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 void kex_init(struct site *st)
811 st->random->generate(st->random->st,NONCELEN,st->localN);
814 static bool_t generate_msg1(struct site *st, const struct msg *prompt_maybe_0)
817 return generate_msg(st,LABEL_MSG1,"site:MSG1",prompt_maybe_0);
820 static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
821 const struct comm_addr *src,
824 /* We've already determined we're in an appropriate state to
825 process an incoming MSG1, and that the MSG1 has correct values
828 st->setup_session_id=m->source;
829 st->remote_capabilities=m->remote_capabilities;
830 memcpy(st->remoteN,m->nR,NONCELEN);
834 static bool_t generate_msg2(struct site *st,
835 const struct msg *prompt_may_be_null)
838 return generate_msg(st,LABEL_MSG2,"site:MSG2",prompt_may_be_null);
841 static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
842 const struct comm_addr *src,
843 struct msg *m /* returned */)
847 if (!unpick_msg(st,LABEL_MSG2,msg2,m)) return False;
848 if (!check_msg(st,LABEL_MSG2,m,&err)) {
849 slog(st,LOG_SEC,"msg2: %s",err);
852 st->setup_session_id=m->source;
853 st->remote_capabilities=m->remote_capabilities;
855 /* Select the transform to use */
857 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
858 if (!remote_crypto_caps)
859 /* old secnets only had this one transform */
860 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
862 #define CHOOSE_CRYPTO(kind, whats) do { \
863 struct kind##_if *iface; \
864 uint32_t bit, ours = 0; \
866 for (i= 0; i < st->n##kind##s; i++) { \
867 iface=st->kind##s[i]; \
868 bit = 1UL << iface->capab_bit; \
869 if (bit & remote_crypto_caps) goto kind##_found; \
872 slog(st,LOG_ERROR,"no " whats " in common" \
873 " (us %#"PRIx32"; them: %#"PRIx32")", \
874 st->local_capabilities & ours, remote_crypto_caps); \
877 st->chosen_##kind = iface; \
880 CHOOSE_CRYPTO(transform, "transforms");
884 memcpy(st->remoteN,m->nR,NONCELEN);
888 static bool_t generate_msg3(struct site *st, const struct msg *prompt)
890 /* Now we have our nonce and their nonce. Think of a secret key,
891 and create message number 3. */
892 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
893 return generate_msg(st,
894 (st->remote_capabilities & CAPAB_TRANSFORM_MASK)
900 static bool_t process_msg3_msg4(struct site *st, struct msg *m)
902 /* Check signature and store g^x mod m */
903 if (!st->pubkey->check(st->pubkey->st,
904 m->hashstart,m->hashlen,
906 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
910 st->remote_adv_mtu=m->remote_mtu;
915 static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
916 const struct comm_addr *src, uint32_t msgtype,
917 struct msg *m /* returned */)
922 case CASES_MSG3_KNOWN: break;
926 if (!unpick_msg(st,msgtype,msg3,m)) return False;
927 if (!check_msg(st,msgtype,m,&err)) {
928 slog(st,LOG_SEC,"msg3: %s",err);
931 uint32_t capab_adv_late = m->remote_capabilities
932 & ~st->remote_capabilities & st->early_capabilities;
933 if (capab_adv_late) {
934 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
935 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
936 capab_adv_late, st->remote_capabilities, m->remote_capabilities);
940 #define CHOSE_CRYPTO(kind, what) do { \
941 struct kind##_if *iface; \
943 for (i=0; i<st->n##kind##s; i++) { \
944 iface=st->kind##s[i]; \
945 if (iface->capab_bit == m->capab_##kind##num) \
948 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
949 m->capab_##kind##num); \
952 st->chosen_##kind=iface; \
955 CHOSE_CRYPTO(transform, "transform");
959 if (!process_msg3_msg4(st,m))
962 /* Update our idea of the remote site's capabilities, now that we've
963 * verified that its message was authentic.
965 * Our previous idea of the remote site's capabilities came from the
966 * unauthenticated MSG1. We've already checked that this new message
967 * doesn't change any of the bits we relied upon in the past, but it may
968 * also have set additional capability bits. We simply throw those away
969 * now, and use the authentic capabilities from this MSG3. */
970 st->remote_capabilities=m->remote_capabilities;
972 /* Terminate their DH public key with a '0' */
974 /* Invent our DH secret key */
975 st->random->generate(st->random->st,st->dh->len,st->dhsecret);
977 /* Generate the shared key and set up the transform */
978 if (!set_new_transform(st,m->pk)) return False;
983 static bool_t generate_msg4(struct site *st, const struct msg *prompt)
985 /* We have both nonces, their public key and our private key. Generate
986 our public key, sign it and send it to them. */
987 return generate_msg(st,LABEL_MSG4,"site:MSG4",prompt);
990 static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
991 const struct comm_addr *src,
992 struct msg *m /* returned */)
996 if (!unpick_msg(st,LABEL_MSG4,msg4,m)) return False;
997 if (!check_msg(st,LABEL_MSG4,m,&err)) {
998 slog(st,LOG_SEC,"msg4: %s",err);
1002 if (!process_msg3_msg4(st,m))
1005 /* Terminate their DH public key with a '0' */
1008 /* Generate the shared key and set up the transform */
1009 if (!set_new_transform(st,m->pk)) return False;
1020 static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
1023 CHECK_AVAIL(msg0,4);
1024 m->dest=buf_unprepend_uint32(msg0);
1025 CHECK_AVAIL(msg0,4);
1026 m->source=buf_unprepend_uint32(msg0);
1027 CHECK_AVAIL(msg0,4);
1028 m->type=buf_unprepend_uint32(msg0);
1030 /* Leaves transformed part of buffer untouched */
1033 static bool_t generate_msg5(struct site *st, const struct msg *prompt)
