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 generate_msg1(struct site *st, const struct msg *prompt_maybe_0)
811 st->random->generate(st->random->st,NONCELEN,st->localN);
812 return generate_msg(st,LABEL_MSG1,"site:MSG1",prompt_maybe_0);
815 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
816 const struct comm_addr *src,
819 /* We've already determined we're in an appropriate state to
820 process an incoming MSG1, and that the MSG1 has correct values
823 st->setup_session_id=m->source;
824 st->remote_capabilities=m->remote_capabilities;
825 memcpy(st->remoteN,m->nR,NONCELEN);
829 static bool_t generate_msg2(struct site *st,
830 const struct msg *prompt_may_be_null)
832 st->random->generate(st->random->st,NONCELEN,st->localN);
833 return generate_msg(st,LABEL_MSG2,"site:MSG2",prompt_may_be_null);
836 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
837 const struct comm_addr *src,
838 struct msg *m /* returned */)
842 if (!unpick_msg(st,LABEL_MSG2,msg2,m)) return False;
843 if (!check_msg(st,LABEL_MSG2,m,&err)) {
844 slog(st,LOG_SEC,"msg2: %s",err);
847 st->setup_session_id=m->source;
848 st->remote_capabilities=m->remote_capabilities;
850 /* Select the transform to use */
852 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
853 if (!remote_crypto_caps)
854 /* old secnets only had this one transform */
855 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
857 #define CHOOSE_CRYPTO(kind, whats) do { \
858 struct kind##_if *iface; \
859 uint32_t bit, ours = 0; \
861 for (i= 0; i < st->n##kind##s; i++) { \
862 iface=st->kind##s[i]; \
863 bit = 1UL << iface->capab_bit; \
864 if (bit & remote_crypto_caps) goto kind##_found; \
867 slog(st,LOG_ERROR,"no " whats " in common" \
868 " (us %#"PRIx32"; them: %#"PRIx32")", \
869 st->local_capabilities & ours, remote_crypto_caps); \
872 st->chosen_##kind = iface; \
875 CHOOSE_CRYPTO(transform, "transforms");
879 memcpy(st->remoteN,m->nR,NONCELEN);
883 static bool_t generate_msg3(struct site *st, const struct msg *prompt)
885 /* Now we have our nonce and their nonce. Think of a secret key,
886 and create message number 3. */
887 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
888 return generate_msg(st,
889 (st->remote_capabilities & CAPAB_TRANSFORM_MASK)
895 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
897 /* Check signature and store g^x mod m */
898 if (!st->pubkey->check(st->pubkey->st,
899 m->hashstart,m->hashlen,
901 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
905 st->remote_adv_mtu=m->remote_mtu;
910 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
911 const struct comm_addr *src, uint32_t msgtype,
912 struct msg *m /* returned */)
917 case CASES_MSG3_KNOWN: break;
921 if (!unpick_msg(st,msgtype,msg3,m)) return False;
922 if (!check_msg(st,msgtype,m,&err)) {
923 slog(st,LOG_SEC,"msg3: %s",err);
926 uint32_t capab_adv_late = m->remote_capabilities
927 & ~st->remote_capabilities & st->early_capabilities;
928 if (capab_adv_late) {
929 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
930 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
931 capab_adv_late, st->remote_capabilities, m->remote_capabilities);
935 #define CHOSE_CRYPTO(kind, what) do { \
936 struct kind##_if *iface; \
938 for (i=0; i<st->n##kind##s; i++) { \
939 iface=st->kind##s[i]; \
940 if (iface->capab_bit == m->capab_##kind##num) \
943 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
944 m->capab_##kind##num); \
947 st->chosen_##kind=iface; \
950 CHOSE_CRYPTO(transform, "transform");
954 if (!process_msg3_msg4(st,m))
957 /* Update our idea of the remote site's capabilities, now that we've
958 * verified that its message was authentic.
960 * Our previous idea of the remote site's capabilities came from the
961 * unauthenticated MSG1. We've already checked that this new message
962 * doesn't change any of the bits we relied upon in the past, but it may
963 * also have set additional capability bits. We simply throw those away
964 * now, and use the authentic capabilities from this MSG3. */
965 st->remote_capabilities=m->remote_capabilities;
967 /* Terminate their DH public key with a '0' */
969 /* Invent our DH secret key */
970 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
972 /* Generate the shared key and set up the transform */
973 if (!set_new_transform(st,m->pk)) return False;
978 static bool_t generate_msg4(struct site *st, const struct msg *prompt)
980 /* We have both nonces, their public key and our private key. Generate
981 our public key, sign it and send it to them. */
982 return generate_msg(st,LABEL_MSG4,"site:MSG4",prompt);
985 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
986 const struct comm_addr *src,
987 struct msg *m /* returned */)
991 if (!unpick_msg(st,LABEL_MSG4,msg4,m)) return False;
992 if (!check_msg(st,LABEL_MSG4,m,&err)) {
993 slog(st,LOG_SEC,"msg4: %s",err);
997 if (!process_msg3_msg4(st,m))
1000 /* Terminate their DH public key with a '0' */
1003 /* Generate the shared key and set up the transform */
1004 if (!set_new_transform(st,m->pk)) return False;
1015 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1018 CHECK_AVAIL(msg0,4);
1019 m->dest=buf_unprepend_uint32(msg0);
1020 CHECK_AVAIL(msg0,4);
1021 m->source=buf_unprepend_uint32(msg0);
1022 CHECK_AVAIL(msg0,4);
1023 m->type=buf_unprepend_uint32(msg0);
1025 /* Leaves transformed part of buffer untouched */
1028 static bool_t generate_msg5(struct site *st, const struct msg *prompt)
