site.c: Pass the length of the actual shared secret to the transform.
[secnet] / site.c
CommitLineData
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1/* site.c - manage communication with a remote network site */
2
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3/*
4 * This file is part of secnet.
5 * See README for full list of copyright holders.
6 *
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
9c6a8729 9 * the Free Software Foundation; either version 3 of the License, or
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10 * (at your option) any later version.
11 *
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.
16 *
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.
20 */
21
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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). */
30
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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. */
34
8689b3a9 35#include "secnet.h"
2fe58dfd 36#include <stdio.h>
469fd1d9 37#include <string.h>
fe5e9cc4 38#include <limits.h>
58650a70 39#include <assert.h>
8689b3a9 40#include <sys/socket.h>
2fe58dfd 41
8689b3a9 42#include <sys/mman.h>
2fe58dfd 43#include "util.h"
59635212 44#include "unaligned.h"
ff05a229 45#include "magic.h"
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46
47#define SETUP_BUFFER_LEN 2048
48
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49#define DEFAULT_KEY_LIFETIME (3600*1000) /* [ms] */
50#define DEFAULT_KEY_RENEGOTIATE_GAP (5*60*1000) /* [ms] */
2fe58dfd 51#define DEFAULT_SETUP_RETRIES 5
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52#define DEFAULT_SETUP_RETRY_INTERVAL (2*1000) /* [ms] */
53#define DEFAULT_WAIT_TIME (20*1000) /* [ms] */
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54
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] */
60
446353cd 61#define DEFAULT_MOBILE_PEER_EXPIRY (2*60) /* [s] */
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62
63/* Each site can be in one of several possible states. */
64
65/* 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
80 SITE_SENTMSG1
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
84 SITE_SENTMSG2
85 -> SITE_SENTMSG4 upon valid incoming message 3
86 -> SITE_WAIT on timeout
87 SITE_SENTMSG3
88 -> SITE_SENTMSG5 upon valid incoming message 4
89 -> SITE_WAIT on timeout
90 SITE_SENTMSG4
91 -> SITE_RUN upon valid incoming message 5
92 -> SITE_WAIT on timeout
93 SITE_SENTMSG5
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
98 */
99
100#define SITE_STOP 0
101#define SITE_RUN 1
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
108#define SITE_WAIT 8
109
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110int32_t site_max_start_pad = 4*4;
111
fe5e9cc4 112static cstring_t state_name(uint32_t state)
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113{
114 switch (state) {
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115 case 0: return "STOP";
116 case 1: return "RUN";
117 case 2: return "RESOLVE";
118 case 3: return "SENTMSG1";
119 case 4: return "SENTMSG2";
120 case 5: return "SENTMSG3";
121 case 6: return "SENTMSG4";
122 case 7: return "SENTMSG5";
123 case 8: return "WAIT";
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124 default: return "*bad state*";
125 }
126}
127
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128#define NONCELEN 8
129
130#define LOG_UNEXPECTED 0x00000001
131#define LOG_SETUP_INIT 0x00000002
132#define LOG_SETUP_TIMEOUT 0x00000004
133#define LOG_ACTIVATE_KEY 0x00000008
134#define LOG_TIMEOUT_KEY 0x00000010
9d3a4132 135#define LOG_SEC 0x00000020
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136#define LOG_STATE 0x00000040
137#define LOG_DROP 0x00000080
138#define LOG_DUMP 0x00000100
139#define LOG_ERROR 0x00000400
446353cd 140#define LOG_PEER_ADDRS 0x00000800
2fe58dfd 141
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142static struct flagstr log_event_table[]={
143 { "unexpected", LOG_UNEXPECTED },
144 { "setup-init", LOG_SETUP_INIT },
145 { "setup-timeout", LOG_SETUP_TIMEOUT },
146 { "activate-key", LOG_ACTIVATE_KEY },
147 { "timeout-key", LOG_TIMEOUT_KEY },
148 { "security", LOG_SEC },
149 { "state-change", LOG_STATE },
150 { "packet-drop", LOG_DROP },
151 { "dump-packets", LOG_DUMP },
152 { "errors", LOG_ERROR },
446353cd 153 { "peer-addrs", LOG_PEER_ADDRS },
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154 { "default", LOG_SETUP_INIT|LOG_SETUP_TIMEOUT|
155 LOG_ACTIVATE_KEY|LOG_TIMEOUT_KEY|LOG_SEC|LOG_ERROR },
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156 { "all", 0xffffffff },
157 { NULL, 0 }
158};
159
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160
161/***** TRANSPORT PEERS declarations *****/
162
163/* Details of "mobile peer" semantics:
f6eff504 164
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165 - We use the same data structure for the different configurations,
166 but manage it with different algorithms.
446353cd 167
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168 - We record up to mobile_peers_max peer address/port numbers
169 ("peers") for key setup, and separately up to mobile_peers_max
170 for data transfer.
171
172 - In general, we make a new set of addrs (see below) when we start
173 a new key exchange; the key setup addrs become the data transport
174 addrs when key setup complets.
175
176 If our peer is mobile:
177
178 - We send to all recent addresses of incoming packets, plus
179 initially all configured addresses (which we also expire).
180
181 - So, we record addrs of good incoming packets, as follows:
182 1. expire any peers last seen >120s ("mobile-peer-expiry") ago
183 2. add the peer of the just received packet to the applicable list
184 (possibly evicting the oldest entries to make room)
185 NB that we do not expire peers until an incoming packet arrives.
446353cd 186
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187 - If the peer has a configured address or name, we record them the
188 same way, but only as a result of our own initiation of key
189 setup. (We might evict some incoming packet addrs to make room.)
446353cd 190
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191 - The default number of addrs to keep is 3, or 4 if we have a
192 configured name or address. That's space for two configured
193 addresses (one IPv6 and one IPv4), plus two received addresses.
194
195 - Outgoing packets are sent to every recorded address in the
196 applicable list. Any unsupported[1] addresses are deleted from
197 the list right away. (This should only happen to configured
198 addresses, of course, but there is no need to check that.)
199
200 - When we successfully complete a key setup, we merge the key setup
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201 peers into the data transfer peers.
202
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203 [1] An unsupported address is one for whose AF we don't have a
204 socket (perhaps because we got EAFNOSUPPORT or some such) or for
205 which sendto gives ENETUNREACH.
206
207 If neither end is mobile:
208
209 - When peer initiated the key exchange, we use the incoming packet
210 address.
211
212 - When we initiate the key exchange, we try configured addresses
213 until we get one which isn't unsupported then fixate on that.
214
215 - When we complete a key setup, we replace the data transport peers
216 with those from the key setup.
446353cd 217
f6eff504 218 If we are mobile:
446353cd 219
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220 - We can't tell when local network setup changes so we can't cache
221 the unsupported addrs and completely remove the spurious calls to
222 sendto, but we can optimise things a bit by deprioritising addrs
223 which seem to be unsupported.
446353cd 224
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225 - Use only configured addresses. (Except, that if our peer
226 initiated a key exchange we use the incoming packet address until
227 our name resolution completes.)
446353cd 228
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229 - When we send a packet, try each address in turn; if addr
230 supported, put that address to the end of the list for future
231 packets, and go onto the next address.
446353cd 232
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233 - When we complete a key setup, we replace the data transport peers
234 with those from the key setup.
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235
236 */
237
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238typedef struct {
239 struct timeval last;
240 struct comm_addr addr;
241} transport_peer;
242
243typedef struct {
244/* configuration information */
245/* runtime information */
246 int npeers;
0f27325c 247 transport_peer peers[MAX_PEER_ADDRS];
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248} transport_peers;
249
8b21a212 250/* Basic operations on transport peer address sets */
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251static void transport_peers_clear(struct site *st, transport_peers *peers);
252static int transport_peers_valid(transport_peers *peers);
253static void transport_peers_copy(struct site *st, transport_peers *dst,
254 const transport_peers *src);
255
8b21a212 256/* Record address of incoming setup packet; resp. data packet. */
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257static void transport_setup_msgok(struct site *st, const struct comm_addr *a);
258static void transport_data_msgok(struct site *st, const struct comm_addr *a);
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259
260/* Initialise the setup addresses. Called before we send the first
261 * packet in a key exchange. If we are the initiator, as a result of
262 * resolve completing (or being determined not to be relevant) or an
263 * incoming PROD; if we are the responder, as a result of the MSG1. */
446353cd 264static bool_t transport_compute_setupinit_peers(struct site *st,
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265 const struct comm_addr *configured_addrs /* 0 if none or not found */,
266 int n_configured_addrs /* 0 if none or not found */,
a96fda35 267 const struct comm_addr *incoming_packet_addr /* 0 if none */);
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268
269/* Called if we are the responder in a key setup, when the resolve
270 * completes. transport_compute_setupinit_peers will hvae been called
271 * earlier. If _complete is called, we are still doing the key setup
272 * (and we should use the new values for both the rest of the key
273 * setup and the ongoing data exchange); if _tardy is called, the key
274 * setup is done (either completed or not) and only the data peers are
275 * relevant */
90d7e3ad 276static void transport_resolve_complete(struct site *st,
45a14422 277 const struct comm_addr *addrs, int naddrs);
90d7e3ad 278static void transport_resolve_complete_tardy(struct site *st,
45a14422 279 const struct comm_addr *addrs, int naddrs);
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280
281static void transport_xmit(struct site *st, transport_peers *peers,
282 struct buffer_if *buf, bool_t candebug);
283
284 /***** END of transport peers declarations *****/
285
286
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287struct data_key {
288 struct transform_inst_if *transform;
289 uint64_t key_timeout; /* End of life of current key */
290 uint32_t remote_session_id;
291};
292
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293struct site {
294 closure_t cl;
295 struct site_if ops;
296/* configuration information */
297 string_t localname;
298 string_t remotename;
e6d6991c 299 bool_t keepalive;
0391d9ee 300 bool_t local_mobile, peer_mobile; /* Mobile client support */
446353cd 301 int32_t transport_peers_max;
ff05a229 302 string_t tunname; /* localname<->remotename by default, used in logs */
83dbdd3f 303 cstring_t *addresses; /* DNS name or address(es) for bootstrapping, optional */
ff05a229 304 int remoteport; /* Port for bootstrapping, optional */
3ed1846a 305 uint32_t mtu_target;
2fe58dfd 306 struct netlink_if *netlink;
59533c16 307 struct comm_if **comms;
5dfe538b 308 struct comm_clientinfo **commclientinfos;
59533c16 309 int ncomms;
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310 struct resolver_if *resolver;
311 struct log_if *log;
312 struct random_if *random;
313 struct rsaprivkey_if *privkey;
2fe58dfd 314 struct rsapubkey_if *pubkey;
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315 struct transform_if **transforms;
316 int ntransforms;
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317 struct dh_if *dh;
318 struct hash_if *hash;
2fe58dfd 319
58650a70 320 uint32_t index; /* Index of this site */
5d903efd 321 uint32_t early_capabilities;
09a385fb 322 uint32_t local_capabilities;
1caa23ff 323 int32_t setup_retries; /* How many times to send setup packets */
e7f8ec2a 324 int32_t setup_retry_interval; /* Initial timeout for setup packets */
f7a86234 325 int32_t wait_timeout_mean; /* How long to wait if setup unsuccessful */
446353cd 326 int32_t mobile_peer_expiry; /* How long to remember 2ary addresses */
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327 int32_t key_lifetime; /* How long a key lasts once set up */
328 int32_t key_renegotiate_time; /* If we see traffic (or a keepalive)
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329 after this time, initiate a new
330 key exchange */
2fe58dfd 331
ffafab08 332 bool_t our_name_later; /* our name > peer name */
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333 uint32_t log_events;
334
335/* runtime information */
336 uint32_t state;
337 uint64_t now; /* Most recently seen time */
dd9209d1 338 bool_t allow_send_prod;
8b978d45 339 bool_t msg1_crossed_logged;
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340 int resolving_count;
341 int resolving_n_results_all;
342 int resolving_n_results_stored;
343 struct comm_addr resolving_results[MAX_PEER_ADDRS];
2fe58dfd 344
ff05a229 345 /* The currently established session */
19e9a588 346 struct data_key current;
02b0959b 347 struct data_key auxiliary_key;
bd98cd6b 348 bool_t auxiliary_is_new;
ff05a229 349 uint64_t renegotiate_key_time; /* When we can negotiate a new key */
bd98cd6b 350 uint64_t auxiliary_renegotiate_key_time;
446353cd 351 transport_peers peers; /* Current address(es) of peer for data traffic */
2fe58dfd 352
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353 /* The current key setup protocol exchange. We can only be
354 involved in one of these at a time. There's a potential for
355 denial of service here (the attacker keeps sending a setup
356 packet; we keep trying to continue the exchange, and have to
357 timeout before we can listen for another setup packet); perhaps
358 we should keep a list of 'bad' sources for setup packets. */
09a385fb 359 uint32_t remote_capabilities;
3ed1846a 360 uint16_t remote_adv_mtu;
5b5f297f 361 struct transform_if *chosen_transform;
2fe58dfd 362 uint32_t setup_session_id;
446353cd 363 transport_peers setup_peers;
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364 uint8_t localN[NONCELEN]; /* Nonces for key exchange */
365 uint8_t remoteN[NONCELEN];
366 struct buffer_if buffer; /* Current outgoing key exchange packet */
05f39b4d 367 struct buffer_if scratch;
4a8aed08 368 int32_t retries; /* Number of retries remaining */
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369 uint64_t timeout; /* Timeout for current state */
370 uint8_t *dhsecret;
371 uint8_t *sharedsecret;
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372 struct transform_inst_if *new_transform; /* For key setup/verify */
373};
374
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375static uint32_t event_log_priority(struct site *st, uint32_t event)
376{
377 if (!(event&st->log_events))
378 return 0;
379 switch(event) {
380 case LOG_UNEXPECTED: return M_INFO;
381 case LOG_SETUP_INIT: return M_INFO;
382 case LOG_SETUP_TIMEOUT: return M_NOTICE;
383 case LOG_ACTIVATE_KEY: return M_INFO;
384 case LOG_TIMEOUT_KEY: return M_INFO;
385 case LOG_SEC: return M_SECURITY;
386 case LOG_STATE: return M_DEBUG;
387 case LOG_DROP: return M_DEBUG;
388 case LOG_DUMP: return M_DEBUG;
389 case LOG_ERROR: return M_ERR;
390 case LOG_PEER_ADDRS: return M_DEBUG;
391 default: return M_ERR;
392 }
393}
394
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395static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
396FORMAT(printf,3,0);
397static void vslog(struct site *st, uint32_t event, cstring_t msg, va_list ap)
2fe58dfd 398{
b2a56f7c 399 uint32_t class;
2fe58dfd 400
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401 class=event_log_priority(st, event);
402 if (class) {
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403 slilog_part(st->log,class,"%s: ",st->tunname);
404 vslilog_part(st->log,class,msg,ap);
405 slilog_part(st->log,class,"\n");
2fe58dfd 406 }
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407}
408
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409static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
410FORMAT(printf,3,4);
411static void slog(struct site *st, uint32_t event, cstring_t msg, ...)
