct site *st);
460 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
461 static void delete_one_key(struct site *st, struct data_key *key,
462 const char *reason /* may be 0 meaning don't log*/,
463 const char *which /* ignored if !reasonn */,
464 uint32_t loglevel /* ignored if !reasonn */);
465 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
466 const struct comm_addr *prod_hint);
467 static void enter_state_run(struct site *st);
468 static bool_t enter_state_resolve(struct site *st);
469 static void decrement_resolving_count(struct site *st, int by);
470 static bool_t enter_new_state(struct site *st,uint32_t next,
471 const struct msg *prompt
472 /* may be 0 for SENTMSG1 */);
473 static void enter_state_wait(struct site *st);
474 static void activate_new_key(struct site *st);
476 static bool_t is_transform_valid(struct transform_inst_if *transform)
478 return transform && transform->valid(transform->st);
481 static bool_t current_valid(struct site *st)
483 return is_transform_valid(st->current.transform);
486 #define DEFINE_CALL_TRANSFORM(fwdrev) \
487 static transform_apply_return \
488 call_transform_##fwdrev(struct site *st, \
489 struct transform_inst_if *transform, \
490 struct buffer_if *buf, \
491 const char **errmsg) \
493 if (!is_transform_valid(transform)) { \
494 *errmsg="transform not set up"; \
495 return transform_apply_err; \
497 return transform->fwdrev(transform->st,buf,errmsg); \
500 DEFINE_CALL_TRANSFORM(forwards)
501 DEFINE_CALL_TRANSFORM(reverse)
503 static void dispose_transform(struct transform_inst_if **transform_var)
505 struct transform_inst_if *transform=*transform_var;
507 transform->delkey(transform->st);
508 transform->destroy(transform->st);
513 #define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
514 #define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
515 #define CHECK_TYPE(b,t) do { uint32_t type; \
516 CHECK_AVAIL((b),4); \
517 type=buf_unprepend_uint32((b)); \
518 if (type!=(t)) return False; } while(0)
520 static _Bool type_is_msg34(uint32_t type)
523 case CASES_MSG3_KNOWN: case LABEL_MSG4: return True;
524 default: return False;
531 struct buffer_if extrainfo;
538 struct parsedname remote;
539 struct parsedname local;
540 uint32_t remote_capabilities;
542 int capab_transformnum;
548 struct alg_msg_data sig;
551 static int32_t wait_timeout(struct site *st) {
552 int32_t t = st->wait_timeout_mean;
555 st->random->generate(st->random->st,sizeof(factor),&factor);
556 t += (t / 256) * factor;
561 static _Bool set_new_transform(struct site *st, char *pk)
565 /* Make room for the shared key */
566 st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len;
567 assert(st->sharedsecretlen);
568 if (st->sharedsecretlen > st->sharedsecretallocd) {
569 st->sharedsecretallocd=st->sharedsecretlen;
570 st->sharedsecret=safe_realloc_ary(st->sharedsecret,1,
571 st->sharedsecretallocd,
572 "site:sharedsecret");
575 /* Generate the shared key */
576 st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->len,pk,
577 st->sharedsecret,st->sharedsecretlen);
579 /* Set up the transform */
580 struct transform_if *generator=st->chosen_transform;
581 struct transform_inst_if *generated=generator->create(generator->st);
582 ok = generated->setkey(generated->st,st->sharedsecret,
583 st->sharedsecretlen,st->our_name_later);
585 dispose_transform(&st->new_transform);
586 if (!ok) return False;
587 st->new_transform=generated;
589 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
590 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
591 st->chosen_transform->capab_bit,
592 st->local_capabilities, st->remote_capabilities);
597 int32_t lenpos, afternul;
599 static void append_string_xinfo_start(struct buffer_if *buf,
600 struct xinfoadd *xia,
602 /* Helps construct one of the names with additional info as found
603 * in MSG1..4. Call this function first, then append all the
604 * desired extra info (not including the nul byte) to the buffer,
605 * then call append_string_xinfo_done. */
607 xia->lenpos = buf->size;
608 buf_append_string(buf,str);
609 buf_append_uint8(buf,0);
610 xia->afternul = buf->size;
612 static void append_string_xinfo_done(struct buffer_if *buf,
613 struct xinfoadd *xia)
615 /* we just need to adjust the string length */
616 if (buf->size == xia->afternul) {
617 /* no extra info, strip the nul too */
618 buf_unappend_uint8(buf);
620 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
624 /* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
625 out using a transform of config data supplied by netlink */
626 static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what,
627 const struct msg *prompt
628 /* may be 0 for MSG1 */)
633 st->retries=st->setup_retries;
634 BUF_ALLOC(&st->buffer,what);
635 buffer_init(&st->buffer,0);
636 buf_append_uint32(&st->buffer,
637 (type==LABEL_MSG1?0:st->setup_session_id));
638 buf_append_uint32(&st->buffer,st->index);
639 buf_append_uint32(&st->buffer,type);
642 append_string_xinfo_start(&st->buffer,&xia,st->localname);
643 if ((st->local_capabilities & st->early_capabilities) ||
644 (type != LABEL_MSG1)) {
645 buf_append_uint32(&st->buffer,st->local_capabilities);
647 if (type_is_msg34(type)) {
648 buf_append_uint16(&st->buffer,st->mtu_target);
650 append_string_xinfo_done(&st->buffer,&xia);
652 buf_append_string(&st->buffer,st->remotename);
653 BUF_ADD_OBJ(append,&st->buffer,st->localN);
654 if (type==LABEL_MSG1) return True;
655 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
656 if (type==LABEL_MSG2) return True;
658 if (hacky_par_mid_failnow()) return False;
660 if (MSGMAJOR(type) == 3) do {
661 minor = MSGMINOR(type);
662 if (minor < 1) break;
663 buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
666 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->len);
667 buf_append_string(&st->buffer,dhpub);
670 bool_t ok=st->privkey->sign(st->privkey->st,
681 static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
684 nm->len=buf_unprepend_uint16(msg);
685 CHECK_AVAIL(msg,nm->len);
686 nm->name=buf_unprepend(msg,nm->len);
687 uint8_t *nul=memchr(nm->name,0,nm->len);
689 buffer_readonly_view(&nm->extrainfo,0,0);
691 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
692 nm->len=nul-nm->name;
