projects / project / odhcp6c.git / blob
? search:


de03b814f95efa86bde343374a14b6769e04cd02
[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 = 120;
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 // Server candidates need deep-delete
232 size_t cand_len;
233 struct dhcpv6_server_cand *cand = odhcp6c_get_state(STATE_SERVER_CAND, &cand_len);
234 for (size_t i = 0; i < cand_len / sizeof(*cand); ++i) {
235 free(cand[i].ia_na);
236 free(cand[i].ia_pd);
237 }
238 odhcp6c_clear_state(STATE_SERVER_CAND);
239
240 syslog(LOG_NOTICE, "(re)starting transaction on %s", ifname);
241
242 do_signal = 0;
243 int res = dhcpv6_request(DHCPV6_MSG_SOLICIT);
244 odhcp6c_signal_process();
245
246 if (res <= 0) {
247 continue; // Might happen if we got a signal
248 } else if (res == DHCPV6_STATELESS) { // Stateless mode
249 while (do_signal == 0 || do_signal == SIGUSR1) {
250 do_signal = 0;
251
252 res = dhcpv6_request(DHCPV6_MSG_INFO_REQ);
253 odhcp6c_signal_process();
254 if (do_signal == SIGUSR1)
255 continue;
256 else if (res < 0)
257 break;
258 else if (res > 0)
259 script_call("informed");
260
261 bound = true;
262 syslog(LOG_NOTICE, "entering stateless-mode on %s", ifname);
263
264 if (dhcpv6_poll_reconfigure() > 0)
265 script_call("informed");
266 }
267
268 continue;
269 }
270
271 // Stateful mode
272 if (dhcpv6_request(DHCPV6_MSG_REQUEST) <= 0)
273 continue;
274
275 odhcp6c_signal_process();
276 script_call("bound");
277 bound = true;
278 syslog(LOG_NOTICE, "entering stateful-mode on %s", ifname);
279 #ifdef EXT_BFD_PING
280 if (bfd_interval > 0)
281 bfd_start(ifname, bfd_loss, bfd_interval);
282 #endif
283
284 while (do_signal == 0 || do_signal == SIGUSR1) {
285 // Renew Cycle
286 // Wait for T1 to expire or until we get a reconfigure
287 int res = dhcpv6_poll_reconfigure();
288 odhcp6c_signal_process();
289 if (res > 0) {
290 script_call("updated");
291 continue;
292 }
293
294 // Handle signal, if necessary
295 if (do_signal == SIGUSR1)
296 do_signal = 0; // Acknowledged
297 else if (do_signal > 0)
298 break; // Other signal type
299
300 size_t ia_pd_len, ia_na_len, ia_pd_new, ia_na_new;
301 odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
302 odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
303
304 // If we have any IAs, send renew, otherwise request
305 int r;
306 if (ia_pd_len == 0 && ia_na_len == 0)
307 r = dhcpv6_request(DHCPV6_MSG_REQUEST);
308 else
309 r = dhcpv6_request(DHCPV6_MSG_RENEW);
310 odhcp6c_signal_process();
311 if (r > 0) { // Renew was succesfull
312 // Publish updates
313 script_call("updated");
314 continue; // Renew was successful
315 }
316
317 odhcp6c_clear_state(STATE_SERVER_ID); // Remove binding
318
319 // If we have IAs, try rebind otherwise restart
320 res = dhcpv6_request(DHCPV6_MSG_REBIND);
321 odhcp6c_signal_process();
322
323 odhcp6c_get_state(STATE_IA_PD, &ia_pd_new);
324 odhcp6c_get_state(STATE_IA_NA, &ia_na_new);
325 if (res <= 0 || (ia_pd_new == 0 && ia_pd_len) ||
326 (ia_na_new == 0 && ia_na_len))
327 break; // We lost all our IAs, restart
328 else if (res > 0)
329 script_call("rebound");
330 }
331
332 #ifdef EXT_BFD_PING
333 bfd_stop();
334 #endif
335
336
337 size_t ia_pd_len, ia_na_len, server_id_len;
338 odhcp6c_get_state(STATE_IA_PD, &ia_pd_len);
339 odhcp6c_get_state(STATE_IA_NA, &ia_na_len);
340 odhcp6c_get_state(STATE_SERVER_ID, &server_id_len);
341
342 // Add all prefixes to lost prefixes
343 bound = false;
344 script_call("unbound");
345
