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Tomato 1.21
[tomato.git] / release / src / router / busybox / networking / udhcp / dhcpc.c
blob2c93db54efe72a542d7866bcd3b982c9ea82f7fa
1 /* dhcpc.c
2 *
3 * udhcp DHCP client
4 *
5 * Russ Dill <Russ.Dill@asu.edu> July 2001
6 *
7 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
8 */
9
10 #include <sys/file.h>
11 #include <unistd.h>
12 #include <getopt.h>
13 #include <stdlib.h>
14 #include <sys/socket.h>
15 #include <netinet/in.h>
16 #include <arpa/inet.h>
17 #include <signal.h>
18 #include <time.h>
19 #include <string.h>
20 #include <sys/ioctl.h>
21 #include <net/if.h>
22 #include <errno.h>
23
24 #include "common.h"
25 #include "dhcpd.h"
26 #include "dhcpc.h"
27 #include "options.h"
28 #include "clientpacket.h"
29 #include "clientsocket.h"
30 #include "socket.h"
31 #include "signalpipe.h"
32 #include "arpping.h"
33
34 static int state;
35 static unsigned long requested_ip; /* = 0 */
36 static unsigned long server_addr;
37 static unsigned long timeout;
38 static int packet_num; /* = 0 */
39 static int fd = -1;
40
41 #define LISTEN_NONE 0
42 #define LISTEN_KERNEL 1
43 #define LISTEN_RAW 2
44 static int listen_mode;
45
46 struct client_config_t client_config = {
47 /* Default options. */
48 .abort_if_no_lease = 0,
49 .foreground = 0,
50 .quit_after_lease = 0,
51 .background_if_no_lease = 0,
52 .interface = "eth0",
53 .pidfile = NULL,
54 .script = DEFAULT_SCRIPT,
55 .clientid = NULL,
56 .vendorclass = NULL,
57 .hostname = NULL,
58 .fqdn = NULL,
59 .ifindex = 0,
60 .retries = 3,
61 .timeout = 3,
62 .arp = "\0\0\0\0\0\0", /* appease gcc-3.0 */
63 .lan_interface = NULL
64 };
65
66 /* just a little helper */
67 static void change_mode(int new_mode)
68 {
69 DEBUG(LOG_INFO, "entering %s listen mode",
70 new_mode ? (new_mode == 1 ? "kernel" : "raw") : "none");
71 if (fd >= 0) close(fd);
72 fd = -1;
73 listen_mode = new_mode;
74 }
75
76
77 /* perform a renew */
78 static void perform_renew(void)
79 {
80 LOG(LOG_INFO, "Performing a DHCP renew");
81 switch (state) {
82 case BOUND:
83 change_mode(LISTEN_KERNEL);
84 case RENEWING:
85 case REBINDING:
86 state = RENEW_REQUESTED;
87 break;
88 case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
89 udhcp_run_script(NULL, "deconfig");
90 case REQUESTING:
91 case RELEASED:
92 change_mode(LISTEN_RAW);
93 state = INIT_SELECTING;
94 break;
95 case INIT_SELECTING:
96 break;
97 }
98
99 /* start things over */
100 packet_num = 0;
101
102 /* Kill any timeouts because the user wants this to hurry along */
103 timeout = 0;
104 }
105
106
107 /* perform a release */
108 static void perform_release(void)
109 {
110 char buffer[16];
111 struct in_addr temp_addr;
112
113 /* send release packet */
114 if (state == BOUND || state == RENEWING || state == REBINDING) {
115 temp_addr.s_addr = server_addr;
116 sprintf(buffer, "%s", inet_ntoa(temp_addr));
117 temp_addr.s_addr = requested_ip;
118 LOG(LOG_INFO, "Unicasting a release of %s to %s",
119 inet_ntoa(temp_addr), buffer);
120 send_release(server_addr, requested_ip); /* unicast */
121 udhcp_run_script(NULL, "deconfig");
122 }
123 LOG(LOG_INFO, "Entering released state");
124
125 change_mode(LISTEN_NONE);
126 state = RELEASED;
127 timeout = 0x7fffffff;
128 }
129
130
131 static void client_background(void)
132 {
133 udhcp_background(client_config.pidfile);
