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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_NONE;
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 (ia_pd_mode == IA_MODE_NONE)
108 ia_pd_mode = IA_MODE_TRY;
109
110 if (allow_slaac_only >= 0 && allow_slaac_only < 10)
111 allow_slaac_only = 10;
112
113 char *iaid_begin;
114 int iaid_len = 0;
115
116 int prefix_length = strtoul(optarg, &iaid_begin, 10);
117
118 if (*iaid_begin != '\0' && *iaid_begin != ',') {
119 syslog(LOG_ERR, "invalid argument: '%s'", optarg);
120 return 1;
121 }
122
123 struct odhcp6c_request_prefix prefix = { 0, prefix_length };
124
125 if (*iaid_begin == ',' && (iaid_len = strlen(iaid_begin)) > 1)
126 memcpy(&prefix.iaid, iaid_begin + 1, iaid_len > 4 ? 4 : iaid_len);
127 else
128 prefix.iaid = ++ia_pd_iaid_index;
129
130 odhcp6c_add_state(STATE_IA_PD_INIT, &prefix, sizeof(prefix));
131
132 break;
133
134 case 'F':
135 allow_slaac_only = -1;
136 ia_pd_mode = IA_MODE_FORCE;
137 break;
138
139 #ifdef EXT_BFD_PING
140 case 'B':
141 bfd_interval = atoi(optarg);
142 break;
143 #endif
144
145 case 'c':
146 l = script_unhexlify(&buf[4], sizeof(buf) - 4, optarg);
147 if (l > 0) {
148 buf[0] = 0;
149 buf[1] = DHCPV6_OPT_CLIENTID;
150 buf[2] = 0;
151 buf[3] = l;
152 odhcp6c_add_state(STATE_CLIENT_ID, buf, l + 4);
153 } else {
154 help = true;
155 }
156 break;
157
158 case 'i':
159 if (inet_pton(AF_INET6, optarg, &ifid) != 1)
160 help = true;
161 break;
162
163 case 'r':
164 optpos = optarg;
165 while (optpos[0]) {
166 opttype = htons(strtoul(optarg, &optpos, 10));
167 if (optpos == optarg)
168 break;
169 else if (optpos[0])
170 optarg = &optpos[1];
171 odhcp6c_add_state(STATE_ORO, &opttype, 2);
172 }
173 break;
174
175 case 'R':
176 client_options |= DHCPV6_STRICT_OPTIONS;
177 break;
178
179 case 's':
180 script = optarg;
181 break;
182
183 case 'k':
184 release = false;
185 break;
186
187 case 't':
188 sol_timeout = atoi(optarg);
189 break;
190
191 case 'e':
192 logopt |= LOG_PERROR;
193 break;
194
195 case 'd':
196 daemonize = true;
197 break;
198
199 case 'p':
200 pidfile = optarg;
201 break;
202
203 case 'f':
204 client_options &= ~DHCPV6_CLIENT_FQDN;
205 break;
206
207 case 'a':
208 client_options &= ~DHCPV6_ACCEPT_RECONFIGURE;
209 break;
210
211 default:
212 help = true;
213 break;
214 }
215 }
216
217 openlog("odhcp6c", logopt, LOG_DAEMON);
218 const char *ifname = argv[optind];
219
220 if (help || !ifname)
221 return usage();
222
223 signal(SIGIO, sighandler);
224 signal(SIGHUP, sighandler);
225 signal(SIGINT, sighandler);
226 signal(SIGCHLD, sighandler);
227 signal(SIGTERM, sighandler);
228 signal(SIGUSR1, sighandler);
229 signal(SIGUSR2, sighandler);
230
231 if ((urandom_fd = open("/dev/urandom", O_CLOEXEC | O_RDONLY)) < 0 ||
232 init_dhcpv6(ifname, client_options, sol_timeout) ||
233 ra_init(ifname, &ifid) || script_init(script, ifname)) {
234 syslog(LOG_ERR, "failed to initialize: %s", strerror(errno));
235 return 3;
236 }
237
238 if (daemonize) {
239 openlog("odhcp6c", LOG_PID, LOG_DAEMON); // Disable LOG_PERROR
240 if (daemon(0, 0)) {
241 syslog(LOG_ERR, "Failed to daemonize: %s",
242 strerror(errno));
243 return 4;
244 }
245
246 char pidbuf[128];
247 if (!pidfile) {
248 snprintf(pidbuf, sizeof(pidbuf),
249 "/var/run/odhcp6c.%s.pid", ifname);
250 pidfile = pidbuf;
251 }
252
253 int fd = open(pidfile, O_WRONLY | O_CREAT);
254 if (fd >= 0) {
255 char buf[8];
256 int len = snprintf(buf, sizeof(buf), "%i\n", getpid());
257 write(fd, buf, len);
258 close(fd);
259 }
260 }
261
262 script_call("started");
263
264 while (!signal_term) { // Main logic
265 odhcp6c_clear_state(STATE_SERVER_ID);
266 odhcp6c_clear_state(STATE_IA_NA);
267 odhcp6c_clear_state(STATE_IA_PD);
268 odhcp6c_clear_state(STATE_SNTP_IP);
269 odhcp6c_clear_state(STATE_NTP_IP);
270 odhcp6c_clear_state(STATE_NTP_FQDN);
271 odhcp6c_clear_state(STATE_SIP_IP);
272 odhcp6c_clear_state(STATE_SIP_FQDN);
273 dhcpv6_set_ia_mode(ia_na_mode, ia_pd_mode);
274 bound = false;
275
276 syslog(LOG_NOTICE, "(re)starting transaction on %s", ifname);
277
278 signal_usr1 = signal_usr2 = false;
279 int mode = dhcpv6_request(DHCPV6_MSG_SOLICIT);
280 odhcp6c_signal_process();
281
282 if (mode < 0)
283 continue;
284
285 do {
286 int res = dhcpv6_request(mode == DHCPV6_STATELESS ?