346 if (server_id_len > 0 && (ia_pd_len > 0 || ia_na_len > 0) && release)
347 dhcpv6_request(DHCPV6_MSG_RELEASE);
348
349 odhcp6c_clear_state(STATE_IA_NA);
350 odhcp6c_clear_state(STATE_IA_PD);
351 }
352
353 script_call("stopped");
354 return 0;
355 }
356
357
358 static int usage(void)
359 {
360 const char buf[] =
361 "Usage: odhcp6c [options] <interface>\n"
362 "\nFeature options:\n"
363 " -S <time> Wait at least <time> sec for a DHCP-server (0)\n"
364 " -N <mode> Mode for requesting addresses [try|force|none]\n"
365 " -P <length> Request IPv6-Prefix (0 = auto)\n"
366 " -F Force IPv6-Prefix\n"
367 #ifdef EXT_BFD_PING
368 " -B <interval> Enable BFD ping check\n"
369 #endif
370 " -c <clientid> Override client-ID (base-16 encoded)\n"
371 " -i <iface-id> Use a custom interface identifier for RA handling\n"
372 " -r <options> Options to be requested (comma-separated)\n"
373 " -s <script> Status update script (/usr/sbin/odhcp6c-update)\n"
374 " -k Don't send a RELEASE when stopping\n"
375 " -t <seconds> Maximum timeout for DHCPv6-SOLICIT (120)\n"
376 "\nInvocation options:\n"
377 " -p <pidfile> Set pidfile (/var/run/6relayd.pid)\n"
378 " -d Daemonize\n"
379 " -e Write logmessages to stderr\n"
380 //" -v Increase logging verbosity\n"
381 " -h Show this help\n\n";
382 write(STDERR_FILENO, buf, sizeof(buf));
383 return 1;
384 }
385
386
387 // Don't want to pull-in librt and libpthread just for a monotonic clock...
388 uint64_t odhcp6c_get_milli_time(void)
389 {
390 struct timespec t = {0, 0};
391 syscall(SYS_clock_gettime, CLOCK_MONOTONIC, &t);
392 return t.tv_sec * 1000 + t.tv_nsec / 1000000;
393 }
394
395
396 static uint8_t* odhcp6c_resize_state(enum odhcp6c_state state, ssize_t len)
397 {
398 if (len == 0)
399 return state_data[state] + state_len[state];
400 else if (state_len[state] + len > 1024)
401 return NULL;
402
403 uint8_t *n = realloc(state_data[state], state_len[state] + len);
404 if (n || state_len[state] + len == 0) {
405 state_data[state] = n;
406 n += state_len[state];
407 state_len[state] += len;
408 }
409 return n;
410 }
411
412
413 bool odhcp6c_signal_process(void)
414 {
415 if (do_signal == SIGIO) {
416 do_signal = 0;
417 bool ra_updated = ra_process();
418
419 if (ra_link_up())
420 do_signal = SIGUSR2;
421
422 if (ra_updated && (bound || allow_slaac_only == 0))
423 script_call("ra-updated"); // Immediate process urgent events
424 else if (ra_updated && !bound && allow_slaac_only > 0)
425 script_delay_call("ra-updated", allow_slaac_only);
426
427 #ifdef EXT_BFD_PING
428 bfd_receive();
429 #endif
430 }
431
432 return do_signal != 0;
433 }
434
435
436 void odhcp6c_clear_state(enum odhcp6c_state state)
437 {
438 state_len[state] = 0;
439 }
440
441
442 void odhcp6c_add_state(enum odhcp6c_state state, const void *data, size_t len)
443 {
444 uint8_t *n = odhcp6c_resize_state(state, len);
445 if (n)
446 memcpy(n, data, len);
447 }
448
449
450 size_t odhcp6c_remove_state(enum odhcp6c_state state, size_t offset, size_t len)
451 {
452 uint8_t *data = state_data[state];
453 ssize_t len_after = state_len[state] - (offset + len);
454 if (len_after < 0)
455 return state_len[state];
456
457 memmove(data + offset, data + offset + len, len_after);
458 return state_len[state] -= len;
459 }
460
461
462 void* odhcp6c_move_state(enum odhcp6c_state state, size_t *len)
463 {
464 *len = state_len[state];
465 void *data = state_data[state];
466
467 state_len[state] = 0;
468 state_data[state] = NULL;
469
470 return data;
471 }
472
473