412{
413 va_list ap;
414 va_start(ap,msg);
415 vslog(st,event,msg,ap);
416 va_end(ap);
417}
418
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419static void logtimeout(struct site *st, const char *fmt, ...)
420FORMAT(printf,2,3);
421static void logtimeout(struct site *st, const char *fmt, ...)
422{
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423 uint32_t class=event_log_priority(st,LOG_SETUP_TIMEOUT);
424 if (!class)
425 return;
426
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427 va_list ap;
428 va_start(ap,fmt);
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429
430 slilog_part(st->log,class,"%s: ",st->tunname);
431 vslilog_part(st->log,class,fmt,ap);
432
433 const char *delim;
434 int i;
435 for (i=0, delim=" (tried ";
436 i<st->setup_peers.npeers;
437 i++, delim=", ") {
438 transport_peer *peer=&st->setup_peers.peers[i];
439 const char *s=comm_addr_to_string(&peer->addr);
440 slilog_part(st->log,class,"%s%s",delim,s);
441 }
442
443 slilog_part(st->log,class,")\n");
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444 va_end(ap);
445}
446
9d3a4132 447static void set_link_quality(struct site *st);
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448static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel);
449static void delete_one_key(struct site *st, struct data_key *key,
450 const char *reason /* may be 0 meaning don't log*/,
451 const char *which /* ignored if !reasonn */,
452 uint32_t loglevel /* ignored if !reasonn */);
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453static bool_t initiate_key_setup(struct site *st, cstring_t reason,
454 const struct comm_addr *prod_hint);
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455static void enter_state_run(struct site *st);
456static bool_t enter_state_resolve(struct site *st);
83dbdd3f 457static void decrement_resolving_count(struct site *st, int by);
ff05a229 458static bool_t enter_new_state(struct site *st,uint32_t next);
2fe58dfd 459static void enter_state_wait(struct site *st);
05f39b4d 460static void activate_new_key(struct site *st);
2fe58dfd 461
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462static bool_t is_transform_valid(struct transform_inst_if *transform)
463{
fcad4b0b 464 return transform && transform->valid(transform->st);
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465}
466
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467static bool_t current_valid(struct site *st)
468{
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469 return is_transform_valid(st->current.transform);
470}
471
472#define DEFINE_CALL_TRANSFORM(fwdrev) \
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473static transform_apply_return \
474call_transform_##fwdrev(struct site *st, \
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475 struct transform_inst_if *transform, \
476 struct buffer_if *buf, \
477 const char **errmsg) \
478{ \
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479 if (!is_transform_valid(transform)) { \
480 *errmsg="transform not set up"; \
14f78812 481 return transform_apply_err; \
fcad4b0b 482 } \
0afd257e 483 return transform->fwdrev(transform->st,buf,errmsg); \
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484}
485
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486DEFINE_CALL_TRANSFORM(forwards)
487DEFINE_CALL_TRANSFORM(reverse)
488
489static void dispose_transform(struct transform_inst_if **transform_var)
490{
0afd257e 491 struct transform_inst_if *transform=*transform_var;
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492 if (transform) {
493 transform->delkey(transform->st);
494 transform->destroy(transform->st);
495 }
496 *transform_var = 0;
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497}
498
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499#define CHECK_AVAIL(b,l) do { if ((b)->size<(l)) return False; } while(0)
500#define CHECK_EMPTY(b) do { if ((b)->size!=0) return False; } while(0)
501#define CHECK_TYPE(b,t) do { uint32_t type; \
502 CHECK_AVAIL((b),4); \
59635212 503 type=buf_unprepend_uint32((b)); \
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504 if (type!=(t)) return False; } while(0)
505
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506static _Bool type_is_msg34(uint32_t type)
507{
508 return
509 type == LABEL_MSG3 ||
510 type == LABEL_MSG3BIS ||
511 type == LABEL_MSG4;
512}
513
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514struct parsedname {
515 int32_t len;
516 uint8_t *name;
09a385fb 517 struct buffer_if extrainfo;
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518};
519
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520struct msg {
521 uint8_t *hashstart;
522 uint32_t dest;
523 uint32_t source;
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524 struct parsedname remote;
525 struct parsedname local;
09a385fb 526 uint32_t remote_capabilities;
3ed1846a 527 uint16_t remote_mtu;
5b5f297f 528 int capab_transformnum;
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529 uint8_t *nR;
530 uint8_t *nL;
1caa23ff 531 int32_t pklen;
3e8addad 532 char *pk;
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533 int32_t hashlen;
534 int32_t siglen;
3e8addad 535 char *sig;
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536};
537
f7a86234 538static int32_t wait_timeout(struct site *st) {
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539 int32_t t = st->wait_timeout_mean;
540 int8_t factor;
541 if (t < INT_MAX/2) {
542 st->random->generate(st->random->st,sizeof(factor),&factor);
543 t += (t / 256) * factor;
544 }
545 return t;
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546}
547
6f0c71c5 548static _Bool set_new_transform(struct site *st, char *pk)
0afd257e 549{
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550 _Bool ok;
551
5b5f297f 552 /* Generate the shared key */
5f679c36 553 if (!st->dh->makeshared(st->dh->st,st->dhsecret,st->dh->secret_len,
3f488f14 554 pk, st->sharedsecret,st->dh->shared_len))
29c2f818 555 return False;
5b5f297f
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556
557 /* Set up the transform */
558 struct transform_if *generator=st->chosen_transform;
fcad4b0b 559 struct transform_inst_if *generated=generator->create(generator->st);
6f0c71c5 560 ok = generated->setkey(generated->st,st->sharedsecret,
3f488f14 561 st->dh->shared_len,st->our_name_later);
6f0c71c5 562
fcad4b0b 563 dispose_transform(&st->new_transform);
6f0c71c5 564 if (!ok) return False;
fcad4b0b 565 st->new_transform=generated;
5b5f297f
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566
567 slog(st,LOG_SETUP_INIT,"key exchange negotiated transform"
568 " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")",
92cc0bca 569 st->chosen_transform->capab_bit,
5b5f297f 570 st->local_capabilities, st->remote_capabilities);
6f0c71c5 571 return True;
0afd257e
IJ
572}
573
09a385fb
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574struct xinfoadd {
575 int32_t lenpos, afternul;
576};
577static void append_string_xinfo_start(struct buffer_if *buf,
578 struct xinfoadd *xia,
579 const char *str)
580 /* Helps construct one of the names with additional info as found
581 * in MSG1..4. Call this function first, then append all the
582 * desired extra info (not including the nul byte) to the buffer,
583 * then call append_string_xinfo_done. */
584{
585 xia->lenpos = buf->size;
586 buf_append_string(buf,str);
587 buf_append_uint8(buf,0);
588 xia->afternul = buf->size;
589}
590static void append_string_xinfo_done(struct buffer_if *buf,
591 struct xinfoadd *xia)
592{
593 /* we just need to adjust the string length */
594 if (buf->size == xia->afternul) {
595 /* no extra info, strip the nul too */
596 buf_unappend_uint8(buf);
597 } else {
598 put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
599 }
600}
601
ff05a229
SE
602/* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
603 out using a transform of config data supplied by netlink */
fe5e9cc4 604static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what)
2fe58dfd
SE
605{
606 void *hst;
3b83c932 607 uint8_t *hash;
2fe58dfd
SE
608 string_t dhpub, sig;
609
610 st->retries=st->setup_retries;
611 BUF_ALLOC(&st->buffer,what);
612 buffer_init(&st->buffer,0);
59635212
SE
613 buf_append_uint32(&st->buffer,
614 (type==LABEL_MSG1?0:st->setup_session_id));
58650a70 615 buf_append_uint32(&st->buffer,st->index);
59635212 616 buf_append_uint32(&st->buffer,type);
09a385fb
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617
618 struct xinfoadd xia;
619 append_string_xinfo_start(&st->buffer,&xia,st->localname);
5d903efd
MW
620 if ((st->local_capabilities & st->early_capabilities) ||
621 (type != LABEL_MSG1)) {
09a385fb
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622 buf_append_uint32(&st->buffer,st->local_capabilities);
623 }
3ed1846a
IJ
624 if (type_is_msg34(type)) {
625 buf_append_uint16(&st->buffer,st->mtu_target);
626 }
09a385fb
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627 append_string_xinfo_done(&st->buffer,&xia);
628
2fe58dfd 629 buf_append_string(&st->buffer,st->remotename);
4f28e77e 630 BUF_ADD_OBJ(append,&st->buffer,st->localN);
2fe58dfd 631 if (type==LABEL_MSG1) return True;
4f28e77e 632 BUF_ADD_OBJ(append,&st->buffer,st->remoteN);
2fe58dfd 633 if (type==LABEL_MSG2) return True;
3b83c932
SE
634
635 if (hacky_par_mid_failnow()) return False;
636
5b5f297f 637 if (type==LABEL_MSG3BIS)
92cc0bca 638 buf_append_uint8(&st->buffer,st->chosen_transform->capab_bit);
5b5f297f 639
5f679c36 640 dhpub=st->dh->makepublic(st->dh->st,st->dhsecret,st->dh->secret_len);
2fe58dfd
SE
641 buf_append_string(&st->buffer,dhpub);
642 free(dhpub);
3b83c932 643 hash=safe_malloc(st->hash->len, "generate_msg");
2fe58dfd
SE
644 hst=st->hash->init();
645 st->hash->update(hst,st->buffer.start,st->buffer.size);
646 st->hash->final(hst,hash);
647 sig=st->privkey->sign(st->privkey->st,hash,st->hash->len);
648 buf_append_string(&st->buffer,sig);
649 free(sig);
3b83c932 650 free(hash);
2fe58dfd
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651 return True;
652}
653
1737eeef
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654static bool_t unpick_name(struct buffer_if *msg, struct parsedname *nm)
655{
656 CHECK_AVAIL(msg,2);
657 nm->len=buf_unprepend_uint16(msg);
658 CHECK_AVAIL(msg,nm->len);
659 nm->name=buf_unprepend(msg,nm->len);
660 uint8_t *nul=memchr(nm->name,0,nm->len);
661 if (!nul) {
09a385fb 662 buffer_readonly_view(&nm->extrainfo,0,0);
1737eeef 663 } else {
09a385fb 664 buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
1737eeef
IJ
665 nm->len=nul-nm->name;
666 }
667 return True;
668}
669
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670static bool_t unpick_msg(struct site *st, uint32_t type,
671 struct buffer_if *msg, struct msg *m)
672{
5b5f297f 673 m->capab_transformnum=-1;
2fe58dfd
SE
674 m->hashstart=msg->start;
675 CHECK_AVAIL(msg,4);
59635212 676 m->dest=buf_unprepend_uint32(msg);
2fe58dfd 677 CHECK_AVAIL(msg,4);
59635212 678 m->source=buf_unprepend_uint32(msg);
2fe58dfd 679 CHECK_TYPE(msg,type);
1737eeef 680 if (!unpick_name(msg,&m->remote)) return False;
09a385fb 681 m->remote_capabilities=0;
3ed1846a 682 m->remote_mtu=0;
09a385fb
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683 if (m->remote.extrainfo.size) {
684 CHECK_AVAIL(&m->remote.extrainfo,4);
685 m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
686 }
3ed1846a
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687 if (type_is_msg34(type) && m->remote.extrainfo.size) {
688 CHECK_AVAIL(&m->remote.extrainfo,2);
689 m->remote_mtu=buf_unprepend_uint16(&m->remote.extrainfo);
690 }
1737eeef 691 if (!unpick_name(msg,&m->local)) return False;
dd9209d1
IJ
692 if (type==LABEL_PROD) {
693 CHECK_EMPTY(msg);
694 return True;
695 }
2fe58dfd
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696 CHECK_AVAIL(msg,NONCELEN);
697 m->nR=buf_unprepend(msg,NONCELEN);
698 if (type==LABEL_MSG1) {
699 CHECK_EMPTY(msg);
700 return True;
701 }
702 CHECK_AVAIL(msg,NONCELEN);
703 m->nL=buf_unprepend(msg,NONCELEN);
704 if (type==LABEL_MSG2) {
705 CHECK_EMPTY(msg);
706 return True;
707 }
5b5f297f
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708 if (type==LABEL_MSG3BIS) {
709 CHECK_AVAIL(msg,1);
710 m->capab_transformnum = buf_unprepend_uint8(msg);
711 } else {
92cc0bca 712 m->capab_transformnum = CAPAB_BIT_ANCIENTTRANSFORM;
5b5f297f 713 }
2fe58dfd 714 CHECK_AVAIL(msg,2);
59635212 715 m->pklen=buf_unprepend_uint16(msg);
2fe58dfd
SE
716 CHECK_AVAIL(msg,m->pklen);
717 m->pk=buf_unprepend(msg,m->pklen);
718 m->hashlen=msg->start-m->hashstart;
719 CHECK_AVAIL(msg,2);
59635212 720 m->siglen=buf_unprepend_uint16(msg);
2fe58dfd
SE
721 CHECK_AVAIL(msg,m->siglen);
722 m->sig=buf_unprepend(msg,m->siglen);
723 CHECK_EMPTY(msg);
534fb389
MW
724
725 /* In `process_msg3_msg4' below, we assume that we can write a nul
726 * terminator following the signature. Make sure there's enough space.