1035 cstring_t transform_err;
1037 BUF_ALLOC(&st->buffer,"site:MSG5");
1038 /* We are going to add four words to the message */
1039 buffer_init(&st->buffer,calculate_max_start_pad());
1040 /* Give the netlink code an opportunity to put its own stuff in the
1041 message (configuration information, etc.) */
1042 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1043 if (call_transform_forwards(st,st->new_transform,
1044 &st->buffer,&transform_err))
1046 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
1047 buf_prepend_uint32(&st->buffer,st->index);
1048 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1050 st->retries=st->setup_retries;
1054 static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
1055 const struct comm_addr *src,
1056 struct transform_inst_if *transform)
1059 cstring_t transform_err;
1061 if (!unpick_msg0(st,msg5,&m)) return False;
1063 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
1064 /* There's a problem */
1065 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
1068 /* Buffer should now contain untransformed PING packet data */
1069 CHECK_AVAIL(msg5,4);
1070 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
1071 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
1074 /* Older versions of secnet used to write some config data here
1075 * which we ignore. So we don't CHECK_EMPTY */
1079 static void create_msg6(struct site *st, struct transform_inst_if *transform,
1080 uint32_t session_id)
1082 cstring_t transform_err;
1084 BUF_ALLOC(&st->buffer,"site:MSG6");
1085 /* We are going to add four words to the message */
1086 buffer_init(&st->buffer,calculate_max_start_pad());
1087 /* Give the netlink code an opportunity to put its own stuff in the
1088 message (configuration information, etc.) */
1089 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1090 transform_apply_return problem =
1091 call_transform_forwards(st,transform,
1092 &st->buffer,&transform_err);
1094 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
1095 buf_prepend_uint32(&st->buffer,st->index);
1096 buf_prepend_uint32(&st->buffer,session_id);
1099 static bool_t generate_msg6(struct site *st, const struct msg *prompt)
1101 if (!is_transform_valid(st->new_transform))
1103 create_msg6(st,st->new_transform,st->setup_session_id);
1104 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
1108 static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
1109 const struct comm_addr *src)
1112 cstring_t transform_err;
1114 if (!unpick_msg0(st,msg6,&m)) return False;
1116 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
1117 /* There's a problem */
1118 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
1121 /* Buffer should now contain untransformed PING packet data */
1122 CHECK_AVAIL(msg6,4);
1123 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1124 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
1127 /* Older versions of secnet used to write some config data here
1128 * which we ignore. So we don't CHECK_EMPTY */
1132 static transform_apply_return
1133 decrypt_msg0(struct site *st, struct buffer_if *msg0,
1134 const struct comm_addr *src)
1136 cstring_t transform_err, auxkey_err, newkey_err="n/a";
1138 transform_apply_return problem;
1140 if (!unpick_msg0(st,msg0,&m)) return False;
1142 /* Keep a copy so we can try decrypting it with multiple keys */
1143 buffer_copy(&st->scratch, msg0);
1145 problem = call_transform_reverse(st,st->current.transform,
1146 msg0,&transform_err);
1148 if (!st->auxiliary_is_new)
1149 delete_one_key(st,&st->auxiliary_key,
1150 "peer has used new key","auxiliary key",LOG_SEC);
1153 if (transform_apply_return_badseq(problem))
1156 buffer_copy(msg0, &st->scratch);
1157 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1160 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
1161 if (st->auxiliary_is_new) {
1162 /* We previously timed out in state SENTMSG5 but it turns
1163 * out that our peer did in fact get our MSG5 and is
1164 * using the new key. So we should switch to it too. */
1165 /* This is a bit like activate_new_key. */
1168 st->current=st->auxiliary_key;
1169 st->auxiliary_key=t;
1171 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1172 "previous key",LOG_SEC);
1173 st->auxiliary_is_new=0;
1174 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1178 if (transform_apply_return_badseq(problem))
1181 if (st->state==SITE_SENTMSG5) {
1182 buffer_copy(msg0, &st->scratch);
1183 problem = call_transform_reverse(st,st->new_transform,
1186 /* It looks like we didn't get the peer's MSG6 */
1187 /* This is like a cut-down enter_new_state(SITE_RUN) */
1188 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1189 BUF_FREE(&st->buffer);
1191 activate_new_key(st);
1192 return 0; /* do process the data in this packet */
1194 if (transform_apply_return_badseq(problem))
1198 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1199 transform_err,auxkey_err,newkey_err);
1200 initiate_key_setup(st,"incoming message would not decrypt",0);
1201 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
1206 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
1211 static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1212 const struct comm_addr *src)
1215 transform_apply_return problem;
1217 problem = decrypt_msg0(st,msg0,src);
1218 if (problem==transform_apply_seqdupe) {
1219 /* We recently received another copy of this packet, maybe due
1220 * to polypath. That's not a problem; indeed, for the
1221 * purposes of transport address management it is a success.