134 client_config.foreground = 1; /* Do not fork again. */
135 client_config.background_if_no_lease = 0;
136 }
137
138
139 int udhcpc_main(int argc, char *argv[])
140 {
141 uint8_t *temp, *message;
142 unsigned long t1 = 0, t2 = 0, xid = 0;
143 unsigned long start = 0, lease;
144 fd_set rfds;
145 int retval;
146 struct timeval tv;
147 int c, len;
148 struct dhcpMessage packet;
149 struct in_addr temp_addr;
150 long now;
151 int max_fd;
152 int sig;
153 int no_clientid = 0;
154
155 static const struct option arg_options[] = {
156 {"clientid", required_argument, 0, 'c'},
157 {"clientid-none", no_argument, 0, 'C'},
158 {"vendorclass", required_argument, 0, 'V'},
159 {"foreground", no_argument, 0, 'f'},
160 {"background", no_argument, 0, 'b'},
161 {"hostname", required_argument, 0, 'H'},
162 {"hostname", required_argument, 0, 'h'},
163 {"fqdn", required_argument, 0, 'F'},
164 {"interface", required_argument, 0, 'i'},
165 {"laniface", required_argument, 0, 'l'},
166 {"now", no_argument, 0, 'n'},
167 {"pidfile", required_argument, 0, 'p'},
168 {"quit", no_argument, 0, 'q'},
169 {"request", required_argument, 0, 'r'},
170 {"script", required_argument, 0, 's'},
171 {"timeout", required_argument, 0, 'T'},
172 {"version", no_argument, 0, 'v'},
173 {"retries", required_argument, 0, 't'},
174 {0, 0, 0, 0}
175 };
176
177 /* get options */
178 while (1) {
179 int option_index = 0;
180 c = getopt_long(argc, argv, "c:CV:fbH:h:F:i:np:qr:s:T:t:vl:mQ", arg_options, &option_index);
181 if (c == -1) break;
182
183 switch (c) {
184 case 'l':
185 client_config.lan_interface = optarg;
186 break;
187 case 'm':
188 minpkt = 1;
189 break;
190 case 'c':
191 if (no_clientid) bb_show_usage();
192 len = strlen(optarg) > 255 ? 255 : strlen(optarg);
193 free(client_config.clientid);
194 client_config.clientid = xmalloc(len + 2);
195 client_config.clientid[OPT_CODE] = DHCP_CLIENT_ID;
196 client_config.clientid[OPT_LEN] = len;
197 client_config.clientid[OPT_DATA] = '\0';
198 strncpy((char*)client_config.clientid + OPT_DATA, optarg, len);
199 break;
200 case 'C':
201 if (client_config.clientid) bb_show_usage();
202 no_clientid = 1;
203 break;
204 case 'V':
205 len = strlen(optarg) > 255 ? 255 : strlen(optarg);
206 free(client_config.vendorclass);
207 client_config.vendorclass = xmalloc(len + 2);
208 client_config.vendorclass[OPT_CODE] = DHCP_VENDOR;
209 client_config.vendorclass[OPT_LEN] = len;
210 strncpy((char*)client_config.vendorclass + OPT_DATA, optarg, len);
211 break;
212 case 'f':
213 client_config.foreground = 1;
214 break;
215 case 'b':
216 client_config.background_if_no_lease = 1;
217 break;
218 case 'h':
219 case 'H':
220 len = strlen(optarg) > 255 ? 255 : strlen(optarg);
221 free(client_config.hostname);
222 client_config.hostname = xmalloc(len + 2);
223 client_config.hostname[OPT_CODE] = DHCP_HOST_NAME;
224 client_config.hostname[OPT_LEN] = len;
225 strncpy((char*)client_config.hostname + 2, optarg, len);
226 break;
227 case 'F':
228 len = strlen(optarg) > 255 ? 255 : strlen(optarg);
229 free(client_config.fqdn);
230 client_config.fqdn = xmalloc(len + 5);
231 client_config.fqdn[OPT_CODE] = DHCP_FQDN;
232 client_config.fqdn[OPT_LEN] = len + 3;
233 /* Flags: 0000NEOS
234 S: 1 => Client requests Server to update A RR in DNS as well as PTR
235 O: 1 => Server indicates to client that DNS has been updated regardless
