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authorMike Frysinger <vapier@gentoo.org>2006-03-23 23:44:29 +0000
committerMike Frysinger <vapier@gentoo.org>2006-03-23 23:44:29 +0000
commit787140df3992ccc3ebdc09f6d2dcb584f580f49f (patch)
tree666fdb071676c676f52bdc204f6df801b17e7196 /networking/udhcp/dhcpc.c
parente0fe93759339a9e043cd0489f5bfabd59b5fcb78 (diff)
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Diffstat (limited to 'networking/udhcp/dhcpc.c')
-rw-r--r--networking/udhcp/dhcpc.c573
1 files changed, 0 insertions, 573 deletions
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
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--- a/networking/udhcp/dhcpc.c
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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/time.h>
11#include <sys/file.h>
12#include <unistd.h>
13#include <getopt.h>
14#include <stdlib.h>
15#include <sys/socket.h>
16#include <netinet/in.h>
17#include <arpa/inet.h>
18#include <signal.h>
19#include <time.h>
20#include <string.h>
21#include <sys/ioctl.h>
22#include <net/if.h>
23#include <errno.h>
24
25#include "common.h"
26#include "dhcpd.h"
27#include "dhcpc.h"
28#include "options.h"
29#include "clientpacket.h"
30#include "clientsocket.h"
31#include "script.h"
32#include "socket.h"
33#include "signalpipe.h"
34
35static int state;
36static unsigned long requested_ip; /* = 0 */
37static unsigned long server_addr;
38static unsigned long timeout;
39static int packet_num; /* = 0 */
40static int fd = -1;
41
42#define LISTEN_NONE 0
43#define LISTEN_KERNEL 1
44#define LISTEN_RAW 2
45static int listen_mode;
46
47struct client_config_t client_config = {
48 /* Default options. */
49 .abort_if_no_lease = 0,
50 .foreground = 0,
51 .quit_after_lease = 0,
52 .background_if_no_lease = 0,
53 .interface = "eth0",
54 .pidfile = NULL,
55 .script = DEFAULT_SCRIPT,
56 .clientid = NULL,
57 .vendorclass = NULL,
58 .hostname = NULL,
59 .fqdn = NULL,
60 .ifindex = 0,
61 .retries = 3,
62 .timeout = 3,
63 .arp = "\0\0\0\0\0\0", /* appease gcc-3.0 */
64};
65
66#ifndef IN_BUSYBOX
67static void ATTRIBUTE_NORETURN show_usage(void)
68{
69 printf(
70"Usage: udhcpc [OPTIONS]\n\n"
71" -c, --clientid=CLIENTID Set client identifier - type is first char\n"
72" -C, --clientid-none Suppress default client identifier\n"
73" -V, --vendorclass=CLASSID Set vendor class identifier\n"
74" -H, --hostname=HOSTNAME Client hostname\n"
75" -h Alias for -H\n"
76" -F, --fqdn=FQDN Client fully qualified domain name\n"
77" -f, --foreground Do not fork after getting lease\n"
78" -b, --background Fork to background if lease cannot be\n"
79" immediately negotiated.\n"
80" -i, --interface=INTERFACE Interface to use (default: eth0)\n"
81" -n, --now Exit with failure if lease cannot be\n"
82" immediately negotiated.\n"
83" -p, --pidfile=file Store process ID of daemon in file\n"
84" -q, --quit Quit after obtaining lease\n"
85" -r, --request=IP IP address to request (default: none)\n"
86" -s, --script=file Run file at dhcp events (default:\n"
87" " DEFAULT_SCRIPT ")\n"
88" -T, --timeout=seconds Try to get the lease for the amount of\n"
89" seconds (default: 3)\n"
90" -v, --version Display version\n"
91 );
92 exit(0);
93}
94#else
95#define show_usage bb_show_usage
96extern void show_usage(void) ATTRIBUTE_NORETURN;
97#endif
98
99
100/* just a little helper */
101static void change_mode(int new_mode)
102{
103 DEBUG(LOG_INFO, "entering %s listen mode",
104 new_mode ? (new_mode == 1 ? "kernel" : "raw") : "none");
105 if (fd >= 0) close(fd);
106 fd = -1;
107 listen_mode = new_mode;
108}
109
110
111/* perform a renew */
112static void perform_renew(void)
113{
114 LOG(LOG_INFO, "Performing a DHCP renew");
115 switch (state) {
116 case BOUND:
117 change_mode(LISTEN_KERNEL);
118 case RENEWING:
119 case REBINDING:
120 state = RENEW_REQUESTED;
121 break;
122 case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
123 run_script(NULL, "deconfig");
124 case REQUESTING:
125 case RELEASED:
126 change_mode(LISTEN_RAW);
127 state = INIT_SELECTING;
128 break;
129 case INIT_SELECTING:
130 break;
131 }
132
133 /* start things over */
134 packet_num = 0;
135
136 /* Kill any timeouts because the user wants this to hurry along */
137 timeout = 0;
138}
139
140
141/* perform a release */
142static void perform_release(void)
143{
144 char buffer[16];
145 struct in_addr temp_addr;
146
147 /* send release packet */
148 if (state == BOUND || state == RENEWING || state == REBINDING) {
149 temp_addr.s_addr = server_addr;
150 sprintf(buffer, "%s", inet_ntoa(temp_addr));
151 temp_addr.s_addr = requested_ip;
152 LOG(LOG_INFO, "Unicasting a release of %s to %s",