1222 * But we don't want to process the packet. */
1223 transport_data_msgok(st,src);
1229 CHECK_AVAIL(msg0,4);
1230 type=buf_unprepend_uint32(msg0);
1233 /* We must forget about the current session. */
1234 delete_keys(st,"request from peer",LOG_SEC);
1235 /* probably, the peer is shutting down, and this is going to fail,
1236 * but we need to be trying to bring the link up again */
1238 initiate_key_setup(st,"peer requested key teardown",0);
1241 /* Deliver to netlink layer */
1242 st->netlink->deliver(st->netlink->st,msg0);
1243 transport_data_msgok(st,src);
1244 /* See whether we should start negotiating a new key */
1245 if (st->now > st->renegotiate_key_time)
1246 initiate_key_setup(st,"incoming packet in renegotiation window",0);
1249 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1256 static void dump_packet(struct site *st, struct buffer_if *buf,
1257 const struct comm_addr *addr, bool_t incoming,
1260 uint32_t dest=get_uint32(buf->start);
1261 uint32_t source=get_uint32(buf->start+4);
1262 uint32_t msgtype=get_uint32(buf->start+8);
1264 if (st->log_events & LOG_DUMP)
1265 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
1266 st->tunname,incoming?"incoming":"outgoing",
1267 dest,source,msgtype,comm_addr_to_string(addr),
1271 static bool_t comm_addr_sendmsg(struct site *st,
1272 const struct comm_addr *dest,
1273 struct buffer_if *buf)
1276 struct comm_clientinfo *commclientinfo = 0;
1278 for (i=0; i < st->ncomms; i++) {
1279 if (st->comms[i] == dest->comm) {
1280 commclientinfo = st->commclientinfos[i];
1284 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
1287 static uint32_t site_status(void *st)
1292 static bool_t send_msg(struct site *st)
1294 if (st->retries>0) {
1295 transport_xmit(st, &st->setup_peers, &st->buffer, True);
1296 st->timeout=st->now+st->setup_retry_interval;
1299 } else if (st->state==SITE_SENTMSG5) {
1300 logtimeout(st,"timed out sending MSG5, stashing new key");
1301 /* We stash the key we have produced, in case it turns out that
1302 * our peer did see our MSG5 after all and starts using it. */
1303 /* This is a bit like some of activate_new_key */
1304 struct transform_inst_if *t;
1305 t=st->auxiliary_key.transform;
1306 st->auxiliary_key.transform=st->new_transform;
1307 st->new_transform=t;
1308 dispose_transform(&st->new_transform);
1310 st->auxiliary_is_new=1;
1311 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1312 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1313 st->auxiliary_key.remote_session_id=st->setup_session_id;
1315 enter_state_wait(st);
1318 logtimeout(st,"timed out sending key setup packet "
1319 "(in state %s)",state_name(st->state));
1320 enter_state_wait(st);
1325 static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
1326 int stored_naddrs, int all_naddrs,
1327 const char *address, const char *failwhy)
1329 struct site *st=sst;
1331 if (!stored_naddrs) {
1332 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1334 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1335 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1337 int space=st->transport_peers_max-st->resolving_n_results_stored;
1338 int n_tocopy=MIN(stored_naddrs,space);
1339 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1342 st->resolving_n_results_stored += n_tocopy;
1343 st->resolving_n_results_all += all_naddrs;
1346 decrement_resolving_count(st,1);
1349 static void decrement_resolving_count(struct site *st, int by)
1351 assert(st->resolving_count>0);
1352 st->resolving_count-=by;
1354 if (st->resolving_count)
1357 /* OK, we are done with them all. Handle combined results. */
1359 const struct comm_addr *addrs=st->resolving_results;
1360 int naddrs=st->resolving_n_results_stored;
1361 assert(naddrs<=st->transport_peers_max);
1364 if (naddrs != st->resolving_n_results_all) {
1365 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1366 " yielded too many results (%d > %d), some ignored",
1367 st->resolving_n_results_all, naddrs);
1369 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
1370 naddrs, iaddr_to_string(&addrs[0].ia));;
1373 switch (st->state) {
1375 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
1376 enter_new_state(st,SITE_SENTMSG1,0);
1378 /* Can't figure out who to try to to talk to */
1379 slog(st,LOG_SETUP_INIT,
1380 "key exchange failed: cannot find peer address");
1381 enter_state_run(st);
1384 case SITE_SENTMSG1: case SITE_SENTMSG2:
1385 case SITE_SENTMSG3: case SITE_SENTMSG4:
1388 /* We start using the address immediately for data too.
1389 * It's best to store it in st->peers now because we might
1390 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1391 * the new key (without updating the data peer addrs). */
1392 transport_resolve_complete(st,addrs,naddrs);
1393 } else if (st->local_mobile) {
1394 /* We can't let this rest because we may have a peer
1395 * address which will break in the future. */
1396 slog(st,LOG_SETUP_INIT,"resolution failed: "
1397 "abandoning key exchange");
1398 enter_state_wait(st);
1400 slog(st,LOG_SETUP_INIT,"resolution failed: "
1401 " continuing to use source address of peer's packets"
1402 " for key exchange and ultimately data");
1407 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1408 " updating peer address(es)");
1409 transport_resolve_complete_tardy(st,addrs,naddrs);
1410 } else if (st->local_mobile) {
1411 /* Not very good. We should queue (another) renegotiation
1412 * so that we can update the peer address. */
1413 st->key_renegotiate_time=st->now+wait_timeout(st);
1415 slog(st,LOG_SETUP_INIT,"resolution failed: "
1416 " continuing to use source address of peer's packets");
1426 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1427 const struct comm_addr *prod_hint)
1429 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
1430 if (st->state!=SITE_RUN) return False;
1431 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
1432 if (st->addresses) {
1433 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
1434 return enter_state_resolve(st);
1435 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
1436 return enter_new_state(st,SITE_SENTMSG1,0);
1438 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
1442 static void activate_new_key(struct site *st)
1444 struct transform_inst_if *t;
1446 /* We have three transform instances, which we swap between old,
1448 t=st->auxiliary_key.transform;
1449 st->auxiliary_key.transform=st->current.transform;
1450 st->current.transform=st->new_transform;
1451 st->new_transform=t;
1452 dispose_transform(&st->new_transform);
1455 st->auxiliary_is_new=0;
1456 st->auxiliary_key.key_timeout=st->current.key_timeout;
1457 st->current.key_timeout=st->now+st->key_lifetime;
1458 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
1459 transport_peers_copy(st,&st->peers,&st->setup_peers);
1460 st->current.remote_session_id=st->setup_session_id;
1462 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1463 * But their mtu be unspecified, in which case we just use ours. */