1030 cstring_t transform_err;
1032 BUF_ALLOC(&st->buffer,"site:MSG5");
1033 /* We are going to add four words to the message */
1034 buffer_init(&st->buffer,calculate_max_start_pad());
1035 /* Give the netlink code an opportunity to put its own stuff in the
1036 message (configuration information, etc.) */
1037 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1038 if (call_transform_forwards(st,st->new_transform,
1039 &st->buffer,&transform_err))
1041 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1042 buf_prepend_uint32(&st->buffer,st->index);
1043 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1045 st->retries=st->setup_retries;
1049 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1050 const struct comm_addr *src,
1051 struct transform_inst_if *transform)
1054 cstring_t transform_err;
1056 if (!unpick_msg0(st,msg5,&m)) return False;
1058 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1059 /* There's a problem */
1060 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1063 /* Buffer should now contain untransformed PING packet data */
1064 CHECK_AVAIL(msg5,4);
1065 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1066 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1069 /* Older versions of secnet used to write some config data here
1070 * which we ignore. So we don't CHECK_EMPTY */
1074 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1075 uint32_t session_id)
1077 cstring_t transform_err;
1079 BUF_ALLOC(&st->buffer,"site:MSG6");
1080 /* We are going to add four words to the message */
1081 buffer_init(&st->buffer,calculate_max_start_pad());
1082 /* Give the netlink code an opportunity to put its own stuff in the
1083 message (configuration information, etc.) */
1084 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1085 transform_apply_return problem =
1086 call_transform_forwards(st,transform,
1087 &st->buffer,&transform_err);
1089 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1090 buf_prepend_uint32(&st->buffer,st->index);
1091 buf_prepend_uint32(&st->buffer,session_id);
1094 static bool_t generate_msg6(struct site *st, const struct msg *prompt)
1096 if (!is_transform_valid(st->new_transform))
1098 create_msg6(st,st->new_transform,st->setup_session_id);
1099 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1103 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1104 const struct comm_addr *src)
1107 cstring_t transform_err;
1109 if (!unpick_msg0(st,msg6,&m)) return False;
1111 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1112 /* There's a problem */
1113 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1116 /* Buffer should now contain untransformed PING packet data */
1117 CHECK_AVAIL(msg6,4);
1118 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1119 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1122 /* Older versions of secnet used to write some config data here
1123 * which we ignore. So we don't CHECK_EMPTY */
1127 static transform_apply_return
1128 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1129 const struct comm_addr *src)
1131 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1133 transform_apply_return problem;
1135 if (!unpick_msg0(st,msg0,&m)) return False;
1137 /* Keep a copy so we can try decrypting it with multiple keys */
1138 buffer_copy(&st->scratch, msg0);
1140 problem = call_transform_reverse(st,st->current.transform,
1141 msg0,&transform_err);
1143 if (!st->auxiliary_is_new)
1144 delete_one_key(st,&st->auxiliary_key,
1145 "peer has used new key","auxiliary key",LOG_SEC);
1148 if (transform_apply_return_badseq(problem))
1151 buffer_copy(msg0, &st->scratch);
1152 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1155 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1156 if (st->auxiliary_is_new) {
1157 /* We previously timed out in state SENTMSG5 but it turns
1158 * out that our peer did in fact get our MSG5 and is
1159 * using the new key. So we should switch to it too. */
1160 /* This is a bit like activate_new_key. */
1163 st->current=st->auxiliary_key;
1164 st->auxiliary_key=t;
1166 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1167 "previous key",LOG_SEC);
1168 st->auxiliary_is_new=0;
1169 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1173 if (transform_apply_return_badseq(problem))
1176 if (st->state==SITE_SENTMSG5) {
1177 buffer_copy(msg0, &st->scratch);
1178 problem = call_transform_reverse(st,st->new_transform,
1181 /* It looks like we didn't get the peer's MSG6 */
1182 /* This is like a cut-down enter_new_state(SITE_RUN) */
1183 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1184 BUF_FREE(&st->buffer);
1186 activate_new_key(st);
1187 return 0; /* do process the data in this packet */
1189 if (transform_apply_return_badseq(problem))
1193 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1194 transform_err,auxkey_err,newkey_err);
1195 initiate_key_setup(st,"incoming message would not decrypt",0);
1196 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1201 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1206 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1207 const struct comm_addr *src)
1210 transform_apply_return problem;
1212 problem = decrypt_msg0(st,msg0,src);
1213 if (problem==transform_apply_seqdupe) {
1214 /* We recently received another copy of this packet, maybe due
1215 * to polypath. That's not a problem; indeed, for the
1216 * purposes of transport address management it is a success.