236 E: 1 => Name data is DNS format, i.e. <4>host<6>domain<4>com<0> not "host.domain.com"
237 N: 1 => Client requests Server to not update DNS
238 */
239 client_config.fqdn[OPT_LEN + 1] = 0x1;
240 client_config.fqdn[OPT_LEN + 2] = 0;
241 client_config.fqdn[OPT_LEN + 3] = 0;
242 strncpy((char*)client_config.fqdn + 5, optarg, len);
243 break;
244 case 'i':
245 client_config.interface = optarg;
246 break;
247 case 'n':
248 client_config.abort_if_no_lease = 1;
249 break;
250 case 'p':
251 client_config.pidfile = optarg;
252 break;
253 case 'q':
254 client_config.quit_after_lease = 1;
255 break;
256 case 'r':
257 requested_ip = inet_addr(optarg);
258 break;
259 case 's':
260 client_config.script = optarg;
261 break;
262 case 'T':
263 client_config.timeout = atoi(optarg);
264 break;
265 case 't':
266 client_config.retries = atoi(optarg);
267 break;
268 case 'v':
269 printf("version %s\n\n", BB_VER);
270 return 0;
271 break;
272 case 'Q':
273 setlogmask(LOG_UPTO(LOG_ERR));
274 break;
275 default:
276 bb_show_usage();
277 }
278 }
279
280 /* Start the log, sanitize fd's, and write a pid file */
281 #ifdef CONFIG_FEATURE_UDHCP_DEBUG
282 udhcp_start_log_and_pid("udhcpc_debug", client_config.pidfile);
283 #else
284 udhcp_start_log_and_pid("udhcpc", client_config.pidfile);
285 #endif
286
287 if (read_interface(client_config.interface, &client_config.ifindex,
288 NULL, client_config.arp) < 0)
289 return 1;
290
291 /* if not set, and not suppressed, setup the default client ID */
292 if (!client_config.clientid && !no_clientid) {
293 client_config.clientid = xmalloc(6 + 3);
294 client_config.clientid[OPT_CODE] = DHCP_CLIENT_ID;
295 client_config.clientid[OPT_LEN] = 7;
296 client_config.clientid[OPT_DATA] = 1;
297 memcpy(client_config.clientid + 3, client_config.arp, 6);
298 }
299
300 if (!client_config.vendorclass) {
301 client_config.vendorclass = xmalloc(sizeof("udhcp "BB_VER) + 2);
302 client_config.vendorclass[OPT_CODE] = DHCP_VENDOR;
303 client_config.vendorclass[OPT_LEN] = sizeof("udhcp "BB_VER) - 1;
304 client_config.vendorclass[OPT_DATA] = 1;
305 memcpy(&client_config.vendorclass[OPT_DATA],
306 "udhcp "BB_VER, sizeof("udhcp "BB_VER) - 1);
307 }
308
309
310 /* setup the signal pipe */
311 udhcp_sp_setup();
312
313 #if 0
314 printf("DEBUG %s\n", __TIME__);
315 state = BOUND;
316 server_addr = inet_addr("192.168.5.5");
317 requested_ip = inet_addr("192.168.5.3");
318 perform_release();
319 printf("done\n");
320 exit(0);
321 #endif
322
323 state = INIT_SELECTING;
324 udhcp_run_script(NULL, "deconfig");
325 change_mode(LISTEN_RAW);
326
327 for (;;) {
328
329 tv.tv_sec = timeout - uptime();
330 tv.tv_usec = 0;
331
332 if (listen_mode != LISTEN_NONE && fd < 0) {
333 if (listen_mode == LISTEN_KERNEL)
334 fd = listen_socket(INADDR_ANY, CLIENT_PORT, client_config.interface);
335 else
336 fd = raw_socket(client_config.ifindex);
337 if (fd < 0) {
338 LOG(LOG_ERR, "FATAL: couldn't listen on socket, %m");
339 return 0;
340 }
341 }
342 max_fd = udhcp_sp_fd_set(&rfds, fd);
343
344 if (tv.tv_sec > 0) {
345 DEBUG(LOG_INFO, "Waiting on select...");
346 retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
347 } else retval = 0; /* If we already timed out, fall through */
348
349 now = uptime();
350 if (retval == 0) {
351 DEBUG(LOG_DEBUG, "T/O: state=%d packet_num=%d", state, packet_num);
352
353 /* timeout dropped to zero */
