projects / project / odhcp6c.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
history | raw | HEAD
Avoid of waiting for Advertise in stateless-only mode
[project/odhcp6c.git] / src / odhcp6c.c
1 /**
2 * Copyright (C) 2012-2014 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
36
37 static void sighandler(int signal);
38 static int usage(void);
39
40 static uint8_t *state_data[_STATE_MAX] = {NULL};
41 static size_t state_len[_STATE_MAX] = {0};
42
43 static volatile bool signal_io = false;
44 static volatile bool signal_usr1 = false;
45 static volatile bool signal_usr2 = false;
46 static volatile bool signal_term = false;
47
48 static int urandom_fd = -1, allow_slaac_only = 0;
49 static bool bound = false, release = true;
50 static time_t last_update = 0;
51
52 static unsigned int min_update_interval = DEFAULT_MIN_UPDATE_INTERVAL;
53
54 int main(_unused int argc, char* const argv[])
55 {
56 // Allocate ressources
57 const char *pidfile = NULL;
58 const char *script = "/usr/sbin/odhcp6c-update";
59 ssize_t l;
60 uint8_t buf[134];
61 char *optpos;
62 uint16_t opttype;
63 uint16_t optlen;
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 int verbosity = 0;
70
71
72 bool help = false, daemonize = false;
73 int logopt = LOG_PID;
74 int c;
75 unsigned int client_options = DHCPV6_CLIENT_FQDN | DHCPV6_ACCEPT_RECONFIGURE;
76
77 while ((c = getopt(argc, argv, "S::N:V:P:FB:c:i:r:Ru:s:kt:m:hedp:fav")) != -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 'V':
97 l = script_unhexlify(buf, sizeof(buf), optarg);
98 if (!l)
99 help=true;
100
101 odhcp6c_add_state(STATE_VENDORCLASS, buf, l);
102
103 break;
104 case 'P':
105 if (ia_pd_mode == IA_MODE_NONE)
106 ia_pd_mode = IA_MODE_TRY;
107
108 if (allow_slaac_only >= 0 && allow_slaac_only < 10)
109 allow_slaac_only = 10;
110
111 char *iaid_begin;
112 int iaid_len = 0;
113
114 int prefix_length = strtoul(optarg, &iaid_begin, 10);
115
116 if (*iaid_begin != '\0' && *iaid_begin != ',' && *iaid_begin != ':') {
117 syslog(LOG_ERR, "invalid argument: '%s'", optarg);
118 return 1;
119 }
120
121 struct odhcp6c_request_prefix prefix = { 0, prefix_length };
122
123 if (*iaid_begin == ',' && (iaid_len = strlen(iaid_begin)) > 1)
124 memcpy(&prefix.iaid, iaid_begin + 1, iaid_len > 4 ? 4 : iaid_len);
125 else if (*iaid_begin == ':')
126 prefix.iaid = htonl((uint32_t)strtoul(&iaid_begin[1], NULL, 16));
127 else
128 prefix.iaid = htonl(++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 case 'c':
140 l = script_unhexlify(&buf[4], sizeof(buf) - 4, optarg);
141 if (l > 0) {
142 buf[0] = 0;
143 buf[1] = DHCPV6_OPT_CLIENTID;
144 buf[2] = 0;
145 buf[3] = l;
146 odhcp6c_add_state(STATE_CLIENT_ID, buf, l + 4);
147 } else {
148 help = true;
149 }
150 break;
151
152 case 'i':
153 if (inet_pton(AF_INET6, optarg, &ifid) != 1)
154 help = true;
155 break;
156
157 case 'r':
158 optpos = optarg;
159 while (optpos[0]) {
160 opttype = htons(strtoul(optarg, &optpos, 10));