474 void* odhcp6c_get_state(enum odhcp6c_state state, size_t *len)
475 {
476 *len = state_len[state];
477 return state_data[state];
478 }
479
480
481 struct odhcp6c_entry* odhcp6c_find_entry(enum odhcp6c_state state, const struct odhcp6c_entry *new)
482 {
483 size_t len, cmplen = offsetof(struct odhcp6c_entry, target) + new->length / 8;
484 struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
485 struct odhcp6c_entry *x = NULL;
486
487 for (struct odhcp6c_entry *c = start; !x && c < &start[len/sizeof(*c)]; ++c)
488 if (!memcmp(c, new, cmplen))
489 return c;
490
491 return NULL;
492 }
493
494
495 bool odhcp6c_update_entry_safe(enum odhcp6c_state state, struct odhcp6c_entry *new, uint32_t safe)
496 {
497 size_t len;
498 struct odhcp6c_entry *x = odhcp6c_find_entry(state, new);
499 struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
500
501 if (x && x->valid > new->valid && new->valid < safe)
502 new->valid = safe;
503
504 if (new->valid > 0) {
505 if (x) {
506 if (new->valid >= x->valid && new->valid - x->valid < 60 &&
507 new->preferred >= x->preferred &&
508 new->preferred - x->preferred < 60 &&
509 x->class == new->class)
510 return false;
511 x->valid = new->valid;
512 x->preferred = new->preferred;
513 x->t1 = new->t1;
514 x->t2 = new->t2;
515 x->class = new->class;
516 } else {
517 odhcp6c_add_state(state, new, sizeof(*new));
518 }
519 } else if (x) {
520 odhcp6c_remove_state(state, (x - start) * sizeof(*x), sizeof(*x));
521 }
522 return true;
523 }
524
525
526 bool odhcp6c_update_entry(enum odhcp6c_state state, struct odhcp6c_entry *new)
527 {
528 return odhcp6c_update_entry_safe(state, new, 0);
529 }
530
531
532 static void odhcp6c_expire_list(enum odhcp6c_state state, uint32_t elapsed)
533 {
534 size_t len;
535 struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
536 for (struct odhcp6c_entry *c = start; c < &start[len / sizeof(*c)]; ++c) {
537 if (c->t1 < elapsed)
538 c->t1 = 0;
539 else if (c->t1 != UINT32_MAX)
540 c->t1 -= elapsed;
541
542 if (c->t2 < elapsed)
543 c->t2 = 0;
544 else if (c->t2 != UINT32_MAX)
545 c->t2 -= elapsed;
546
547 if (c->preferred < elapsed)
548 c->preferred = 0;
549 else if (c->preferred != UINT32_MAX)
550 c->preferred -= elapsed;
551
552 if (c->valid < elapsed)
553 c->valid = 0;
554 else if (c->valid != UINT32_MAX)
555 c->valid -= elapsed;
556
557 if (!c->valid)
558 odhcp6c_remove_state(state, (c - start) * sizeof(*c), sizeof(*c));
559 }
560 }
561
562
563 void odhcp6c_expire(void)
564 {
565 time_t now = odhcp6c_get_milli_time() / 1000;
566 uint32_t elapsed = (last_update > 0) ? now - last_update : 0;
567 last_update = now;
568
569 odhcp6c_expire_list(STATE_RA_PREFIX, elapsed);
570 odhcp6c_expire_list(STATE_RA_ROUTE, elapsed);
571 odhcp6c_expire_list(STATE_RA_DNS, elapsed);
572 odhcp6c_expire_list(STATE_IA_NA, elapsed);
573 odhcp6c_expire_list(STATE_IA_PD, elapsed);
574 }
575
576
577 uint32_t odhcp6c_elapsed(void)
578 {
579 return odhcp6c_get_milli_time() / 1000 - last_update;
580 }
581
582
583 void odhcp6c_random(void *buf, size_t len)
584 {
585 read(urandom_fd, buf, len);
586 }
587
588 bool odhcp6c_is_bound(void)
589 {
590 return bound;
591 }
592
593 static void sighandler(int signal)
594 {
595 if (signal == SIGCHLD)
596 while (waitpid(-1, NULL, WNOHANG) > 0);
597 else if (signal == SIGUSR1)
598 do_signal = SIGUSR1;
599 else if (signal == SIGUSR2)
600 do_signal = SIGUSR2;
601 else if (signal == SIGIO)
602 do_signal = SIGIO;
603 else
604 do_signal = SIGTERM;
605 }
Openwrt DHCPv6 Client