697 static bool_t unpick_msg(struct site *st, uint32_t type,
698 struct buffer_if *msg, struct msg *m)
702 m->capab_transformnum=-1;
703 m->hashstart=msg->start;
705 m->dest=buf_unprepend_uint32(msg);
707 m->source=buf_unprepend_uint32(msg);
708 CHECK_TYPE(msg,type);
709 if (!unpick_name(msg,&m->remote)) return False;
710 m->remote_capabilities=0;
712 if (m->remote.extrainfo.size) {
713 CHECK_AVAIL(&m->remote.extrainfo,4);
714 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
716 if (type_is_msg34(type) && m->remote.extrainfo.size) {
717 CHECK_AVAIL(&m->remote.extrainfo,2);
718 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
720 if (!unpick_name(msg,&m->local)) return False;
721 if (type==LABEL_PROD) {
725 CHECK_AVAIL(msg,NONCELEN);
726 m->nR=buf_unprepend(msg,NONCELEN);
727 if (type==LABEL_MSG1) {
731 CHECK_AVAIL(msg,NONCELEN);
732 m->nL=buf_unprepend(msg,NONCELEN);
733 if (type==LABEL_MSG2) {
737 if (MSGMAJOR(type) == 3) do {
738 minor = MSGMINOR(type);
739 #define MAYBE_READ_CAP(minminor, kind, dflt) do { \
740 if (minor < (minminor)) \
741 m->capab_##kind##num = (dflt); \
743 CHECK_AVAIL(msg, 1); \
744 m->capab_##kind##num = buf_unprepend_uint8(msg); \
747 MAYBE_READ_CAP(1, transform, CAPAB_BIT_ANCIENTTRANSFORM);
748 #undef MAYBE_READ_CAP
751 m->pklen=buf_unprepend_uint16(msg);
752 CHECK_AVAIL(msg,m->pklen);
753 m->pk=buf_unprepend(msg,m->pklen);
754 m->hashlen=msg->start-m->hashstart;
756 if (!st->pubkey->unpick(st->pubkey->st,msg,&m->sig)) {
765 static bool_t name_matches(const struct parsedname *nm, const char *expected)
767 int expected_len=strlen(expected);
769 nm->len == expected_len &&
770 !memcmp(nm->name, expected, expected_len);
773 static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
776 if (type==LABEL_MSG1) return True;
778 /* Check that the site names and our nonce have been sent
779 back correctly, and then store our peer's nonce. */
780 if (!name_matches(&m->remote,st->remotename)) {
781 *error="wrong remote site name";
784 if (!name_matches(&m->local,st->localname)) {
785 *error="wrong local site name";
788 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
789 *error="wrong locally-generated nonce";
792 if (type==LABEL_MSG2) return True;
793 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
794 *error="wrong remotely-generated nonce";
797 /* MSG3 has complicated rules about capabilities, which are
798 * handled in process_msg3. */
799 if (MSGMAJOR(type) == 3) return True;
800 if (m->remote_capabilities!=st->remote_capabilities) {
801 *error="remote capabilities changed";
804 if (type==LABEL_MSG4) return True;
805 *error="unknown message type";
809 static bool_t kex_init(struct site *st)
811 st->random->generate(st->random->st,NONCELEN,st->localN);
815 static bool_t generate_msg1(struct site *st, const struct msg *prompt_maybe_0)
818 generate_msg(st,LABEL_MSG1,"site:MSG1",prompt_maybe_0);
821 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
822 const struct comm_addr *src,
825 /* We've already determined we're in an appropriate state to
826 process an incoming MSG1, and that the MSG1 has correct values
829 st->setup_session_id=m->source;
830 st->remote_capabilities=m->remote_capabilities;
831 memcpy(st->remoteN,m->nR,NONCELEN);
835 static bool_t generate_msg2(struct site *st,
836 const struct msg *prompt_may_be_null)
839 generate_msg(st,LABEL_MSG2,"site:MSG2",prompt_may_be_null);
842 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
843 const struct comm_addr *src,
844 struct msg *m /* returned */)
848 if (!unpick_msg(st,LABEL_MSG2,msg2,m)) return False;
849 if (!check_msg(st,LABEL_MSG2,m,&err)) {
850 slog(st,LOG_SEC,"msg2: %s",err);
853 st->setup_session_id=m->source;
854 st->remote_capabilities=m->remote_capabilities;
856 /* Select the transform to use */
858 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
859 if (!remote_crypto_caps)
860 /* old secnets only had this one transform */
861 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
863 #define CHOOSE_CRYPTO(kind, whats) do { \
864 struct kind##_if *iface; \
865 uint32_t bit, ours = 0; \
867 for (i= 0; i < st->n##kind##s; i++) { \
868 iface=st->kind##s[i]; \
869 bit = 1UL << iface->capab_bit; \
870 if (bit & remote_crypto_caps) goto kind##_found; \
873 slog(st,LOG_ERROR,"no " whats " in common" \
874 " (us %#"PRIx32"; them: %#"PRIx32")", \
875 st->local_capabilities & ours, remote_crypto_caps); \
878 st->chosen_##kind = iface; \
881 CHOOSE_CRYPTO(transform, "transforms");
885 memcpy(st->remoteN,m->nR,NONCELEN);
889 static bool_t generate_msg3(struct site *st, const struct msg *prompt)
891 /* Now we have our nonce and their nonce. Think of a secret key,
892 and create message number 3. */
893 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
894 return generate_msg(st,
895 (st->remote_capabilities & CAPAB_TRANSFORM_MASK)
901 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
903 /* Check signature and store g^x mod m */
904 if (!st->pubkey->check(st->pubkey->st,
905 m->hashstart,m->hashlen,
907 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
911 st->remote_adv_mtu=m->remote_mtu;
916 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
917 const struct comm_addr *src, uint32_t msgtype,
918 struct msg *m /* returned */)
923 case CASES_MSG3_KNOWN: break;
927 if (!unpick_msg(st,msgtype,msg3,m)) return False;
928 if (!check_msg(st,msgtype,m,&err)) {
929 slog(st,LOG_SEC,"msg3: %s",err);
932 uint32_t capab_adv_late = m->remote_capabilities
933 & ~st->remote_capabilities & st->early_capabilities;
934 if (capab_adv_late) {
935 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
936 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
937 capab_adv_late, st->remote_capabilities, m->remote_capabilities);
941 #define CHOSE_CRYPTO(kind, what) do { \
942 struct kind##_if *iface; \
944 for (i=0; i<st->n##kind##s; i++) { \
945 iface=st->kind##s[i]; \
946 if (iface->capab_bit == m->capab_##kind##num) \
949 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
950 m->capab_##kind##num); \
953 st->chosen_##kind=iface; \
956 CHOSE_CRYPTO(transform, "transform");
960 if (!process_msg3_msg4(st,m))
963 /* Update our idea of the remote site's capabilities, now that we've
964 * verified that its message was authentic.
