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Revert to old behaviour regarding information requests
[project/odhcp6c.git] / src / odhcp6c.c
1 /**
2 * Copyright (C) 2012-2013 Steven Barth <steven@midlink.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License v2 as published by
6 * the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 */
14
15 #include <time.h>
16 #include <errno.h>
17 #include <fcntl.h>
18 #include <stdio.h>
19 #include <stdlib.h>
20 #include <stddef.h>
21 #include <unistd.h>
22 #include <syslog.h>
23 #include <signal.h>
24 #include <string.h>
25 #include <stdbool.h>
26
27 #include <net/if.h>
28 #include <sys/wait.h>
29 #include <sys/syscall.h>
30 #include <arpa/inet.h>
31
32 #include "odhcp6c.h"
33 #include "ra.h"
34
35 #ifdef EXT_BFD_PING
36 #include "bfd.h"
37 #endif
38
39
40 static void sighandler(int signal);
41 static int usage(void);
42
43 static uint8_t *state_data[_STATE_MAX] = {NULL};
44 static size_t state_len[_STATE_MAX] = {0};
45
46 static volatile int do_signal = 0;
47 static int urandom_fd = -1, allow_slaac_only = 0;
48 static bool bound = false, release = true;
49 static time_t last_update = 0;
50
51
52 int main(_unused int argc, char* const argv[])
53 {
54 // Allocate ressources
55 const char *pidfile = NULL;
56 const char *script = "/usr/sbin/odhcp6c-update";
57 ssize_t l;
58 uint8_t buf[134];
59 char *optpos;
60 uint16_t opttype;
61 enum odhcp6c_ia_mode ia_na_mode = IA_MODE_TRY;
62 enum odhcp6c_ia_mode ia_pd_mode = IA_MODE_TRY;
63 static struct in6_addr ifid = IN6ADDR_ANY_INIT;
64 int sol_timeout = DHCPV6_SOL_MAX_RT;
65
66 #ifdef EXT_BFD_PING
67 int bfd_interval = 0, bfd_loss = 3;
68 #endif
69
70 bool help = false, daemonize = false;
71 int logopt = LOG_PID;
72 int c, request_pd = 0;
73 while ((c = getopt(argc, argv, "S::N:P:FB:c:i:r:s:kt:hedp:")) != -1) {
74 switch (c) {
75 case 'S':
76 allow_slaac_only = (optarg) ? atoi(optarg) : -1;
77 break;
78
79 case 'N':
80 if (!strcmp(optarg, "force")) {
81 ia_na_mode = IA_MODE_FORCE;
82 allow_slaac_only = -1;
83 } else if (!strcmp(optarg, "none")) {
84 ia_na_mode = IA_MODE_NONE;
85 } else if (!strcmp(optarg, "try")) {
86 ia_na_mode = IA_MODE_TRY;
87 } else{
88 help = true;
89 }
90 break;
91
92 case 'P':
93 if (allow_slaac_only >= 0 && allow_slaac_only < 10)
94 allow_slaac_only = 10;
95
96 request_pd = strtoul(optarg, NULL, 10);
97 if (request_pd == 0)
98 request_pd = -1;
99
100 break;
101
102 case 'F':
103 allow_slaac_only = -1;
104 ia_pd_mode = IA_MODE_FORCE;
105 break;
106
107 #ifdef EXT_BFD_PING
108 case 'B':
109 bfd_interval = atoi(optarg);
110 break;
111 #endif
112
113 case 'c':
114 l = script_unhexlify(&buf[4], sizeof(buf) - 4, optarg);
115 if (l > 0) {
116 buf[0] = 0;
117 buf[1] = DHCPV6_OPT_CLIENTID;
118 buf[2] = 0;