161 if (optpos == optarg)
162 break;
163 else if (optpos[0])
164 optarg = &optpos[1];
165 odhcp6c_add_state(STATE_ORO, &opttype, 2);
166 }
167 break;
168
169 case 'R':
170 client_options |= DHCPV6_STRICT_OPTIONS;
171 break;
172
173 case 'u':
174 optlen = htons(strlen(optarg));
175 odhcp6c_add_state(STATE_USERCLASS, &optlen, 2);
176 odhcp6c_add_state(STATE_USERCLASS, optarg, strlen(optarg));
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 'm':
192 min_update_interval = atoi(optarg);
193 break;
194
195 case 'e':
196 logopt |= LOG_PERROR;
197 break;
198
199 case 'd':
200 daemonize = true;
201 break;
202
203 case 'p':
204 pidfile = optarg;
205 break;
206
207 case 'f':
208 client_options &= ~DHCPV6_CLIENT_FQDN;
209 break;
210
211 case 'a':
212 client_options &= ~DHCPV6_ACCEPT_RECONFIGURE;
213 break;
214
215 case 'v':
216 ++verbosity;
217 break;
218
219 default:
220 help = true;
221 break;
222 }
223 }
224
225 openlog("odhcp6c", logopt, LOG_DAEMON);
226 if (!verbosity)
227 setlogmask(LOG_UPTO(LOG_WARNING));
228
229 const char *ifname = argv[optind];
230
231 if (help || !ifname)
232 return usage();
233
234 signal(SIGIO, sighandler);
235 signal(SIGHUP, sighandler);
236 signal(SIGINT, sighandler);
237 signal(SIGCHLD, sighandler);
238 signal(SIGTERM, sighandler);
239 signal(SIGUSR1, sighandler);
240 signal(SIGUSR2, sighandler);
241
242 if ((urandom_fd = open("/dev/urandom", O_CLOEXEC | O_RDONLY)) < 0 ||
243 init_dhcpv6(ifname, client_options, sol_timeout) ||
244 ra_init(ifname, &ifid) || script_init(script, ifname)) {
245 syslog(LOG_ERR, "failed to initialize: %s", strerror(errno));
246 return 3;
247 }
248
249 if (daemonize) {
250 openlog("odhcp6c", LOG_PID, LOG_DAEMON); // Disable LOG_PERROR
251 if (daemon(0, 0)) {
252 syslog(LOG_ERR, "Failed to daemonize: %s",
253 strerror(errno));
254 return 4;
255 }
256
257 if (!pidfile) {
258 snprintf((char*)buf, sizeof(buf), "/var/run/odhcp6c.%s.pid", ifname);
259 pidfile = (char*)buf;
260 }
261
262 FILE *fp = fopen(pidfile, "w");
263 if (fp) {
264 fprintf(fp, "%i\n", getpid());
265 fclose(fp);
266 }
267 }
268
269 script_call("started");
270
271 while (!signal_term) { // Main logic
272 odhcp6c_clear_state(STATE_SERVER_ID);
273 odhcp6c_clear_state(STATE_SERVER_ADDR);
274 odhcp6c_clear_state(STATE_IA_NA);
275 odhcp6c_clear_state(STATE_IA_PD);
276 odhcp6c_clear_state(STATE_SNTP_IP);
277 odhcp6c_clear_state(STATE_NTP_IP);
278 odhcp6c_clear_state(STATE_NTP_FQDN);
279 odhcp6c_clear_state(STATE_SIP_IP);
280 odhcp6c_clear_state(STATE_SIP_FQDN);
281 bound = false;
282
283 syslog(LOG_NOTICE, "(re)starting transaction on %s", ifname);
284
285 signal_usr1 = signal_usr2 = false;
286 int mode = dhcpv6_set_ia_mode(ia_na_mode, ia_pd_mode);
287 if (mode != DHCPV6_STATELESS)
288 mode = dhcpv6_request(DHCPV6_MSG_SOLICIT);
289 odhcp6c_signal_process();
290
291 if (mode < 0)
292 continue;
293
294 do {
295 int res = dhcpv6_request(mode == DHCPV6_STATELESS ?