1464 uint32_t intersite_mtu=
1465 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1466 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1468 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1469 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1470 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
1471 enter_state_run(st);
1474 static void delete_one_key(struct site *st, struct data_key *key,
1475 cstring_t reason, cstring_t which, uint32_t loglevel)
1477 if (!is_transform_valid(key->transform)) return;
1478 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
1479 dispose_transform(&key->transform);
1483 static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
1485 if (current_valid(st)) {
1486 slog(st,loglevel,"session closed (%s)",reason);
1488 delete_one_key(st,&st->current,0,0,0);
1489 set_link_quality(st);
1491 delete_one_key(st,&st->auxiliary_key,0,0,0);
1494 static void state_assert(struct site *st, bool_t ok)
1496 if (!ok) fatal("site:state_assert");
1499 static void enter_state_stop(struct site *st)
1501 st->state=SITE_STOP;
1503 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
1504 dispose_transform(&st->new_transform);
1507 static void set_link_quality(struct site *st)
1510 if (current_valid(st))
1511 quality=LINK_QUALITY_UP;
1512 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1513 quality=LINK_QUALITY_DOWN;
1514 else if (st->addresses)
1515 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
1516 else if (transport_peers_valid(&st->peers))
1517 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1519 quality=LINK_QUALITY_DOWN;
1521 st->netlink->set_quality(st->netlink->st,quality);
1524 static void enter_state_run(struct site *st)
1526 slog(st,LOG_STATE,"entering state RUN%s",
1527 current_valid(st) ? " (keyed)" : " (unkeyed)");
1531 st->setup_session_id=0;
1532 transport_peers_clear(st,&st->setup_peers);
1533 FILLZERO(st->localN);
1534 FILLZERO(st->remoteN);
1535 dispose_transform(&st->new_transform);
1536 memset(st->dhsecret,0,st->dh->len);
1537 if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen);
1538 set_link_quality(st);
1540 if (st->keepalive && !current_valid(st))
1541 initiate_key_setup(st, "keepalive", 0);
1544 static bool_t ensure_resolving(struct site *st)
1546 /* Reentrancy hazard: may call site_resolve_callback and hence
1547 * enter_new_state, enter_state_* and generate_msg*. */
1548 if (st->resolving_count)
1551 assert(st->addresses);
1553 /* resolver->request might reentrantly call site_resolve_callback
1554 * which will decrement st->resolving, so we need to increment it
1555 * twice beforehand to prevent decrement from thinking we're
1556 * finished, and decrement it ourselves. Alternatively if
1557 * everything fails then there are no callbacks due and we simply
1558 * set it to 0 and return false.. */
1559 st->resolving_n_results_stored=0;
1560 st->resolving_n_results_all=0;
1561 st->resolving_count+=2;
1562 const char **addrp=st->addresses;
1563 const char *address;
1565 for (; (address=*addrp++); ) {
1566 bool_t ok = st->resolver->request(st->resolver->st,address,
1567 st->remoteport,st->comms[0],
1568 site_resolve_callback,st);
1570 st->resolving_count++;
1574 st->resolving_count=0;
1577 decrement_resolving_count(st,2);
1581 static bool_t enter_state_resolve(struct site *st)
1583 /* Reentrancy hazard! See ensure_resolving. */
1584 state_assert(st,st->state==SITE_RUN);
1585 slog(st,LOG_STATE,"entering state RESOLVE");
1586 st->state=SITE_RESOLVE;
1587 return ensure_resolving(st);
1590 static bool_t enter_new_state(struct site *st, uint32_t next,
1591 const struct msg *prompt
1592 /* may be 0 for SENTMSG1 */)
1594 bool_t (*gen)(struct site *st, const struct msg *prompt);
1597 slog(st,LOG_STATE,"entering state %s",state_name(next));
1600 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1602 st->msg1_crossed_logged = False;
1605 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1606 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1610 state_assert(st,st->state==SITE_SENTMSG1);
1611 BUF_FREE(&st->buffer);
1615 state_assert(st,st->state==SITE_SENTMSG2);
1616 BUF_FREE(&st->buffer);
1620 state_assert(st,st->state==SITE_SENTMSG3);
1621 BUF_FREE(&st->buffer);
1625 state_assert(st,st->state==SITE_SENTMSG4);
1626 BUF_FREE(&st->buffer);
1631 fatal("enter_new_state(%s): invalid new state",state_name(next));
1635 if (hacky_par_start_failnow()) return False;
1637 r= gen(st,prompt) && send_msg(st);
1640 st->setup_retries, st->setup_retry_interval,
1645 if (next==SITE_RUN) {
1646 BUF_FREE(&st->buffer); /* Never reused */
1647 st->timeout=0; /* Never retransmit */
1648 activate_new_key(st);
1652 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1653 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1654 in either state, and enter_state_wait() will
1656 enter_state_wait(st);
1660 /* msg7 tells our peer that we're about to forget our key */
1661 static bool_t send_msg7(struct site *st, cstring_t reason)
1663 cstring_t transform_err;
1665 if (current_valid(st) && st->buffer.free
1666 && transport_peers_valid(&st->peers)) {
1667 BUF_ALLOC(&st->buffer,"site:MSG7");
1668 buffer_init(&st->buffer,calculate_max_start_pad());
1669 buf_append_uint32(&st->buffer,LABEL_MSG7);
1670 buf_append_string(&st->buffer,reason);
1671 if (call_transform_forwards(st, st->current.transform,
1672 &st->buffer, &transform_err))
1674 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
1675 buf_prepend_uint32(&st->buffer,st->index);
1676 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
1677 transport_xmit(st,&st->peers,&st->buffer,True);
1678 BUF_FREE(&st->buffer);
1685 /* We go into this state if our peer becomes uncommunicative. Similar to
1686 the "stop" state, we forget all session keys for a while, before
1687 re-entering the "run" state. */
1688 static void enter_state_wait(struct site *st)
1690 slog(st,LOG_STATE,"entering state WAIT");
1691 st->timeout=st->now+wait_timeout(st);
1692 st->state=SITE_WAIT;
1693 set_link_quality(st);
1694 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1695 /* XXX Erase keys etc. */
1698 static void generate_prod(struct site *st, struct buffer_if *buf)
1701 buf_append_uint32(buf,0);
1702 buf_append_uint32(buf,0);
1703 buf_append_uint32(buf,LABEL_PROD);
1704 buf_append_string(buf,st->localname);
1705 buf_append_string(buf,st->remotename);
1708 static void generate_send_prod(struct site *st,
1709 const struct comm_addr *source)
1711 if (!st->allow_send_prod) return; /* too soon */
1712 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1713 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1715 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1716 st->allow_send_prod=0;
1717 generate_prod(st,&st->scratch);
1718 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
1719 dump_packet(st,&st->scratch,source,False,ok);
1722 static inline void site_settimeout(uint64_t timeout, int *timeout_io)