1217 * But we don't want to process the packet. */
1218 transport_data_msgok(st,src);
1224 CHECK_AVAIL(msg0,4);
1225 type=buf_unprepend_uint32(msg0);
1228 /* We must forget about the current session. */
1229 delete_keys(st,"request from peer",LOG_SEC);
1230 /* probably, the peer is shutting down, and this is going to fail,
1231 * but we need to be trying to bring the link up again */
1233 initiate_key_setup(st,"peer requested key teardown",0);
1236 /* Deliver to netlink layer */
1237 st->netlink->deliver(st->netlink->st,msg0);
1238 transport_data_msgok(st,src);
1239 /* See whether we should start negotiating a new key */
1240 if (st->now > st->renegotiate_key_time)
1241 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1244 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1251 static void dump_packet(struct site *st, struct buffer_if *buf,
1252 const struct comm_addr *addr, bool_t incoming,
1255 uint32_t dest=get_uint32(buf->start);
1256 uint32_t source=get_uint32(buf->start+4);
1257 uint32_t msgtype=get_uint32(buf->start+8);
1259 if (st->log_events & LOG_DUMP)
1260 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1261 st->tunname,incoming?"incoming":"outgoing",
1262 dest,source,msgtype,comm_addr_to_string(addr),
1266 static bool_t comm_addr_sendmsg(struct site *st,
1267 const struct comm_addr *dest,
1268 struct buffer_if *buf)
1271 struct comm_clientinfo *commclientinfo = 0;
1273 for (i=0; i < st->ncomms; i++) {
1274 if (st->comms[i] == dest->comm) {
1275 commclientinfo = st->commclientinfos[i];
1279 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1282 static uint32_t site_status(void *st)
1287 static bool_t send_msg(struct site *st)
1289 if (st->retries>0) {
1290 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1291 st->timeout=st->now+st->setup_retry_interval;
1294 } else if (st->state==SITE_SENTMSG5) {
1295 logtimeout(st,"timed out sending MSG5, stashing new key");
1296 /* We stash the key we have produced, in case it turns out that
1297 * our peer did see our MSG5 after all and starts using it. */
1298 /* This is a bit like some of activate_new_key */
1299 struct transform_inst_if *t;
1300 t=st->auxiliary_key.transform;
1301 st->auxiliary_key.transform=st->new_transform;
1302 st->new_transform=t;
1303 dispose_transform(&st->new_transform);
1305 st->auxiliary_is_new=1;
1306 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1307 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1308 st->auxiliary_key.remote_session_id=st->setup_session_id;
1310 enter_state_wait(st);
1313 logtimeout(st,"timed out sending key setup packet "
1314 "(in state %s)",state_name(st->state));
1315 enter_state_wait(st);
1320 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1321 int stored_naddrs, int all_naddrs,
1322 const char *address, const char *failwhy)
1324 struct site *st=sst;
1326 if (!stored_naddrs) {
1327 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1329 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1330 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1332 int space=st->transport_peers_max-st->resolving_n_results_stored;
1333 int n_tocopy=MIN(stored_naddrs,space);
1334 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1337 st->resolving_n_results_stored += n_tocopy;
1338 st->resolving_n_results_all += all_naddrs;
1341 decrement_resolving_count(st,1);
1344 static void decrement_resolving_count(struct site *st, int by)
1346 assert(st->resolving_count>0);
1347 st->resolving_count-=by;
1349 if (st->resolving_count)
1352 /* OK, we are done with them all. Handle combined results. */
1354 const struct comm_addr *addrs=st->resolving_results;
1355 int naddrs=st->resolving_n_results_stored;
1356 assert(naddrs<=st->transport_peers_max);
1359 if (naddrs != st->resolving_n_results_all) {
1360 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1361 " yielded too many results (%d > %d), some ignored",
1362 st->resolving_n_results_all, naddrs);
1364 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1365 naddrs, iaddr_to_string(&addrs[0].ia));;
1368 switch (st->state) {
1370 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1371 enter_new_state(st,SITE_SENTMSG1,0);
1373 /* Can't figure out who to try to to talk to */
1374 slog(st,LOG_SETUP_INIT,
1375 "key exchange failed: cannot find peer address");
1376 enter_state_run(st);
1379 case SITE_SENTMSG1: case SITE_SENTMSG2:
1380 case SITE_SENTMSG3: case SITE_SENTMSG4:
1383 /* We start using the address immediately for data too.
1384 * It's best to store it in st->peers now because we might
1385 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1386 * the new key (without updating the data peer addrs). */
1387 transport_resolve_complete(st,addrs,naddrs);
1388 } else if (st->local_mobile) {
1389 /* We can't let this rest because we may have a peer
1390 * address which will break in the future. */
1391 slog(st,LOG_SETUP_INIT,"resolution failed: "
1392 "abandoning key exchange");
1393 enter_state_wait(st);
1395 slog(st,LOG_SETUP_INIT,"resolution failed: "
1396 " continuing to use source address of peer's packets"
1397 " for key exchange and ultimately data");
1402 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1403 " updating peer address(es)");
1404 transport_resolve_complete_tardy(st,addrs,naddrs);
1405 } else if (st->local_mobile) {
1406 /* Not very good. We should queue (another) renegotiation
1407 * so that we can update the peer address. */
1408 st->key_renegotiate_time=st->now+wait_timeout(st);
1410 slog(st,LOG_SETUP_INIT,"resolution failed: "
1411 " continuing to use source address of peer's packets");
1421 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1422 const struct comm_addr *prod_hint)
1424 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1425 if (st->state!=SITE_RUN) return False;
1426 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1427 if (st->addresses) {
1428 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1429 return enter_state_resolve(st);
1430 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1431 return enter_new_state(st,SITE_SENTMSG1,0);
1433 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1437 static void activate_new_key(struct site *st)
1439 struct transform_inst_if *t;
1441 /* We have three transform instances, which we swap between old,
1443 t=st->auxiliary_key.transform;
1444 st->auxiliary_key.transform=st->current.transform;
1445 st->current.transform=st->new_transform;
1446 st->new_transform=t;
1447 dispose_transform(&st->new_transform);
1450 st->auxiliary_is_new=0;
1451 st->auxiliary_key.key_timeout=st->current.key_timeout;
1452 st->current.key_timeout=st->now+st->key_lifetime;
1453 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1454 transport_peers_copy(st,&st->peers,&st->setup_peers);
1455 st->current.remote_session_id=st->setup_session_id;
1457 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1458 * But their mtu be unspecified, in which case we just use ours. */