727 */
728 if (msg->start >= msg->base + msg->alloclen)
729 return False;
730
2fe58dfd
SE
731 return True;
732}
733
1737eeef
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734static bool_t name_matches(const struct parsedname *nm, const char *expected)
735{
736 int expected_len=strlen(expected);
737 return
738 nm->len == expected_len &&
739 !memcmp(nm->name, expected, expected_len);
740}
741
ff05a229 742static bool_t check_msg(struct site *st, uint32_t type, struct msg *m,
fe5e9cc4 743 cstring_t *error)
ff05a229
SE
744{
745 if (type==LABEL_MSG1) return True;
746
747 /* Check that the site names and our nonce have been sent
748 back correctly, and then store our peer's nonce. */
1737eeef 749 if (!name_matches(&m->remote,st->remotename)) {
ff05a229
SE
750 *error="wrong remote site name";
751 return False;
752 }
1737eeef 753 if (!name_matches(&m->local,st->localname)) {
ff05a229
SE
754 *error="wrong local site name";
755 return False;
756 }
757 if (memcmp(m->nL,st->localN,NONCELEN)!=0) {
758 *error="wrong locally-generated nonce";
759 return False;
760 }
761 if (type==LABEL_MSG2) return True;
30ba82a5 762 if (!consttime_memeq(m->nR,st->remoteN,NONCELEN)) {
ff05a229
SE
763 *error="wrong remotely-generated nonce";
764 return False;
765 }
09a385fb
IJ
766 /* MSG3 has complicated rules about capabilities, which are
767 * handled in process_msg3. */
5b5f297f 768 if (type==LABEL_MSG3 || type==LABEL_MSG3BIS) return True;
09a385fb
IJ
769 if (m->remote_capabilities!=st->remote_capabilities) {
770 *error="remote capabilities changed";
771 return False;
772 }
ff05a229
SE
773 if (type==LABEL_MSG4) return True;
774 *error="unknown message type";
775 return False;
776}
777
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778static bool_t generate_msg1(struct site *st)
779{
780 st->random->generate(st->random->st,NONCELEN,st->localN);
781 return generate_msg(st,LABEL_MSG1,"site:MSG1");
782}
783
784static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
7e29719e 785 const struct comm_addr *src, struct msg *m)
2fe58dfd 786{
2fe58dfd
SE
787 /* We've already determined we're in an appropriate state to
788 process an incoming MSG1, and that the MSG1 has correct values
789 of A and B. */
790
7e29719e 791 st->setup_session_id=m->source;
09a385fb 792 st->remote_capabilities=m->remote_capabilities;
7e29719e 793 memcpy(st->remoteN,m->nR,NONCELEN);
2fe58dfd
SE
794 return True;
795}
796
797static bool_t generate_msg2(struct site *st)
798{
799 st->random->generate(st->random->st,NONCELEN,st->localN);
800 return generate_msg(st,LABEL_MSG2,"site:MSG2");
801}
802
803static bool_t process_msg2(struct site *st, struct buffer_if *msg2,
a15faeb2 804 const struct comm_addr *src)
2fe58dfd
SE
805{
806 struct msg m;
fe5e9cc4 807 cstring_t err;
2fe58dfd
SE
808
809 if (!unpick_msg(st,LABEL_MSG2,msg2,&m)) return False;
ff05a229
SE
810 if (!check_msg(st,LABEL_MSG2,&m,&err)) {
811 slog(st,LOG_SEC,"msg2: %s",err);
2fe58dfd
SE
812 return False;
813 }
814 st->setup_session_id=m.source;
09a385fb 815 st->remote_capabilities=m.remote_capabilities;
5b5f297f
IJ
816
817 /* Select the transform to use */
818
10b7d092
MW
819 uint32_t remote_crypto_caps = st->remote_capabilities & CAPAB_TRANSFORM_MASK;
820 if (!remote_crypto_caps)
5b5f297f 821 /* old secnets only had this one transform */
10b7d092 822 remote_crypto_caps = 1UL << CAPAB_BIT_ANCIENTTRANSFORM;
5b5f297f 823
8bb8c22a
MW
824#define CHOOSE_CRYPTO(kind, whats) do { \
825 struct kind##_if *iface; \
826 uint32_t bit, ours = 0; \
827 int i; \
828 for (i= 0; i < st->n##kind##s; i++) { \
829 iface=st->kind##s[i]; \
830 bit = 1UL << iface->capab_bit; \
831 if (bit & remote_crypto_caps) goto kind##_found; \
832 ours |= bit; \
833 } \
834 slog(st,LOG_ERROR,"no " whats " in common" \
835 " (us %#"PRIx32"; them: %#"PRIx32")", \
836 st->local_capabilities & ours, remote_crypto_caps); \
837 return False; \
838kind##_found: \
839 st->chosen_##kind = iface; \
840} while (0)
841
842 CHOOSE_CRYPTO(transform, "transforms");
843
844#undef CHOOSE_CRYPTO
5b5f297f 845
2fe58dfd
SE
846 memcpy(st->remoteN,m.nR,NONCELEN);
847 return True;
848}
849
850static bool_t generate_msg3(struct site *st)
851{
852 /* Now we have our nonce and their nonce. Think of a secret key,
853 and create message number 3. */
5f679c36 854 st->random->generate(st->random->st,st->dh->secret_len,st->dhsecret);
5b5f297f
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855 return generate_msg(st,
856 (st->remote_capabilities & CAPAB_TRANSFORM_MASK
857 ? LABEL_MSG3BIS : LABEL_MSG3),
858 "site:MSG3");
2fe58dfd
SE
859}
860
e001e8c0
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861static bool_t process_msg3_msg4(struct site *st, struct msg *m)
862{
863 uint8_t *hash;
864 void *hst;
865
866 /* Check signature and store g^x mod m */
867 hash=safe_malloc(st->hash->len, "process_msg3_msg4");
868 hst=st->hash->init();
869 st->hash->update(hst,m->hashstart,m->hashlen);
870 st->hash->final(hst,hash);
534fb389 871 /* Terminate signature with a '0' - already checked that this will fit */
e001e8c0
IJ
872 m->sig[m->siglen]=0;
873 if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m->sig)) {
874 slog(st,LOG_SEC,"msg3/msg4 signature failed check!");
875 free(hash);
876 return False;
877 }
878 free(hash);
879
3ed1846a
IJ
880 st->remote_adv_mtu=m->remote_mtu;
881
e001e8c0
IJ
882 return True;
883}
884
2fe58dfd 885static bool_t process_msg3(struct site *st, struct buffer_if *msg3,
5b5f297f 886 const struct comm_addr *src, uint32_t msgtype)
2fe58dfd
SE
887{
888 struct msg m;
fe5e9cc4 889 cstring_t err;
2fe58dfd 890
5b5f297f
IJ
891 assert(msgtype==LABEL_MSG3 || msgtype==LABEL_MSG3BIS);
892
893 if (!unpick_msg(st,msgtype,msg3,&m)) return False;
894 if (!check_msg(st,msgtype,&m,&err)) {
ff05a229 895 slog(st,LOG_SEC,"msg3: %s",err);
2fe58dfd
SE
896 return False;
897 }
09a385fb 898 uint32_t capab_adv_late = m.remote_capabilities
5d903efd 899 & ~st->remote_capabilities & st->early_capabilities;
09a385fb
IJ
900 if (capab_adv_late) {
901 slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
902 " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
903 capab_adv_late, st->remote_capabilities, m.remote_capabilities);
904 return False;
905 }
906 st->remote_capabilities|=m.remote_capabilities;
ff05a229 907
8bb8c22a
MW
908#define CHOSE_CRYPTO(kind, what) do { \
909 struct kind##_if *iface; \
910 int i; \
911 for (i=0; i<st->n##kind##s; i++) { \
912 iface=st->kind##s[i]; \
913 if (iface->capab_bit == m.capab_##kind##num) \
914 goto kind##_found; \
915 } \
916 slog(st,LOG_SEC,"peer chose unknown-to-us " what " %d!", \
917 m.capab_##kind##num); \
918 return False; \
919kind##_found: \
920 st->chosen_##kind=iface; \
921} while (0)
922
923 CHOSE_CRYPTO(transform, "transform");
924
925#undef CHOSE_CRYPTO
5b5f297f 926
e001e8c0 927 if (!process_msg3_msg4(st,&m))
2fe58dfd 928 return False;
2fe58dfd
SE
929
930 /* Terminate their DH public key with a '0' */
931 m.pk[m.pklen]=0;
932 /* Invent our DH secret key */
5f679c36 933 st->random->generate(st->random->st,st->dh->secret_len,st->dhsecret);
2fe58dfd 934
5b5f297f 935 /* Generate the shared key and set up the transform */
6f0c71c5 936 if (!set_new_transform(st,m.pk)) return False;
2fe58dfd
SE
937
938 return True;
939}
940
941static bool_t generate_msg4(struct site *st)
942{
943 /* We have both nonces, their public key and our private key. Generate
944 our public key, sign it and send it to them. */
945 return generate_msg(st,LABEL_MSG4,"site:MSG4");
946}
947
948static bool_t process_msg4(struct site *st, struct buffer_if *msg4,
a15faeb2 949 const struct comm_addr *src)
2fe58dfd
SE
950{
951 struct msg m;
fe5e9cc4 952 cstring_t err;
2fe58dfd
SE
953
954 if (!unpick_msg(st,LABEL_MSG4,msg4,&m)) return False;
ff05a229
SE
955 if (!check_msg(st,LABEL_MSG4,&m,&err)) {
956 slog(st,LOG_SEC,"msg4: %s",err);
2fe58dfd
SE
957 return False;
958 }
959
e001e8c0 960 if (!process_msg3_msg4(st,&m))
2fe58dfd 961 return False;
2fe58dfd
SE
962
963 /* Terminate their DH public key with a '0' */
964 m.pk[m.pklen]=0;
5b5f297f
IJ
965
966 /* Generate the shared key and set up the transform */
6f0c71c5 967 if (!set_new_transform(st,m.pk)) return False;
2fe58dfd
SE
968
969 return True;
970}
971
2fe58dfd
SE
972struct msg0 {
973 uint32_t dest;
974 uint32_t source;
975 uint32_t type;
976};
977
978static bool_t unpick_msg0(struct site *st, struct buffer_if *msg0,
979 struct msg0 *m)
980{
981 CHECK_AVAIL(msg0,4);
59635212 982 m->dest=buf_unprepend_uint32(msg0);
2fe58dfd 983 CHECK_AVAIL(msg0,4);
59635212 984 m->source=buf_unprepend_uint32(msg0);
2fe58dfd 985 CHECK_AVAIL(msg0,4);
59635212 986 m->type=buf_unprepend_uint32(msg0);
2fe58dfd
SE
987 return True;
988 /* Leaves transformed part of buffer untouched */
989}
990
ff05a229
SE
991static bool_t generate_msg5(struct site *st)
992{
fe5e9cc4 993 cstring_t transform_err;
ff05a229
SE
994
995 BUF_ALLOC(&st->buffer,"site:MSG5");
996 /* We are going to add four words to the message */
3abd18e8 997 buffer_init(&st->buffer,calculate_max_start_pad());
ff05a229
SE
998 /* Give the netlink code an opportunity to put its own stuff in the
999 message (configuration information, etc.) */
ff05a229 1000 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
0afd257e
IJ
1001 if (call_transform_forwards(st,st->new_transform,
1002 &st->buffer,&transform_err))
1003 return False;
ff05a229 1004 buf_prepend_uint32(&st->buffer,LABEL_MSG5);
58650a70 1005 buf_prepend_uint32(&st->buffer,st->index);
ff05a229
SE
1006 buf_prepend_uint32(&st->buffer,st->setup_session_id);
1007
1008 st->retries=st->setup_retries;
1009 return True;
1010}
1011
2fe58dfd 1012static bool_t process_msg5(struct site *st, struct buffer_if *msg5,
c90cc2a7
IJ
1013 const struct comm_addr *src,
1014 struct transform_inst_if *transform)
2fe58dfd
SE
1015{
1016 struct msg0 m;
fe5e9cc4 1017 cstring_t transform_err;
2fe58dfd
SE
1018
1019 if (!unpick_msg0(st,msg5,&m)) return False;
1020
0afd257e 1021 if (call_transform_reverse(st,transform,msg5,&transform_err)) {
2fe58dfd 1022 /* There's a problem */
59635212 1023 slog(st,LOG_SEC,"process_msg5: transform: %s",transform_err);
2fe58dfd
SE
1024 return False;
1025 }
1026 /* Buffer should now contain untransformed PING packet data */
1027 CHECK_AVAIL(msg5,4);
59635212 1028 if (buf_unprepend_uint32(msg5)!=LABEL_MSG5) {
ff05a229 1029 slog(st,LOG_SEC,"MSG5/PING packet contained wrong label");
2fe58dfd
SE
1030 return False;
1031 }
ff7cdc9e
IJ
1032 /* Older versions of secnet used to write some config data here
1033 * which we ignore. So we don't CHECK_EMPTY */
2fe58dfd
SE
1034 return True;
1035}
1036
c90cc2a7
IJ
1037static void create_msg6(struct site *st, struct transform_inst_if *transform,
1038 uint32_t session_id)
2fe58dfd 1039{
fe5e9cc4 1040 cstring_t transform_err;
2fe58dfd
SE
1041
1042 BUF_ALLOC(&st->buffer,"site:MSG6");
ff05a229 1043 /* We are going to add four words to the message */
3abd18e8 1044 buffer_init(&st->buffer,calculate_max_start_pad());
794f2398
SE
1045 /* Give the netlink code an opportunity to put its own stuff in the
1046 message (configuration information, etc.) */
ff05a229 1047 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
14f78812
IJ
1048 transform_apply_return problem =
1049 call_transform_forwards(st,transform,