287 DHCPV6_MSG_INFO_REQ : DHCPV6_MSG_REQUEST);
288 bool signalled = odhcp6c_signal_process();
289
290 if (res > 0)
291 break;
292 else if (signalled) {
293 mode = -1;
294 break;
295 }
296
297 mode = dhcpv6_promote_server_cand();
298 } while (mode > DHCPV6_UNKNOWN);
299
300 if (mode < 0)
301 continue;
302
303 switch (mode) {
304 case DHCPV6_STATELESS:
305 bound = true;
306 syslog(LOG_NOTICE, "entering stateless-mode on %s", ifname);
307
308 while (!signal_usr2 && !signal_term) {
309 signal_usr1 = false;
310 script_call("informed");
311
312 int res = dhcpv6_poll_reconfigure();
313 odhcp6c_signal_process();
314
315 if (res > 0)
316 continue;
317
318 if (signal_usr1) {
319 signal_usr1 = false; // Acknowledged
320 continue;
321 }
322 if (signal_usr2 || signal_term)
323 break;
324
325 res = dhcpv6_request(DHCPV6_MSG_INFO_REQ);
326 odhcp6c_signal_process();
327 if (signal_usr1)
328 continue;
329 else if (res < 0)
330 break;
331 }
332 break;
333
334 case DHCPV6_STATEFUL:
335 script_call("bound");
336 bound = true;
337 syslog(LOG_NOTICE, "entering stateful-mode on %s", ifname);
338 #ifdef EXT_BFD_PING
339 if (bfd_interval > 0)
340 bfd_start(ifname, bfd_loss, bfd_interval);
341 #endif
342
343 while (!signal_usr2 && !signal_term) {
344 // Renew Cycle
345 // Wait for T1 to expire or until we get a reconfigure
346 int res = dhcpv6_poll_reconfigure();
347 odhcp6c_signal_process();
348 if (res > 0) {
349 script_call("updated");
350 continue;
351 }
352
353 // Handle signal, if necessary
354 if (signal_usr1)
355 signal_usr1 = false; // Acknowledged
356 if (signal_usr2 || signal_term)
357 break; // Other signal type
358
359 // Send renew as T1 expired
360 size_t ia_pd_len, ia_na_len;
361 odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
362 odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
363
364 // If we have any IAs, send renew, otherwise request
365 if (ia_pd_len == 0 && ia_na_len == 0)
366 res = dhcpv6_request(DHCPV6_MSG_REQUEST);
367 else
368 res = dhcpv6_request(DHCPV6_MSG_RENEW);
369
370 odhcp6c_signal_process();
371 if (res > 0) { // Renew was succesfull
372 // Publish updates
373 script_call("updated");
374 continue; // Renew was successful
375 }
376
377 odhcp6c_clear_state(STATE_SERVER_ID); // Remove binding
378
379 // If we have IAs, try rebind otherwise restart
380 res = dhcpv6_request(DHCPV6_MSG_REBIND);
381 odhcp6c_signal_process();
382
383 if (res > 0)
384 script_call("rebound");
385 else {
386 #ifdef EXT_BFD_PING
387 bfd_stop();
388 #endif
389 break;
390 }
391 }
392 break;
393
394 default:
395 break;
396 }
397
398 size_t ia_pd_len, ia_na_len, server_id_len;
399 odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
400 odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
401 odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
402
403 // Add all prefixes to lost prefixes
404 bound = false;
405 script_call("unbound");
406
407 if (server_id_len > 0 && (ia_pd_len > 0 || ia_na_len > 0) && release)
408 dhcpv6_request(DHCPV6_MSG_RELEASE);
409
410 odhcp6c_clear_state(STATE_IA_NA);
411 odhcp6c_clear_state(STATE_IA_PD);
412 }
413
414 script_call("stopped");
415 return 0;
416 }
417
418
419 static int usage(void)
420 {
421 const char buf[] =
422 "Usage: odhcp6c [options] <interface>\n"
423 "\nFeature options:\n"
424 " -S <time> Wait at least <time> sec for a DHCP-server (0)\n"
425 " -N <mode> Mode for requesting addresses [try|force|none]\n"
426 " -P <length> Request IPv6-Prefix (0 = auto)\n"
427 " -F Force IPv6-Prefix\n"