966 * Our previous idea of the remote site's capabilities came from the
967 * unauthenticated MSG1. We've already checked that this new message
968 * doesn't change any of the bits we relied upon in the past, but it may
969 * also have set additional capability bits. We simply throw those away
970 * now, and use the authentic capabilities from this MSG3. */
971 st->remote_capabilities=m->remote_capabilities;
973 /* Terminate their DH public key with a '0' */
975 /* Invent our DH secret key */
976 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
978 /* Generate the shared key and set up the transform */
979 if (!set_new_transform(st,m->pk)) return False;
984 static bool_t generate_msg4(struct site *st, const struct msg *prompt)
986 /* We have both nonces, their public key and our private key. Generate
987 our public key, sign it and send it to them. */
988 return generate_msg(st,LABEL_MSG4,"site:MSG4",prompt);
991 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
992 const struct comm_addr *src,
993 struct msg *m /* returned */)
997 if (!unpick_msg(st,LABEL_MSG4,msg4,m)) return False;
998 if (!check_msg(st,LABEL_MSG4,m,&err)) {
999 slog(st,LOG_SEC,"msg4: %s",err);
1003 if (!process_msg3_msg4(st,m))
1006 /* Terminate their DH public key with a '0' */
1009 /* Generate the shared key and set up the transform */
1010 if (!set_new_transform(st,m->pk)) return False;
1021 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1024 CHECK_AVAIL(msg0,4);
1025 m->dest=buf_unprepend_uint32(msg0);
1026 CHECK_AVAIL(msg0,4);
1027 m->source=buf_unprepend_uint32(msg0);
1028 CHECK_AVAIL(msg0,4);
1029 m->type=buf_unprepend_uint32(msg0);
1031 /* Leaves transformed part of buffer untouched */
1034 static bool_t generate_msg5(struct site *st, const struct msg *prompt)
1036 cstring_t transform_err;
1038 BUF_ALLOC(&st->buffer,"site:MSG5");
1039 /* We are going to add four words to the message */
1040 buffer_init(&st->buffer,calculate_max_start_pad());
1041 /* Give the netlink code an opportunity to put its own stuff in the
1042 message (configuration information, etc.) */
1043 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1044 if (call_transform_forwards(st,st->new_transform,
1045 &st->buffer,&transform_err))
1047 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1048 buf_prepend_uint32(&st->buffer,st->index);
1049 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1051 st->retries=st->setup_retries;
1055 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1056 const struct comm_addr *src,
1057 struct transform_inst_if *transform)
1060 cstring_t transform_err;
1062 if (!unpick_msg0(st,msg5,&m)) return False;
1064 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1065 /* There's a problem */
1066 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1069 /* Buffer should now contain untransformed PING packet data */
1070 CHECK_AVAIL(msg5,4);
1071 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1072 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1075 /* Older versions of secnet used to write some config data here
1076 * which we ignore. So we don't CHECK_EMPTY */
1080 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1081 uint32_t session_id)
1083 cstring_t transform_err;
1085 BUF_ALLOC(&st->buffer,"site:MSG6");
1086 /* We are going to add four words to the message */
1087 buffer_init(&st->buffer,calculate_max_start_pad());
1088 /* Give the netlink code an opportunity to put its own stuff in the
1089 message (configuration information, etc.) */
1090 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1091 transform_apply_return problem =
1092 call_transform_forwards(st,transform,
1093 &st->buffer,&transform_err);
1095 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1096 buf_prepend_uint32(&st->buffer,st->index);
1097 buf_prepend_uint32(&st->buffer,session_id);
1100 static bool_t generate_msg6(struct site *st, const struct msg *prompt)
1102 if (!is_transform_valid(st->new_transform))
1104 create_msg6(st,st->new_transform,st->setup_session_id);
1105 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1109 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1110 const struct comm_addr *src)
1113 cstring_t transform_err;
1115 if (!unpick_msg0(st,msg6,&m)) return False;
1117 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1118 /* There's a problem */
1119 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1122 /* Buffer should now contain untransformed PING packet data */
1123 CHECK_AVAIL(msg6,4);
1124 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1125 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1128 /* Older versions of secnet used to write some config data here
1129 * which we ignore. So we don't CHECK_EMPTY */
1133 static transform_apply_return
1134 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1135 const struct comm_addr *src)
1137 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1139 transform_apply_return problem;
1141 if (!unpick_msg0(st,msg0,&m)) return False;
1143 /* Keep a copy so we can try decrypting it with multiple keys */
1144 buffer_copy(&st->scratch, msg0);
1146 problem = call_transform_reverse(st,st->current.transform,
1147 msg0,&transform_err);
1149 if (!st->auxiliary_is_new)
1150 delete_one_key(st,&st->auxiliary_key,
1151 "peer has used new key","auxiliary key",LOG_SEC);
1154 if (transform_apply_return_badseq(problem))
1157 buffer_copy(msg0, &st->scratch);
1158 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1161 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1162 if (st->auxiliary_is_new) {
1163 /* We previously timed out in state SENTMSG5 but it turns
1164 * out that our peer did in fact get our MSG5 and is
1165 * using the new key. So we should switch to it too. */
1166 /* This is a bit like activate_new_key. */
1169 st->current=st->auxiliary_key;
1170 st->auxiliary_key=t;
1172 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1173 "previous key",LOG_SEC);
1174 st->auxiliary_is_new=0;
1175 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1179 if (transform_apply_return_badseq(problem))
1182 if (st->state==SITE_SENTMSG5) {
1183 buffer_copy(msg0, &st->scratch);
1184 problem = call_transform_reverse(st,st->new_transform,
1187 /* It looks like we didn't get the peer's MSG6 */
1188 /* This is like a cut-down enter_new_state(SITE_RUN) */
1189 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1190 BUF_FREE(&st->buffer);
1192 activate_new_key(st);
1193 return 0; /* do process the data in this packet */
1195 if (transform_apply_return_badseq(problem))
1199 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1200 transform_err,auxkey_err,newkey_err);
1201 initiate_key_setup(st,"incoming message would not decrypt",0);
1202 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1207 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1212 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1213 const struct comm_addr *src)
1216 transform_apply_return problem;
1218 problem = decrypt_msg0(st,msg0,src);
1219 if (problem==transform_apply_seqdupe) {
1220 /* We recently received another copy of this packet, maybe due
1221 * to polypath. That's not a problem; indeed, for the
1222 * purposes of transport address management it is a success.