119 buf[3] = l;
120 odhcp6c_add_state(STATE_CLIENT_ID, buf, l + 4);
121 } else {
122 help = true;
123 }
124 break;
125
126 case 'i':
127 if (inet_pton(AF_INET6, optarg, &ifid) != 1)
128 help = true;
129 break;
130
131 case 'r':
132 optpos = optarg;
133 while (optpos[0]) {
134 opttype = htons(strtoul(optarg, &optpos, 10));
135 if (optpos == optarg)
136 break;
137 else if (optpos[0])
138 optarg = &optpos[1];
139 odhcp6c_add_state(STATE_ORO, &opttype, 2);
140 }
141 break;
142
143 case 's':
144 script = optarg;
145 break;
146
147 case 'k':
148 release = false;
149 break;
150
151 case 't':
152 sol_timeout = atoi(optarg);
153 break;
154
155 case 'e':
156 logopt |= LOG_PERROR;
157 break;
158
159 case 'd':
160 daemonize = true;
161 break;
162
163 case 'p':
164 pidfile = optarg;
165 break;
166
167 default:
168 help = true;
169 break;
170 }
171 }
172
173 openlog("odhcp6c", logopt, LOG_DAEMON);
174 const char *ifname = argv[optind];
175
176 if (help || !ifname)
177 return usage();
178
179 signal(SIGIO, sighandler);
180 signal(SIGHUP, sighandler);
181 signal(SIGINT, sighandler);
182 signal(SIGCHLD, sighandler);
183 signal(SIGTERM, sighandler);
184 signal(SIGUSR1, sighandler);
185 signal(SIGUSR2, sighandler);
186
187 if ((urandom_fd = open("/dev/urandom", O_CLOEXEC | O_RDONLY)) < 0 ||
188 init_dhcpv6(ifname, request_pd, sol_timeout) ||
189 ra_init(ifname, &ifid) || script_init(script, ifname)) {
190 syslog(LOG_ERR, "failed to initialize: %s", strerror(errno));
191 return 3;
192 }
193
194 if (daemonize) {
195 openlog("odhcp6c", LOG_PID, LOG_DAEMON); // Disable LOG_PERROR
196 if (daemon(0, 0)) {
197 syslog(LOG_ERR, "Failed to daemonize: %s",
198 strerror(errno));
199 return 4;
200 }
201
202 char pidbuf[128];
203 if (!pidfile) {
204 snprintf(pidbuf, sizeof(pidbuf),
205 "/var/run/odhcp6c.%s.pid", ifname);
206 pidfile = pidbuf;
207 }
208
209 int fd = open(pidfile, O_WRONLY | O_CREAT);
210 if (fd >= 0) {
211 char buf[8];
212 int len = snprintf(buf, sizeof(buf), "%i\n", getpid());
213 write(fd, buf, len);
214 close(fd);
215 }
216 }
217
218 script_call("started");
219
220 while (do_signal != SIGTERM) { // Main logic
221 odhcp6c_clear_state(STATE_SERVER_ID);
222 odhcp6c_clear_state(STATE_IA_NA);
223 odhcp6c_clear_state(STATE_IA_PD);
224 odhcp6c_clear_state(STATE_SNTP_IP);
225 odhcp6c_clear_state(STATE_SNTP_FQDN);
226 odhcp6c_clear_state(STATE_SIP_IP);
227 odhcp6c_clear_state(STATE_SIP_FQDN);
228 dhcpv6_set_ia_mode(ia_na_mode, ia_pd_mode);
229 bound = false;
230
231 syslog(LOG_NOTICE, "(re)starting transaction on %s", ifname);
232
233 do_signal = 0;
234 int mode = dhcpv6_request(DHCPV6_MSG_SOLICIT);
235 odhcp6c_signal_process();
236
237 if (mode < 0)
238 continue;
239
240 do {
241 int res = dhcpv6_request(mode == DHCPV6_STATELESS ?