428 " -V <hex-string> Set vendor-class option. string length must be a multiple of 2\n"
429 #ifdef EXT_BFD_PING
430 " -B <interval> Enable BFD ping check\n"
431 #endif
432 " -c <clientid> Override client-ID (base-16 encoded)\n"
433 " -i <iface-id> Use a custom interface identifier for RA handling\n"
434 " -r <options> Options to be requested (comma-separated)\n"
435 " -R Do not request any options except those specified with -r\n"
436 " -s <script> Status update script (/usr/sbin/odhcp6c-update)\n"
437 " -a Don't send Accept Reconfigure option\n"
438 " -f Don't send Client FQDN option\n"
439 " -k Don't send a RELEASE when stopping\n"
440 " -t <seconds> Maximum timeout for DHCPv6-SOLICIT (120)\n"
441 "\nInvocation options:\n"
442 " -p <pidfile> Set pidfile (/var/run/odhcp6c.pid)\n"
443 " -d Daemonize\n"
444 " -e Write logmessages to stderr\n"
445 //" -v Increase logging verbosity\n"
446 " -h Show this help\n\n";
447 write(STDERR_FILENO, buf, sizeof(buf));
448 return 1;
449 }
450
451
452 // Don't want to pull-in librt and libpthread just for a monotonic clock...
453 uint64_t odhcp6c_get_milli_time(void)
454 {
455 struct timespec t = {0, 0};
456 syscall(SYS_clock_gettime, CLOCK_MONOTONIC, &t);
457 return t.tv_sec * 1000 + t.tv_nsec / 1000000;
458 }
459
460
461 static uint8_t* odhcp6c_resize_state(enum odhcp6c_state state, ssize_t len)
462 {
463 if (len == 0)
464 return state_data[state] + state_len[state];
465 else if (state_len[state] + len > 1024)
466 return NULL;
467
468 uint8_t *n = realloc(state_data[state], state_len[state] + len);
469 if (n || state_len[state] + len == 0) {
470 state_data[state] = n;
471 n += state_len[state];
472 state_len[state] += len;
473 }
474 return n;
475 }
476
477
478 bool odhcp6c_signal_process(void)
479 {
480 while (signal_io) {
481 signal_io = false;
482
483 bool ra_updated = ra_process();
484
485 if (ra_link_up())
486 signal_usr2 = true;
487
488 if (ra_updated && (bound || allow_slaac_only == 0))
489 script_call("ra-updated"); // Immediate process urgent events
490 else if (ra_updated && !bound && allow_slaac_only > 0)
491 script_delay_call("ra-updated", allow_slaac_only);
492
493 #ifdef EXT_BFD_PING
494 bfd_receive();
495 #endif
496 }
497
498 return signal_usr1 || signal_usr2 || signal_term;
499 }
500
501
502 void odhcp6c_clear_state(enum odhcp6c_state state)
503 {
504 state_len[state] = 0;
505 }
506
507
508 void odhcp6c_add_state(enum odhcp6c_state state, const void *data, size_t len)
509 {
510 uint8_t *n = odhcp6c_resize_state(state, len);
511 if (n)
512 memcpy(n, data, len);
513 }
514
515 void odhcp6c_insert_state(enum odhcp6c_state state, size_t offset, const void *data, size_t len)
516 {
517 ssize_t len_after = state_len[state] - offset;
518 if (len_after < 0)
519 return;
520
521 uint8_t *n = odhcp6c_resize_state(state, len);
522 if (n) {
523 uint8_t *sdata = state_data[state];
524
525 memmove(sdata + offset + len, sdata + offset, len_after);
526 memcpy(sdata + offset, data, len);
527 }
528 }
529
530 size_t odhcp6c_remove_state(enum odhcp6c_state state, size_t offset, size_t len)
531 {
532 uint8_t *data = state_data[state];
533 ssize_t len_after = state_len[state] - (offset + len);
534 if (len_after < 0)
535 return state_len[state];
536
537 memmove(data + offset, data + offset + len, len_after);
538 return state_len[state] -= len;
539 }
540
541
542 void* odhcp6c_move_state(enum odhcp6c_state state, size_t *len)
543 {
544 *len = state_len[state];
545 void *data = state_data[state];
546
547 state_len[state] = 0;
548 state_data[state] = NULL;
549
550 return data;