1223 * But we don't want to process the packet. */
1224 transport_data_msgok(st,src);
1230 CHECK_AVAIL(msg0,4);
1231 type=buf_unprepend_uint32(msg0);
1234 /* We must forget about the current session. */
1235 delete_keys(st,"request from peer",LOG_SEC);
1236 /* probably, the peer is shutting down, and this is going to fail,
1237 * but we need to be trying to bring the link up again */
1239 initiate_key_setup(st,"peer requested key teardown",0);
1242 /* Deliver to netlink layer */
1243 st->netlink->deliver(st->netlink->st,msg0);
1244 transport_data_msgok(st,src);
1245 /* See whether we should start negotiating a new key */
1246 if (st->now > st->renegotiate_key_time)
1247 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1250 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1257 static void dump_packet(struct site *st, struct buffer_if *buf,
1258 const struct comm_addr *addr, bool_t incoming,
1261 uint32_t dest=get_uint32(buf->start);
1262 uint32_t source=get_uint32(buf->start+4);
1263 uint32_t msgtype=get_uint32(buf->start+8);
1265 if (st->log_events & LOG_DUMP)
1266 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1267 st->tunname,incoming?"incoming":"outgoing",
1268 dest,source,msgtype,comm_addr_to_string(addr),
1272 static bool_t comm_addr_sendmsg(struct site *st,
1273 const struct comm_addr *dest,
1274 struct buffer_if *buf)
1277 struct comm_clientinfo *commclientinfo = 0;
1279 for (i=0; i < st->ncomms; i++) {
1280 if (st->comms[i] == dest->comm) {
1281 commclientinfo = st->commclientinfos[i];
1285 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1288 static uint32_t site_status(void *st)
1293 static bool_t send_msg(struct site *st)
1295 if (st->retries>0) {
1296 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1297 st->timeout=st->now+st->setup_retry_interval;
1300 } else if (st->state==SITE_SENTMSG5) {
1301 logtimeout(st,"timed out sending MSG5, stashing new key");
1302 /* We stash the key we have produced, in case it turns out that
1303 * our peer did see our MSG5 after all and starts using it. */
1304 /* This is a bit like some of activate_new_key */
1305 struct transform_inst_if *t;
1306 t=st->auxiliary_key.transform;
1307 st->auxiliary_key.transform=st->new_transform;
1308 st->new_transform=t;
1309 dispose_transform(&st->new_transform);
1311 st->auxiliary_is_new=1;
1312 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1313 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1314 st->auxiliary_key.remote_session_id=st->setup_session_id;
1316 enter_state_wait(st);
1319 logtimeout(st,"timed out sending key setup packet "
1320 "(in state %s)",state_name(st->state));
1321 enter_state_wait(st);
1326 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1327 int stored_naddrs, int all_naddrs,
1328 const char *address, const char *failwhy)
1330 struct site *st=sst;
1332 if (!stored_naddrs) {
1333 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1335 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1336 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1338 int space=st->transport_peers_max-st->resolving_n_results_stored;
1339 int n_tocopy=MIN(stored_naddrs,space);
1340 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1343 st->resolving_n_results_stored += n_tocopy;
1344 st->resolving_n_results_all += all_naddrs;
1347 decrement_resolving_count(st,1);
1350 static void decrement_resolving_count(struct site *st, int by)
1352 assert(st->resolving_count>0);
1353 st->resolving_count-=by;
1355 if (st->resolving_count)
1358 /* OK, we are done with them all. Handle combined results. */
1360 const struct comm_addr *addrs=st->resolving_results;
1361 int naddrs=st->resolving_n_results_stored;
1362 assert(naddrs<=st->transport_peers_max);
1365 if (naddrs != st->resolving_n_results_all) {
1366 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1367 " yielded too many results (%d > %d), some ignored",
1368 st->resolving_n_results_all, naddrs);
1370 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1371 naddrs, iaddr_to_string(&addrs[0].ia));;
1374 switch (st->state) {
1376 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1377 enter_new_state(st,SITE_SENTMSG1,0);
1379 /* Can't figure out who to try to to talk to */
1380 slog(st,LOG_SETUP_INIT,
1381 "key exchange failed: cannot find peer address");
1382 enter_state_run(st);
1385 case SITE_SENTMSG1: case SITE_SENTMSG2:
1386 case SITE_SENTMSG3: case SITE_SENTMSG4:
1389 /* We start using the address immediately for data too.
1390 * It's best to store it in st->peers now because we might
1391 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1392 * the new key (without updating the data peer addrs). */
1393 transport_resolve_complete(st,addrs,naddrs);
1394 } else if (st->local_mobile) {
1395 /* We can't let this rest because we may have a peer
1396 * address which will break in the future. */
1397 slog(st,LOG_SETUP_INIT,"resolution failed: "
1398 "abandoning key exchange");
1399 enter_state_wait(st);
1401 slog(st,LOG_SETUP_INIT,"resolution failed: "
1402 " continuing to use source address of peer's packets"
1403 " for key exchange and ultimately data");
1408 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1409 " updating peer address(es)");
1410 transport_resolve_complete_tardy(st,addrs,naddrs);
1411 } else if (st->local_mobile) {
1412 /* Not very good. We should queue (another) renegotiation
1413 * so that we can update the peer address. */
1414 st->key_renegotiate_time=st->now+wait_timeout(st);
1416 slog(st,LOG_SETUP_INIT,"resolution failed: "
1417 " continuing to use source address of peer's packets");
1427 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1428 const struct comm_addr *prod_hint)
1430 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1431 if (st->state!=SITE_RUN) return False;
1432 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1433 if (st->addresses) {
1434 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1435 return enter_state_resolve(st);
1436 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1437 return enter_new_state(st,SITE_SENTMSG1,0);
1439 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1443 static void activate_new_key(struct site *st)
1445 struct transform_inst_if *t;
1447 /* We have three transform instances, which we swap between old,
1449 t=st->auxiliary_key.transform;
1450 st->auxiliary_key.transform=st->current.transform;
1451 st->current.transform=st->new_transform;
1452 st->new_transform=t;
1453 dispose_transform(&st->new_transform);
1456 st->auxiliary_is_new=0;
1457 st->auxiliary_key.key_timeout=st->current.key_timeout;
1458 st->current.key_timeout=st->now+st->key_lifetime;
1459 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1460 transport_peers_copy(st,&st->peers,&st->setup_peers);
1461 st->current.remote_session_id=st->setup_session_id;
1463 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1464 * But their mtu be unspecified, in which case we just use ours. */
1465 uint32_t intersite_mtu=
1466 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1467 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1469 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1470 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1471 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1472 enter_state_run(st);
1475 static void delete_one_key(struct site *st, struct data_key *key,
1476 cstring_t reason, cstring_t which, uint32_t loglevel)
1478 if (!is_transform_valid(key->transform)) return;
1479 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1480 dispose_transform(&key->transform);
1484 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1486 if (current_valid(st)) {
1487 slog(st,loglevel,"session closed (%s)",reason);
1489 delete_one_key(st,&st->current,0,0,0);
1490 set_link_quality(st);
1492 delete_one_key(st,&st->auxiliary_key,0,0,0);
1495 static void state_assert(struct site *st, bool_t ok)
1497 if (!ok) fatal("site:state_assert");
1500 static void enter_state_stop(struct site *st)
1502 st->state=SITE_STOP;
1504 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1505 dispose_transform(&st->new_transform);
1508 static void set_link_quality(struct site *st)
1511 if (current_valid(st))
