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[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 bool signal_io = false;
47 static volatile bool signal_usr1 = false;
48 static volatile bool signal_usr2 = false;
49 static volatile bool signal_term = false;
50
51 static int urandom_fd = -1, allow_slaac_only = 0;
52 static bool bound = false, release = true;
53 static time_t last_update = 0;
54
55 int main(_unused int argc, char* const argv[])
56 {
57 // Allocate ressources
58 const char *pidfile = NULL;
59 const char *script = "/usr/sbin/odhcp6c-update";
60 ssize_t l;
61 uint8_t buf[134];
62 char *optpos;
63 uint16_t opttype;
64 enum odhcp6c_ia_mode ia_na_mode = IA_MODE_TRY;
65 enum odhcp6c_ia_mode ia_pd_mode = IA_MODE_TRY;
66 int ia_pd_iaid_index = 0;
67 static struct in6_addr ifid = IN6ADDR_ANY_INIT;
68 int sol_timeout = DHCPV6_SOL_MAX_RT;
69
70 #ifdef EXT_BFD_PING
71 int bfd_interval = 0, bfd_loss = 3;
72 #endif
73
74 bool help = false, daemonize = false;
75 int logopt = LOG_PID;
76 int c;
77 unsigned int client_options = DHCPV6_CLIENT_FQDN | DHCPV6_ACCEPT_RECONFIGURE;
78
79 while ((c = getopt(argc, argv, "S::N:V:P:FB:c:i:r:Rs:kt:hedp:fa")) != -1) {
80 switch (c) {
81 case 'S':
82 allow_slaac_only = (optarg) ? atoi(optarg) : -1;
83 break;
84
85 case 'N':
86 if (!strcmp(optarg, "force")) {
87 ia_na_mode = IA_MODE_FORCE;
88 allow_slaac_only = -1;
89 } else if (!strcmp(optarg, "none")) {
90 ia_na_mode = IA_MODE_NONE;
91 } else if (!strcmp(optarg, "try")) {
92 ia_na_mode = IA_MODE_TRY;
93 } else{
94 help = true;
95 }
96 break;
97
98 case 'V':
99 l = script_unhexlify(buf, sizeof(buf), optarg);
100 if (!l)
101 help=true;
102
103 odhcp6c_add_state(STATE_VENDORCLASS, buf, l);
104
105 break;
106 case 'P':
107 if (allow_slaac_only >= 0 && allow_slaac_only < 10)
108 allow_slaac_only = 10;
109
110 char *iaid_begin;
111 int iaid_len = 0;
112
113 int prefix_length = strtoul(optarg, &iaid_begin, 10);
114
115 if (*iaid_begin != '\0' && *iaid_begin != ',') {
116 syslog(LOG_ERR, "invalid argument: '%s'", optarg);
117 return 1;
118 }
119
120 struct odhcp6c_request_prefix prefix = { 0, prefix_length };
121
122 if (*iaid_begin == ',' && (iaid_len = strlen(iaid_begin)) > 1)
123 memcpy(&prefix.iaid, iaid_begin + 1, iaid_len > 4 ? 4 : iaid_len);
124 else
125 prefix.iaid = ++ia_pd_iaid_index;
126
127 odhcp6c_add_state(STATE_IA_PD_INIT, &prefix, sizeof(prefix));
128
129 break;
130
131 case 'F':
132 allow_slaac_only = -1;
133 ia_pd_mode = IA_MODE_FORCE;
134 break;
135
136 #ifdef EXT_BFD_PING
137 case 'B':
138 bfd_interval = atoi(optarg);
139 break;
140 #endif
141
142 case 'c':
143 l = script_unhexlify(&buf[4], sizeof(buf) - 4, optarg);
144 if (l > 0) {
145 buf[0] = 0;
146 buf[1] = DHCPV6_OPT_CLIENTID;
147 buf[2] = 0;
148 buf[3] = l;
149 odhcp6c_add_state(STATE_CLIENT_ID, buf, l + 4);
150 } else {
151 help = true;
152 }
153 break;
154
155 case 'i':