1725 int64_t offset=timeout-*now;
1726 if (offset<0) offset=0;
1727 if (offset>INT_MAX) offset=INT_MAX;
1728 if (*timeout_io<0 || offset<*timeout_io)
1733 static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
1736 struct site *st=sst;
1738 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
1741 /* Work out when our next timeout is. The earlier of 'timeout' or
1742 'current.key_timeout'. A stored value of '0' indicates no timeout
1744 site_settimeout(st->timeout, timeout_io);
1745 site_settimeout(st->current.key_timeout, timeout_io);
1746 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
1748 return 0; /* success */
1751 static void check_expiry(struct site *st, struct data_key *key,
1754 if (key->key_timeout && *now>key->key_timeout) {
1755 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1759 /* NB site_afterpoll will be called before site_beforepoll is ever called */
1760 static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
1762 struct site *st=sst;
1765 if (st->timeout && *now>st->timeout) {
1767 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1768 if (!hacky_par_start_failnow())
1770 } else if (st->state==SITE_WAIT) {
1771 enter_state_run(st);
1773 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1777 check_expiry(st,&st->current,"current key");
1778 check_expiry(st,&st->auxiliary_key,"auxiliary key");
1781 /* This function is called by the netlink device to deliver packets
1782 intended for the remote network. The packet is in "raw" wire
1783 format, but is guaranteed to be word-aligned. */
1784 static void site_outgoing(void *sst, struct buffer_if *buf)
1786 struct site *st=sst;
1787 cstring_t transform_err;
1789 if (st->state==SITE_STOP) {
1794 st->allow_send_prod=1;
1796 /* In all other states we consider delivering the packet if we have
1797 a valid key and a valid address to send it to. */
1798 if (current_valid(st) && transport_peers_valid(&st->peers)) {
1799 /* Transform it and send it */
1801 buf_prepend_uint32(buf,LABEL_MSG9);
1802 if (call_transform_forwards(st, st->current.transform,
1803 buf, &transform_err))
1805 buf_prepend_uint32(buf,LABEL_MSG0);
1806 buf_prepend_uint32(buf,st->index);
1807 buf_prepend_uint32(buf,st->current.remote_session_id);
1808 transport_xmit(st,&st->peers,buf,False);
1815 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
1817 initiate_key_setup(st,"outgoing packet",0);
1820 static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1821 uint32_t type, struct msg *m)
1822 /* For packets which are identified by the local and remote names.
1823 * If it has our name and our peer's name in it it's for us. */
1825 struct buffer_if buf[1];
1826 buffer_readonly_clone(buf,buf_in);
1827 return unpick_msg(st,type,buf,m)
1828 && name_matches(&m->remote,st->remotename)
1829 && name_matches(&m->local,st->localname);
1832 static bool_t we_have_priority(struct site *st, const struct msg *m) {
1833 if (st->local_capabilities & m->remote_capabilities &
1834 CAPAB_PRIORITY_MOBILE) {
1835 if (st->local_mobile) return True;
1836 if (st-> peer_mobile) return False;
1838 return st->our_name_later;
1841 static bool_t setup_late_msg_ok(struct site *st,
1842 const struct buffer_if *buf_in,
1844 const struct comm_addr *source,
1845 struct msg *m /* returned */) {
1846 /* For setup packets which seem from their type like they are
1847 * late. Maybe they came via a different path. All we do is make
1848 * a note of the sending address, iff they look like they are part
1849 * of the current key setup attempt. */
1850 if (!named_for_us(st,buf_in,msgtype,m))
1851 /* named_for_us calls unpick_msg which gets the nonces */
1853 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN) ||
1854 !consttime_memeq(m->nL,st->localN, NONCELEN))
1855 /* spoof ? from stale run ? who knows */
1857 transport_setup_msgok(st,source);
1861 /* This function is called by the communication device to deliver
1862 packets from our peers.
1863 It should return True if the packet is recognised as being for
1864 this current site instance (and should therefore not be processed
1865 by other sites), even if the packet was otherwise ignored. */
1866 static bool_t site_incoming(void *sst, struct buffer_if *buf,
1867 const struct comm_addr *source)
1869 struct site *st=sst;
1871 if (buf->size < 12) return False;
1873 uint32_t dest=get_uint32(buf->start);
1874 uint32_t msgtype=get_uint32(buf->start+8);
1876 /* initialised by named_for_us, or process_msgN for N!=1 */
1878 if (msgtype==LABEL_MSG1) {
1879 if (!named_for_us(st,buf,msgtype,&msg))
1881 /* It's a MSG1 addressed to us. Decide what to do about it. */
1882 dump_packet(st,buf,source,True,True);
1883 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1884 st->state==SITE_WAIT) {
1885 /* We should definitely process it */
1886 transport_compute_setupinit_peers(st,0,0,source);
1887 if (process_msg1(st,buf,source,&msg)) {
1888 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
1889 bool_t entered=enter_new_state(st,SITE_SENTMSG2,&msg);
1890 if (entered && st->addresses && st->local_mobile)
1891 /* We must do this as the very last thing, because
1892 the resolver callback might reenter us. */
1893 ensure_resolving(st);
1895 slog(st,LOG_ERROR,"failed to process incoming msg1");
1899 } else if (st->state==SITE_SENTMSG1) {
1900 /* We've just sent a message 1! They may have crossed on
1901 the wire. If we have priority then we ignore the
1902 incoming one, otherwise we process it as usual. */
1903 if (we_have_priority(st,&msg)) {
1905 if (!st->msg1_crossed_logged++)
1906 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
1907 "priority => ignore incoming msg1");
1910 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
1911 "priority => use incoming msg1");
1912 if (process_msg1(st,buf,source,&msg)) {
1913 BUF_FREE(&st->buffer); /* Free our old message 1 */
1914 transport_setup_msgok(st,source);
1915 enter_new_state(st,SITE_SENTMSG2,&msg);
1917 slog(st,LOG_ERROR,"failed to process an incoming "
1918 "crossed msg1 (we have low priority)");
1923 } else if (st->state==SITE_SENTMSG2 ||
1924 st->state==SITE_SENTMSG4) {
1925 if (consttime_memeq(msg.nR,st->remoteN,NONCELEN)) {
1926 /* We are ahead in the protocol, but that msg1 had the
1927 * peer's nonce so presumably it is from this key
1928 * exchange run, via a slower route */
1929 transport_setup_msgok(st,source);
1931 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
1936 /* The message 1 was received at an unexpected stage of the
1937 key setup. Well, they lost the race. */
1938 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1942 if (msgtype==LABEL_PROD) {
1943 if (!named_for_us(st,buf,msgtype,&msg))
1945 dump_packet(st,buf,source,True,True);
1946 if (st->state!=SITE_RUN) {
1947 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1948 } else if (current_valid(st)) {
1949 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1951 initiate_key_setup(st,"peer sent PROD packet",source);