1459 uint32_t intersite_mtu=
1460 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1461 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1463 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1464 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1465 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1466 enter_state_run(st);
1469 static void delete_one_key(struct site *st, struct data_key *key,
1470 cstring_t reason, cstring_t which, uint32_t loglevel)
1472 if (!is_transform_valid(key->transform)) return;
1473 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1474 dispose_transform(&key->transform);
1478 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1480 if (current_valid(st)) {
1481 slog(st,loglevel,"session closed (%s)",reason);
1483 delete_one_key(st,&st->current,0,0,0);
1484 set_link_quality(st);
1486 delete_one_key(st,&st->auxiliary_key,0,0,0);
1489 static void state_assert(struct site *st, bool_t ok)
1491 if (!ok) fatal("site:state_assert");
1494 static void enter_state_stop(struct site *st)
1496 st->state=SITE_STOP;
1498 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1499 dispose_transform(&st->new_transform);
1502 static void set_link_quality(struct site *st)
1505 if (current_valid(st))
1506 quality=LINK_QUALITY_UP;
1507 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1508 quality=LINK_QUALITY_DOWN;
1509 else if (st->addresses)
1510 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1511 else if (transport_peers_valid(&st->peers))
1512 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1514 quality=LINK_QUALITY_DOWN;
1516 st->netlink->set_quality(st->netlink->st,quality);
1519 static void enter_state_run(struct site *st)
1521 slog(st,LOG_STATE,"entering state RUN%s",
1522 current_valid(st) ? " (keyed)" : " (unkeyed)");
1526 st->setup_session_id=0;
1527 transport_peers_clear(st,&st->setup_peers);
1528 FILLZERO(st->localN);
1529 FILLZERO(st->remoteN);
1530 dispose_transform(&st->new_transform);
1531 memset(st->dhsecret,0,st->dh->len);
1532 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1533 set_link_quality(st);
1535 if (st->keepalive && !current_valid(st))
1536 initiate_key_setup(st, "keepalive", 0);
1539 static bool_t ensure_resolving(struct site *st)
1541 /* Reentrancy hazard: may call site_resolve_callback and hence
1542 * enter_new_state, enter_state_* and generate_msg*. */
1543 if (st->resolving_count)
1546 assert(st->addresses);
1548 /* resolver->request might reentrantly call site_resolve_callback
1549 * which will decrement st->resolving, so we need to increment it
1550 * twice beforehand to prevent decrement from thinking we're
1551 * finished, and decrement it ourselves. Alternatively if
1552 * everything fails then there are no callbacks due and we simply
1553 * set it to 0 and return false.. */
1554 st->resolving_n_results_stored=0;
1555 st->resolving_n_results_all=0;
1556 st->resolving_count+=2;
1557 const char **addrp=st->addresses;
1558 const char *address;
1560 for (; (address=*addrp++); ) {
1561 bool_t ok = st->resolver->request(st->resolver->st,address,
1562 st->remoteport,st->comms[0],
1563 site_resolve_callback,st);
1565 st->resolving_count++;
1569 st->resolving_count=0;
1572 decrement_resolving_count(st,2);
1576 static bool_t enter_state_resolve(struct site *st)
1578 /* Reentrancy hazard! See ensure_resolving. */
1579 state_assert(st,st->state==SITE_RUN);
1580 slog(st,LOG_STATE,"entering state RESOLVE");
1581 st->state=SITE_RESOLVE;
1582 return ensure_resolving(st);
1585 static bool_t enter_new_state(struct site *st, uint32_t next,
1586 const struct msg *prompt
1587 /* may be 0 for SENTMSG1 */)
1589 bool_t (*gen)(struct site *st, const struct msg *prompt);
1592 slog(st,LOG_STATE,"entering state %s",state_name(next));
1595 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1597 st->msg1_crossed_logged = False;
1600 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1601 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1605 state_assert(st,st->state==SITE_SENTMSG1);
1606 BUF_FREE(&st->buffer);
1610 state_assert(st,st->state==SITE_SENTMSG2);
1611 BUF_FREE(&st->buffer);
1615 state_assert(st,st->state==SITE_SENTMSG3);
1616 BUF_FREE(&st->buffer);
1620 state_assert(st,st->state==SITE_SENTMSG4);
1621 BUF_FREE(&st->buffer);
1626 fatal("enter_new_state(%s): invalid new state",state_name(next));
1630 if (hacky_par_start_failnow()) return False;
1632 r= gen(st,prompt) && send_msg(st);
1635 st->setup_retries, st->setup_retry_interval,
1640 if (next==SITE_RUN) {
1641 BUF_FREE(&st->buffer); /* Never reused */
1642 st->timeout=0; /* Never retransmit */
1643 activate_new_key(st);
1647 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1648 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1649 in either state, and enter_state_wait() will
1651 enter_state_wait(st);
1655 /* msg7 tells our peer that we're about to forget our key */
1656 static bool_t send_msg7(struct site *st, cstring_t reason)
1658 cstring_t transform_err;
1660 if (current_valid(st) && st->buffer.free
1661 && transport_peers_valid(&st->peers)) {
1662 BUF_ALLOC(&st->buffer,"site:MSG7");
1663 buffer_init(&st->buffer,calculate_max_start_pad());
1664 buf_append_uint32(&st->buffer,LABEL_MSG7);
1665 buf_append_string(&st->buffer,reason);
1666 if (call_transform_forwards(st, st->current.transform,
1667 &st->buffer, &transform_err))
1669 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1670 buf_prepend_uint32(&st->buffer,st->index);
1671 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1672 transport_xmit(st,&st->peers,&st->buffer,True);
1673 BUF_FREE(&st->buffer);
1680 /* We go into this state if our peer becomes uncommunicative. Similar to
1681 the "stop" state, we forget all session keys for a while, before
1682 re-entering the "run" state. */
1683 static void enter_state_wait(struct site *st)
1685 slog(st,LOG_STATE,"entering state WAIT");
1686 st->timeout=st->now+wait_timeout(st);
1687 st->state=SITE_WAIT;
1688 set_link_quality(st);
1689 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1690 /* XXX Erase keys etc. */
1693 static void generate_prod(struct site *st, struct buffer_if *buf)
1696 buf_append_uint32(buf,0);
1697 buf_append_uint32(buf,0);
1698 buf_append_uint32(buf,LABEL_PROD);
1699 buf_append_string(buf,st->localname);
1700 buf_append_string(buf,st->remotename);
1703 static void generate_send_prod(struct site *st,
1704 const struct comm_addr *source)
1706 if (!st->allow_send_prod) return; /* too soon */
1707 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1708 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1710 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1711 st->allow_send_prod=0;
1712 generate_prod(st,&st->scratch);
1713 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1714 dump_packet(st,&st->scratch,source,False,ok);