296 DHCPV6_MSG_INFO_REQ : DHCPV6_MSG_REQUEST);
297 bool signalled = odhcp6c_signal_process();
298
299 if (res > 0)
300 break;
301 else if (signalled) {
302 mode = -1;
303 break;
304 }
305
306 mode = dhcpv6_promote_server_cand();
307 } while (mode > DHCPV6_UNKNOWN);
308
309 if (mode < 0)
310 continue;
311
312 switch (mode) {
313 case DHCPV6_STATELESS:
314 bound = true;
315 syslog(LOG_NOTICE, "entering stateless-mode on %s", ifname);
316
317 while (!signal_usr2 && !signal_term) {
318 signal_usr1 = false;
319 script_call("informed");
320
321 int res = dhcpv6_poll_reconfigure();
322 odhcp6c_signal_process();
323
324 if (res > 0)
325 continue;
326
327 if (signal_usr1) {
328 signal_usr1 = false; // Acknowledged
329 continue;
330 }
331 if (signal_usr2 || signal_term)
332 break;
333
334 res = dhcpv6_request(DHCPV6_MSG_INFO_REQ);
335 odhcp6c_signal_process();
336 if (signal_usr1)
337 continue;
338 else if (res < 0)
339 break;
340 }
341 break;
342
343 case DHCPV6_STATEFUL:
344 bound = true;
345 script_call("bound");
346 syslog(LOG_NOTICE, "entering stateful-mode on %s", ifname);
347
348 while (!signal_usr2 && !signal_term) {
349 // Renew Cycle
350 // Wait for T1 to expire or until we get a reconfigure
351 int res = dhcpv6_poll_reconfigure();
352 odhcp6c_signal_process();
353 if (res > 0) {
354 script_call("updated");
355 continue;
356 }
357
358 // Handle signal, if necessary
359 if (signal_usr1)
360 signal_usr1 = false; // Acknowledged
361 if (signal_usr2 || signal_term)
362 break; // Other signal type
363
364 // Send renew as T1 expired
365 res = dhcpv6_request(DHCPV6_MSG_RENEW);
366 odhcp6c_signal_process();
367 if (res > 0) { // Renew was succesfull
368 // Publish updates
369 script_call("updated");
370 continue; // Renew was successful
371 }
372
373 odhcp6c_clear_state(STATE_SERVER_ID); // Remove binding
374 odhcp6c_clear_state(STATE_SERVER_ADDR);
375
376 size_t ia_pd_len, ia_na_len;
377 odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
378 odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
379
380 if (ia_pd_len == 0 && ia_na_len == 0)
381 break;
382
383 // If we have IAs, try rebind otherwise restart
384 res = dhcpv6_request(DHCPV6_MSG_REBIND);
385 odhcp6c_signal_process();
386
387 if (res > 0)
388 script_call("rebound");
389 else {
390 break;
391 }
392 }
393 break;
394
395 default:
396 break;
397 }
398
399 odhcp6c_expire();
400
401 size_t ia_pd_len, ia_na_len, server_id_len;
402 odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
403 odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
404 odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
405
406 // Add all prefixes to lost prefixes
407 bound = false;
408 script_call("unbound");
409
410 if (server_id_len > 0 && (ia_pd_len > 0 || ia_na_len > 0) && release)
411 dhcpv6_request(DHCPV6_MSG_RELEASE);
412
413 odhcp6c_clear_state(STATE_IA_NA);
414 odhcp6c_clear_state(STATE_IA_PD);
415 }
416
417 script_call("stopped");
418 return 0;
419 }
420
421
422 static int usage(void)
423 {
424 const char buf[] =
425 "Usage: odhcp6c [options] <interface>\n"
426 "\nFeature options:\n"
427 " -S <time> Wait at least <time> sec for a DHCP-server (0)\n"
428 " -N <mode> Mode for requesting addresses [try|force|none]\n"
429 " -P <length> Request IPv6-Prefix (0 = auto)\n"
430 " -F Force IPv6-Prefix\n"
431 " -V <class> Set vendor-class option (base-16 encoded)\n"
432 " -u <user-class> Set user-class option string\n"
433 " -c <clientid> Override client-ID (base-16 encoded 16-bit type + value)\n"
434 " -i <iface-id> Use a custom interface identifier for RA handling\n"
435 " -r <options> Options to be requested (comma-separated)\n"
436 " -R Do not request any options except those specified with -r\n"
437 " -s <script> Status update script (/usr/sbin/odhcp6c-update)\n"
438 " -a Don't send Accept Reconfigure option\n"
439 " -f Don't send Client FQDN option\n"
440 " -k Don't send a RELEASE when stopping\n"
441 " -t <seconds> Maximum timeout for DHCPv6-SOLICIT (120)\n"
442 " -m <seconds> Minimum time between accepting updates (30)\n"
443 "\nInvocation options:\n"
444 " -p <pidfile> Set pidfile (/var/run/odhcp6c.pid)\n"
445 " -d Daemonize\n"
446 " -e Write logmessages to stderr\n"
447 " -v Increase logging verbosity\n"
448 " -h Show this help\n\n";
449 fputs(buf, stderr);
450 return 1;
451 }
452
453
454 // Don't want to pull-in librt and libpthread just for a monotonic clock...