1956 if (dest==st->index) {
1957 /* Explicitly addressed to us */
1958 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
1961 /* If the source is our current peer then initiate a key setup,
1962 because our peer's forgotten the key */
1963 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
1965 initiated = initiate_key_setup(st,"received a NAK",source);
1966 if (!initiated) generate_send_prod(st,source);
1968 slog(st,LOG_SEC,"bad incoming NAK");
1972 process_msg0(st,buf,source);
1975 /* Setup packet: should not have been explicitly addressed
1977 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
1980 /* Setup packet: expected only in state SENTMSG1 */
1981 if (st->state!=SITE_SENTMSG1) {
1982 if ((st->state==SITE_SENTMSG3 ||
1983 st->state==SITE_SENTMSG5) &&
1984 setup_late_msg_ok(st,buf,msgtype,source,&msg))
1986 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
1987 } else if (process_msg2(st,buf,source,&msg)) {
1988 transport_setup_msgok(st,source);
1989 enter_new_state(st,SITE_SENTMSG3,&msg);
1991 slog(st,LOG_SEC,"invalid MSG2");
1994 case CASES_MSG3_KNOWN:
1995 /* Setup packet: expected only in state SENTMSG2 */
1996 if (st->state!=SITE_SENTMSG2) {
1997 if ((st->state==SITE_SENTMSG4) &&
1998 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2000 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
2001 } else if (process_msg3(st,buf,source,msgtype,&msg)) {
2002 transport_setup_msgok(st,source);
2003 enter_new_state(st,SITE_SENTMSG4,&msg);
2005 slog(st,LOG_SEC,"invalid MSG3");
2009 /* Setup packet: expected only in state SENTMSG3 */
2010 if (st->state!=SITE_SENTMSG3) {
2011 if ((st->state==SITE_SENTMSG5) &&
2012 setup_late_msg_ok(st,buf,msgtype,source,&msg))
2014 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
2015 } else if (process_msg4(st,buf,source,&msg)) {
2016 transport_setup_msgok(st,source);
2017 enter_new_state(st,SITE_SENTMSG5,&msg);
2019 slog(st,LOG_SEC,"invalid MSG4");
2023 /* Setup packet: expected only in state SENTMSG4 */
2024 /* (may turn up in state RUN if our return MSG6 was lost
2025 and the new key has already been activated. In that
2026 case we discard it. The peer will realise that we
2027 are using the new key when they see our data packets.
2028 Until then the peer's data packets to us get discarded. */
2029 if (st->state==SITE_SENTMSG4) {
2030 if (process_msg5(st,buf,source,st->new_transform)) {
2031 transport_setup_msgok(st,source);
2032 enter_new_state(st,SITE_RUN,&msg);
2034 slog(st,LOG_SEC,"invalid MSG5");
2036 } else if (st->state==SITE_RUN) {
2037 if (process_msg5(st,buf,source,st->current.transform)) {
2038 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
2039 transport_setup_msgok(st,source);
2040 create_msg6(st,st->current.transform,
2041 st->current.remote_session_id);
2042 transport_xmit(st,&st->peers,&st->buffer,True);
2043 BUF_FREE(&st->buffer);
2045 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2048 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2052 /* Setup packet: expected only in state SENTMSG5 */
2053 if (st->state!=SITE_SENTMSG5) {
2054 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2055 } else if (process_msg6(st,buf,source)) {
2056 BUF_FREE(&st->buffer); /* Free message 5 */
2057 transport_setup_msgok(st,source);
2058 activate_new_key(st);
2060 slog(st,LOG_SEC,"invalid MSG6");
2064 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2075 static void site_control(void *vst, bool_t run)
2077 struct site *st=vst;
2078 if (run) enter_state_run(st);
2079 else enter_state_stop(st);
2082 static void site_phase_hook(void *sst, uint32_t newphase)
2084 struct site *st=sst;
2086 /* The program is shutting down; tell our peer */
2087 send_msg7(st,"shutting down");
2090 static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2092 struct site *st=sst;
2093 dispose_transform(&st->current.transform);
2094 dispose_transform(&st->auxiliary_key.transform);
2095 dispose_transform(&st->new_transform);
2096 /* Not much point overwiting the signing key, since we loaded it
2097 from disk, and it is only valid prospectively if at all,
2099 /* XXX it would be best to overwrite the DH state, because that
2100 _is_ relevant to forward secrecy. However we have no
2101 convenient interface for doing that and in practice gmp has
2102 probably dribbled droppings all over the malloc arena. A good
2103 way to fix this would be to have a privsep child for asymmetric
2104 crypto operations, but that's a task for another day. */
2107 static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2110 static uint32_t index_sequence;
2118 st->cl.description="site";
2119 st->cl.type=CL_SITE;
2121 st->cl.interface=&st->ops;
2123 st->ops.control=site_control;
2124 st->ops.status=site_status;
2126 /* First parameter must be a dict */
2127 item=list_elem(args,0);
2128 if (!item || item->type!=t_dict)
2129 cfgfatal(loc,"site","parameter must be a dictionary\n");
2131 dict=item->data.dict;
2132 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2133 st->remotename=dict_read_string(dict, "name", True, "site", loc);
2135 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2137 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
2139 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2141 /* Sanity check (which also allows the 'sites' file to include
2142 site() closures for all sites including our own): refuse to
2143 talk to ourselves */
2144 if (strcmp(st->localname,st->remotename)==0) {
2145 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
2147 if (st->peer_mobile != st->local_mobile)
2148 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2149 " but our local-mobile=%d\n",
2150 st->localname, st->peer_mobile, st->local_mobile);
2154 if (st->peer_mobile && st->local_mobile) {
2155 Message(M_WARNING,"site %s: site is mobile but so are we"
2156 " -> ignoring this site\n", st->remotename);
2161 assert(index_sequence < 0xffffffffUL);
2162 st->index = ++index_sequence;
2163 st->local_capabilities = 0;
2164 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
2165 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
2167 #define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2168 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2169 if (!things##_cfg) \
2170 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2171 st->nthings=list_length(things##_cfg); \
2172 NEW_ARY(st->things,st->nthings); \
2173 assert(st->nthings); \
2174 for (i=0; i<st->nthings; i++) { \
2175 item_t *item=list_elem(things##_cfg,i); \
2176 if (item->type!=t_closure) \
2177 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2178 closure_t *cl=item->data.closure; \
2179 if (cl->type!=CL_TYPE) \
2180 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2181 st->things[i]=cl->interface; \
2185 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
2187 NEW_ARY(st->commclientinfos, st->ncomms);
2188 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2189 for (i=0; i<st->ncomms; i++) {