1050 &st->buffer,&transform_err);
0afd257e 1051 assert(!problem);
59635212 1052 buf_prepend_uint32(&st->buffer,LABEL_MSG6);
58650a70 1053 buf_prepend_uint32(&st->buffer,st->index);
c90cc2a7
IJ
1054 buf_prepend_uint32(&st->buffer,session_id);
1055}
2fe58dfd 1056
c90cc2a7
IJ
1057static bool_t generate_msg6(struct site *st)
1058{
0afd257e
IJ
1059 if (!is_transform_valid(st->new_transform))
1060 return False;
c90cc2a7 1061 create_msg6(st,st->new_transform,st->setup_session_id);
ff05a229 1062 st->retries=1; /* Peer will retransmit MSG5 if this packet gets lost */
2fe58dfd
SE
1063 return True;
1064}
1065
1066static bool_t process_msg6(struct site *st, struct buffer_if *msg6,
a15faeb2 1067 const struct comm_addr *src)
2fe58dfd
SE
1068{
1069 struct msg0 m;
fe5e9cc4 1070 cstring_t transform_err;
2fe58dfd
SE
1071
1072 if (!unpick_msg0(st,msg6,&m)) return False;
1073
0afd257e 1074 if (call_transform_reverse(st,st->new_transform,msg6,&transform_err)) {
2fe58dfd 1075 /* There's a problem */
59635212 1076 slog(st,LOG_SEC,"process_msg6: transform: %s",transform_err);
2fe58dfd
SE
1077 return False;
1078 }
1079 /* Buffer should now contain untransformed PING packet data */
1080 CHECK_AVAIL(msg6,4);
59635212
SE
1081 if (buf_unprepend_uint32(msg6)!=LABEL_MSG6) {
1082 slog(st,LOG_SEC,"MSG6/PONG packet contained invalid data");
2fe58dfd
SE
1083 return False;
1084 }
ff7cdc9e
IJ
1085 /* Older versions of secnet used to write some config data here
1086 * which we ignore. So we don't CHECK_EMPTY */
2fe58dfd
SE
1087 return True;
1088}
1089
3cdb830c
IJ
1090static transform_apply_return
1091decrypt_msg0(struct site *st, struct buffer_if *msg0,
48b97423 1092 const struct comm_addr *src)
2fe58dfd 1093{
02b0959b 1094 cstring_t transform_err, auxkey_err, newkey_err="n/a";
065e1922 1095 struct msg0 m;
14f78812 1096 transform_apply_return problem;
2fe58dfd 1097
2fe58dfd
SE
1098 if (!unpick_msg0(st,msg0,&m)) return False;
1099
05f39b4d
IJ
1100 /* Keep a copy so we can try decrypting it with multiple keys */
1101 buffer_copy(&st->scratch, msg0);
1102
0afd257e
IJ
1103 problem = call_transform_reverse(st,st->current.transform,
1104 msg0,&transform_err);
02b0959b 1105 if (!problem) {
bd98cd6b
IJ
1106 if (!st->auxiliary_is_new)
1107 delete_one_key(st,&st->auxiliary_key,
1108 "peer has used new key","auxiliary key",LOG_SEC);
3cdb830c 1109 return 0;
02b0959b 1110 }
31dd0788
IJ
1111 if (transform_apply_return_badseq(problem))
1112 goto badseq;
07e4774c 1113
02b0959b 1114 buffer_copy(msg0, &st->scratch);
fcad4b0b
IJ
1115 problem = call_transform_reverse(st,st->auxiliary_key.transform,
1116 msg0,&auxkey_err);
14f78812 1117 if (!problem) {
02b0959b 1118 slog(st,LOG_DROP,"processing packet which uses auxiliary key");
bd98cd6b
IJ
1119 if (st->auxiliary_is_new) {
1120 /* We previously timed out in state SENTMSG5 but it turns
1121 * out that our peer did in fact get our MSG5 and is
1122 * using the new key. So we should switch to it too. */
1123 /* This is a bit like activate_new_key. */
1124 struct data_key t;
1125 t=st->current;
1126 st->current=st->auxiliary_key;
1127 st->auxiliary_key=t;
1128
1129 delete_one_key(st,&st->auxiliary_key,"peer has used new key",
1130 "previous key",LOG_SEC);
1131 st->auxiliary_is_new=0;
1132 st->renegotiate_key_time=st->auxiliary_renegotiate_key_time;
1133 }
3cdb830c 1134 return 0;
02b0959b 1135 }
31dd0788
IJ
1136 if (transform_apply_return_badseq(problem))
1137 goto badseq;
02b0959b 1138
05f39b4d
IJ
1139 if (st->state==SITE_SENTMSG5) {
1140 buffer_copy(msg0, &st->scratch);
0afd257e
IJ
1141 problem = call_transform_reverse(st,st->new_transform,
1142 msg0,&newkey_err);
48b97423 1143 if (!problem) {
05f39b4d
IJ
1144 /* It looks like we didn't get the peer's MSG6 */
1145 /* This is like a cut-down enter_new_state(SITE_RUN) */
1146 slog(st,LOG_STATE,"will enter state RUN (MSG0 with new key)");
1147 BUF_FREE(&st->buffer);
1148 st->timeout=0;
1149 activate_new_key(st);
3cdb830c 1150 return 0; /* do process the data in this packet */
05f39b4d 1151 }
31dd0788
IJ
1152 if (transform_apply_return_badseq(problem))
1153 goto badseq;
05f39b4d
IJ
1154 }
1155
02b0959b
IJ
1156 slog(st,LOG_SEC,"transform: %s (aux: %s, new: %s)",
1157 transform_err,auxkey_err,newkey_err);
dd9209d1 1158 initiate_key_setup(st,"incoming message would not decrypt",0);
48b97423 1159 send_nak(src,m.dest,m.source,m.type,msg0,"message would not decrypt");
3cdb830c
IJ
1160 assert(problem);
1161 return problem;
48b97423 1162
31dd0788
IJ
1163 badseq:
1164 slog(st,LOG_DROP,"transform: %s (bad seq.)",transform_err);
37acaef1
IJ
1165 assert(problem);
1166 return problem;
065e1922
IJ
1167}
1168
1169static bool_t process_msg0(struct site *st, struct buffer_if *msg0,
1170 const struct comm_addr *src)
1171{
1172 uint32_t type;
3cdb830c 1173 transform_apply_return problem;
065e1922 1174
3cdb830c 1175 problem = decrypt_msg0(st,msg0,src);
cbc25196
IJ
1176 if (problem==transform_apply_seqdupe) {
1177 /* We recently received another copy of this packet, maybe due
1178 * to polypath. That's not a problem; indeed, for the
1179 * purposes of transport address management it is a success.
1180 * But we don't want to process the packet. */
1181 transport_data_msgok(st,src);
1182 return False;
1183 }
3cdb830c 1184 if (problem)
065e1922
IJ
1185 return False;
1186
2fe58dfd 1187 CHECK_AVAIL(msg0,4);
59635212 1188 type=buf_unprepend_uint32(msg0);
2fe58dfd 1189 switch(type) {
794f2398
SE
1190 case LABEL_MSG7:
1191 /* We must forget about the current session. */
1d388569 1192 delete_keys(st,"request from peer",LOG_SEC);
e0d2e637
IJ
1193 /* probably, the peer is shutting down, and this is going to fail,
1194 * but we need to be trying to bring the link up again */
1195 if (st->keepalive)
1196 initiate_key_setup(st,"peer requested key teardown",0);
794f2398 1197 return True;
2fe58dfd
SE
1198 case LABEL_MSG9:
1199 /* Deliver to netlink layer */
469fd1d9 1200 st->netlink->deliver(st->netlink->st,msg0);
446353cd 1201 transport_data_msgok(st,src);
837cf01e
IJ
1202 /* See whether we should start negotiating a new key */
1203 if (st->now > st->renegotiate_key_time)
dd9209d1 1204 initiate_key_setup(st,"incoming packet in renegotiation window",0);
2fe58dfd 1205 return True;
2fe58dfd 1206 default:
ff05a229
SE
1207 slog(st,LOG_SEC,"incoming encrypted message of type %08x "
1208 "(unknown)",type);
2fe58dfd
SE
1209 break;
1210 }
1211 return False;
1212}
1213
1214static void dump_packet(struct site *st, struct buffer_if *buf,
62846523
IJ
1215 const struct comm_addr *addr, bool_t incoming,
1216 bool_t ok)
2fe58dfd 1217{
0a6cbade
IJ
1218 uint32_t dest=get_uint32(buf->start);
1219 uint32_t source=get_uint32(buf->start+4);
1220 uint32_t msgtype=get_uint32(buf->start+8);
2fe58dfd
SE
1221
1222 if (st->log_events & LOG_DUMP)
62846523 1223 slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x: %s%s",
040ee979 1224 st->tunname,incoming?"incoming":"outgoing",
62846523
IJ
1225 dest,source,msgtype,comm_addr_to_string(addr),
1226 ok?"":" - fail");
2fe58dfd
SE
1227}
1228
eff48c12
IJ
1229static bool_t comm_addr_sendmsg(struct site *st,
1230 const struct comm_addr *dest,
1231 struct buffer_if *buf)
1232{
5dfe538b
IJ
1233 int i;
1234 struct comm_clientinfo *commclientinfo = 0;
1235
1236 for (i=0; i < st->ncomms; i++) {
1237 if (st->comms[i] == dest->comm) {
1238 commclientinfo = st->commclientinfos[i];
1239 break;
1240 }
1241 }
1242 return dest->comm->sendmsg(dest->comm->st, buf, dest, commclientinfo);
eff48c12
IJ
1243}
1244
2fe58dfd
SE
1245static uint32_t site_status(void *st)
1246{
1247 return 0;
1248}
1249
1250static bool_t send_msg(struct site *st)
1251{
1252 if (st->retries>0) {
446353cd 1253 transport_xmit(st, &st->setup_peers, &st->buffer, True);
e7f8ec2a 1254 st->timeout=st->now+st->setup_retry_interval;
2fe58dfd
SE
1255 st->retries--;
1256 return True;
bd98cd6b 1257 } else if (st->state==SITE_SENTMSG5) {
4f3c75ac 1258 logtimeout(st,"timed out sending MSG5, stashing new key");
bd98cd6b
IJ
1259 /* We stash the key we have produced, in case it turns out that
1260 * our peer did see our MSG5 after all and starts using it. */
1261 /* This is a bit like some of activate_new_key */
1262 struct transform_inst_if *t;
1263 t=st->auxiliary_key.transform;
1264 st->auxiliary_key.transform=st->new_transform;
1265 st->new_transform=t;
0afd257e 1266 dispose_transform(&st->new_transform);
bd98cd6b 1267
bd98cd6b
IJ
1268 st->auxiliary_is_new=1;
1269 st->auxiliary_key.key_timeout=st->now+st->key_lifetime;
1270 st->auxiliary_renegotiate_key_time=st->now+st->key_renegotiate_time;
1271 st->auxiliary_key.remote_session_id=st->setup_session_id;
1272
1273 enter_state_wait(st);
1274 return False;
2fe58dfd 1275 } else {
4f3c75ac 1276 logtimeout(st,"timed out sending key setup packet "
3454dce4 1277 "(in state %s)",state_name(st->state));
2fe58dfd
SE
1278 enter_state_wait(st);
1279 return False;
1280 }
1281}
1282
cc420616 1283static void site_resolve_callback(void *sst, const struct comm_addr *addrs,
83dbdd3f 1284 int stored_naddrs, int all_naddrs,
bc07424d 1285 const char *address, const char *failwhy)
2fe58dfd
SE
1286{
1287 struct site *st=sst;
1288
83dbdd3f
IJ
1289 if (!stored_naddrs) {
1290 slog(st,LOG_ERROR,"resolution of %s failed: %s",address,failwhy);
1291 } else {
1292 slog(st,LOG_PEER_ADDRS,"resolution of %s completed, %d addrs, eg: %s",
1293 address, all_naddrs, comm_addr_to_string(&addrs[0]));;
1294
1295 int space=st->transport_peers_max-st->resolving_n_results_stored;
1296 int n_tocopy=MIN(stored_naddrs,space);
1297 COPY_ARRAY(st->resolving_results + st->resolving_n_results_stored,
1298 addrs,
1299 n_tocopy);
1300 st->resolving_n_results_stored += n_tocopy;
1301 st->resolving_n_results_all += all_naddrs;
1302 }
1303
1304 decrement_resolving_count(st,1);
1305}
1306
1307static void decrement_resolving_count(struct site *st, int by)
1308{
1309 assert(st->resolving_count>0);
1310 st->resolving_count-=by;
1311
1312 if (st->resolving_count)
1313 return;
1314
1315 /* OK, we are done with them all. Handle combined results. */
1316
1317 const struct comm_addr *addrs=st->resolving_results;
1318 int naddrs=st->resolving_n_results_stored;
1319 assert(naddrs<=st->transport_peers_max);
5c19b79c 1320
cc420616 1321 if (naddrs) {
83dbdd3f 1322 if (naddrs != st->resolving_n_results_all) {
cc420616
IJ
1323 slog(st,LOG_SETUP_INIT,"resolution of supplied addresses/names"
1324 " yielded too many results (%d > %d), some ignored",
83dbdd3f 1325 st->resolving_n_results_all, naddrs);
cc420616 1326 }
83dbdd3f 1327 slog(st,LOG_STATE,"resolution completed, %d addrs, eg: %s",
d9d101ea 1328 naddrs, iaddr_to_string(&addrs[0].ia));;
446353cd 1329 }
c22c3541
IJ
1330
1331 switch (st->state) {
1332 case SITE_RESOLVE:
45a14422 1333 if (transport_compute_setupinit_peers(st,addrs,naddrs,0)) {
c22c3541
IJ
1334 enter_new_state(st,SITE_SENTMSG1);
1335 } else {
1336 /* Can't figure out who to try to to talk to */
1337 slog(st,LOG_SETUP_INIT,
1338 "key exchange failed: cannot find peer address");
1339 enter_state_run(st);
1340 }
1341 break;
1342 case SITE_SENTMSG1: case SITE_SENTMSG2:
1343 case SITE_SENTMSG3: case SITE_SENTMSG4:
1344 case SITE_SENTMSG5:
45a14422 1345 if (naddrs) {
c22c3541
IJ
1346 /* We start using the address immediately for data too.