1717 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1720 int64_t offset=timeout-*now;
1721 if (offset<0) offset=0;
1722 if (offset>INT_MAX) offset=INT_MAX;
1723 if (*timeout_io<0 || offset<*timeout_io)
1728 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1731 struct site *st=sst;
1733 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1736 /* Work out when our next timeout is. The earlier of 'timeout' or
1737 'current.key_timeout'. A stored value of '0' indicates no timeout
1739 site_settimeout(st->timeout, timeout_io);
1740 site_settimeout(st->current.key_timeout, timeout_io);
1741 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1743 return 0; /* success */
1746 static void check_expiry(struct site *st, struct data_key *key,
1749 if (key->key_timeout && *now>key->key_timeout) {
1750 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1754 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1755 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1757 struct site *st=sst;
1760 if (st->timeout && *now>st->timeout) {
1762 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1763 if (!hacky_par_start_failnow())
1765 } else if (st->state==SITE_WAIT) {
1766 enter_state_run(st);
1768 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1772 check_expiry(st,&st->current,"current key");
1773 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1776 /* This function is called by the netlink device to deliver packets
1777 intended for the remote network. The packet is in "raw" wire
1778 format, but is guaranteed to be word-aligned. */
1779 static void site_outgoing(void *sst, struct buffer_if *buf)
1781 struct site *st=sst;
1782 cstring_t transform_err;
1784 if (st->state==SITE_STOP) {
1789 st->allow_send_prod=1;
1791 /* In all other states we consider delivering the packet if we have
1792 a valid key and a valid address to send it to. */
1793 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1794 /* Transform it and send it */
1796 buf_prepend_uint32(buf,LABEL_MSG9);
1797 if (call_transform_forwards(st, st->current.transform,
1798 buf, &transform_err))
1800 buf_prepend_uint32(buf,LABEL_MSG0);
1801 buf_prepend_uint32(buf,st->index);
1802 buf_prepend_uint32(buf,st->current.remote_session_id);
1803 transport_xmit(st,&st->peers,buf,False);
1810 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1812 initiate_key_setup(st,"outgoing packet",0);
1815 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1816 uint32_t type, struct msg *m)
1817 /* For packets which are identified by the local and remote names.
1818 * If it has our name and our peer's name in it it's for us. */
1820 struct buffer_if buf[1];
1821 buffer_readonly_clone(buf,buf_in);
1822 return unpick_msg(st,type,buf,m)
1823 && name_matches(&m->remote,st->remotename)
1824 && name_matches(&m->local,st->localname);
1827 static bool_t we_have_priority(struct site *st, const struct msg *m) {
1828 if (st->local_capabilities & m->remote_capabilities &
1829 CAPAB_PRIORITY_MOBILE) {
1830 if (st->local_mobile) return True;
1831 if (st-> peer_mobile) return False;
1833 return st->our_name_later;
1836 static bool_t setup_late_msg_ok(struct site *st,
1837 const struct buffer_if *buf_in,
1839 const struct comm_addr *source,
1840 struct msg *m /* returned */) {
1841 /* For setup packets which seem from their type like they are
1842 * late. Maybe they came via a different path. All we do is make
1843 * a note of the sending address, iff they look like they are part
1844 * of the current key setup attempt. */
1845 if (!named_for_us(st,buf_in,msgtype,m))
1846 /* named_for_us calls unpick_msg which gets the nonces */
1848 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN) ||
1849 !consttime_memeq(m->nL,st->localN, NONCELEN))
1850 /* spoof ? from stale run ? who knows */
1852 transport_setup_msgok(st,source);
1856 /* This function is called by the communication device to deliver
1857 packets from our peers.
1858 It should return True if the packet is recognised as being for
1859 this current site instance (and should therefore not be processed
1860 by other sites), even if the packet was otherwise ignored. */
1861 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1862 const struct comm_addr *source)
1864 struct site *st=sst;
1866 if (buf->size < 12) return False;
1868 uint32_t dest=get_uint32(buf->start);
1869 uint32_t msgtype=get_uint32(buf->start+8);
1871 /* initialised by named_for_us, or process_msgN for N!=1 */
1873 if (msgtype==LABEL_MSG1) {
1874 if (!named_for_us(st,buf,msgtype,&msg))
1876 /* It's a MSG1 addressed to us. Decide what to do about it. */
1877 dump_packet(st,buf,source,True,True);
1878 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1879 st->state==SITE_WAIT) {
1880 /* We should definitely process it */
1881 transport_compute_setupinit_peers(st,0,0,source);
1882 if (process_msg1(st,buf,source,&msg)) {
1883 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1884 bool_t entered=enter_new_state(st,SITE_SENTMSG2,&msg);
1885 if (entered && st->addresses && st->local_mobile)
1886 /* We must do this as the very last thing, because
1887 the resolver callback might reenter us. */
1888 ensure_resolving(st);
1890 slog(st,LOG_ERROR,"failed to process incoming msg1");
1894 } else if (st->state==SITE_SENTMSG1) {
1895 /* We've just sent a message 1! They may have crossed on
1896 the wire. If we have priority then we ignore the
1897 incoming one, otherwise we process it as usual. */
1898 if (we_have_priority(st,&msg)) {
1900 if (!st->msg1_crossed_logged++)
1901 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
1902 "priority => ignore incoming msg1");
1905 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
1906 "priority => use incoming msg1");
1907 if (process_msg1(st,buf,source,&msg)) {
1908 BUF_FREE(&st->buffer); /* Free our old message 1 */
1909 transport_setup_msgok(st,source);
1910 enter_new_state(st,SITE_SENTMSG2,&msg);
1912 slog(st,LOG_ERROR,"failed to process an incoming "
1913 "crossed msg1 (we have low priority)");
1918 } else if (st->state==SITE_SENTMSG2 ||
1919 st->state==SITE_SENTMSG4) {
1920 if (consttime_memeq(msg.nR,st->remoteN,NONCELEN)) {
1921 /* We are ahead in the protocol, but that msg1 had the
1922 * peer's nonce so presumably it is from this key
1923 * exchange run, via a slower route */
1924 transport_setup_msgok(st,source);
1926 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
1931 /* The message 1 was received at an unexpected stage of the
1932 key setup. Well, they lost the race. */
1933 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1937 if (msgtype==LABEL_PROD) {
1938 if (!named_for_us(st,buf,msgtype,&msg))
1940 dump_packet(st,buf,source,True,True);
1941 if (st->state!=SITE_RUN) {
1942 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1943 } else if (current_valid(st)) {
1944 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1946 initiate_key_setup(st,"peer sent PROD packet",source);