2190 st->commclientinfos[i] =
2192 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2195 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2196 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2197 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2199 st->privkey=find_cl_if(dict,"local-key",CL_SIGPRIVKEY,True,"site",loc);
2200 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2202 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2203 else st->remoteport=0;
2204 st->pubkey=find_cl_if(dict,"key",CL_SIGPUBKEY,True,"site",loc);
2206 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2208 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2210 if (st->privkey->sethash || st->pubkey->sethash) {
2211 struct hash_if *hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2212 if (st->privkey->sethash) st->privkey->sethash(st->privkey->st,hash);
2213 if (st->pubkey->sethash) st->pubkey->sethash(st->pubkey->st,hash);
2216 #define DEFAULT(D) (st->peer_mobile || st->local_mobile \
2217 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
2218 #define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
2220 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2221 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2222 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
2223 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
2224 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
2226 st->mobile_peer_expiry= dict_read_number(
2227 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2229 const char *peerskey= st->peer_mobile
2230 ? "mobile-peers-max" : "static-peers-max";
2231 st->transport_peers_max= dict_read_number(
2232 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
2233 if (st->transport_peers_max<1 ||
2234 st->transport_peers_max>MAX_PEER_ADDRS) {
2235 cfgfatal(loc,"site", "%s must be in range 1.."
2236 STRING(MAX_PEER_ADDRS) "\n", peerskey);
2239 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
2240 st->key_renegotiate_time=st->key_lifetime/2;
2242 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
2243 st->key_renegotiate_time=dict_read_number(
2244 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
2245 if (st->key_renegotiate_time > st->key_lifetime) {
2246 cfgfatal(loc,"site",
2247 "renegotiate-time must be less than key-lifetime\n");
2250 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2251 log_event_table,"site");
2253 st->resolving_count=0;
2254 st->allow_send_prod=0;
2256 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2258 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2260 /* The information we expect to see in incoming messages of type 1 */
2261 /* fixme: lots of unchecked overflows here, but the results are only
2262 corrupted packets rather than undefined behaviour */
2263 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2265 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2267 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
2268 BUF_ALLOC(&st->scratch,"site:scratch");
2270 /* We are interested in poll(), but only for timeouts. We don't have
2271 any fds of our own. */
2272 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2275 st->remote_capabilities=0;
2276 st->chosen_transform=0;
2277 st->current.key_timeout=0;
2278 st->auxiliary_key.key_timeout=0;
2279 transport_peers_clear(st,&st->peers);
2280 transport_peers_clear(st,&st->setup_peers);
2281 /* XXX mlock these */
2282 st->dhsecret=safe_malloc(st->dh->len,"site:dhsecret");
2283 st->sharedsecretlen=st->sharedsecretallocd=0;
2286 #define SET_CAPBIT(bit) do { \
2287 uint32_t capflag = 1UL << (bit); \
2288 if (st->local_capabilities & capflag) \
2289 slog(st,LOG_ERROR,"capability bit" \
2290 " %d (%#"PRIx32") reused", (bit), capflag); \
2291 st->local_capabilities |= capflag; \
2294 for (i=0; i<st->ntransforms; i++)
2295 SET_CAPBIT(st->transforms[i]->capab_bit);
2299 if (st->local_mobile || st->peer_mobile)
2300 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2302 /* We need to register the remote networks with the netlink device */
2303 uint32_t netlink_mtu; /* local virtual interface mtu */
2304 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2305 if (!st->mtu_target)
2306 st->mtu_target=netlink_mtu;
2308 for (i=0; i<st->ncomms; i++)
2309 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2311 st->current.transform=0;
2312 st->auxiliary_key.transform=0;
2313 st->new_transform=0;
2314 st->auxiliary_is_new=0;
2316 enter_state_stop(st);
2318 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
2319 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
2321 return new_closure(&st->cl);
2324 void site_module(dict_t *dict)
2326 add_closure(dict,"site",site_apply);
2330 /***** TRANSPORT PEERS definitions *****/
2332 static void transport_peers_debug(struct site *st, transport_peers *dst,
2333 const char *didwhat,
2334 int nargs, const struct comm_addr *args,
2339 if (!(st->log_events & LOG_PEER_ADDRS))
2340 return; /* an optimisation */
2342 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2343 (dst==&st->peers ? "data" :
2344 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2345 didwhat, nargs, dst->npeers);
2347 for (i=0, argp=(void*)args;
2349 i++, (argp+=stride?stride:sizeof(*args))) {
2350 const struct comm_addr *ca=(void*)argp;
2351 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
2352 i, comm_addr_to_string(ca));
2354 for (i=0; i<dst->npeers; i++) {
2355 struct timeval diff;
2356 timersub(tv_now,&dst->peers[i].last,&diff);
2357 const struct comm_addr *ca=&dst->peers[i].addr;
2358 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
2359 i, comm_addr_to_string(ca),
2360 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2364 static void transport_peers_expire(struct site *st, transport_peers *peers) {
2365 /* peers must be sorted first */
2366 int previous_peers=peers->npeers;
2367 struct timeval oldest;
2368 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2369 oldest.tv_usec = tv_now->tv_usec;
2370 while (peers->npeers>1 &&
2371 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2373 if (peers->npeers != previous_peers)
2374 transport_peers_debug(st,peers,"expire", 0,0,0);
2377 static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2378 const struct comm_addr *ca,
2379 const struct timeval *tv) {
2380 /* returns false if output is full */
2383 if (peers->npeers >= st->transport_peers_max)
2386 for (search=0; search<peers->npeers; search++)
2387 if (comm_addr_equal(&peers->peers[search].addr, ca))
2390 peers->peers[peers->npeers].addr = *ca;
2391 peers->peers[peers->npeers].last = *tv;
2396 static void transport_record_peers(struct site *st, transport_peers *peers,
2397 const struct comm_addr *addrs, int naddrs,
2399 /* We add addrs into peers. The new entries end up at the front
2400 * and displace entries towards the end (perhaps even off the
2401 * end). Any existing matching entries are moved up to the front.