242 DHCPV6_MSG_INFO_REQ : DHCPV6_MSG_REQUEST);
243
244 odhcp6c_signal_process();
245 if (res > 0)
246 break;
247 else if (do_signal > 0) {
248 mode = -1;
249 break;
250 }
251
252 mode = dhcpv6_promote_server_cand();
253 } while (mode > DHCPV6_UNKNOWN);
254
255 if (mode < 0)
256 continue;
257
258 switch (mode) {
259 case DHCPV6_STATELESS:
260 bound = true;
261 syslog(LOG_NOTICE, "entering stateless-mode on %s", ifname);
262
263 while (do_signal == 0 || do_signal == SIGUSR1) {
264 do_signal = 0;
265 script_call("informed");
266
267 int res = dhcpv6_poll_reconfigure();
268 odhcp6c_signal_process();
269
270 if (res > 0)
271 continue;
272
273 if (do_signal == SIGUSR1) {
274 do_signal = 0; // Acknowledged
275 continue;
276 } else if (do_signal > 0)
277 break;
278
279 res = dhcpv6_request(DHCPV6_MSG_INFO_REQ);
280 odhcp6c_signal_process();
281 if (do_signal == SIGUSR1)
282 continue;
283 else if (res < 0)
284 break;
285 }
286 break;
287
288 case DHCPV6_STATEFUL:
289 script_call("bound");
290 bound = true;
291 syslog(LOG_NOTICE, "entering stateful-mode on %s", ifname);
292 #ifdef EXT_BFD_PING
293 if (bfd_interval > 0)
294 bfd_start(ifname, bfd_loss, bfd_interval);
295 #endif
296
297 while (do_signal == 0 || do_signal == SIGUSR1) {
298 // Renew Cycle
299 // Wait for T1 to expire or until we get a reconfigure
300 int res = dhcpv6_poll_reconfigure();
301 odhcp6c_signal_process();
302 if (res > 0) {
303 script_call("updated");
304 continue;
305 }
306
307 // Handle signal, if necessary
308 if (do_signal == SIGUSR1)
309 do_signal = 0; // Acknowledged
310 else if (do_signal > 0)
311 break; // Other signal type
312
313 // Send renew as T1 expired
314 size_t ia_pd_len, ia_na_len;
315 odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
316 odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
317
318 // If we have any IAs, send renew, otherwise request
319 if (ia_pd_len == 0 && ia_na_len == 0)
320 res = dhcpv6_request(DHCPV6_MSG_REQUEST);
321 else
322 res = dhcpv6_request(DHCPV6_MSG_RENEW);
323
324 odhcp6c_signal_process();
325 if (res > 0) { // Renew was succesfull
326 // Publish updates
327 script_call("updated");
328 continue; // Renew was successful
329 }
330
331 odhcp6c_clear_state(STATE_SERVER_ID); // Remove binding
332
333 // If we have IAs, try rebind otherwise restart
334 res = dhcpv6_request(DHCPV6_MSG_REBIND);
335 odhcp6c_signal_process();
336
337 if (res > 0)
338 script_call("rebound");
339 else {
340 #ifdef EXT_BFD_PING
341 bfd_stop();
342 #endif
343 break;
344 }
345 }
346 break;
347
348 default:
349 break;
350 }
351
352 size_t ia_pd_len, ia_na_len, server_id_len;
353 odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
354 odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
355 odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
356
357 // Add all prefixes to lost prefixes
358 bound = false;
359 script_call("unbound");
360
361 if (server_id_len > 0 && (ia_pd_len > 0 || ia_na_len > 0) && release)
362 dhcpv6_request(DHCPV6_MSG_RELEASE);
363
364 odhcp6c_clear_state(STATE_IA_NA);
365 odhcp6c_clear_state(STATE_IA_PD);
366 }
367
368 script_call("stopped");
369 return 0;
370 }
371
372
373 static int usage(void)
374 {
375 const char buf[] =
376 "Usage: odhcp6c [options] <interface>\n"
377 "\nFeature options:\n"
378 " -S <time> Wait at least <time> sec for a DHCP-server (0)\n"
379 " -N <mode> Mode for requesting addresses [try|force|none]\n"
380 " -P <length> Request IPv6-Prefix (0 = auto)\n"
381 " -F Force IPv6-Prefix\n"
382 #ifdef EXT_BFD_PING
383 " -B <interval> Enable BFD ping check\n"
384 #endif
385 " -c <clientid> Override client-ID (base-16 encoded)\n"
386 " -i <iface-id> Use a custom interface identifier for RA handling\n"
387 " -r <options> Options to be requested (comma-separated)\n"
388 " -s <script> Status update script (/usr/sbin/odhcp6c-update)\n"
389 " -k Don't send a RELEASE when stopping\n"
390 " -t <seconds> Maximum timeout for DHCPv6-SOLICIT (120)\n"
391 "\nInvocation options:\n"
392 " -p <pidfile> Set pidfile (/var/run/6relayd.pid)\n"
393 " -d Daemonize\n"
394 " -e Write logmessages to stderr\n"
395 //" -v Increase logging verbosity\n"
396 " -h Show this help\n\n";
397 write(STDERR_FILENO, buf, sizeof(buf));
398 return 1;
399 }
400
401
402 // Don't want to pull-in librt and libpthread just for a monotonic clock...