551 }
552
553
554 void* odhcp6c_get_state(enum odhcp6c_state state, size_t *len)
555 {
556 *len = state_len[state];
557 return state_data[state];
558 }
559
560
561 struct odhcp6c_entry* odhcp6c_find_entry(enum odhcp6c_state state, const struct odhcp6c_entry *new)
562 {
563 size_t len, cmplen = offsetof(struct odhcp6c_entry, target) + new->length / 8;
564 struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
565 struct odhcp6c_entry *x = NULL;
566
567 for (struct odhcp6c_entry *c = start; !x && c < &start[len/sizeof(*c)]; ++c)
568 if (!memcmp(c, new, cmplen))
569 return c;
570
571 return NULL;
572 }
573
574
575 bool odhcp6c_update_entry_safe(enum odhcp6c_state state, struct odhcp6c_entry *new, uint32_t safe)
576 {
577 size_t len;
578 struct odhcp6c_entry *x = odhcp6c_find_entry(state, new);
579 struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
580
581 if (x && x->valid > new->valid && new->valid < safe)
582 new->valid = safe;
583
584 if (new->valid > 0) {
585 if (x) {
586 if (new->valid >= x->valid && new->valid - x->valid < 60 &&
587 new->preferred >= x->preferred &&
588 new->preferred - x->preferred < 60 &&
589 x->class == new->class)
590 return false;
591 x->valid = new->valid;
592 x->preferred = new->preferred;
593 x->t1 = new->t1;
594 x->t2 = new->t2;
595 x->class = new->class;
596 x->iaid = new->iaid;
597 } else {
598 odhcp6c_add_state(state, new, sizeof(*new));
599 }
600 } else if (x) {
601 odhcp6c_remove_state(state, (x - start) * sizeof(*x), sizeof(*x));
602 }
603 return true;
604 }
605
606
607 bool odhcp6c_update_entry(enum odhcp6c_state state, struct odhcp6c_entry *new)
608 {
609 return odhcp6c_update_entry_safe(state, new, 0);
610 }
611
612
613 static void odhcp6c_expire_list(enum odhcp6c_state state, uint32_t elapsed)
614 {
615 size_t len;
616 struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
617 for (struct odhcp6c_entry *c = start; c < &start[len / sizeof(*c)]; ++c) {
618 if (c->t1 < elapsed)
619 c->t1 = 0;
620 else if (c->t1 != UINT32_MAX)
621 c->t1 -= elapsed;
622
623 if (c->t2 < elapsed)
624 c->t2 = 0;
625 else if (c->t2 != UINT32_MAX)
626 c->t2 -= elapsed;
627
628 if (c->preferred < elapsed)
629 c->preferred = 0;
630 else if (c->preferred != UINT32_MAX)
631 c->preferred -= elapsed;
632
633 if (c->valid < elapsed)
634 c->valid = 0;
635 else if (c->valid != UINT32_MAX)
636 c->valid -= elapsed;
637
638 if (!c->valid)
639 odhcp6c_remove_state(state, (c - start) * sizeof(*c), sizeof(*c));
640 }
641 }
642
643
644 void odhcp6c_expire(void)
645 {
646 time_t now = odhcp6c_get_milli_time() / 1000;
647 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
648 last_update = now;
649
650 odhcp6c_expire_list(STATE_RA_PREFIX, elapsed);
651 odhcp6c_expire_list(STATE_RA_ROUTE, elapsed);
652 odhcp6c_expire_list(STATE_RA_DNS, elapsed);
653 odhcp6c_expire_list(STATE_IA_NA, elapsed);
654 odhcp6c_expire_list(STATE_IA_PD, elapsed);
655 }
656
657
658 uint32_t odhcp6c_elapsed(void)
659 {
660 return odhcp6c_get_milli_time() / 1000 - last_update;
661 }
662
663
664 void odhcp6c_random(void *buf, size_t len)
665 {
666 read(urandom_fd, buf, len);
667 }
668
669 bool odhcp6c_is_bound(void)
670 {
671 return bound;
672 }
673
674 static void sighandler(int signal)
675 {
676 if (signal == SIGCHLD)
677 while (waitpid(-1, NULL, WNOHANG) > 0);
678 else if (signal == SIGUSR1)
679 signal_usr1 = true;
680 else if (signal == SIGUSR2)
681 signal_usr2 = true;
682 else if (signal == SIGIO)
683 signal_io = true;
684 else
685 signal_term = true;
686 }
Openwrt DHCPv6 Client