1512 quality=LINK_QUALITY_UP;
1513 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1514 quality=LINK_QUALITY_DOWN;
1515 else if (st->addresses)
1516 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1517 else if (transport_peers_valid(&st->peers))
1518 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1520 quality=LINK_QUALITY_DOWN;
1522 st->netlink->set_quality(st->netlink->st,quality);
1525 static void enter_state_run(struct site *st)
1527 slog(st,LOG_STATE,"entering state RUN%s",
1528 current_valid(st) ? " (keyed)" : " (unkeyed)");
1532 st->setup_session_id=0;
1533 transport_peers_clear(st,&st->setup_peers);
1534 FILLZERO(st->localN);
1535 FILLZERO(st->remoteN);
1536 dispose_transform(&st->new_transform);
1537 memset(st->dhsecret,0,st->dh->len);
1538 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1539 set_link_quality(st);
1541 if (st->keepalive && !current_valid(st))
1542 initiate_key_setup(st, "keepalive", 0);
1545 static bool_t ensure_resolving(struct site *st)
1547 /* Reentrancy hazard: may call site_resolve_callback and hence
1548 * enter_new_state, enter_state_* and generate_msg*. */
1549 if (st->resolving_count)
1552 assert(st->addresses);
1554 /* resolver->request might reentrantly call site_resolve_callback
1555 * which will decrement st->resolving, so we need to increment it
1556 * twice beforehand to prevent decrement from thinking we're
1557 * finished, and decrement it ourselves. Alternatively if
1558 * everything fails then there are no callbacks due and we simply
1559 * set it to 0 and return false.. */
1560 st->resolving_n_results_stored=0;
1561 st->resolving_n_results_all=0;
1562 st->resolving_count+=2;
1563 const char **addrp=st->addresses;
1564 const char *address;
1566 for (; (address=*addrp++); ) {
1567 bool_t ok = st->resolver->request(st->resolver->st,address,
1568 st->remoteport,st->comms[0],
1569 site_resolve_callback,st);
1571 st->resolving_count++;
1575 st->resolving_count=0;
1578 decrement_resolving_count(st,2);
1582 static bool_t enter_state_resolve(struct site *st)
1584 /* Reentrancy hazard! See ensure_resolving. */
1585 state_assert(st,st->state==SITE_RUN);
1586 slog(st,LOG_STATE,"entering state RESOLVE");
1587 st->state=SITE_RESOLVE;
1588 return ensure_resolving(st);
1591 static bool_t enter_new_state(struct site *st, uint32_t next,
1592 const struct msg *prompt
1593 /* may be 0 for SENTMSG1 */)
1595 bool_t (*gen)(struct site *st, const struct msg *prompt);
1598 slog(st,LOG_STATE,"entering state %s",state_name(next));
1601 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1602 if (!kex_init(st)) return False;
1604 st->msg1_crossed_logged = False;
1607 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1608 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1609 if (!kex_init(st)) return False;
1613 state_assert(st,st->state==SITE_SENTMSG1);
1614 BUF_FREE(&st->buffer);
1618 state_assert(st,st->state==SITE_SENTMSG2);
1619 BUF_FREE(&st->buffer);
1623 state_assert(st,st->state==SITE_SENTMSG3);
1624 BUF_FREE(&st->buffer);
1628 state_assert(st,st->state==SITE_SENTMSG4);
1629 BUF_FREE(&st->buffer);
1634 fatal("enter_new_state(%s): invalid new state",state_name(next));
1638 if (hacky_par_start_failnow()) return False;
1640 r= gen(st,prompt) && send_msg(st);
1643 st->setup_retries, st->setup_retry_interval,
1648 if (next==SITE_RUN) {
1649 BUF_FREE(&st->buffer); /* Never reused */
1650 st->timeout=0; /* Never retransmit */
1651 activate_new_key(st);
1655 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1656 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1657 in either state, and enter_state_wait() will
1659 enter_state_wait(st);
1663 /* msg7 tells our peer that we're about to forget our key */
1664 static bool_t send_msg7(struct site *st, cstring_t reason)
1666 cstring_t transform_err;
1668 if (current_valid(st) && st->buffer.free
1669 && transport_peers_valid(&st->peers)) {
1670 BUF_ALLOC(&st->buffer,"site:MSG7");
1671 buffer_init(&st->buffer,calculate_max_start_pad());
1672 buf_append_uint32(&st->buffer,LABEL_MSG7);
1673 buf_append_string(&st->buffer,reason);
1674 if (call_transform_forwards(st, st->current.transform,
1675 &st->buffer, &transform_err))
1677 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1678 buf_prepend_uint32(&st->buffer,st->index);
1679 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1680 transport_xmit(st,&st->peers,&st->buffer,True);
1681 BUF_FREE(&st->buffer);
1688 /* We go into this state if our peer becomes uncommunicative. Similar to
1689 the "stop" state, we forget all session keys for a while, before
1690 re-entering the "run" state. */
1691 static void enter_state_wait(struct site *st)
1693 slog(st,LOG_STATE,"entering state WAIT");
1694 st->timeout=st->now+wait_timeout(st);
1695 st->state=SITE_WAIT;
1696 set_link_quality(st);
1697 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1698 /* XXX Erase keys etc. */
1701 static void generate_prod(struct site *st, struct buffer_if *buf)
1704 buf_append_uint32(buf,0);
1705 buf_append_uint32(buf,0);
1706 buf_append_uint32(buf,LABEL_PROD);
1707 buf_append_string(buf,st->localname);
1708 buf_append_string(buf,st->remotename);
1711 static void generate_send_prod(struct site *st,
1712 const struct comm_addr *source)
1714 if (!st->allow_send_prod) return; /* too soon */
1715 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1716 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1718 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1719 st->allow_send_prod=0;
1720 generate_prod(st,&st->scratch);
1721 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1722 dump_packet(st,&st->scratch,source,False,ok);
1725 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1728 int64_t offset=timeout-*now;
1729 if (offset<0) offset=0;
1730 if (offset>INT_MAX) offset=INT_MAX;
1731 if (*timeout_io<0 || offset<*timeout_io)
1736 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1739 struct site *st=sst;
1741 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1744 /* Work out when our next timeout is. The earlier of 'timeout' or
1745 'current.key_timeout'. A stored value of '0' indicates no timeout
1747 site_settimeout(st->timeout, timeout_io);
1748 site_settimeout(st->current.key_timeout, timeout_io);
1749 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1751 return 0; /* success */
1754 static void check_expiry(struct site *st, struct data_key *key,
1757 if (key->key_timeout && *now>key->key_timeout) {
1758 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1762 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1763 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1765 struct site *st=sst;
1768 if (st->timeout && *now>st->timeout) {
1770 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1771 if (!hacky_par_start_failnow())
1773 } else if (st->state==SITE_WAIT) {
1774 enter_state_run(st);
1776 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1780 check_expiry(st,&st->current,"current key");
1781 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1784 /* This function is called by the netlink device to deliver packets
1785 intended for the remote network. The packet is in "raw" wire
1786 format, but is guaranteed to be word-aligned. */
1787 static void site_outgoing(void *sst, struct buffer_if *buf)
1789 struct site *st=sst;
1790 cstring_t transform_err;
1792 if (st->state==SITE_STOP) {
1797 st->allow_send_prod=1;
1799 /* In all other states we consider delivering the packet if we have
1800 a valid key and a valid address to send it to. */
1801 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1802 /* Transform it and send it */
1804 buf_prepend_uint32(buf,LABEL_MSG9);
1805 if (call_transform_forwards(st, st->current.transform,
1806 buf, &transform_err))
1808 buf_prepend_uint32(buf,LABEL_MSG0);
1809 buf_prepend_uint32(buf,st->index);
1810 buf_prepend_uint32(buf,st->current.remote_session_id);
1811 transport_xmit(st,&st->peers,buf,False);
1818 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1820 initiate_key_setup(st,"outgoing packet",0);
1823 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1824 uint32_t type, struct msg *m)
1825 /* For packets which are identified by the local and remote names.