354 switch (state) {
355 case INIT_SELECTING:
356 if (packet_num < client_config.retries) {
357 if (packet_num == 0)
358 xid = random_xid();
359
360 /* send discover packet */
361 send_discover(xid, requested_ip); /* broadcast */
362
363 timeout = now + client_config.timeout;
364 packet_num++;
365 } else {
366 udhcp_run_script(NULL, "leasefail");
367 if (client_config.background_if_no_lease) {
368 LOG(LOG_INFO, "No lease, forking to background.");
369 client_background();
370 } else if (client_config.abort_if_no_lease) {
371 LOG(LOG_INFO, "No lease, failing.");
372 return 1;
373 }
374 /* wait to try again */
375 packet_num = 0;
376 timeout = now + 20; // reduced from 60 sec
377 }
378 break;
379 case RENEW_REQUESTED:
380 case REQUESTING:
381 if (packet_num < client_config.retries) {
382 /* send request packet */
383 if (state == RENEW_REQUESTED)
384 send_renew(xid, server_addr, requested_ip); /* unicast */
385 else send_selecting(xid, server_addr, requested_ip); /* broadcast */
386
387 timeout = now + ((packet_num == 2) ? 10 : 2);
388 packet_num++;
389 } else {
390 /* timed out, go back to init state */
391 if (state == RENEW_REQUESTED) udhcp_run_script(NULL, "deconfig");
392 state = INIT_SELECTING;
393 timeout = now;
394 packet_num = 0;
395 change_mode(LISTEN_RAW);
396 }
397 break;
398 case BOUND:
399 /* Lease is starting to run out, time to enter renewing state */
400 state = RENEWING;
401 //change_mode(LISTEN_KERNEL);
402 change_mode(LISTEN_RAW); // Some DHCP server send broadcast ACK after they receive a REQUEST during RENEWING state, by honor
403 DEBUG(LOG_INFO, "Entering renew state");
404 /* fall right through */
405 case RENEWING:
406 /* Either set a new T1, or enter REBINDING state */
407 if ((t2 - t1) <= (lease / 14400 + 1)) {
408 /* timed out, enter rebinding state */
409 state = REBINDING;
410 timeout = now + (t2 - t1);
411 LOG(LOG_INFO, "Entering rebinding state");
412 } else {
413 /* send a request packet */
414 send_renew(xid, server_addr, requested_ip); /* unicast */
415
416 t1 = (t2 - t1) / 2 + t1;
417 timeout = t1 + start;
418 }
419 break;
420 case REBINDING:
421 /* Either set a new T2, or enter INIT state */
422 if ((lease - t2) <= (lease / 14400 + 1)) {
423 /* timed out, enter init state */
424 state = INIT_SELECTING;
425 LOG(LOG_INFO, "Lease lost, entering init state");
426 udhcp_run_script(NULL, "deconfig");
427 timeout = now;
428 packet_num = 0;
429 change_mode(LISTEN_RAW);
430 } else {
431 /* send a request packet */
432 send_renew(xid, 0, requested_ip); /* broadcast */
433
434 t2 = (lease - t2) / 2 + t2;
435 timeout = t2 + start;
436 }
437 break;
438 case RELEASED:
439 /* yah, I know, *you* say it would never happen */
440 timeout = 0x7fffffff;
441 break;
442 }
443 } else if (retval > 0 && listen_mode != LISTEN_NONE && FD_ISSET(fd, &rfds)) {
444 /* a packet is ready, read it */
445 DEBUG(LOG_DEBUG, "R: state=%d", state);
446
447 if (listen_mode == LISTEN_KERNEL)
448 len = udhcp_get_packet(&packet, fd);
449 else len = get_raw_packet(&packet, fd);
450
451 if (len == -1 && errno != EINTR) {
452 DEBUG(LOG_INFO, "error on read, %m, reopening socket");
453 change_mode(listen_mode); /* just close and reopen */
454 }
455 if (len < 0) continue;
456
457 if (packet.xid != xid) {
458 DEBUG(LOG_INFO, "Ignoring XID %lx (our xid is %lx)",
459 (unsigned long) packet.xid, xid);