455 uint64_t odhcp6c_get_milli_time(void)
456 {
457 struct timespec t = {0, 0};
458 syscall(SYS_clock_gettime, CLOCK_MONOTONIC, &t);
459 return ((uint64_t)t.tv_sec) * 1000 + ((uint64_t)t.tv_nsec) / 1000000;
460 }
461
462
463 static uint8_t* odhcp6c_resize_state(enum odhcp6c_state state, ssize_t len)
464 {
465 if (len == 0)
466 return state_data[state] + state_len[state];
467 else if (state_len[state] + len > 1024)
468 return NULL;
469
470 uint8_t *n = realloc(state_data[state], state_len[state] + len);
471 if (n || state_len[state] + len == 0) {
472 state_data[state] = n;
473 n += state_len[state];
474 state_len[state] += len;
475 }
476 return n;
477 }
478
479
480 bool odhcp6c_signal_process(void)
481 {
482 while (signal_io) {
483 signal_io = false;
484
485 bool ra_updated = ra_process();
486
487 if (ra_link_up())
488 signal_usr2 = true;
489
490 if (ra_updated && (bound || allow_slaac_only >= 0))
491 script_call("ra-updated"); // Immediate process urgent events
492 }
493
494 return signal_usr1 || signal_usr2 || signal_term;
495 }
496
497
498 void odhcp6c_clear_state(enum odhcp6c_state state)
499 {
500 state_len[state] = 0;
501 }
502
503
504 void odhcp6c_add_state(enum odhcp6c_state state, const void *data, size_t len)
505 {
506 uint8_t *n = odhcp6c_resize_state(state, len);
507 if (n)
508 memcpy(n, data, len);
509 }
510
511 void odhcp6c_insert_state(enum odhcp6c_state state, size_t offset, const void *data, size_t len)
512 {
513 ssize_t len_after = state_len[state] - offset;
514 if (len_after < 0)
515 return;
516
517 uint8_t *n = odhcp6c_resize_state(state, len);
518 if (n) {
519 uint8_t *sdata = state_data[state];
520
521 memmove(sdata + offset + len, sdata + offset, len_after);
522 memcpy(sdata + offset, data, len);
523 }
524 }
525
526 size_t odhcp6c_remove_state(enum odhcp6c_state state, size_t offset, size_t len)
527 {
528 uint8_t *data = state_data[state];
529 ssize_t len_after = state_len[state] - (offset + len);
530 if (len_after < 0)
531 return state_len[state];
532
533 memmove(data + offset, data + offset + len, len_after);
534 return state_len[state] -= len;
535 }
536
537
538 void* odhcp6c_move_state(enum odhcp6c_state state, size_t *len)
539 {
540 *len = state_len[state];
541 void *data = state_data[state];
542
543 state_len[state] = 0;
544 state_data[state] = NULL;
545
546 return data;
547 }
548
549
550 void* odhcp6c_get_state(enum odhcp6c_state state, size_t *len)
551 {
552 *len = state_len[state];
553 return state_data[state];
554 }
555
556
557 static struct odhcp6c_entry* odhcp6c_find_entry(enum odhcp6c_state state, const struct odhcp6c_entry *new)
558 {
559 size_t len, cmplen = offsetof(struct odhcp6c_entry, target) + ((new->length + 7) / 8);
560 uint8_t *start = odhcp6c_get_state(state, &len);
561
562 for (struct odhcp6c_entry *c = (struct odhcp6c_entry*)start;
563 (uint8_t*)c < &start[len] && &c->auxtarget[c->auxlen] <= &start[len];
564 c = (struct odhcp6c_entry*)(&c->auxtarget[c->auxlen]))
565 if (!memcmp(c, new, cmplen) && !memcmp(c->auxtarget, new->auxtarget, new->auxlen))