1347 * It's best to store it in st->peers now because we might
1348 * go via SENTMSG5, WAIT, and a MSG0, straight into using
1349 * the new key (without updating the data peer addrs). */
45a14422 1350 transport_resolve_complete(st,addrs,naddrs);
c22c3541
IJ
1351 } else if (st->local_mobile) {
1352 /* We can't let this rest because we may have a peer
1353 * address which will break in the future. */
83dbdd3f
IJ
1354 slog(st,LOG_SETUP_INIT,"resolution failed: "
1355 "abandoning key exchange");
c22c3541
IJ
1356 enter_state_wait(st);
1357 } else {
83dbdd3f 1358 slog(st,LOG_SETUP_INIT,"resolution failed: "
c22c3541 1359 " continuing to use source address of peer's packets"
83dbdd3f 1360 " for key exchange and ultimately data");
c22c3541
IJ
1361 }
1362 break;
1363 case SITE_RUN:
45a14422 1364 if (naddrs) {
83dbdd3f
IJ
1365 slog(st,LOG_SETUP_INIT,"resolution completed tardily,"
1366 " updating peer address(es)");
45a14422 1367 transport_resolve_complete_tardy(st,addrs,naddrs);
c22c3541
IJ
1368 } else if (st->local_mobile) {
1369 /* Not very good. We should queue (another) renegotiation
1370 * so that we can update the peer address. */
f7a86234 1371 st->key_renegotiate_time=st->now+wait_timeout(st);
c22c3541 1372 } else {
83dbdd3f
IJ
1373 slog(st,LOG_SETUP_INIT,"resolution failed: "
1374 " continuing to use source address of peer's packets");
c22c3541
IJ
1375 }
1376 break;
1377 case SITE_WAIT:
1378 case SITE_STOP:
1379 /* oh well */
1380 break;
2fe58dfd
SE
1381 }
1382}
1383
dd9209d1
IJ
1384static bool_t initiate_key_setup(struct site *st, cstring_t reason,
1385 const struct comm_addr *prod_hint)
9d3a4132 1386{
77effe1d 1387 /* Reentrancy hazard: can call enter_new_state/enter_state_* */
9d3a4132 1388 if (st->state!=SITE_RUN) return False;
794f2398 1389 slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
83dbdd3f
IJ
1390 if (st->addresses) {
1391 slog(st,LOG_SETUP_INIT,"resolving peer address(es)");
9d3a4132 1392 return enter_state_resolve(st);
45a14422 1393 } else if (transport_compute_setupinit_peers(st,0,0,prod_hint)) {
ff05a229 1394 return enter_new_state(st,SITE_SENTMSG1);
9d3a4132 1395 }
ff05a229 1396 slog(st,LOG_SETUP_INIT,"key exchange failed: no address for peer");
9d3a4132
SE
1397 return False;
1398}
1399
2fe58dfd
SE
1400static void activate_new_key(struct site *st)
1401{
1402 struct transform_inst_if *t;
1403
02b0959b
IJ
1404 /* We have three transform instances, which we swap between old,
1405 active and setup */
1406 t=st->auxiliary_key.transform;
1407 st->auxiliary_key.transform=st->current.transform;
19e9a588 1408 st->current.transform=st->new_transform;
2fe58dfd 1409 st->new_transform=t;
0afd257e 1410 dispose_transform(&st->new_transform);
2fe58dfd 1411
2fe58dfd 1412 st->timeout=0;
bd98cd6b 1413 st->auxiliary_is_new=0;
02b0959b 1414 st->auxiliary_key.key_timeout=st->current.key_timeout;
19e9a588 1415 st->current.key_timeout=st->now+st->key_lifetime;
ff05a229 1416 st->renegotiate_key_time=st->now+st->key_renegotiate_time;
446353cd 1417 transport_peers_copy(st,&st->peers,&st->setup_peers);
19e9a588 1418 st->current.remote_session_id=st->setup_session_id;
2fe58dfd 1419
3ed1846a
IJ
1420 /* Compute the inter-site MTU. This is min( our_mtu, their_mtu ).
1421 * But their mtu be unspecified, in which case we just use ours. */
1422 uint32_t intersite_mtu=
1423 MIN(st->mtu_target, st->remote_adv_mtu ?: ~(uint32_t)0);
1424 st->netlink->set_mtu(st->netlink->st,intersite_mtu);
1425
1426 slog(st,LOG_ACTIVATE_KEY,"new key activated"
1427 " (mtu ours=%"PRId32" theirs=%"PRId32" intersite=%"PRId32")",
1428 st->mtu_target, st->remote_adv_mtu, intersite_mtu);
9d3a4132 1429 enter_state_run(st);
2fe58dfd
SE
1430}
1431
1d388569
IJ
1432static void delete_one_key(struct site *st, struct data_key *key,
1433 cstring_t reason, cstring_t which, uint32_t loglevel)
1434{
0afd257e 1435 if (!is_transform_valid(key->transform)) return;
1d388569 1436 if (reason) slog(st,loglevel,"%s deleted (%s)",which,reason);
0afd257e 1437 dispose_transform(&key->transform);
1d388569
IJ
1438 key->key_timeout=0;
1439}
1440
1441static void delete_keys(struct site *st, cstring_t reason, uint32_t loglevel)
794f2398 1442{
3d8d8f4e 1443 if (current_valid(st)) {
794f2398
SE
1444 slog(st,loglevel,"session closed (%s)",reason);
1445
1d388569 1446 delete_one_key(st,&st->current,0,0,0);
794f2398
SE
1447 set_link_quality(st);
1448 }
02b0959b 1449 delete_one_key(st,&st->auxiliary_key,0,0,0);
794f2398
SE
1450}
1451
2fe58dfd
SE
1452static void state_assert(struct site *st, bool_t ok)
1453{
4f5e39ec 1454 if (!ok) fatal("site:state_assert");
2fe58dfd
SE
1455}
1456
1457static void enter_state_stop(struct site *st)
1458{
1459 st->state=SITE_STOP;
1460 st->timeout=0;
1d388569 1461 delete_keys(st,"entering state STOP",LOG_TIMEOUT_KEY);
0afd257e 1462 dispose_transform(&st->new_transform);
2fe58dfd
SE
1463}
1464
9d3a4132
SE
1465static void set_link_quality(struct site *st)
1466{
1467 uint32_t quality;
3d8d8f4e 1468 if (current_valid(st))
9d3a4132
SE
1469 quality=LINK_QUALITY_UP;
1470 else if (st->state==SITE_WAIT || st->state==SITE_STOP)
1471 quality=LINK_QUALITY_DOWN;
83dbdd3f 1472 else if (st->addresses)
9d3a4132 1473 quality=LINK_QUALITY_DOWN_CURRENT_ADDRESS;
446353cd 1474 else if (transport_peers_valid(&st->peers))
9d3a4132
SE
1475 quality=LINK_QUALITY_DOWN_STALE_ADDRESS;
1476 else
1477 quality=LINK_QUALITY_DOWN;
1478
469fd1d9 1479 st->netlink->set_quality(st->netlink->st,quality);
9d3a4132
SE
1480}
1481
2fe58dfd
SE
1482static void enter_state_run(struct site *st)
1483{
c02fba3b
IJ
1484 slog(st,LOG_STATE,"entering state RUN%s",
1485 current_valid(st) ? " (keyed)" : " (unkeyed)");
2fe58dfd
SE
1486 st->state=SITE_RUN;
1487 st->timeout=0;
9d3a4132 1488
ff05a229 1489 st->setup_session_id=0;
446353cd 1490 transport_peers_clear(st,&st->setup_peers);
4f28e77e
IJ
1491 FILLZERO(st->localN);
1492 FILLZERO(st->remoteN);
0afd257e 1493 dispose_transform(&st->new_transform);
5f679c36 1494 memset(st->dhsecret,0,st->dh->secret_len);
3f488f14 1495 memset(st->sharedsecret,0,st->dh->shared_len);
9d3a4132 1496 set_link_quality(st);
e6d6991c
IJ
1497
1498 if (st->keepalive && !current_valid(st))
1499 initiate_key_setup(st, "keepalive", 0);
2fe58dfd
SE
1500}
1501
5c19b79c
IJ
1502static bool_t ensure_resolving(struct site *st)
1503{
1504 /* Reentrancy hazard: may call site_resolve_callback and hence
1505 * enter_new_state, enter_state_* and generate_msg*. */
83dbdd3f 1506 if (st->resolving_count)
5c19b79c
IJ
1507 return True;
1508
83dbdd3f 1509 assert(st->addresses);
4ac8a7d2 1510
5c19b79c 1511 /* resolver->request might reentrantly call site_resolve_callback
83dbdd3f
IJ
1512 * which will decrement st->resolving, so we need to increment it
1513 * twice beforehand to prevent decrement from thinking we're
1514 * finished, and decrement it ourselves. Alternatively if
1515 * everything fails then there are no callbacks due and we simply
1516 * set it to 0 and return false.. */
1517 st->resolving_n_results_stored=0;
1518 st->resolving_n_results_all=0;
1519 st->resolving_count+=2;
1520 const char **addrp=st->addresses;
1521 const char *address;
1522 bool_t anyok=False;
1523 for (; (address=*addrp++); ) {
1524 bool_t ok = st->resolver->request(st->resolver->st,address,
1525 st->remoteport,st->comms[0],
1526 site_resolve_callback,st);
1527 if (ok)
1528 st->resolving_count++;
1529 anyok|=ok;
1530 }
1531 if (!anyok) {
1532 st->resolving_count=0;
1533 return False;
1534 }
1535 decrement_resolving_count(st,2);
1536 return True;
5c19b79c
IJ
1537}
1538
2fe58dfd
SE
1539static bool_t enter_state_resolve(struct site *st)
1540{
77effe1d 1541 /* Reentrancy hazard! See ensure_resolving. */
2fe58dfd
SE
1542 state_assert(st,st->state==SITE_RUN);
1543 slog(st,LOG_STATE,"entering state RESOLVE");
1544 st->state=SITE_RESOLVE;
5c19b79c 1545 return ensure_resolving(st);
2fe58dfd
SE
1546}
1547
ff05a229 1548static bool_t enter_new_state(struct site *st, uint32_t next)
2fe58dfd 1549{
ff05a229 1550 bool_t (*gen)(struct site *st);
3b83c932
SE
1551 int r;
1552
ff05a229
SE
1553 slog(st,LOG_STATE,"entering state %s",state_name(next));
1554 switch(next) {
1555 case SITE_SENTMSG1:
1556 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE);
1557 gen=generate_msg1;
8b978d45 1558 st->msg1_crossed_logged = False;
ff05a229
SE
1559 break;
1560 case SITE_SENTMSG2:
1561 state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1562 st->state==SITE_SENTMSG1 || st->state==SITE_WAIT);
1563 gen=generate_msg2;
1564 break;
1565 case SITE_SENTMSG3:
1566 state_assert(st,st->state==SITE_SENTMSG1);
1567 BUF_FREE(&st->buffer);
1568 gen=generate_msg3;
1569 break;
1570 case SITE_SENTMSG4:
1571 state_assert(st,st->state==SITE_SENTMSG2);
1572 BUF_FREE(&st->buffer);
1573 gen=generate_msg4;
1574 break;
1575 case SITE_SENTMSG5:
1576 state_assert(st,st->state==SITE_SENTMSG3);
1577 BUF_FREE(&st->buffer);
1578 gen=generate_msg5;
1579 break;
1580 case SITE_RUN:
1581 state_assert(st,st->state==SITE_SENTMSG4);
1582 BUF_FREE(&st->buffer);
1583 gen=generate_msg6;
1584 break;
1585 default:
1586 gen=NULL;
4f5e39ec 1587 fatal("enter_new_state(%s): invalid new state",state_name(next));
ff05a229 1588 break;
2fe58dfd 1589 }
2fe58dfd 1590
3b83c932
SE
1591 if (hacky_par_start_failnow()) return False;
1592
1593 r= gen(st) && send_msg(st);
1594
1595 hacky_par_end(&r,
e7f8ec2a 1596 st->setup_retries, st->setup_retry_interval,
3b83c932
SE
1597 send_msg, st);
1598
1599 if (r) {
ff05a229
SE
1600 st->state=next;
1601 if (next==SITE_RUN) {
1602 BUF_FREE(&st->buffer); /* Never reused */
1603 st->timeout=0; /* Never retransmit */
1604 activate_new_key(st);
1605 }
2fe58dfd
SE
1606 return True;
1607 }
ff05a229
SE
1608 slog(st,LOG_ERROR,"error entering state %s",state_name(next));
1609 st->buffer.free=False; /* Unconditionally use the buffer; it may be
1610 in either state, and enter_state_wait() will
1611 do a BUF_FREE() */
2fe58dfd
SE
1612 enter_state_wait(st);
1613 return False;
1614}
1615
ff05a229 1616/* msg7 tells our peer that we're about to forget our key */
fe5e9cc4 1617static bool_t send_msg7(struct site *st, cstring_t reason)
794f2398 1618{
fe5e9cc4 1619 cstring_t transform_err;
794f2398 1620
3d8d8f4e 1621 if (current_valid(st) && st->buffer.free
446353cd 1622 && transport_peers_valid(&st->peers)) {
794f2398 1623 BUF_ALLOC(&st->buffer,"site:MSG7");
3abd18e8 1624 buffer_init(&st->buffer,calculate_max_start_pad());
794f2398
SE
1625 buf_append_uint32(&st->buffer,LABEL_MSG7);
1626 buf_append_string(&st->buffer,reason);
0afd257e
IJ
1627 if (call_transform_forwards(st, st->current.transform,
1628 &st->buffer, &transform_err))
1629 goto free_out;
794f2398 1630 buf_prepend_uint32(&st->buffer,LABEL_MSG0);
58650a70 1631 buf_prepend_uint32(&st->buffer,st->index);
19e9a588 1632 buf_prepend_uint32(&st->buffer,st->current.remote_session_id);
446353cd 1633 transport_xmit(st,&st->peers,&st->buffer,True);
794f2398 1634 BUF_FREE(&st->buffer);
0afd257e 1635 free_out:
794f2398
SE
1636 return True;
1637 }
1638 return False;
1639}
1640
2fe58dfd
SE
1641/* We go into this state if our peer becomes uncommunicative. Similar to
1642 the "stop" state, we forget all session keys for a while, before
1643 re-entering the "run" state. */
1644static void enter_state_wait(struct site *st)
1645{
1646 slog(st,LOG_STATE,"entering state WAIT");
f7a86234 1647 st->timeout=st->now+wait_timeout(st);
2fe58dfd 1648 st->state=SITE_WAIT;
9d3a4132 1649 set_link_quality(st);
2fe58dfd
SE
1650 BUF_FREE(&st->buffer); /* will have had an outgoing packet in it */
1651 /* XXX Erase keys etc. */
1652}
1653
dd9209d1
IJ
1654static void generate_prod(struct site *st, struct buffer_if *buf)
1655{
1656 buffer_init(buf,0);
1657 buf_append_uint32(buf,0);
1658 buf_append_uint32(buf,0);
1659 buf_append_uint32(buf,LABEL_PROD);
1660 buf_append_string(buf,st->localname);
1661 buf_append_string(buf,st->remotename);
1662}
1663
1664static void generate_send_prod(struct site *st,
1665 const struct comm_addr *source)
1666{
1667 if (!st->allow_send_prod) return; /* too soon */
1668 if (!(st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1669 st->state==SITE_WAIT)) return; /* we'd ignore peer's MSG1 */
1670
1671 slog(st,LOG_SETUP_INIT,"prodding peer for key exchange");
1672 st->allow_send_prod=0;
1673 generate_prod(st,&st->scratch);
