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