156 if (inet_pton(AF_INET6, optarg, &ifid) != 1)
157 help = true;
158 break;
159
160 case 'r':
161 optpos = optarg;
162 while (optpos[0]) {
163 opttype = htons(strtoul(optarg, &optpos, 10));
164 if (optpos == optarg)
165 break;
166 else if (optpos[0])
167 optarg = &optpos[1];
168 odhcp6c_add_state(STATE_ORO, &opttype, 2);
169 }
170 break;
171
172 case 'R':
173 client_options |= DHCPV6_STRICT_OPTIONS;
174 break;
175
176 case 's':
177 script = optarg;
178 break;
179
180 case 'k':
181 release = false;
182 break;
183
184 case 't':
185 sol_timeout = atoi(optarg);
186 break;
187
188 case 'e':
189 logopt |= LOG_PERROR;
190 break;
191
192 case 'd':
193 daemonize = true;
194 break;
195
196 case 'p':
197 pidfile = optarg;
198 break;
199
200 case 'f':
201 client_options &= ~DHCPV6_CLIENT_FQDN;
202 break;
203
204 case 'a':
205 client_options &= ~DHCPV6_ACCEPT_RECONFIGURE;
206 break;
207
208 default:
209 help = true;
210 break;
211 }
212 }
213
214 openlog("odhcp6c", logopt, LOG_DAEMON);
215 const char *ifname = argv[optind];
216
217 if (help || !ifname)
218 return usage();
219
220 signal(SIGIO, sighandler);
221 signal(SIGHUP, sighandler);
222 signal(SIGINT, sighandler);
223 signal(SIGCHLD, sighandler);
224 signal(SIGTERM, sighandler);
225 signal(SIGUSR1, sighandler);
226 signal(SIGUSR2, sighandler);
227
228 if ((urandom_fd = open("/dev/urandom", O_CLOEXEC | O_RDONLY)) < 0 ||
229 init_dhcpv6(ifname, client_options, sol_timeout) ||
230 ra_init(ifname, &ifid) || script_init(script, ifname)) {
231 syslog(LOG_ERR, "failed to initialize: %s", strerror(errno));
232 return 3;
233 }
234
235 if (daemonize) {
236 openlog("odhcp6c", LOG_PID, LOG_DAEMON); // Disable LOG_PERROR
237 if (daemon(0, 0)) {
238 syslog(LOG_ERR, "Failed to daemonize: %s",
239 strerror(errno));
240 return 4;
241 }
242
243 char pidbuf[128];
244 if (!pidfile) {
245 snprintf(pidbuf, sizeof(pidbuf),
246 "/var/run/odhcp6c.%s.pid", ifname);
247 pidfile = pidbuf;
248 }
249
250 int fd = open(pidfile, O_WRONLY | O_CREAT);
251 if (fd >= 0) {
252 char buf[8];
253 int len = snprintf(buf, sizeof(buf), "%i\n", getpid());
254 write(fd, buf, len);
255 close(fd);
256 }
257 }
258
259 script_call("started");
260
261 while (!signal_term) { // Main logic
262 odhcp6c_clear_state(STATE_SERVER_ID);
263 odhcp6c_clear_state(STATE_IA_NA);
264 odhcp6c_clear_state(STATE_IA_PD);
265 odhcp6c_clear_state(STATE_SNTP_IP);
266 odhcp6c_clear_state(STATE_NTP_IP);
267 odhcp6c_clear_state(STATE_NTP_FQDN);
268 odhcp6c_clear_state(STATE_SIP_IP);
269 odhcp6c_clear_state(STATE_SIP_FQDN);
270 dhcpv6_set_ia_mode(ia_na_mode, ia_pd_mode);
271 bound = false;
272
273 syslog(LOG_NOTICE, "(re)starting transaction on %s", ifname);
274
275 signal_usr1 = signal_usr2 = false;
276 int mode = dhcpv6_request(DHCPV6_MSG_SOLICIT);
277 odhcp6c_signal_process();
278
279 if (mode < 0)
280 continue;
281
282 do {
283 int res = dhcpv6_request(mode == DHCPV6_STATELESS ?