eff48c12 1674 bool_t ok = comm_addr_sendmsg(st, source, &st->scratch);
62846523 1675 dump_packet(st,&st->scratch,source,False,ok);
dd9209d1
IJ
1676}
1677
16f73fa6 1678static inline void site_settimeout(uint64_t timeout, int *timeout_io)
fe5e9cc4
SE
1679{
1680 if (timeout) {
0009e60a
IJ
1681 int64_t offset=timeout-*now;
1682 if (offset<0) offset=0;
fe5e9cc4
SE
1683 if (offset>INT_MAX) offset=INT_MAX;
1684 if (*timeout_io<0 || offset<*timeout_io)
1685 *timeout_io=offset;
1686 }
1687}
1688
2fe58dfd 1689static int site_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
90a39563 1690 int *timeout_io)
2fe58dfd
SE
1691{
1692 struct site *st=sst;
1693
ee697dd9 1694 BEFOREPOLL_WANT_FDS(0); /* We don't use any file descriptors */
2fe58dfd
SE
1695 st->now=*now;
1696
1697 /* Work out when our next timeout is. The earlier of 'timeout' or
19e9a588 1698 'current.key_timeout'. A stored value of '0' indicates no timeout
2fe58dfd 1699 active. */
16f73fa6 1700 site_settimeout(st->timeout, timeout_io);
19e9a588 1701 site_settimeout(st->current.key_timeout, timeout_io);
02b0959b 1702 site_settimeout(st->auxiliary_key.key_timeout, timeout_io);
2fe58dfd
SE
1703
1704 return 0; /* success */
1705}
1706
1d388569
IJ
1707static void check_expiry(struct site *st, struct data_key *key,
1708 const char *which)
1709{
1710 if (key->key_timeout && *now>key->key_timeout) {
1711 delete_one_key(st,key,"maximum life exceeded",which,LOG_TIMEOUT_KEY);
1712 }
1713}
1714
2fe58dfd 1715/* NB site_afterpoll will be called before site_beforepoll is ever called */
90a39563 1716static void site_afterpoll(void *sst, struct pollfd *fds, int nfds)
2fe58dfd
SE
1717{
1718 struct site *st=sst;
1719
1720 st->now=*now;
1721 if (st->timeout && *now>st->timeout) {
2fe58dfd 1722 st->timeout=0;
3b83c932
SE
1723 if (st->state>=SITE_SENTMSG1 && st->state<=SITE_SENTMSG5) {
1724 if (!hacky_par_start_failnow())
1725 send_msg(st);
1726 } else if (st->state==SITE_WAIT) {
2fe58dfd
SE
1727 enter_state_run(st);
1728 } else {
1729 slog(st,LOG_ERROR,"site_afterpoll: unexpected timeout, state=%d",
1730 st->state);
1731 }
1732 }
1d388569 1733 check_expiry(st,&st->current,"current key");
02b0959b 1734 check_expiry(st,&st->auxiliary_key,"auxiliary key");
2fe58dfd
SE
1735}
1736
1737/* This function is called by the netlink device to deliver packets
1738 intended for the remote network. The packet is in "raw" wire
1739 format, but is guaranteed to be word-aligned. */
469fd1d9 1740static void site_outgoing(void *sst, struct buffer_if *buf)
2fe58dfd
SE
1741{
1742 struct site *st=sst;
fe5e9cc4 1743 cstring_t transform_err;
2fe58dfd
SE
1744
1745 if (st->state==SITE_STOP) {
1746 BUF_FREE(buf);
1747 return;
1748 }
1749
dd9209d1
IJ
1750 st->allow_send_prod=1;
1751
2fe58dfd
SE
1752 /* In all other states we consider delivering the packet if we have
1753 a valid key and a valid address to send it to. */
3d8d8f4e 1754 if (current_valid(st) && transport_peers_valid(&st->peers)) {
2fe58dfd 1755 /* Transform it and send it */
70dc107b
SE
1756 if (buf->size>0) {
1757 buf_prepend_uint32(buf,LABEL_MSG9);
0afd257e
IJ
1758 if (call_transform_forwards(st, st->current.transform,
1759 buf, &transform_err))
1760 goto free_out;
70dc107b 1761 buf_prepend_uint32(buf,LABEL_MSG0);
58650a70 1762 buf_prepend_uint32(buf,st->index);
19e9a588 1763 buf_prepend_uint32(buf,st->current.remote_session_id);
446353cd 1764 transport_xmit(st,&st->peers,buf,False);
70dc107b 1765 }
0afd257e 1766 free_out:
2fe58dfd
SE
1767 BUF_FREE(buf);
1768 return;
1769 }
1770
70dc107b 1771 slog(st,LOG_DROP,"discarding outgoing packet of size %d",buf->size);
2fe58dfd 1772 BUF_FREE(buf);
dd9209d1 1773 initiate_key_setup(st,"outgoing packet",0);
2fe58dfd
SE
1774}
1775
7e29719e
IJ
1776static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
1777 uint32_t type, struct msg *m)
1778 /* For packets which are identified by the local and remote names.
1779 * If it has our name and our peer's name in it it's for us. */
1780{
1781 struct buffer_if buf[1];
1782 buffer_readonly_clone(buf,buf_in);
1783 return unpick_msg(st,type,buf,m)
1784 && name_matches(&m->remote,st->remotename)
1785 && name_matches(&m->local,st->localname);
1786}
1787
67871f70 1788static bool_t we_have_priority(struct site *st, const struct msg *m) {
4c795bdb
MW
1789 if (st->local_capabilities & m->remote_capabilities &
1790 CAPAB_PRIORITY_MOBILE) {
b2de6bd2
IJ
1791 if (st->local_mobile) return True;
1792 if (st-> peer_mobile) return False;
1793 }
67871f70
IJ
1794 return st->our_name_later;
1795}
1796
db6534a3
IJ
1797static bool_t setup_late_msg_ok(struct site *st,
1798 const struct buffer_if *buf_in,
1799 uint32_t msgtype,
1800 const struct comm_addr *source) {
1801 /* For setup packets which seem from their type like they are
1802 * late. Maybe they came via a different path. All we do is make
1803 * a note of the sending address, iff they look like they are part
1804 * of the current key setup attempt. */
1805 struct msg m;
1806 if (!named_for_us(st,buf_in,msgtype,&m))
1807 /* named_for_us calls unpick_msg which gets the nonces */
1808 return False;
1809 if (!consttime_memeq(m.nR,st->remoteN,NONCELEN) ||
1810 !consttime_memeq(m.nL,st->localN, NONCELEN))
1811 /* spoof ? from stale run ? who knows */
1812 return False;
1813 transport_setup_msgok(st,source);
1814 return True;
1815}
1816
2fe58dfd 1817/* This function is called by the communication device to deliver
dd9209d1
IJ
1818 packets from our peers.
1819 It should return True if the packet is recognised as being for
1820 this current site instance (and should therefore not be processed
1821 by other sites), even if the packet was otherwise ignored. */
2fe58dfd 1822static bool_t site_incoming(void *sst, struct buffer_if *buf,
a15faeb2 1823 const struct comm_addr *source)
2fe58dfd
SE
1824{
1825 struct site *st=sst;
20138876
IJ
1826
1827 if (buf->size < 12) return False;
1828
0a6cbade
IJ
1829 uint32_t dest=get_uint32(buf->start);
1830 uint32_t msgtype=get_uint32(buf->start+8);
7e29719e
IJ
1831 struct msg named_msg;
1832
1833 if (msgtype==LABEL_MSG1) {
1834 if (!named_for_us(st,buf,msgtype,&named_msg))
1835 return False;
1836 /* It's a MSG1 addressed to us. Decide what to do about it. */
62846523 1837 dump_packet(st,buf,source,True,True);
7e29719e
IJ
1838 if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
1839 st->state==SITE_WAIT) {
1840 /* We should definitely process it */
45a14422 1841 transport_compute_setupinit_peers(st,0,0,source);
7e29719e
IJ
1842 if (process_msg1(st,buf,source,&named_msg)) {
1843 slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
c22c3541 1844 bool_t entered=enter_new_state(st,SITE_SENTMSG2);
83dbdd3f 1845 if (entered && st->addresses && st->local_mobile)
c22c3541
IJ
1846 /* We must do this as the very last thing, because
1847 the resolver callback might reenter us. */
1848 ensure_resolving(st);
7e29719e
IJ
1849 } else {
1850 slog(st,LOG_ERROR,"failed to process incoming msg1");
1851 }
1852 BUF_FREE(buf);
1853 return True;
1854 } else if (st->state==SITE_SENTMSG1) {
1855 /* We've just sent a message 1! They may have crossed on
1856 the wire. If we have priority then we ignore the
1857 incoming one, otherwise we process it as usual. */
67871f70 1858 if (we_have_priority(st,&named_msg)) {
7e29719e 1859 BUF_FREE(buf);
8b978d45 1860 if (!st->msg1_crossed_logged++)
dea92314 1861 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher "
8b978d45 1862 "priority => ignore incoming msg1");
7e29719e
IJ
1863 return True;
1864 } else {
dea92314 1865 slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower "
7e29719e
IJ
1866 "priority => use incoming msg1");
1867 if (process_msg1(st,buf,source,&named_msg)) {
1868 BUF_FREE(&st->buffer); /* Free our old message 1 */
c22c3541 1869 transport_setup_msgok(st,source);
ff05a229 1870 enter_new_state(st,SITE_SENTMSG2);
2fe58dfd 1871 } else {
7e29719e
IJ
1872 slog(st,LOG_ERROR,"failed to process an incoming "
1873 "crossed msg1 (we have low priority)");
2fe58dfd
SE
1874 }
1875 BUF_FREE(buf);
1876 return True;
2fe58dfd 1877 }
04c5c5d7
IJ
1878 } else if (st->state==SITE_SENTMSG2 ||
1879 st->state==SITE_SENTMSG4) {
1880 if (consttime_memeq(named_msg.nR,st->remoteN,NONCELEN)) {
1881 /* We are ahead in the protocol, but that msg1 had the
1882 * peer's nonce so presumably it is from this key
1883 * exchange run, via a slower route */
1884 transport_setup_msgok(st,source);
1885 } else {
1886 slog(st,LOG_UNEXPECTED,"competing incoming message 1");
1887 }
1888 BUF_FREE(buf);
1889 return True;
2fe58dfd 1890 }
7e29719e 1891 /* The message 1 was received at an unexpected stage of the
04c5c5d7 1892 key setup. Well, they lost the race. */
7e29719e
IJ
1893 slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
1894 BUF_FREE(buf);
1895 return True;
2fe58dfd 1896 }
dd9209d1
IJ
1897 if (msgtype==LABEL_PROD) {
1898 if (!named_for_us(st,buf,msgtype,&named_msg))
1899 return False;
62846523 1900 dump_packet(st,buf,source,True,True);
dd9209d1
IJ
1901 if (st->state!=SITE_RUN) {
1902 slog(st,LOG_DROP,"ignoring PROD when not in state RUN");
1903 } else if (current_valid(st)) {
1904 slog(st,LOG_DROP,"ignoring PROD when we think we have a key");
1905 } else {
1906 initiate_key_setup(st,"peer sent PROD packet",source);
1907 }
1908 BUF_FREE(buf);
1909 return True;
1910 }
58650a70 1911 if (dest==st->index) {
2fe58dfd 1912 /* Explicitly addressed to us */
62846523 1913 if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True,True);
2fe58dfd 1914 switch (msgtype) {
136740e6 1915 case LABEL_NAK:
794f2398
SE
1916 /* If the source is our current peer then initiate a key setup,
1917 because our peer's forgotten the key */
19e9a588 1918 if (get_uint32(buf->start+4)==st->current.remote_session_id) {
dd9209d1 1919 bool_t initiated;
e5e67212 1920 initiated = initiate_key_setup(st,"received a NAK",source);
dd9209d1 1921 if (!initiated) generate_send_prod(st,source);
794f2398
SE
1922 } else {
1923 slog(st,LOG_SEC,"bad incoming NAK");
1924 }
1925 break;
2fe58dfd
SE
1926 case LABEL_MSG0:
1927 process_msg0(st,buf,source);
1928 break;
1929 case LABEL_MSG1:
1930 /* Setup packet: should not have been explicitly addressed
1931 to us */
59635212 1932 slog(st,LOG_SEC,"incoming explicitly addressed msg1");
2fe58dfd
SE
1933 break;
1934 case LABEL_MSG2:
1935 /* Setup packet: expected only in state SENTMSG1 */
1936 if (st->state!=SITE_SENTMSG1) {
db6534a3
IJ
1937 if ((st->state==SITE_SENTMSG3 ||
1938 st->state==SITE_SENTMSG5) &&
1939 setup_late_msg_ok(st,buf,msgtype,source))
1940 break;
2fe58dfd 1941 slog(st,LOG_UNEXPECTED,"unexpected MSG2");
446353cd
IJ
1942 } else if (process_msg2(st,buf,source)) {
1943 transport_setup_msgok(st,source);
ff05a229 1944 enter_new_state(st,SITE_SENTMSG3);
446353cd 1945 } else {
59635212 1946 slog(st,LOG_SEC,"invalid MSG2");
2fe58dfd
SE
1947 }
1948 break;
1949 case LABEL_MSG3:
5b5f297f 1950 case LABEL_MSG3BIS:
2fe58dfd
SE
1951 /* Setup packet: expected only in state SENTMSG2 */
1952 if (st->state!=SITE_SENTMSG2) {
db6534a3
IJ
1953 if ((st->state==SITE_SENTMSG4) &&
1954 setup_late_msg_ok(st,buf,msgtype,source))
1955 break;
2fe58dfd 1956 slog(st,LOG_UNEXPECTED,"unexpected MSG3");
5b5f297f 1957 } else if (process_msg3(st,buf,source,msgtype)) {
446353cd 1958 transport_setup_msgok(st,source);
ff05a229 1959 enter_new_state(st,SITE_SENTMSG4);
446353cd 1960 } else {
59635212 1961 slog(st,LOG_SEC,"invalid MSG3");
2fe58dfd
SE
1962 }
1963 break;
1964 case LABEL_MSG4:
1965 /* Setup packet: expected only in state SENTMSG3 */
1966 if (st->state!=SITE_SENTMSG3) {
db6534a3
IJ
1967 if ((st->state==SITE_SENTMSG5) &&
1968 setup_late_msg_ok(st,buf,msgtype,source))
1969 break;
2fe58dfd 1970 slog(st,LOG_UNEXPECTED,"unexpected MSG4");
446353cd
IJ
1971 } else if (process_msg4(st,buf,source)) {
1972 transport_setup_msgok(st,source);
ff05a229 1973 enter_new_state(st,SITE_SENTMSG5);
446353cd 1974 } else {
59635212 1975 slog(st,LOG_SEC,"invalid MSG4");
2fe58dfd
SE
1976 }
1977 break;
1978 case LABEL_MSG5:
4efd681a
SE
1979 /* Setup packet: expected only in state SENTMSG4 */
1980 /* (may turn up in state RUN if our return MSG6 was lost
1981 and the new key has already been activated. In that
05f39b4d
IJ
1982 case we discard it. The peer will realise that we
1983 are using the new key when they see our data packets.