1826 * If it has our name and our peer's name in it it's for us. */
1828 struct buffer_if buf[1];
1829 buffer_readonly_clone(buf,buf_in);
1830 return unpick_msg(st,type,buf,m)
1831 && name_matches(&m->remote,st->remotename)
1832 && name_matches(&m->local,st->localname);
1835 static bool_t we_have_priority(struct site *st, const struct msg *m) {
1836 if (st->local_capabilities & m->remote_capabilities &
1837 CAPAB_PRIORITY_MOBILE) {
1838 if (st->local_mobile) return True;
1839 if (st-> peer_mobile) return False;
1841 return st->our_name_later;
1844 static bool_t setup_late_msg_ok(struct site *st,
1845 const struct buffer_if *buf_in,
1847 const struct comm_addr *source,
1848 struct msg *m /* returned */) {
1849 /* For setup packets which seem from their type like they are
1850 * late. Maybe they came via a different path. All we do is make
1851 * a note of the sending address, iff they look like they are part
1852 * of the current key setup attempt. */
1853 if (!named_for_us(st,buf_in,msgtype,m))
1854 /* named_for_us calls unpick_msg which gets the nonces */
1856 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN) ||
1857 !consttime_memeq(m->nL,st->localN, NONCELEN))
1858 /* spoof ? from stale run ? who knows */
1860 transport_setup_msgok(st,source);
1864 /* This function is called by the communication device to deliver
1865 packets from our peers.
1866 It should return True if the packet is recognised as being for
1867 this current site instance (and should therefore not be processed
1868 by other sites), even if the packet was otherwise ignored. */
1869 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1870 const struct comm_addr *source)
1872 struct site *st=sst;
1874 if (buf->size < 12) return False;
1876 uint32_t dest=get_uint32(buf->start);
1877 uint32_t msgtype=get_uint32(buf->start+8);
1879 /* initialised by named_for_us, or process_msgN for N!=1 */
1881 if (msgtype==LABEL_MSG1) {
1882 if (!named_for_us(st,buf,msgtype,&msg))
1884 /* It's a MSG1 addressed to us. Decide what to do about it. */
1885 dump_packet(st,buf,source,True,True);
1886 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1887 st->state==SITE_WAIT) {
1888 /* We should definitely process it */
1889 transport_compute_setupinit_peers(st,0,0,source);
1890 if (process_msg1(st,buf,source,&msg)) {
1891 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1892 bool_t entered=enter_new_state(st,SITE_SENTMSG2,&msg);
1893 if (entered && st->addresses && st->local_mobile)
1894 /* We must do this as the very last thing, because
1895 the resolver callback might reenter us. */
1896 ensure_resolving(st);
1898 slog(st,LOG_ERROR,"failed to process incoming msg1");
1902 } else if (st->state==SITE_SENTMSG1) {
1903 /* We've just sent a message 1! They may have crossed on
1904 the wire. If we have priority then we ignore the
1905 incoming one, otherwise we process it as usual. */
1906 if (we_have_priority(st,&msg)) {
1908 if (!st->msg1_crossed_logged++)
1909 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
1910 "priority => ignore incoming msg1");
1913 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
1914 "priority => use incoming msg1");
1915 if (process_msg1(st,buf,source,&msg)) {
1916 BUF_FREE(&st->buffer); /* Free our old message 1 */
1917 transport_setup_msgok(st,source);
1918 enter_new_state(st,SITE_SENTMSG2,&msg);
1920 slog(st,LOG_ERROR,"failed to process an incoming "
1921 "crossed msg1 (we have low priority)");
1926 } else if (st->state==SITE_SENTMSG2 ||
1927 st->state==SITE_SENTMSG4) {
1928 if (consttime_memeq(msg.nR,st->remoteN,NONCELEN)) {
1929 /* We are ahead in the protocol, but that msg1 had the
1930 * peer's nonce so presumably it is from this key
1931 * exchange run, via a slower route */
1932 transport_setup_msgok(st,source);
1934 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
1939 /* The message 1 was received at an unexpected stage of the
1940 key setup. Well, they lost the race. */
1941 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1945 if (msgtype==LABEL_PROD) {
1946 if (!named_for_us(st,buf,msgtype,&msg))
1948 dump_packet(st,buf,source,True,True);
1949 if (st->state!=SITE_RUN) {
1950 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1951 } else if (current_valid(st)) {
1952 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1954 initiate_key_setup(st,"peer sent PROD packet",source);
1959 if (dest==st->index) {
1960 /* Explicitly addressed to us */
1961 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
1964 /* If the source is our current peer then initiate a key setup,
1965 because our peer's forgotten the key */
1966 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
1968 initiated = initiate_key_setup(st,"received a NAK",source);
1969 if (!initiated) generate_send_prod(st,source);
1971 slog(st,LOG_SEC,"bad incoming NAK");
1975 process_msg0(st,buf,source);
1978 /* Setup packet: should not have been explicitly addressed
1980 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
1983 /* Setup packet: expected only in state SENTMSG1 */
1984 if (st->state!=SITE_SENTMSG1) {
1985 if ((st->state==SITE_SENTMSG3 ||
1986 st->state==SITE_SENTMSG5) &&
1987 setup_late_msg_ok(st,buf,msgtype,source,&msg))
1989 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
1990 } else if (process_msg2(st,buf,source,&msg)) {
1991 transport_setup_msgok(st,source);
1992 enter_new_state(st,SITE_SENTMSG3,&msg);
1994 slog(st,LOG_SEC,"invalid MSG2");
1997 case CASES_MSG3_KNOWN:
1998 /* Setup packet: expected only in state SENTMSG2 */
1999 if (st->state!=SITE_SENTMSG2) {
2000 if ((st->state==SITE_SENTMSG4) &&
2001 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2003 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
2004 } else if (process_msg3(st,buf,source,msgtype,&msg)) {
2005 transport_setup_msgok(st,source);
2006 enter_new_state(st,SITE_SENTMSG4,&msg);
2008 slog(st,LOG_SEC,"invalid MSG3");
2012 /* Setup packet: expected only in state SENTMSG3 */
2013 if (st->state!=SITE_SENTMSG3) {
2014 if ((st->state==SITE_SENTMSG5) &&
2015 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2017 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
2018 } else if (process_msg4(st,buf,source,&msg)) {
2019 transport_setup_msgok(st,source);
2020 enter_new_state(st,SITE_SENTMSG5,&msg);
2022 slog(st,LOG_SEC,"invalid MSG4");
2026 /* Setup packet: expected only in state SENTMSG4 */
2027 /* (may turn up in state RUN if our return MSG6 was lost
2028 and the new key has already been activated. In that
2029 case we discard it. The peer will realise that we
2030 are using the new key when they see our data packets.