284 DHCPV6_MSG_INFO_REQ : DHCPV6_MSG_REQUEST);
285 bool signalled = odhcp6c_signal_process();
286
287 if (res > 0)
288 break;
289 else if (signalled) {
290 mode = -1;
291 break;
292 }
293
294 mode = dhcpv6_promote_server_cand();
295 } while (mode > DHCPV6_UNKNOWN);
296
297 if (mode < 0)
298 continue;
299
300 switch (mode) {
301 case DHCPV6_STATELESS:
302 bound = true;
303 syslog(LOG_NOTICE, "entering stateless-mode on %s", ifname);
304
305 while (!signal_usr2 && !signal_term) {
306 signal_usr1 = false;
307 script_call("informed");
308
309 int res = dhcpv6_poll_reconfigure();
310 odhcp6c_signal_process();
311
312 if (res > 0)
313 continue;
314
315 if (signal_usr1) {
316 signal_usr1 = false; // Acknowledged
317 continue;
318 }
319 if (signal_usr2 || signal_term)
320 break;
321
322 res = dhcpv6_request(DHCPV6_MSG_INFO_REQ);
323 odhcp6c_signal_process();
324 if (signal_usr1)
325 continue;
326 else if (res < 0)
327 break;
328 }
329 break;
330
331 case DHCPV6_STATEFUL:
332 script_call("bound");
333 bound = true;
334 syslog(LOG_NOTICE, "entering stateful-mode on %s", ifname);
335 #ifdef EXT_BFD_PING
336 if (bfd_interval > 0)
337 bfd_start(ifname, bfd_loss, bfd_interval);
338 #endif
339
340 while (!signal_usr2 && !signal_term) {
341 // Renew Cycle
342 // Wait for T1 to expire or until we get a reconfigure
343 int res = dhcpv6_poll_reconfigure();
344 odhcp6c_signal_process();
345 if (res > 0) {
346 script_call("updated");
347 continue;
348 }
349
350 // Handle signal, if necessary
351 if (signal_usr1)
352 signal_usr1 = false; // Acknowledged
353 if (signal_usr2 || signal_term)
354 break; // Other signal type
355
356 // Send renew as T1 expired
357 size_t ia_pd_len, ia_na_len;
358 odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
359 odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
360
361 // If we have any IAs, send renew, otherwise request
362 if (ia_pd_len == 0 && ia_na_len == 0)
363 res = dhcpv6_request(DHCPV6_MSG_REQUEST);
364 else
365 res = dhcpv6_request(DHCPV6_MSG_RENEW);
366
367 odhcp6c_signal_process();
368 if (res > 0) { // Renew was succesfull
369 // Publish updates
370 script_call("updated");
371 continue; // Renew was successful
372 }
373
374 odhcp6c_clear_state(STATE_SERVER_ID); // Remove binding
375
376 // If we have IAs, try rebind otherwise restart
377 res = dhcpv6_request(DHCPV6_MSG_REBIND);
378 odhcp6c_signal_process();
379
380 if (res > 0)
381 script_call("rebound");
382 else {
383 #ifdef EXT_BFD_PING
384 bfd_stop();
385 #endif
386 break;
387 }
388 }
389 break;
390
391 default:
392 break;
393 }
394
395 size_t ia_pd_len, ia_na_len, server_id_len;
396 odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
397 odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
398 odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
399
400 // Add all prefixes to lost prefixes
401 bound = false;
402 script_call("unbound");
403
404 if (server_id_len > 0 && (ia_pd_len > 0 || ia_na_len > 0) && release)
405 dhcpv6_request(DHCPV6_MSG_RELEASE);
406
407 odhcp6c_clear_state(STATE_IA_NA);
408 odhcp6c_clear_state(STATE_IA_PD);
409 }
410
411 script_call("stopped");
412 return 0;
413 }
414
415
416 static int usage(void)
417 {
418 const char buf[] =
419 "Usage: odhcp6c [options] <interface>\n"
420 "\nFeature options:\n"
421 " -S <time> Wait at least <time> sec for a DHCP-server (0)\n"
422 " -N <mode> Mode for requesting addresses [try|force|none]\n"
423 " -P <length> Request IPv6-Prefix (0 = auto)\n"
424 " -F Force IPv6-Prefix\n"
425 " -V <hex-string> Set vendor-class option. string length must be a multiple of 2\n"
426 #ifdef EXT_BFD_PING
427 " -B <interval> Enable BFD ping check\n"
428 #endif
429 " -c <clientid> Override client-ID (base-16 encoded)\n"
430 " -i <iface-id> Use a custom interface identifier for RA handling\n"
431 " -r <options> Options to be requested (comma-separated)\n"
432 " -R Do not request any options except those specified with -r\n"
433 " -s <script> Status update script (/usr/sbin/odhcp6c-update)\n"
434 " -a Don't send Accept Reconfigure option\n"
435 " -f Don't send Client FQDN option\n"
436 " -k Don't send a RELEASE when stopping\n"
437 " -t <seconds> Maximum timeout for DHCPv6-SOLICIT (120)\n"
438 "\nInvocation options:\n"
439 " -p <pidfile> Set pidfile (/var/run/6relayd.pid)\n"
440 " -d Daemonize\n"
441 " -e Write logmessages to stderr\n"
442 //" -v Increase logging verbosity\n"
443 " -h Show this help\n\n";
444 write(STDERR_FILENO, buf, sizeof(buf));
445 return 1;
446 }
447
448
449 // Don't want to pull-in librt and libpthread just for a monotonic clock...