1984 Until then the peer's data packets to us get discarded. */
c90cc2a7
IJ
1985 if (st->state==SITE_SENTMSG4) {
1986 if (process_msg5(st,buf,source,st->new_transform)) {
1987 transport_setup_msgok(st,source);
1988 enter_new_state(st,SITE_RUN);
1989 } else {
1990 slog(st,LOG_SEC,"invalid MSG5");
1991 }
1992 } else if (st->state==SITE_RUN) {
19e9a588 1993 if (process_msg5(st,buf,source,st->current.transform)) {
c90cc2a7
IJ
1994 slog(st,LOG_DROP,"got MSG5, retransmitting MSG6");
1995 transport_setup_msgok(st,source);
19e9a588
IJ
1996 create_msg6(st,st->current.transform,
1997 st->current.remote_session_id);
c90cc2a7
IJ
1998 transport_xmit(st,&st->peers,&st->buffer,True);
1999 BUF_FREE(&st->buffer);
2000 } else {
2001 slog(st,LOG_SEC,"invalid MSG5 (in state RUN)");
2002 }
2fe58dfd 2003 } else {
c90cc2a7 2004 slog(st,LOG_UNEXPECTED,"unexpected MSG5");
2fe58dfd
SE
2005 }
2006 break;
2007 case LABEL_MSG6:
2008 /* Setup packet: expected only in state SENTMSG5 */
2009 if (st->state!=SITE_SENTMSG5) {
2010 slog(st,LOG_UNEXPECTED,"unexpected MSG6");
2011 } else if (process_msg6(st,buf,source)) {
2012 BUF_FREE(&st->buffer); /* Free message 5 */
446353cd 2013 transport_setup_msgok(st,source);
2fe58dfd
SE
2014 activate_new_key(st);
2015 } else {
59635212 2016 slog(st,LOG_SEC,"invalid MSG6");
2fe58dfd
SE
2017 }
2018 break;
2fe58dfd 2019 default:
59635212 2020 slog(st,LOG_SEC,"received message of unknown type 0x%08x",
2fe58dfd
SE
2021 msgtype);
2022 break;
2023 }
2024 BUF_FREE(buf);
2025 return True;
2026 }
2027
2028 return False;
2029}
2030
2031static void site_control(void *vst, bool_t run)
2032{
2033 struct site *st=vst;
2034 if (run) enter_state_run(st);
2035 else enter_state_stop(st);
2036}
2037
794f2398
SE
2038static void site_phase_hook(void *sst, uint32_t newphase)
2039{
2040 struct site *st=sst;
2041
2042 /* The program is shutting down; tell our peer */
2043 send_msg7(st,"shutting down");
2044}
2045
32654a31
IJ
2046static void site_childpersist_clearkeys(void *sst, uint32_t newphase)
2047{
2048 struct site *st=sst;
2049 dispose_transform(&st->current.transform);
2050 dispose_transform(&st->auxiliary_key.transform);
2051 dispose_transform(&st->new_transform);
2052 /* Not much point overwiting the signing key, since we loaded it
2053 from disk, and it is only valid prospectively if at all,
2054 anyway. */
2055 /* XXX it would be best to overwrite the DH state, because that
2056 _is_ relevant to forward secrecy. However we have no
2057 convenient interface for doing that and in practice gmp has
2058 probably dribbled droppings all over the malloc arena. A good
2059 way to fix this would be to have a privsep child for asymmetric
2060 crypto operations, but that's a task for another day. */
2061}
2062
2fe58dfd
SE
2063static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context,
2064 list_t *args)
2065{
58650a70 2066 static uint32_t index_sequence;
2fe58dfd
SE
2067 struct site *st;
2068 item_t *item;
2069 dict_t *dict;
59533c16 2070 int i;
2fe58dfd 2071
b7886fd4 2072 NEW(st);
2fe58dfd
SE
2073
2074 st->cl.description="site";
2075 st->cl.type=CL_SITE;
2076 st->cl.apply=NULL;
2077 st->cl.interface=&st->ops;
2078 st->ops.st=st;
2079 st->ops.control=site_control;
2080 st->ops.status=site_status;
2081
2082 /* First parameter must be a dict */
2083 item=list_elem(args,0);
2084 if (!item || item->type!=t_dict)
2085 cfgfatal(loc,"site","parameter must be a dictionary\n");
2086
2087 dict=item->data.dict;
558fa3fb
SE
2088 st->localname=dict_read_string(dict, "local-name", True, "site", loc);
2089 st->remotename=dict_read_string(dict, "name", True, "site", loc);
dba19f84 2090
e6d6991c
IJ
2091 st->keepalive=dict_read_bool(dict,"keepalive",False,"site",loc,False);
2092
dba19f84 2093 st->peer_mobile=dict_read_bool(dict,"mobile",False,"site",loc,False);
0391d9ee 2094 st->local_mobile=
dba19f84
IJ
2095 dict_read_bool(dict,"local-mobile",False,"site",loc,False);
2096
558fa3fb
SE
2097 /* Sanity check (which also allows the 'sites' file to include
2098 site() closures for all sites including our own): refuse to
2099 talk to ourselves */
2100 if (strcmp(st->localname,st->remotename)==0) {
b2a56f7c 2101 Message(M_DEBUG,"site %s: local-name==name -> ignoring this site\n",
baa06aeb 2102 st->localname);
0391d9ee 2103 if (st->peer_mobile != st->local_mobile)
dba19f84
IJ
2104 cfgfatal(loc,"site","site %s's peer-mobile=%d"
2105 " but our local-mobile=%d\n",
0391d9ee 2106 st->localname, st->peer_mobile, st->local_mobile);
dba19f84
IJ
2107 free(st);
2108 return NULL;
2109 }
0391d9ee 2110 if (st->peer_mobile && st->local_mobile) {
dba19f84
IJ
2111 Message(M_WARNING,"site %s: site is mobile but so are we"
2112 " -> ignoring this site\n", st->remotename);
558fa3fb
SE
2113 free(st);
2114 return NULL;
2115 }
dba19f84 2116
58650a70
RK
2117 assert(index_sequence < 0xffffffffUL);
2118 st->index = ++index_sequence;
09a385fb 2119 st->local_capabilities = 0;
5d903efd 2120 st->early_capabilities = CAPAB_PRIORITY_MOBILE;
469fd1d9 2121 st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
59533c16 2122
5b5f297f
IJ
2123#define GET_CLOSURE_LIST(dictkey,things,nthings,CL_TYPE) do{ \
2124 list_t *things##_cfg=dict_lookup(dict,dictkey); \
2125 if (!things##_cfg) \
2126 cfgfatal(loc,"site","closure list \"%s\" not found\n",dictkey); \
2127 st->nthings=list_length(things##_cfg); \
b4ececfc 2128 NEW_ARY(st->things,st->nthings); \
5b5f297f
IJ
2129 assert(st->nthings); \
2130 for (i=0; i<st->nthings; i++) { \
2131 item_t *item=list_elem(things##_cfg,i); \
2132 if (item->type!=t_closure) \
2133 cfgfatal(loc,"site","%s is not a closure\n",dictkey); \
2134 closure_t *cl=item->data.closure; \
2135 if (cl->type!=CL_TYPE) \
2136 cfgfatal(loc,"site","%s closure wrong type\n",dictkey); \
2137 st->things[i]=cl->interface; \
2138 } \
2139}while(0)
2140
2141 GET_CLOSURE_LIST("comm",comms,ncomms,CL_COMM);
59533c16 2142
5dfe538b
IJ
2143 NEW_ARY(st->commclientinfos, st->ncomms);
2144 dict_t *comminfo = dict_read_dict(dict,"comm-info",False,"site",loc);
2145 for (i=0; i<st->ncomms; i++) {
2146 st->commclientinfos[i] =
2147 !comminfo ? 0 :
2148 st->comms[i]->clientinfo(st->comms[i],comminfo,loc);
2149 }
2150
2fe58dfd
SE
2151 st->resolver=find_cl_if(dict,"resolver",CL_RESOLVER,True,"site",loc);
2152 st->log=find_cl_if(dict,"log",CL_LOG,True,"site",loc);
2153 st->random=find_cl_if(dict,"random",CL_RANDOMSRC,True,"site",loc);
2154
2fe58dfd 2155 st->privkey=find_cl_if(dict,"local-key",CL_RSAPRIVKEY,True,"site",loc);
83dbdd3f
IJ
2156 st->addresses=dict_read_string_array(dict,"address",False,"site",loc,0);
2157 if (st->addresses)
3454dce4
SE
2158 st->remoteport=dict_read_number(dict,"port",True,"site",loc,0);
2159 else st->remoteport=0;
2fe58dfd
SE
2160 st->pubkey=find_cl_if(dict,"key",CL_RSAPUBKEY,True,"site",loc);
2161
5b5f297f 2162 GET_CLOSURE_LIST("transform",transforms,ntransforms,CL_TRANSFORM);
2fe58dfd
SE
2163
2164 st->dh=find_cl_if(dict,"dh",CL_DH,True,"site",loc);
2165 st->hash=find_cl_if(dict,"hash",CL_HASH,True,"site",loc);
2166
0391d9ee 2167#define DEFAULT(D) (st->peer_mobile || st->local_mobile \
e57264d6 2168 ? DEFAULT_MOBILE_##D : DEFAULT_##D)
e7f8ec2a 2169#define CFG_NUMBER(k,D) dict_read_number(dict,(k),False,"site",loc,DEFAULT(D));
c27ca22f 2170
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2171 st->key_lifetime= CFG_NUMBER("key-lifetime", KEY_LIFETIME);
2172 st->setup_retries= CFG_NUMBER("setup-retries", SETUP_RETRIES);
2173 st->setup_retry_interval= CFG_NUMBER("setup-timeout", SETUP_RETRY_INTERVAL);
f7a86234 2174 st->wait_timeout_mean= CFG_NUMBER("wait-time", WAIT_TIME);
3ed1846a 2175 st->mtu_target= dict_read_number(dict,"mtu-target",False,"site",loc,0);
e7f8ec2a 2176
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2177 st->mobile_peer_expiry= dict_read_number(
2178 dict,"mobile-peer-expiry",False,"site",loc,DEFAULT_MOBILE_PEER_EXPIRY);
2179
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2180 const char *peerskey= st->peer_mobile
2181 ? "mobile-peers-max" : "static-peers-max";
2182 st->transport_peers_max= dict_read_number(
83dbdd3f 2183 dict,peerskey,False,"site",loc, st->addresses ? 4 : 3);
446353cd 2184 if (st->transport_peers_max<1 ||
0f27325c
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2185 st->transport_peers_max>MAX_PEER_ADDRS) {
2186 cfgfatal(loc,"site", "%s must be in range 1.."