403 uint64_t odhcp6c_get_milli_time(void)
404 {
405 struct timespec t = {0, 0};
406 syscall(SYS_clock_gettime, CLOCK_MONOTONIC, &t);
407 return t.tv_sec * 1000 + t.tv_nsec / 1000000;
408 }
409
410
411 static uint8_t* odhcp6c_resize_state(enum odhcp6c_state state, ssize_t len)
412 {
413 if (len == 0)
414 return state_data[state] + state_len[state];
415 else if (state_len[state] + len > 1024)
416 return NULL;
417
418 uint8_t *n = realloc(state_data[state], state_len[state] + len);
419 if (n || state_len[state] + len == 0) {
420 state_data[state] = n;
421 n += state_len[state];
422 state_len[state] += len;
423 }
424 return n;
425 }
426
427
428 bool odhcp6c_signal_process(void)
429 {
430 if (do_signal == SIGIO) {
431 do_signal = 0;
432 bool ra_updated = ra_process();
433
434 if (ra_link_up())
435 do_signal = SIGUSR2;
436
437 if (ra_updated && (bound || allow_slaac_only == 0))
438 script_call("ra-updated"); // Immediate process urgent events
439 else if (ra_updated && !bound && allow_slaac_only > 0)
440 script_delay_call("ra-updated", allow_slaac_only);
441
442 #ifdef EXT_BFD_PING
443 bfd_receive();
444 #endif
445 }
446
447 return do_signal != 0;
448 }
449
450
451 void odhcp6c_clear_state(enum odhcp6c_state state)
452 {
453 state_len[state] = 0;
454 }
455
456
457 void odhcp6c_add_state(enum odhcp6c_state state, const void *data, size_t len)
458 {
459 uint8_t *n = odhcp6c_resize_state(state, len);
460 if (n)
461 memcpy(n, data, len);
462 }
463
464 void odhcp6c_insert_state(enum odhcp6c_state state, size_t offset, const void *data, size_t len)
465 {
466 ssize_t len_after = state_len[state] - offset;
467 if (len_after < 0)
468 return;
469
470 uint8_t *n = odhcp6c_resize_state(state, len);
471 if (n) {
472 uint8_t *sdata = state_data[state];
473
474 memmove(sdata + offset + len, sdata + offset, len_after);
475 memcpy(sdata + offset, data, len);
476 }
477 }
478
479 size_t odhcp6c_remove_state(enum odhcp6c_state state, size_t offset, size_t len)
480 {
481 uint8_t *data = state_data[state];
482 ssize_t len_after = state_len[state] - (offset + len);
483 if (len_after < 0)
484 return state_len[state];
485
486 memmove(data + offset, data + offset + len, len_after);
487 return state_len[state] -= len;
488 }
489
490
491 void* odhcp6c_move_state(enum odhcp6c_state state, size_t *len)
492 {
493 *len = state_len[state];
494 void *data = state_data[state];
495
496 state_len[state] = 0;
497 state_data[state] = NULL;
498
499 return data;
500 }
501
502
503 void* odhcp6c_get_state(enum odhcp6c_state state, size_t *len)
504 {
505 *len = state_len[state];
506 return state_data[state];
507 }
508
509
510 struct odhcp6c_entry* odhcp6c_find_entry(enum odhcp6c_state state, const struct odhcp6c_entry *new)
511 {
512 size_t len, cmplen = offsetof(struct odhcp6c_entry, target) + new->length / 8;
513 struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
514 struct odhcp6c_entry *x = NULL;
515
516 for (struct odhcp6c_entry *c = start; !x && c < &start[len/sizeof(*c)]; ++c)