2031 Until then the peer's data packets to us get discarded. */
2032 if (st->state==SITE_SENTMSG4) {
2033 if (process_msg5(st,buf,source,st->new_transform)) {
2034 transport_setup_msgok(st,source);
2035 enter_new_state(st,SITE_RUN,&msg);
2037 slog(st,LOG_SEC,"invalid MSG5");
2039 } else if (st->state==SITE_RUN) {
2040 if (process_msg5(st,buf,source,st->current.transform)) {
2041 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2042 transport_setup_msgok(st,source);
2043 create_msg6(st,st->current.transform,
2044 st->current.remote_session_id);
2045 transport_xmit(st,&st->peers,&st->buffer,True);
2046 BUF_FREE(&st->buffer);
2048 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2051 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2055 /* Setup packet: expected only in state SENTMSG5 */
2056 if (st->state!=SITE_SENTMSG5) {
2057 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2058 } else if (process_msg6(st,buf,source)) {
2059 BUF_FREE(&st->buffer); /* Free message 5 */
2060 transport_setup_msgok(st,source);
2061 activate_new_key(st);
2063 slog(st,LOG_SEC,"invalid MSG6");
2067 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2078 static void site_control(void *vst, bool_t run)
2080 struct site *st=vst;
2081 if (run) enter_state_run(st);
2082 else enter_state_stop(st);
2085 static void site_phase_hook(void *sst, uint32_t newphase)
2087 struct site *st=sst;
2089 /* The program is shutting down; tell our peer */
2090 send_msg7(st,"shutting down");
2093 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2095 struct site *st=sst;
2096 dispose_transform(&st->current.transform);
2097 dispose_transform(&st->auxiliary_key.transform);
2098 dispose_transform(&st->new_transform);
2099 /* Not much point overwiting the signing key, since we loaded it
2100 from disk, and it is only valid prospectively if at all,
2102 /* XXX it would be best to overwrite the DH state, because that
2103 _is_ relevant to forward secrecy. However we have no
2104 convenient interface for doing that and in practice gmp has
2105 probably dribbled droppings all over the malloc arena. A good
2106 way to fix this would be to have a privsep child for asymmetric
2107 crypto operations, but that's a task for another day. */
2110 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2113 static uint32_t index_sequence;
2121 st->cl.description="site";
2122 st->cl.type=CL_SITE;
2124 st->cl.interface=&st->ops;
2126 st->ops.control=site_control;
2127 st->ops.status=site_status;
2129 /* First parameter must be a dict */
2130 item=list_elem(args,0);
2131 if (!item || item->type!=t_dict)
2132 cfgfatal(loc,"site","parameter must be a dictionary\n");
2134 dict=item->data.dict;
2135 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2136 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2138 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2140 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2142 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2144 /* Sanity check (which also allows the 'sites' file to include
2145 site() closures for all sites including our own): refuse to
2146 talk to ourselves */
2147 if (strcmp(st->localname,st->remotename)==0) {
2148 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2150 if (st->peer_mobile != st->local_mobile)
2151 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2152 " but our local-mobile=%d\n",
2153 st->localname, st->peer_mobile, st->local_mobile);
2157 if (st->peer_mobile && st->local_mobile) {
2158 Message(M_WARNING,"site %s: site is mobile but so are we"
2159 " -> ignoring this site\n", st->remotename);
2164 assert(index_sequence < 0xffffffffUL);
2165 st->index = ++index_sequence;
2166 st->local_capabilities = 0;
2167 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2168 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2170 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2171 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2172 if (!things##_cfg) \
2173 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2174 st->nthings=list_length(things##_cfg); \
2175 NEW_ARY(st->things,st->nthings); \
2176 assert(st->nthings); \
2177 for (i=0; i<st->nthings; i++) { \
2178 item_t *item=list_elem(things##_cfg,i); \
2179 if (item->type!=t_closure) \
2180 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2181 closure_t *cl=item->data.closure; \
2182 if (cl->type!=CL_TYPE) \
2183 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2184 st->things[i]=cl->interface; \
2188 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2190 NEW_ARY(st->commclientinfos, st->ncomms);
2191 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2192 for (i=0; i<st->ncomms; i++) {
2193 st->commclientinfos[i] =
2195 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2198 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2199 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2200 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2202 st->privkey=find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2203 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2205 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2206 else st->remoteport=0;
2207 st->pubkey=find_cl_if(dict,"key",CL_SIGPUBKEY,True,"site",loc);
2209 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2211 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2213 if (st->privkey->sethash || st->pubkey->sethash) {
2214 struct hash_if *hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2215 if (st->privkey->sethash) st->privkey->sethash(st->privkey->st,hash);
2216 if (st->pubkey->sethash) st->pubkey->sethash(st->pubkey->st,hash);
2219 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2220 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2221 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2223 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2224 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2225 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2226 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2227 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2229 st->mobile_peer_expiry= dict_read_number(
2230 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2232 const char *peerskey= st->peer_mobile
2233 ? "mobile-peers-max" : "static-peers-max";
2234 st->transport_peers_max= dict_read_number(
2235 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2236 if (st->transport_peers_max<1 ||
2237 st->transport_peers_max>MAX_PEER_ADDRS) {
2238 cfgfatal(loc,"site", "%s must be in range 1.."