2187 STRING(MAX_PEER_ADDRS) "\n", peerskey);
446353cd
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2188 }
2189
e7f8ec2a 2190 if (st->key_lifetime < DEFAULT(KEY_RENEGOTIATE_GAP)*2)
c27ca22f
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2191 st->key_renegotiate_time=st->key_lifetime/2;
2192 else
e7f8ec2a 2193 st->key_renegotiate_time=st->key_lifetime-DEFAULT(KEY_RENEGOTIATE_GAP);
9d3a4132 2194 st->key_renegotiate_time=dict_read_number(
cce0051f 2195 dict,"renegotiate-time",False,"site",loc,st->key_renegotiate_time);
9d3a4132
SE
2196 if (st->key_renegotiate_time > st->key_lifetime) {
2197 cfgfatal(loc,"site",
2198 "renegotiate-time must be less than key-lifetime\n");
2199 }
9d3a4132
SE
2200
2201 st->log_events=string_list_to_word(dict_lookup(dict,"log-events"),
2202 log_event_table,"site");
2fe58dfd 2203
83dbdd3f 2204 st->resolving_count=0;
dd9209d1
IJ
2205 st->allow_send_prod=0;
2206
4efd681a
SE
2207 st->tunname=safe_malloc(strlen(st->localname)+strlen(st->remotename)+5,
2208 "site_apply");
2209 sprintf(st->tunname,"%s<->%s",st->localname,st->remotename);
2210
2fe58dfd 2211 /* The information we expect to see in incoming messages of type 1 */
59230b9b
IJ
2212 /* fixme: lots of unchecked overflows here, but the results are only
2213 corrupted packets rather than undefined behaviour */
ffafab08 2214 st->our_name_later=(strcmp(st->localname,st->remotename)>0);
2fe58dfd
SE
2215
2216 buffer_new(&st->buffer,SETUP_BUFFER_LEN);
2217
8aaaa634 2218 buffer_new(&st->scratch,SETUP_BUFFER_LEN);
05f39b4d
IJ
2219 BUF_ALLOC(&st->scratch,"site:scratch");
2220
2fe58dfd
SE
2221 /* We are interested in poll(), but only for timeouts. We don't have
2222 any fds of our own. */
32fc582f 2223 register_for_poll(st, site_beforepoll, site_afterpoll, "site");
2fe58dfd
SE
2224 st->timeout=0;
2225
09a385fb 2226 st->remote_capabilities=0;
5b5f297f 2227 st->chosen_transform=0;
19e9a588 2228 st->current.key_timeout=0;
02b0959b 2229 st->auxiliary_key.key_timeout=0;
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IJ
2230 transport_peers_clear(st,&st->peers);
2231 transport_peers_clear(st,&st->setup_peers);
2fe58dfd 2232 /* XXX mlock these */
5f679c36 2233 st->dhsecret=safe_malloc(st->dh->secret_len,"site:dhsecret");
3f488f14 2234 st->sharedsecret=safe_malloc(st->dh->shared_len, "site:sharedsecret");
5b5f297f 2235
8bb8c22a
MW
2236#define SET_CAPBIT(bit) do { \
2237 uint32_t capflag = 1UL << (bit); \
2238 if (st->local_capabilities & capflag) \
2239 slog(st,LOG_ERROR,"capability bit" \
2240 " %d (%#"PRIx32") reused", (bit), capflag); \
2241 st->local_capabilities |= capflag; \
2242} while (0)
2243
2244 for (i=0; i<st->ntransforms; i++)
2245 SET_CAPBIT(st->transforms[i]->capab_bit);
2246
2247#undef SET_CAPBIT
59533c16 2248
b2de6bd2
IJ
2249 if (st->local_mobile || st->peer_mobile)
2250 st->local_capabilities |= CAPAB_PRIORITY_MOBILE;
2251
2fe58dfd 2252 /* We need to register the remote networks with the netlink device */
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IJ
2253 uint32_t netlink_mtu; /* local virtual interface mtu */
2254 st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu);
2255 if (!st->mtu_target)
2256 st->mtu_target=netlink_mtu;
ff05a229 2257
59533c16
IJ
2258 for (i=0; i<st->ncomms; i++)
2259 st->comms[i]->request_notify(st->comms[i]->st, st, site_incoming);
2fe58dfd 2260
fcad4b0b
IJ
2261 st->current.transform=0;
2262 st->auxiliary_key.transform=0;
2263 st->new_transform=0;
bd98cd6b 2264 st->auxiliary_is_new=0;
2fe58dfd
SE
2265
2266 enter_state_stop(st);
2267
794f2398 2268 add_hook(PHASE_SHUTDOWN,site_phase_hook,st);
32654a31 2269 add_hook(PHASE_CHILDPERSIST,site_childpersist_clearkeys,st);
794f2398 2270
2fe58dfd
SE
2271 return new_closure(&st->cl);
2272}
2273
2fe58dfd
SE
2274void site_module(dict_t *dict)
2275{
2276 add_closure(dict,"site",site_apply);
2277}
446353cd
IJ
2278
2279
2280/***** TRANSPORT PEERS definitions *****/
2281
2282static void transport_peers_debug(struct site *st, transport_peers *dst,
2283 const char *didwhat,
2284 int nargs, const struct comm_addr *args,
2285 size_t stride) {
2286 int i;
2287 char *argp;
2288
2289 if (!(st->log_events & LOG_PEER_ADDRS))
2290 return; /* an optimisation */
2291
2292 slog(st, LOG_PEER_ADDRS, "peers (%s) %s nargs=%d => npeers=%d",
2293 (dst==&st->peers ? "data" :
2294 dst==&st->setup_peers ? "setup" : "UNKNOWN"),
2295 didwhat, nargs, dst->npeers);
2296
2297 for (i=0, argp=(void*)args;
2298 i<nargs;
2299 i++, (argp+=stride?stride:sizeof(*args))) {
2300 const struct comm_addr *ca=(void*)argp;
2301 slog(st, LOG_PEER_ADDRS, " args: addrs[%d]=%s",
1a448682 2302 i, comm_addr_to_string(ca));
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IJ
2303 }
2304 for (i=0; i<dst->npeers; i++) {
2305 struct timeval diff;
2306 timersub(tv_now,&dst->peers[i].last,&diff);
2307 const struct comm_addr *ca=&dst->peers[i].addr;
2308 slog(st, LOG_PEER_ADDRS, " peers: addrs[%d]=%s T-%ld.%06ld",
1a448682 2309 i, comm_addr_to_string(ca),
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IJ
2310 (unsigned long)diff.tv_sec, (unsigned long)diff.tv_usec);
2311 }
2312}
2313
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2314static void transport_peers_expire(struct site *st, transport_peers *peers) {
2315 /* peers must be sorted first */
2316 int previous_peers=peers->npeers;
2317 struct timeval oldest;
2318 oldest.tv_sec = tv_now->tv_sec - st->mobile_peer_expiry;
2319 oldest.tv_usec = tv_now->tv_usec;
2320 while (peers->npeers>1 &&
2321 timercmp(&peers->peers[peers->npeers-1].last, &oldest, <))
2322 peers->npeers--;
2323 if (peers->npeers != previous_peers)
2324 transport_peers_debug(st,peers,"expire", 0,0,0);
2325}
2326
51fc5a74
IJ
2327static bool_t transport_peer_record_one(struct site *st, transport_peers *peers,
2328 const struct comm_addr *ca,
2329 const struct timeval *tv) {
2330 /* returns false if output is full */
2331 int search;
446353cd 2332
51fc5a74
IJ
2333 if (peers->npeers >= st->transport_peers_max)
2334 return 0;
446353cd 2335
51fc5a74 2336 for (search=0; search<peers->npeers; search++)
2093fb5c 2337 if (comm_addr_equal(&peers->peers[search].addr, ca))
51fc5a74
IJ
2338 return 1;
2339
2340 peers->peers[peers->npeers].addr = *ca;
2341 peers->peers[peers->npeers].last = *tv;
2342 peers->npeers++;
2343 return 1;
2344}
2345
2346static void transport_record_peers(struct site *st, transport_peers *peers,
2347 const struct comm_addr *addrs, int naddrs,
2348 const char *m) {
2349 /* We add addrs into peers. The new entries end up at the front
2350 * and displace entries towards the end (perhaps even off the
2351 * end). Any existing matching entries are moved up to the front.
2352 *
2353 * Caller must first call transport_peers_expire. */
2354
fdef47ec
IJ
2355 if (naddrs==1) {
2356 /* avoids debug for uninteresting updates */
2357 int i;
2358 for (i=0; i<peers->npeers; i++) {
2359 if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) {
2360 memmove(peers->peers+1, peers->peers,
2361 sizeof(peers->peers[0]) * i);
2362 peers->peers[0].addr = addrs[0];
2363 peers->peers[0].last = *tv_now;
2364 return;
2365 }
2366 }
51fc5a74 2367 }
446353cd 2368
51fc5a74
IJ
2369 int old_npeers=peers->npeers;
2370 transport_peer old_peers[old_npeers];
2371 COPY_ARRAY(old_peers,peers->peers,old_npeers);
446353cd 2372
51fc5a74
IJ
2373 peers->npeers=0;
2374 int i;
2375 for (i=0; i<naddrs; i++) {
2376 if (!transport_peer_record_one(st,peers, &addrs[i], tv_now))
2377 break;
2378 }
2379 for (i=0; i<old_npeers; i++) {
2380 const transport_peer *old=&old_peers[i];
2381 if (!transport_peer_record_one(st,peers, &old->addr, &old->last))
2382 break;
2383 }
446353cd 2384
51fc5a74
IJ
2385 transport_peers_debug(st,peers,m, naddrs,addrs,0);
2386}
2387
2388static void transport_expire_record_peers(struct site *st,
2389 transport_peers *peers,
2390 const struct comm_addr *addrs,
2391 int naddrs, const char *m) {
2392 /* Convenience function */
2393 transport_peers_expire(st,peers);
2394 transport_record_peers(st,peers,addrs,naddrs,m);
446353cd
IJ
2395}
2396
2397static bool_t transport_compute_setupinit_peers(struct site *st,
45a14422
IJ
2398 const struct comm_addr *configured_addrs /* 0 if none or not found */,
2399 int n_configured_addrs /* 0 if none or not found */,
a96fda35 2400 const struct comm_addr *incoming_packet_addr /* 0 if none */) {
45a14422 2401 if (!n_configured_addrs && !incoming_packet_addr &&
dd9209d1 2402 !transport_peers_valid(&st->peers))
446353cd
IJ
2403 return False;
2404
2405 slog(st,LOG_SETUP_INIT,
45a14422
IJ
2406 "using: %d configured addr(s);%s %d old peer addrs(es)",
2407 n_configured_addrs,
a96fda35 2408 incoming_packet_addr ? " incoming packet address;" : "",
779837e1 2409 st->peers.npeers);
446353cd 2410
0f27325c
IJ
2411 /* Non-mobile peers try addresses until one is plausible. The
2412 * effect is that this code always tries first the configured
2413 * address if supplied, or otherwise the address of the incoming
2414 * PROD, or finally the existing data peer if one exists; this is
2415 * as desired. */
446353cd
IJ
2416
2417 transport_peers_copy(st,&st->setup_peers,&st->peers);
51fc5a74 2418 transport_peers_expire(st,&st->setup_peers);
446353cd 2419
a96fda35 2420 if (incoming_packet_addr)
51fc5a74
IJ
2421 transport_record_peers(st,&st->setup_peers,
2422 incoming_packet_addr,1, "incoming");
dd9209d1 2423
45a14422 2424 if (n_configured_addrs)
51fc5a74 2425 transport_record_peers(st,&st->setup_peers,
45a14422 2426 configured_addrs,n_configured_addrs, "setupinit");
446353cd
IJ
2427
2428 assert(transport_peers_valid(&st->setup_peers));
2429 return True;
2430}
2431
2432static void transport_setup_msgok(struct site *st, const struct comm_addr *a) {
2433 if (st->peer_mobile)
51fc5a74 2434 transport_expire_record_peers(st,&st->setup_peers,a,1,"setupmsg");
446353cd
IJ
2435}
2436static void transport_data_msgok(struct site *st, const struct comm_addr *a) {
2437 if (st->peer_mobile)
51fc5a74 2438 transport_expire_record_peers(st,&st->peers,a,1,"datamsg");
446353cd
IJ
2439}
2440
2441static int transport_peers_valid(transport_peers *peers) {
2442 return peers->npeers;
2443}
2444static void transport_peers_clear(struct site *st, transport_peers *peers) {
2445 peers->npeers= 0;
2446 transport_peers_debug(st,peers,"clear",0,0,0);
2447}
2448static void transport_peers_copy(struct site *st, transport_peers *dst,
2449 const transport_peers *src) {
2450 dst->npeers=src->npeers;
4f28e77e 2451 COPY_ARRAY(dst->peers, src->peers, dst->npeers);
446353cd 2452 transport_peers_debug(st,dst,"copy",
a620a048 2453 src->npeers, &src->peers->addr, sizeof(*src->peers));
446353cd
IJ
2454}
2455
90d7e3ad 2456static void transport_resolve_complete(struct site *st,
45a14422
IJ
2457 const struct comm_addr *addrs,
2458 int naddrs) {
2459 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2460 "resolved data");
2461 transport_expire_record_peers(st,&st->setup_peers,addrs,naddrs,
2462 "resolved setup");
90d7e3ad
IJ
2463}
2464
2465static void transport_resolve_complete_tardy(struct site *st,
45a14422
IJ
2466 const struct comm_addr *addrs,
2467 int naddrs) {
2468 transport_expire_record_peers(st,&st->peers,addrs,naddrs,
2469 "resolved tardily");
90d7e3ad
IJ
2470}
2471
027a218f
IJ
2472static void transport_peers__copy_by_mask(transport_peer *out, int *nout_io,
2473 unsigned mask,
2474 const transport_peers *inp) {
2475 /* out and in->peers may be the same region, or nonoverlapping */
2476 const transport_peer *in=inp->peers;
2477 int slot;
2478 for (slot=0; slot<inp->npeers; slot++) {
2479 if (!(mask & (1U << slot)))
2480 continue;
2481 if (!(out==in && slot==*nout_io))
2482 COPY_OBJ(out[*nout_io], in[slot]);
2483 (*nout_io)++;
2484 }
2485}
2486
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2487void transport_xmit(struct site *st, transport_peers *peers,
2488 struct buffer_if *buf, bool_t candebug) {
2489 int slot;
2490 transport_peers_expire(st, peers);
027a218f 2491 unsigned failed=0; /* bitmask */
0f27325c 2492 assert(MAX_PEER_ADDRS < sizeof(unsigned)*CHAR_BIT);
027a218f
IJ
2493
2494 int nfailed=0;
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IJ
2495 for (slot=0; slot<peers->npeers; slot++) {
2496 transport_peer *peer=&peers->peers[slot];
eff48c12 2497 bool_t ok = comm_addr_sendmsg(st, &peer->addr, buf);
62846523
IJ
2498 if (candebug)
2499 dump_packet(st, buf, &peer->addr, False, ok);
027a218f
IJ
2500 if (!ok) {
2501 failed |= 1U << slot;
2502 nfailed++;
2503 }
2504 if (ok && !st->peer_mobile)
2505 break;
2506 }
2507 /* Now we need to demote/delete failing addrs: if we are mobile we
2508 * merely demote them; otherwise we delete them. */
2509 if (st->local_mobile) {
2510 unsigned expected = ((1U << nfailed)-1) << (peers->npeers-nfailed);
2511 /* `expected' has all the failures at the end already */
2512 if (failed != expected) {
2513 int fslot=0;
2514 transport_peer failedpeers[nfailed];
2515 transport_peers__copy_by_mask(failedpeers, &fslot, failed,peers);
2516 assert(fslot == nfailed);
2517 int wslot=0;
2518 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2519 assert(wslot+nfailed == peers->npeers);
2520 COPY_ARRAY(peers->peers+wslot, failedpeers, nfailed);
92ae57c5 2521 transport_peers_debug(st,peers,"mobile failure reorder",0,0,0);
027a218f
IJ
2522 }
2523 } else {
2524 if (failed && peers->npeers > 1) {
2525 int wslot=0;
2526 transport_peers__copy_by_mask(peers->peers,&wslot,~failed,peers);
2527 peers->npeers=wslot;
92ae57c5 2528 transport_peers_debug(st,peers,"non-mobile failure cleanup",0,0,0);
027a218f 2529 }
446353cd
IJ
2530 }
2531}
2532
2533/***** END of transport peers declarations *****/