1951 if (dest==st->index) {
1952 /* Explicitly addressed to us */
1953 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
1956 /* If the source is our current peer then initiate a key setup,
1957 because our peer's forgotten the key */
1958 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
1960 initiated = initiate_key_setup(st,"received a NAK",source);
1961 if (!initiated) generate_send_prod(st,source);
1963 slog(st,LOG_SEC,"bad incoming NAK");
1967 process_msg0(st,buf,source);
1970 /* Setup packet: should not have been explicitly addressed
1972 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
1975 /* Setup packet: expected only in state SENTMSG1 */
1976 if (st->state!=SITE_SENTMSG1) {
1977 if ((st->state==SITE_SENTMSG3 ||
1978 st->state==SITE_SENTMSG5) &&
1979 setup_late_msg_ok(st,buf,msgtype,source,&msg))
1981 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
1982 } else if (process_msg2(st,buf,source,&msg)) {
1983 transport_setup_msgok(st,source);
1984 enter_new_state(st,SITE_SENTMSG3,&msg);
1986 slog(st,LOG_SEC,"invalid MSG2");
1989 case CASES_MSG3_KNOWN:
1990 /* Setup packet: expected only in state SENTMSG2 */
1991 if (st->state!=SITE_SENTMSG2) {
1992 if ((st->state==SITE_SENTMSG4) &&
1993 setup_late_msg_ok(st,buf,msgtype,source,&msg))
1995 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
1996 } else if (process_msg3(st,buf,source,msgtype,&msg)) {
1997 transport_setup_msgok(st,source);
1998 enter_new_state(st,SITE_SENTMSG4,&msg);
2000 slog(st,LOG_SEC,"invalid MSG3");
2004 /* Setup packet: expected only in state SENTMSG3 */
2005 if (st->state!=SITE_SENTMSG3) {
2006 if ((st->state==SITE_SENTMSG5) &&
2007 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2009 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
2010 } else if (process_msg4(st,buf,source,&msg)) {
2011 transport_setup_msgok(st,source);
2012 enter_new_state(st,SITE_SENTMSG5,&msg);
2014 slog(st,LOG_SEC,"invalid MSG4");
2018 /* Setup packet: expected only in state SENTMSG4 */
2019 /* (may turn up in state RUN if our return MSG6 was lost
2020 and the new key has already been activated. In that
2021 case we discard it. The peer will realise that we
2022 are using the new key when they see our data packets.
2023 Until then the peer's data packets to us get discarded. */
2024 if (st->state==SITE_SENTMSG4) {
2025 if (process_msg5(st,buf,source,st->new_transform)) {
2026 transport_setup_msgok(st,source);
2027 enter_new_state(st,SITE_RUN,&msg);
2029 slog(st,LOG_SEC,"invalid MSG5");
2031 } else if (st->state==SITE_RUN) {
2032 if (process_msg5(st,buf,source,st->current.transform)) {
2033 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2034 transport_setup_msgok(st,source);
2035 create_msg6(st,st->current.transform,
2036 st->current.remote_session_id);
2037 transport_xmit(st,&st->peers,&st->buffer,True);
2038 BUF_FREE(&st->buffer);
2040 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2043 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2047 /* Setup packet: expected only in state SENTMSG5 */
2048 if (st->state!=SITE_SENTMSG5) {
2049 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2050 } else if (process_msg6(st,buf,source)) {
2051 BUF_FREE(&st->buffer); /* Free message 5 */
2052 transport_setup_msgok(st,source);
2053 activate_new_key(st);
2055 slog(st,LOG_SEC,"invalid MSG6");
2059 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2070 static void site_control(void *vst, bool_t run)
2072 struct site *st=vst;
2073 if (run) enter_state_run(st);
2074 else enter_state_stop(st);
2077 static void site_phase_hook(void *sst, uint32_t newphase)
2079 struct site *st=sst;
2081 /* The program is shutting down; tell our peer */
2082 send_msg7(st,"shutting down");
2085 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2087 struct site *st=sst;
2088 dispose_transform(&st->current.transform);
2089 dispose_transform(&st->auxiliary_key.transform);
2090 dispose_transform(&st->new_transform);
2091 /* Not much point overwiting the signing key, since we loaded it
2092 from disk, and it is only valid prospectively if at all,
2094 /* XXX it would be best to overwrite the DH state, because that
2095 _is_ relevant to forward secrecy. However we have no
2096 convenient interface for doing that and in practice gmp has
2097 probably dribbled droppings all over the malloc arena. A good
2098 way to fix this would be to have a privsep child for asymmetric
2099 crypto operations, but that's a task for another day. */
2102 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2105 static uint32_t index_sequence;
2113 st->cl.description="site";
2114 st->cl.type=CL_SITE;
2116 st->cl.interface=&st->ops;
2118 st->ops.control=site_control;
2119 st->ops.status=site_status;
2121 /* First parameter must be a dict */
2122 item=list_elem(args,0);
2123 if (!item || item->type!=t_dict)
2124 cfgfatal(loc,"site","parameter must be a dictionary\n");
2126 dict=item->data.dict;
2127 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2128 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2130 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2132 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2134 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2136 /* Sanity check (which also allows the 'sites' file to include
2137 site() closures for all sites including our own): refuse to
2138 talk to ourselves */
2139 if (strcmp(st->localname,st->remotename)==0) {
2140 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2142 if (st->peer_mobile != st->local_mobile)
2143 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2144 " but our local-mobile=%d\n",
2145 st->localname, st->peer_mobile, st->local_mobile);
2149 if (st->peer_mobile && st->local_mobile) {
2150 Message(M_WARNING,"site %s: site is mobile but so are we"
2151 " -> ignoring this site\n", st->remotename);
2156 assert(index_sequence < 0xffffffffUL);
2157 st->index = ++index_sequence;
2158 st->local_capabilities = 0;
2159 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2160 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2162 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2163 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2164 if (!things##_cfg) \
2165 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2166 st->nthings=list_length(things##_cfg); \
2167 NEW_ARY(st->things,st->nthings); \
2168 assert(st->nthings); \
2169 for (i=0; i<st->nthings; i++) { \
2170 item_t *item=list_elem(things##_cfg,i); \
2171 if (item->type!=t_closure) \
2172 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2173 closure_t *cl=item->data.closure; \
2174 if (cl->type!=CL_TYPE) \
2175 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2176 st->things[i]=cl->interface; \
2180 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2182 NEW_ARY(st->commclientinfos, st->ncomms);
2183 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2184 for (i=0; i<st->ncomms; i++) {