460 continue;
461 }
462
463 /* Ignore packets that aren't for us */
464 if (memcmp(packet.chaddr, client_config.arp, 6)) {
465 DEBUG(LOG_INFO, "packet does not have our chaddr -- ignoring");
466 continue;
467 }
468
469 if ((message = get_option(&packet, DHCP_MESSAGE_TYPE)) == NULL) {
470 DEBUG(LOG_ERR, "couldnt get option from packet -- ignoring");
471 continue;
472 }
473
474 DEBUG(LOG_DEBUG, "R: message=%d", *message);
475 switch (state) {
476 case INIT_SELECTING:
477 /* Must be a DHCPOFFER to one of our xid's */
478 if (*message == DHCPOFFER) {
479 if ((temp = get_option(&packet, DHCP_SERVER_ID))) {
480 memcpy(&server_addr, temp, 4);
481 xid = packet.xid;
482 requested_ip = packet.yiaddr;
483
484
485 // if the wan ip address exists in our lan, decline
486
487 int ifindex;
488 u_int32_t lan_ip;
489 unsigned char lan_mac[6];
490
491 if ((client_config.lan_interface != NULL) &&
492 (read_interface(client_config.lan_interface, &ifindex, &lan_ip, lan_mac) >= 0)) {
493 if (arpping(requested_ip, lan_ip, lan_mac, client_config.lan_interface) == 0) {
494 temp_addr.s_addr = requested_ip;
495 LOG(LOG_ERR, "Offered IP address %s exists in the network. Declining.", inet_ntoa(temp_addr));
496 send_decline(xid, requested_ip);
497 continue;
498 }
499 }
500
501
502 /* enter requesting state */
503 state = REQUESTING;
504 timeout = now;
505 packet_num = 0;
506 } else {
507 DEBUG(LOG_ERR, "No server ID in message");
508 }
509 }
510 break;
511 case RENEW_REQUESTED:
512 case REQUESTING:
513 case RENEWING:
514 case REBINDING:
515 if (*message == DHCPACK) {
516 if (!(temp = get_option(&packet, DHCP_LEASE_TIME))) {
517 LOG(LOG_ERR, "No lease time with ACK, using 1 hour lease");
518 lease = 60 * 60;
519 } else {
520 memcpy(&lease, temp, 4);
521 lease = ntohl(lease);
522 }
523
524 /* enter bound state */
525 t1 = lease / 2;
526
527 /* little fixed point for n * .875 */
528 t2 = (lease * 0x7) >> 3;
529 temp_addr.s_addr = packet.yiaddr;
530 LOG(LOG_INFO, "Lease of %s obtained, lease time %ld",
531 inet_ntoa(temp_addr), lease);
532 start = now;
533 timeout = t1 + start;
534 requested_ip = packet.yiaddr;
535 udhcp_run_script(&packet,
536 ((state == RENEWING || state == REBINDING) ? "renew" : "bound"));
537
538 state = BOUND;
539 change_mode(LISTEN_NONE);
540 if (client_config.quit_after_lease)
541 return 0;
542 if (!client_config.foreground)
543 client_background();
544
545 } else if (*message == DHCPNAK) {
546 /* return to init state */
547 LOG(LOG_INFO, "Received DHCP NAK");
548 udhcp_run_script(&packet, "nak");
549 if (state != REQUESTING)
550 udhcp_run_script(NULL, "deconfig");
551 state = INIT_SELECTING;
552 timeout = now;
553 requested_ip = 0;
554 packet_num = 0;
555 change_mode(LISTEN_RAW);
556 sleep(3); /* avoid excessive network traffic */
557 }
558 break;
559 /* case BOUND, RELEASED: - ignore all packets */
560 }
561 } else if (retval > 0 && (sig = udhcp_sp_read(&rfds))) {
562 switch (sig) {
563 case SIGUSR1:
564 perform_renew();
565 break;
566 case SIGUSR2:
567 perform_release();
568 break;
569 case SIGTERM:
570 LOG(LOG_INFO, "Received SIGTERM");
571 return 0;
572 }
573 } else if (retval == -1 && errno == EINTR) {
574 /* a signal was caught */
575 } else {
576 /* An error occured */
577 DEBUG(LOG_ERR, "Error on select");
578 }
579
580 }
581 return 0;
582 }
Tomato firmware and modifications.