517 if (!memcmp(c, new, cmplen))
518 return c;
519
520 return NULL;
521 }
522
523
524 bool odhcp6c_update_entry_safe(enum odhcp6c_state state, struct odhcp6c_entry *new, uint32_t safe)
525 {
526 size_t len;
527 struct odhcp6c_entry *x = odhcp6c_find_entry(state, new);
528 struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
529
530 if (x && x->valid > new->valid && new->valid < safe)
531 new->valid = safe;
532
533 if (new->valid > 0) {
534 if (x) {
535 if (new->valid >= x->valid && new->valid - x->valid < 60 &&
536 new->preferred >= x->preferred &&
537 new->preferred - x->preferred < 60 &&
538 x->class == new->class)
539 return false;
540 x->valid = new->valid;
541 x->preferred = new->preferred;
542 x->t1 = new->t1;
543 x->t2 = new->t2;
544 x->class = new->class;
545 } else {
546 odhcp6c_add_state(state, new, sizeof(*new));
547 }
548 } else if (x) {
549 odhcp6c_remove_state(state, (x - start) * sizeof(*x), sizeof(*x));
550 }
551 return true;
552 }
553
554
555 bool odhcp6c_update_entry(enum odhcp6c_state state, struct odhcp6c_entry *new)
556 {
557 return odhcp6c_update_entry_safe(state, new, 0);
558 }
559
560
561 static void odhcp6c_expire_list(enum odhcp6c_state state, uint32_t elapsed)
562 {
563 size_t len;
564 struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
565 for (struct odhcp6c_entry *c = start; c < &start[len / sizeof(*c)]; ++c) {
566 if (c->t1 < elapsed)
567 c->t1 = 0;
568 else if (c->t1 != UINT32_MAX)
569 c->t1 -= elapsed;
570
571 if (c->t2 < elapsed)
572 c->t2 = 0;
573 else if (c->t2 != UINT32_MAX)
574 c->t2 -= elapsed;
575
576 if (c->preferred < elapsed)
577 c->preferred = 0;
578 else if (c->preferred != UINT32_MAX)
579 c->preferred -= elapsed;
580
581 if (c->valid < elapsed)
582 c->valid = 0;
583 else if (c->valid != UINT32_MAX)
584 c->valid -= elapsed;
585
586 if (!c->valid)
587 odhcp6c_remove_state(state, (c - start) * sizeof(*c), sizeof(*c));
588 }
589 }
590
591
592 void odhcp6c_expire(void)
593 {
594 time_t now = odhcp6c_get_milli_time() / 1000;
595 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
596 last_update = now;
597
598 odhcp6c_expire_list(STATE_RA_PREFIX, elapsed);
599 odhcp6c_expire_list(STATE_RA_ROUTE, elapsed);
600 odhcp6c_expire_list(STATE_RA_DNS, elapsed);
601 odhcp6c_expire_list(STATE_IA_NA, elapsed);
602 odhcp6c_expire_list(STATE_IA_PD, elapsed);
603 }
604
605
606 uint32_t odhcp6c_elapsed(void)
607 {
608 return odhcp6c_get_milli_time() / 1000 - last_update;
609 }
610
611
612 void odhcp6c_random(void *buf, size_t len)
613 {
614 read(urandom_fd, buf, len);
615 }
616
617 bool odhcp6c_is_bound(void)
618 {
619 return bound;
620 }
621
622 static void sighandler(int signal)
623 {
624 if (signal == SIGCHLD)
625 while (waitpid(-1, NULL, WNOHANG) > 0);
626 else if (signal == SIGUSR1)
627 do_signal = SIGUSR1;
628 else if (signal == SIGUSR2)
629 do_signal = SIGUSR2;
630 else if (signal == SIGIO)
631 do_signal = SIGIO;
632 else
633 do_signal = SIGTERM;
634 }
Openwrt DHCPv6 Client