450 uint64_t odhcp6c_get_milli_time(void)
451 {
452 struct timespec t = {0, 0};
453 syscall(SYS_clock_gettime, CLOCK_MONOTONIC, &t);
454 return t.tv_sec * 1000 + t.tv_nsec / 1000000;
455 }
456
457
458 static uint8_t* odhcp6c_resize_state(enum odhcp6c_state state, ssize_t len)
459 {
460 if (len == 0)
461 return state_data[state] + state_len[state];
462 else if (state_len[state] + len > 1024)
463 return NULL;
464
465 uint8_t *n = realloc(state_data[state], state_len[state] + len);
466 if (n || state_len[state] + len == 0) {
467 state_data[state] = n;
468 n += state_len[state];
469 state_len[state] += len;
470 }
471 return n;
472 }
473
474
475 bool odhcp6c_signal_process(void)
476 {
477 while (signal_io) {
478 signal_io = false;
479
480 bool ra_updated = ra_process();
481
482 if (ra_link_up())
483 signal_usr2 = true;
484
485 if (ra_updated && (bound || allow_slaac_only == 0))
486 script_call("ra-updated"); // Immediate process urgent events
487 else if (ra_updated && !bound && allow_slaac_only > 0)
488 script_delay_call("ra-updated", allow_slaac_only);
489
490 #ifdef EXT_BFD_PING
491 bfd_receive();
492 #endif
493 }
494
495 return signal_usr1 || signal_usr2 || signal_term;
496 }
497
498
499 void odhcp6c_clear_state(enum odhcp6c_state state)
500 {
501 state_len[state] = 0;
502 }
503
504
505 void odhcp6c_add_state(enum odhcp6c_state state, const void *data, size_t len)
506 {
507 uint8_t *n = odhcp6c_resize_state(state, len);
508 if (n)
509 memcpy(n, data, len);
510 }
511
512 void odhcp6c_insert_state(enum odhcp6c_state state, size_t offset, const void *data, size_t len)
513 {
514 ssize_t len_after = state_len[state] - offset;
515 if (len_after < 0)
516 return;
517
518 uint8_t *n = odhcp6c_resize_state(state, len);
519 if (n) {
520 uint8_t *sdata = state_data[state];
521
522 memmove(sdata + offset + len, sdata + offset, len_after);
523 memcpy(sdata + offset, data, len);
524 }
525 }
526
527 size_t odhcp6c_remove_state(enum odhcp6c_state state, size_t offset, size_t len)
528 {
529 uint8_t *data = state_data[state];
530 ssize_t len_after = state_len[state] - (offset + len);
531 if (len_after < 0)
532 return state_len[state];
533
534 memmove(data + offset, data + offset + len, len_after);
535 return state_len[state] -= len;
536 }
537
538
539 void* odhcp6c_move_state(enum odhcp6c_state state, size_t *len)
540 {
541 *len = state_len[state];
542 void *data = state_data[state];
543
544 state_len[state] = 0;
545 state_data[state] = NULL;
546
547 return data;
548 }
549
550
551 void* odhcp6c_get_state(enum odhcp6c_state state, size_t *len)
552 {
553 *len = state_len[state];
554 return state_data[state];
555 }
556
557
558 struct odhcp6c_entry* odhcp6c_find_entry(enum odhcp6c_state state, const struct odhcp6c_entry *new)
559 {
560 size_t len, cmplen = offsetof(struct odhcp6c_entry, target) + new->length / 8;
561 struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
562 struct odhcp6c_entry *x = NULL;
563
564 for (struct odhcp6c_entry *c = start; !x && c < &start[len/sizeof(*c)]; ++c)