2185 st->commclientinfos[i] =
2187 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2190 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2191 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2192 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2194 st->privkey=find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2195 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2197 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2198 else st->remoteport=0;
2199 st->pubkey=find_cl_if(dict,"key",CL_SIGPUBKEY,True,"site",loc);
2201 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2203 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2205 if (st->privkey->sethash || st->pubkey->sethash) {
2206 struct hash_if *hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2207 if (st->privkey->sethash) st->privkey->sethash(st->privkey->st,hash);
2208 if (st->pubkey->sethash) st->pubkey->sethash(st->pubkey->st,hash);
2211 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2212 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2213 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2215 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2216 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2217 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2218 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2219 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2221 st->mobile_peer_expiry= dict_read_number(
2222 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2224 const char *peerskey= st->peer_mobile
2225 ? "mobile-peers-max" : "static-peers-max";
2226 st->transport_peers_max= dict_read_number(
2227 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2228 if (st->transport_peers_max<1 ||
2229 st->transport_peers_max>MAX_PEER_ADDRS) {
2230 cfgfatal(loc,"site", "%s must be in range 1.."
2231 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2234 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2235 st->key_renegotiate_time=st->key_lifetime/2;
2237 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2238 st->key_renegotiate_time=dict_read_number(
2239 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2240 if (st->key_renegotiate_time > st->key_lifetime) {
2241 cfgfatal(loc,"site",
2242 "renegotiate-time must be less than key-lifetime\n");
2245 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2246 log_event_table,"site");
2248 st->resolving_count=0;
2249 st->allow_send_prod=0;
2251 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2253 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2255 /* The information we expect to see in incoming messages of type 1 */
2256 /* fixme: lots of unchecked overflows here, but the results are only
2257 corrupted packets rather than undefined behaviour */
2258 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2260 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2262 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2263 BUF_ALLOC(&st->scratch,"site:scratch");
2265 /* We are interested in poll(), but only for timeouts. We don't have
2266 any fds of our own. */
2267 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2270 st->remote_capabilities=0;
2271 st->chosen_transform=0;
2272 st->current.key_timeout=0;
2273 st->auxiliary_key.key_timeout=0;
2274 transport_peers_clear(st,&st->peers);
2275 transport_peers_clear(st,&st->setup_peers);
2276 /* XXX mlock these */
2277 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2278 st->sharedsecretlen=st->sharedsecretallocd=0;
2281 #define SET_CAPBIT(bit) do { \
2282 uint32_t capflag = 1UL << (bit); \
2283 if (st->local_capabilities & capflag) \
2284 slog(st,LOG_ERROR,"capability bit" \
2285 " %d (%#"PRIx32") reused", (bit), capflag); \
2286 st->local_capabilities |= capflag; \
2289 for (i=0; i<st->ntransforms; i++)
2290 SET_CAPBIT(st->transforms[i]->capab_bit);
2294 if (st->local_mobile || st->peer_mobile)
2295 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2297 /* We need to register the remote networks with the netlink device */
2298 uint32_t netlink_mtu; /* local virtual interface mtu */
2299 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2300 if (!st->mtu_target)
2301 st->mtu_target=netlink_mtu;
2303 for (i=0; i<st->ncomms; i++)
2304 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2306 st->current.transform=0;
2307 st->auxiliary_key.transform=0;
2308 st->new_transform=0;
2309 st->auxiliary_is_new=0;
2311 enter_state_stop(st);
2313 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2314 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2316 return new_closure(&st->cl);
2319 void site_module(dict_t *dict)
2321 add_closure(dict,"site",site_apply);
2325 /***** TRANSPORT PEERS definitions *****/
2327 static void transport_peers_debug(struct site *st, transport_peers *dst,
2328 const char *didwhat,
2329 int nargs, const struct comm_addr *args,
2334 if (!(st->log_events & LOG_PEER_ADDRS))
2335 return; /* an optimisation */
2337 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2338 (dst==&st->peers ? "data" :
2339 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2340 didwhat, nargs, dst->npeers);
2342 for (i=0, argp=(void*)args;
2344 i++, (argp+=stride?stride:sizeof(*args))) {
2345 const struct comm_addr *ca=(void*)argp;
2346 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2347 i, comm_addr_to_string(ca));
2349 for (i=0; i<dst->npeers; i++) {
2350 struct timeval diff;
2351 timersub(tv_now,&dst->peers[i].last,&diff);
2352 const struct comm_addr *ca=&dst->peers[i].addr;
2353 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2354 i, comm_addr_to_string(ca),
2355 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2359 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2360 /* peers must be sorted first */
2361 int previous_peers=peers->npeers;
2362 struct timeval oldest;
2363 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2364 oldest.tv_usec = tv_now->tv_usec;
2365 while (peers->npeers>1 &&
2366 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2368 if (peers->npeers != previous_peers)
2369 transport_peers_debug(st,peers,"expire", 0,0,0);
2372 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2373 const struct comm_addr *ca,
2374 const struct timeval *tv) {
2375 /* returns false if output is full */
2378 if (peers->npeers >= st->transport_peers_max)
2381 for (search=0; search<peers->npeers; search++)
2382 if (comm_addr_equal(&peers->peers[search].addr, ca))
2385 peers->peers[peers->npeers].addr = *ca;
2386 peers->peers[peers->npeers].last = *tv;
2391 static void transport_record_peers(struct site *st, transport_peers *peers,
2392 const struct comm_addr *addrs, int naddrs,
2394 /* We add addrs into peers. The new entries end up at the front
2395 * and displace entries towards the end (perhaps even off the
2396 * end). Any existing matching entries are moved up to the front.