2403 * Caller must first call transport_peers_expire. */
2406 /* avoids debug for uninteresting updates */
2408 for (i=0; i<peers->npeers; i++) {
2409 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2410 memmove(peers->peers+1, peers->peers,
2411 sizeof(peers->peers[0]) * i);
2412 peers->peers[0].addr = addrs[0];
2413 peers->peers[0].last = *tv_now;
2419 int old_npeers=peers->npeers;
2420 transport_peer old_peers[old_npeers];
2421 COPY_ARRAY(old_peers,peers->peers,old_npeers);
2425 for (i=0; i<naddrs; i++) {
2426 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2429 for (i=0; i<old_npeers; i++) {
2430 const transport_peer *old=&old_peers[i];
2431 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2435 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2438 static void transport_expire_record_peers(struct site *st,
2439 transport_peers *peers,
2440 const struct comm_addr *addrs,
2441 int naddrs, const char *m) {
2442 /* Convenience function */
2443 transport_peers_expire(st,peers);
2444 transport_record_peers(st,peers,addrs,naddrs,m);
2447 static bool_t transport_compute_setupinit_peers(struct site *st,
2448 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2449 int n_configured_addrs /* 0 if none or not found */,
2450 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
2451 if (!n_configured_addrs && !incoming_packet_addr &&
2452 !transport_peers_valid(&st->peers))
2455 slog(st,LOG_SETUP_INIT,
2456 "using: %d configured addr(s);%s %d old peer addrs(es)",
2458 incoming_packet_addr ? " incoming packet address;" : "",
2461 /* Non-mobile peers try addresses until one is plausible. The
2462 * effect is that this code always tries first the configured
2463 * address if supplied, or otherwise the address of the incoming
2464 * PROD, or finally the existing data peer if one exists; this is
2467 transport_peers_copy(st,&st->setup_peers,&st->peers);
2468 transport_peers_expire(st,&st->setup_peers);
2470 if (incoming_packet_addr)
2471 transport_record_peers(st,&st->setup_peers,
2472 incoming_packet_addr,1, "incoming");
2474 if (n_configured_addrs)
2475 transport_record_peers(st,&st->setup_peers,
2476 configured_addrs,n_configured_addrs, "setupinit");
2478 assert(transport_peers_valid(&st->setup_peers));
2482 static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2483 if (st->peer_mobile)
2484 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
2486 static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2487 if (st->peer_mobile)
2488 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
2491 static int transport_peers_valid(transport_peers *peers) {
2492 return peers->npeers;
2494 static void transport_peers_clear(struct site *st, transport_peers *peers) {
2496 transport_peers_debug(st,peers,"clear",0,0,0);
2498 static void transport_peers_copy(struct site *st, transport_peers *dst,
2499 const transport_peers *src) {
2500 dst->npeers=src->npeers;
2501 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
2502 transport_peers_debug(st,dst,"copy",
2503 src->npeers, &src->peers->addr, sizeof(*src->peers));
2506 static void transport_resolve_complete(struct site *st,
2507 const struct comm_addr *addrs,
2509 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2511 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2515 static void transport_resolve_complete_tardy(struct site *st,
2516 const struct comm_addr *addrs,
2518 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2519 "resolved tardily");
2522 static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2524 const transport_peers *inp) {
2525 /* out and in->peers may be the same region, or nonoverlapping */
2526 const transport_peer *in=inp->peers;
2528 for (slot=0; slot<inp->npeers; slot++) {
2529 if (!(mask & (1U << slot)))
2531 if (!(out==in && slot==*nout_io))
2532 COPY_OBJ(out[*nout_io], in[slot]);
2537 void transport_xmit(struct site *st, transport_peers *peers,
2538 struct buffer_if *buf, bool_t candebug) {
2540 transport_peers_expire(st, peers);
2541 unsigned failed=0; /* bitmask */
2542 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
2545 for (slot=0; slot<peers->npeers; slot++) {
2546 transport_peer *peer=&peers->peers[slot];
2547 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
2549 dump_packet(st, buf, &peer->addr, False, ok);
2551 failed |= 1U << slot;
2554 if (ok && !st->peer_mobile)
2557 /* Now we need to demote/delete failing addrs: if we are mobile we
2558 * merely demote them; otherwise we delete them. */
2559 if (st->local_mobile) {
2560 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2561 /* `expected' has all the failures at the end already */
2562 if (failed != expected) {
2564 transport_peer failedpeers[nfailed];
2565 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2566 assert(fslot == nfailed);
2568 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2569 assert(wslot+nfailed == peers->npeers);
2570 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
2571 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
2574 if (failed && peers->npeers > 1) {
2576 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2577 peers->npeers=wslot;
2578 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
2583 /***** END of transport peers declarations *****/