2239 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2242 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2243 st->key_renegotiate_time=st->key_lifetime/2;
2245 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2246 st->key_renegotiate_time=dict_read_number(
2247 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2248 if (st->key_renegotiate_time > st->key_lifetime) {
2249 cfgfatal(loc,"site",
2250 "renegotiate-time must be less than key-lifetime\n");
2253 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2254 log_event_table,"site");
2256 st->resolving_count=0;
2257 st->allow_send_prod=0;
2259 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2261 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2263 /* The information we expect to see in incoming messages of type 1 */
2264 /* fixme: lots of unchecked overflows here, but the results are only
2265 corrupted packets rather than undefined behaviour */
2266 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2268 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2270 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2271 BUF_ALLOC(&st->scratch,"site:scratch");
2273 /* We are interested in poll(), but only for timeouts. We don't have
2274 any fds of our own. */
2275 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2278 st->remote_capabilities=0;
2279 st->chosen_transform=0;
2280 st->current.key_timeout=0;
2281 st->auxiliary_key.key_timeout=0;
2282 transport_peers_clear(st,&st->peers);
2283 transport_peers_clear(st,&st->setup_peers);
2284 /* XXX mlock these */
2285 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2286 st->sharedsecretlen=st->sharedsecretallocd=0;
2289 #define SET_CAPBIT(bit) do { \
2290 uint32_t capflag = 1UL << (bit); \
2291 if (st->local_capabilities & capflag) \
2292 slog(st,LOG_ERROR,"capability bit" \
2293 " %d (%#"PRIx32") reused", (bit), capflag); \
2294 st->local_capabilities |= capflag; \
2297 for (i=0; i<st->ntransforms; i++)
2298 SET_CAPBIT(st->transforms[i]->capab_bit);
2302 if (st->local_mobile || st->peer_mobile)
2303 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2305 /* We need to register the remote networks with the netlink device */
2306 uint32_t netlink_mtu; /* local virtual interface mtu */
2307 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2308 if (!st->mtu_target)
2309 st->mtu_target=netlink_mtu;
2311 for (i=0; i<st->ncomms; i++)
2312 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2314 st->current.transform=0;
2315 st->auxiliary_key.transform=0;
2316 st->new_transform=0;
2317 st->auxiliary_is_new=0;
2319 enter_state_stop(st);
2321 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2322 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2324 return new_closure(&st->cl);
2327 void site_module(dict_t *dict)
2329 add_closure(dict,"site",site_apply);
2333 /***** TRANSPORT PEERS definitions *****/
2335 static void transport_peers_debug(struct site *st, transport_peers *dst,
2336 const char *didwhat,
2337 int nargs, const struct comm_addr *args,
2342 if (!(st->log_events & LOG_PEER_ADDRS))
2343 return; /* an optimisation */
2345 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2346 (dst==&st->peers ? "data" :
2347 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2348 didwhat, nargs, dst->npeers);
2350 for (i=0, argp=(void*)args;
2352 i++, (argp+=stride?stride:sizeof(*args))) {
2353 const struct comm_addr *ca=(void*)argp;
2354 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2355 i, comm_addr_to_string(ca));
2357 for (i=0; i<dst->npeers; i++) {
2358 struct timeval diff;
2359 timersub(tv_now,&dst->peers[i].last,&diff);
2360 const struct comm_addr *ca=&dst->peers[i].addr;
2361 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2362 i, comm_addr_to_string(ca),
2363 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2367 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2368 /* peers must be sorted first */
2369 int previous_peers=peers->npeers;
2370 struct timeval oldest;
2371 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2372 oldest.tv_usec = tv_now->tv_usec;
2373 while (peers->npeers>1 &&
2374 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2376 if (peers->npeers != previous_peers)
2377 transport_peers_debug(st,peers,"expire", 0,0,0);
2380 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2381 const struct comm_addr *ca,
2382 const struct timeval *tv) {
2383 /* returns false if output is full */
2386 if (peers->npeers >= st->transport_peers_max)
2389 for (search=0; search<peers->npeers; search++)
2390 if (comm_addr_equal(&peers->peers[search].addr, ca))
2393 peers->peers[peers->npeers].addr = *ca;
2394 peers->peers[peers->npeers].last = *tv;
2399 static void transport_record_peers(struct site *st, transport_peers *peers,
2400 const struct comm_addr *addrs, int naddrs,
2402 /* We add addrs into peers. The new entries end up at the front
2403 * and displace entries towards the end (perhaps even off the
2404 * end). Any existing matching entries are moved up to the front.
2406 * Caller must first call transport_peers_expire. */
2409 /* avoids debug for uninteresting updates */
2411 for (i=0; i<peers->npeers; i++) {
2412 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2413 memmove(peers->peers+1, peers->peers,
2414 sizeof(peers->peers[0]) * i);
2415 peers->peers[0].addr = addrs[0];
2416 peers->peers[0].last = *tv_now;
2422 int old_npeers=peers->npeers;
2423 transport_peer old_peers[old_npeers];
2424 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2428 for (i=0; i<naddrs; i++) {
2429 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2432 for (i=0; i<old_npeers; i++) {
2433 const transport_peer *old=&old_peers[i];
2434 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2438 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2441 static void transport_expire_record_peers(struct site *st,
2442 transport_peers *peers,
2443 const struct comm_addr *addrs,
2444 int naddrs, const char *m) {
2445 /* Convenience function */
2446 transport_peers_expire(st,peers);
2447 transport_record_peers(st,peers,addrs,naddrs,m);
2450 static bool_t transport_compute_setupinit_peers(struct site *st,
2451 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2452 int n_configured_addrs /* 0 if none or not found */,
2453 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2454 if (!n_configured_addrs && !incoming_packet_addr &&
2455 !transport_peers_valid(&st->peers))
2458 slog(st,LOG_SETUP_INIT,
2459 "using: %d configured addr(s);%s %d old peer addrs(es)",
2461 incoming_packet_addr ? " incoming packet address;" : "",
2464 /* Non-mobile peers try addresses until one is plausible. The
2465 * effect is that this code always tries first the configured
2466 * address if supplied, or otherwise the address of the incoming
2467 * PROD, or finally the existing data peer if one exists; this is
2470 transport_peers_copy(st,&st->setup_peers,&st->peers);
2471 transport_peers_expire(st,&st->setup_peers);
2473 if (incoming_packet_addr)
2474 transport_record_peers(st,&st->setup_peers,
2475 incoming_packet_addr,1, "incoming");
2477 if (n_configured_addrs)
2478 transport_record_peers(st,&st->setup_peers,
2479 configured_addrs,n_configured_addrs, "setupinit");
2481 assert(transport_peers_valid(&st->setup_peers));
2485 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2486 if (st->peer_mobile)
2487 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2489 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2490 if (st->peer_mobile)
2491 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2494 static int transport_peers_valid(transport_peers *peers) {
2495 return peers->npeers;
2497 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2499 transport_peers_debug(st,peers,"clear",0,0,0);
2501 static void transport_peers_copy(struct site *st, transport_peers *dst,
2502 const transport_peers *src) {
2503 dst->npeers=src->npeers;
2504 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2505 transport_peers_debug(st,dst,"copy",
2506 src->npeers, &src->peers->addr, sizeof(*src->peers));
2509 static void transport_resolve_complete(struct site *st,
2510 const struct comm_addr *addrs,
2512 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2514 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2518 static void transport_resolve_complete_tardy(struct site *st,
2519 const struct comm_addr *addrs,
2521 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2522 "resolved tardily");
2525 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2527 const transport_peers *inp) {
2528 /* out and in->peers may be the same region, or nonoverlapping */
2529 const transport_peer *in=inp->peers;
2531 for (slot=0; slot<inp->npeers; slot++) {
2532 if (!(mask & (1U << slot)))
2534 if (!(out==in && slot==*nout_io))
2535 COPY_OBJ(out[*nout_io], in[slot]);
2540 void transport_xmit(struct site *st, transport_peers *peers,
2541 struct buffer_if *buf, bool_t candebug) {
2543 transport_peers_expire(st, peers);
2544 unsigned failed=0; /* bitmask */
2545 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2548 for (slot=0; slot<peers->npeers; slot++) {
2549 transport_peer *peer=&peers->peers[slot];
2550 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2552 dump_packet(st, buf, &peer->addr, False, ok);
2554 failed |= 1U << slot;
2557 if (ok && !st->peer_mobile)
2560 /* Now we need to demote/delete failing addrs: if we are mobile we
2561 * merely demote them; otherwise we delete them. */
2562 if (st->local_mobile) {
2563 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2564 /* `expected' has all the failures at the end already */
2565 if (failed != expected) {
2567 transport_peer failedpeers[nfailed];
2568 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2569 assert(fslot == nfailed);
2571 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2572 assert(wslot+nfailed == peers->npeers);
2573 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2574 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2577 if (failed && peers->npeers > 1) {
2579 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2580 peers->npeers=wslot;
2581 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2586 /***** END of transport peers declarations *****/