2398 * Caller must first call transport_peers_expire. */
2401 /* avoids debug for uninteresting updates */
2403 for (i=0; i<peers->npeers; i++) {
2404 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2405 memmove(peers->peers+1, peers->peers,
2406 sizeof(peers->peers[0]) * i);
2407 peers->peers[0].addr = addrs[0];
2408 peers->peers[0].last = *tv_now;
2414 int old_npeers=peers->npeers;
2415 transport_peer old_peers[old_npeers];
2416 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2420 for (i=0; i<naddrs; i++) {
2421 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2424 for (i=0; i<old_npeers; i++) {
2425 const transport_peer *old=&old_peers[i];
2426 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2430 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2433 static void transport_expire_record_peers(struct site *st,
2434 transport_peers *peers,
2435 const struct comm_addr *addrs,
2436 int naddrs, const char *m) {
2437 /* Convenience function */
2438 transport_peers_expire(st,peers);
2439 transport_record_peers(st,peers,addrs,naddrs,m);
2442 static bool_t transport_compute_setupinit_peers(struct site *st,
2443 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2444 int n_configured_addrs /* 0 if none or not found */,
2445 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2446 if (!n_configured_addrs && !incoming_packet_addr &&
2447 !transport_peers_valid(&st->peers))
2450 slog(st,LOG_SETUP_INIT,
2451 "using: %d configured addr(s);%s %d old peer addrs(es)",
2453 incoming_packet_addr ? " incoming packet address;" : "",
2456 /* Non-mobile peers try addresses until one is plausible. The
2457 * effect is that this code always tries first the configured
2458 * address if supplied, or otherwise the address of the incoming
2459 * PROD, or finally the existing data peer if one exists; this is
2462 transport_peers_copy(st,&st->setup_peers,&st->peers);
2463 transport_peers_expire(st,&st->setup_peers);
2465 if (incoming_packet_addr)
2466 transport_record_peers(st,&st->setup_peers,
2467 incoming_packet_addr,1, "incoming");
2469 if (n_configured_addrs)
2470 transport_record_peers(st,&st->setup_peers,
2471 configured_addrs,n_configured_addrs, "setupinit");
2473 assert(transport_peers_valid(&st->setup_peers));
2477 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2478 if (st->peer_mobile)
2479 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2481 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2482 if (st->peer_mobile)
2483 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2486 static int transport_peers_valid(transport_peers *peers) {
2487 return peers->npeers;
2489 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2491 transport_peers_debug(st,peers,"clear",0,0,0);
2493 static void transport_peers_copy(struct site *st, transport_peers *dst,
2494 const transport_peers *src) {
2495 dst->npeers=src->npeers;
2496 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2497 transport_peers_debug(st,dst,"copy",
2498 src->npeers, &src->peers->addr, sizeof(*src->peers));
2501 static void transport_resolve_complete(struct site *st,
2502 const struct comm_addr *addrs,
2504 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2506 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2510 static void transport_resolve_complete_tardy(struct site *st,
2511 const struct comm_addr *addrs,
2513 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2514 "resolved tardily");
2517 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2519 const transport_peers *inp) {
2520 /* out and in->peers may be the same region, or nonoverlapping */
2521 const transport_peer *in=inp->peers;
2523 for (slot=0; slot<inp->npeers; slot++) {
2524 if (!(mask & (1U << slot)))
2526 if (!(out==in && slot==*nout_io))
2527 COPY_OBJ(out[*nout_io], in[slot]);
2532 void transport_xmit(struct site *st, transport_peers *peers,
2533 struct buffer_if *buf, bool_t candebug) {
2535 transport_peers_expire(st, peers);
2536 unsigned failed=0; /* bitmask */
2537 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2540 for (slot=0; slot<peers->npeers; slot++) {
2541 transport_peer *peer=&peers->peers[slot];
2542 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2544 dump_packet(st, buf, &peer->addr, False, ok);
2546 failed |= 1U << slot;
2549 if (ok && !st->peer_mobile)
2552 /* Now we need to demote/delete failing addrs: if we are mobile we
2553 * merely demote them; otherwise we delete them. */
2554 if (st->local_mobile) {
2555 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2556 /* `expected' has all the failures at the end already */
2557 if (failed != expected) {
2559 transport_peer failedpeers[nfailed];
2560 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2561 assert(fslot == nfailed);
2563 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2564 assert(wslot+nfailed == peers->npeers);
2565 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2566 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2569 if (failed && peers->npeers > 1) {
2571 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2572 peers->npeers=wslot;
2573 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2578 /***** END of transport peers declarations *****/