566 return c;
567
568 return NULL;
569 }
570
571
572 bool odhcp6c_update_entry(enum odhcp6c_state state, struct odhcp6c_entry *new,
573 uint32_t safe, bool filterexcess)
574 {
575 size_t len;
576 struct odhcp6c_entry *x = odhcp6c_find_entry(state, new);
577 uint8_t *start = odhcp6c_get_state(state, &len);
578
579 if (x && x->valid > new->valid && new->valid < safe)
580 new->valid = safe;
581
582 if (new->valid > 0) {
583 if (x) {
584 if (filterexcess && new->valid >= x->valid &&
585 new->valid != UINT32_MAX &&
586 new->valid - x->valid < min_update_interval &&
587 new->preferred >= x->preferred &&
588 new->preferred != UINT32_MAX &&
589 new->preferred - x->preferred < min_update_interval)
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->iaid = new->iaid;
596 } else {
597 odhcp6c_add_state(state, new, sizeof(*new) + new->auxlen);
598 }
599 } else if (x) {
600 odhcp6c_remove_state(state, ((uint8_t*)x) - start, sizeof(*x) + x->auxlen);
601 }
602 return true;
603 }
604
605
606 static void odhcp6c_expire_list(enum odhcp6c_state state, uint32_t elapsed)
607 {
608 size_t len;
609 uint8_t *start = odhcp6c_get_state(state, &len);
610 for (struct odhcp6c_entry *c = (struct odhcp6c_entry*)start;
611 (uint8_t*)c < &start[len] && &c->auxtarget[c->auxlen] <= &start[len];
612 c = (struct odhcp6c_entry*)(&c->auxtarget[c->auxlen])) {
613 if (c->t1 < elapsed)
614 c->t1 = 0;
615 else if (c->t1 != UINT32_MAX)
616 c->t1 -= elapsed;
617
618 if (c->t2 < elapsed)
619 c->t2 = 0;
620 else if (c->t2 != UINT32_MAX)
621 c->t2 -= elapsed;
622
623 if (c->preferred < elapsed)
624 c->preferred = 0;
625 else if (c->preferred != UINT32_MAX)
626 c->preferred -= elapsed;
627
628 if (c->valid < elapsed)
629 c->valid = 0;
630 else if (c->valid != UINT32_MAX)
631 c->valid -= elapsed;
632
633 if (!c->valid)
634 odhcp6c_remove_state(state, ((uint8_t*)c) - start, sizeof(*c) + c->auxlen);
635 }
636 }
637
638
639 void odhcp6c_expire(void)
640 {
641 time_t now = odhcp6c_get_milli_time() / 1000;
642 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
643 last_update = now;
644
645 odhcp6c_expire_list(STATE_RA_PREFIX, elapsed);
646 odhcp6c_expire_list(STATE_RA_ROUTE, elapsed);
647 odhcp6c_expire_list(STATE_RA_DNS, elapsed);
648 odhcp6c_expire_list(STATE_RA_SEARCH, elapsed);
649 odhcp6c_expire_list(STATE_IA_NA, elapsed);
650 odhcp6c_expire_list(STATE_IA_PD, elapsed);
651 }
652
653
654 uint32_t odhcp6c_elapsed(void)
655 {
656 return odhcp6c_get_milli_time() / 1000 - last_update;
657 }
658
659
660 int odhcp6c_random(void *buf, size_t len)
661 {
662 return read(urandom_fd, buf, len);
663 }
664
665 bool odhcp6c_is_bound(void)
666 {
667 return bound;
668 }
669
670 static void sighandler(int signal)
671 {
672 if (signal == SIGCHLD)
673 while (waitpid(-1, NULL, WNOHANG) > 0);
674 else if (signal == SIGUSR1)
675 signal_usr1 = true;
676 else if (signal == SIGUSR2)
677 signal_usr2 = true;
678 else if (signal == SIGIO)
679 signal_io = true;
680 else
681 signal_term = true;
682 }
Openwrt DHCPv6 Client