565 if (!memcmp(c, new, cmplen))
566 return c;
567
568 return NULL;
569 }
570
571
572 bool odhcp6c_update_entry_safe(enum odhcp6c_state state, struct odhcp6c_entry *new, uint32_t safe)
573 {
574 size_t len;
575 struct odhcp6c_entry *x = odhcp6c_find_entry(state, new);
576 struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
577
578 if (x && x->valid > new->valid && new->valid < safe)
579 new->valid = safe;
580
581 if (new->valid > 0) {
582 if (x) {
583 if (new->valid >= x->valid && new->valid - x->valid < 60 &&
584 new->preferred >= x->preferred &&
585 new->preferred - x->preferred < 60 &&
586 x->class == new->class)
587 return false;
588 x->valid = new->valid;
589 x->preferred = new->preferred;
590 x->t1 = new->t1;
591 x->t2 = new->t2;
592 x->class = new->class;
593 x->iaid = new->iaid;
594 } else {
595 odhcp6c_add_state(state, new, sizeof(*new));
596 }
597 } else if (x) {
598 odhcp6c_remove_state(state, (x - start) * sizeof(*x), sizeof(*x));
599 }
600 return true;
601 }
602
603
604 bool odhcp6c_update_entry(enum odhcp6c_state state, struct odhcp6c_entry *new)
605 {
606 return odhcp6c_update_entry_safe(state, new, 0);
607 }
608
609
610 static void odhcp6c_expire_list(enum odhcp6c_state state, uint32_t elapsed)
611 {
612 size_t len;
613 struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
614 for (struct odhcp6c_entry *c = start; c < &start[len / sizeof(*c)]; ++c) {
615 if (c->t1 < elapsed)
616 c->t1 = 0;
617 else if (c->t1 != UINT32_MAX)
618 c->t1 -= elapsed;
619
620 if (c->t2 < elapsed)
621 c->t2 = 0;
622 else if (c->t2 != UINT32_MAX)
623 c->t2 -= elapsed;
624
625 if (c->preferred < elapsed)
626 c->preferred = 0;
627 else if (c->preferred != UINT32_MAX)
628 c->preferred -= elapsed;
629
630 if (c->valid < elapsed)
631 c->valid = 0;
632 else if (c->valid != UINT32_MAX)
633 c->valid -= elapsed;
634
635 if (!c->valid)
636 odhcp6c_remove_state(state, (c - start) * sizeof(*c), sizeof(*c));
637 }
638 }
639
640
641 void odhcp6c_expire(void)
642 {
643 time_t now = odhcp6c_get_milli_time() / 1000;
644 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
645 last_update = now;
646
647 odhcp6c_expire_list(STATE_RA_PREFIX, elapsed);
648 odhcp6c_expire_list(STATE_RA_ROUTE, elapsed);
649 odhcp6c_expire_list(STATE_RA_DNS, elapsed);
650 odhcp6c_expire_list(STATE_IA_NA, elapsed);
651 odhcp6c_expire_list(STATE_IA_PD, elapsed);
652 }
653
654
655 uint32_t odhcp6c_elapsed(void)
656 {
657 return odhcp6c_get_milli_time() / 1000 - last_update;
658 }
659
660
661 void odhcp6c_random(void *buf, size_t len)
662 {
663 read(urandom_fd, buf, len);
664 }
665
666 bool odhcp6c_is_bound(void)
667 {
668 return bound;
669 }
670
671 static void sighandler(int signal)
672 {
673 if (signal == SIGCHLD)
674 while (waitpid(-1, NULL, WNOHANG) > 0);
675 else if (signal == SIGUSR1)
676 signal_usr1 = true;
677 else if (signal == SIGUSR2)
678 signal_usr2 = true;
679 else if (signal == SIGIO)
680 signal_io = true;
681 else
682 signal_term = true;
683 }
Openwrt DHCPv6 Client