153 inet_ntoa(temp_addr), buffer);
154 send_release(server_addr, requested_ip); /* unicast */
155 run_script(NULL, "deconfig");
156 }
157 LOG(LOG_INFO, "Entering released state");
158
159 change_mode(LISTEN_NONE);
160 state = RELEASED;
161 timeout = 0x7fffffff;
162}
163
164
165static void client_background(void)
166{
167 background(client_config.pidfile);
168 client_config.foreground = 1; /* Do not fork again. */
169 client_config.background_if_no_lease = 0;
170}
171
172
173#ifdef COMBINED_BINARY
174int udhcpc_main(int argc, char *argv[])
175#else
176int main(int argc, char *argv[])
177#endif
178{
179 uint8_t *temp, *message;
180 unsigned long t1 = 0, t2 = 0, xid = 0;
181 unsigned long start = 0, lease;
182 fd_set rfds;
183 int retval;
184 struct timeval tv;
185 int c, len;
186 struct dhcpMessage packet;
187 struct in_addr temp_addr;
188 long now;
189 int max_fd;
190 int sig;
191 int no_clientid = 0;
192
193 static const struct option arg_options[] = {
194 {"clientid", required_argument, 0, 'c'},
195 {"clientid-none", no_argument, 0, 'C'},
196 {"vendorclass", required_argument, 0, 'V'},
197 {"foreground", no_argument, 0, 'f'},
198 {"background", no_argument, 0, 'b'},
199 {"hostname", required_argument, 0, 'H'},
200 {"hostname", required_argument, 0, 'h'},
201 {"fqdn", required_argument, 0, 'F'},
202 {"interface", required_argument, 0, 'i'},
203 {"now", no_argument, 0, 'n'},
204 {"pidfile", required_argument, 0, 'p'},
205 {"quit", no_argument, 0, 'q'},
206 {"request", required_argument, 0, 'r'},
207 {"script", required_argument, 0, 's'},
208 {"timeout", required_argument, 0, 'T'},
209 {"version", no_argument, 0, 'v'},
210 {"retries", required_argument, 0, 't'},
211 {0, 0, 0, 0}
212 };
213
214 /* get options */
215 while (1) {
216 int option_index = 0;
217 c = getopt_long(argc, argv, "c:CV:fbH:h:F:i:np:qr:s:T:t:v", arg_options, &option_index);
218 if (c == -1) break;
219
220 switch (c) {
221 case 'c':
222 if (no_clientid) show_usage();
223 len = strlen(optarg) > 255 ? 255 : strlen(optarg);
224 free(client_config.clientid);
225 client_config.clientid = xmalloc(len + 2);
226 client_config.clientid[OPT_CODE] = DHCP_CLIENT_ID;
227 client_config.clientid[OPT_LEN] = len;
228 client_config.clientid[OPT_DATA] = '\0';
229 strncpy((char*)client_config.clientid + OPT_DATA, optarg, len);
230 break;
231 case 'C':
232 if (client_config.clientid) show_usage();
233 no_clientid = 1;
234 break;
235 case 'V':
236 len = strlen(optarg) > 255 ? 255 : strlen(optarg);
237 free(client_config.vendorclass);
238 client_config.vendorclass = xmalloc(len + 2);
239 client_config.vendorclass[OPT_CODE] = DHCP_VENDOR;
240 client_config.vendorclass[OPT_LEN] = len;
241 strncpy((char*)client_config.vendorclass + OPT_DATA, optarg, len);
242 break;
243 case 'f':
244 client_config.foreground = 1;
245 break;
246 case 'b':
247 client_config.background_if_no_lease = 1;
248 break;
249 case 'h':
250 case 'H':
251 len = strlen(optarg) > 255 ? 255 : strlen(optarg);
252 free(client_config.hostname);
253 client_config.hostname = xmalloc(len + 2);
254 client_config.hostname[OPT_CODE] = DHCP_HOST_NAME;
255 client_config.hostname[OPT_LEN] = len;
256 strncpy((char*)client_config.hostname + 2, optarg, len);
257 break;
258 case 'F':
259 len = strlen(optarg) > 255 ? 255 : strlen(optarg);
260 free(client_config.fqdn);
261 client_config.fqdn = xmalloc(len + 5);
262 client_config.fqdn[OPT_CODE] = DHCP_FQDN;
263 client_config.fqdn[OPT_LEN] = len + 3;
264 /* Flags: 0000NEOS
265 S: 1 => Client requests Server to update A RR in DNS as well as PTR
266 O: 1 => Server indicates to client that DNS has been updated regardless
267 E: 1 => Name data is DNS format, i.e. <4>host<6>domain<4>com<0> not "host.domain.com"
268 N: 1 => Client requests Server to not update DNS
269 */
270 client_config.fqdn[OPT_LEN + 1] = 0x1;
271 client_config.fqdn[OPT_LEN + 2] = 0;
272 client_config.fqdn[OPT_LEN + 3] = 0;
273 strncpy((char*)client_config.fqdn + 5, optarg, len);
274 break;
275 case 'i':
276 client_config.interface = optarg;
277 break;
278 case 'n':
279 client_config.abort_if_no_lease = 1;
280 break;
281 case 'p':
282 client_config.pidfile = optarg;
283 break;
284 case 'q':
285 client_config.quit_after_lease = 1;
286 break;
287 case 'r':
288 requested_ip = inet_addr(optarg);
289 break;
290 case 's':
291 client_config.script = optarg;
292 break;
293 case 'T':
294 client_config.timeout = atoi(optarg);
295 break;
296 case 't':
297 client_config.retries = atoi(optarg);
298 break;
299 case 'v':
300 printf("udhcpcd, version %s\n\n", VERSION);
301 return 0;
302 break;
303 default:
304 show_usage();
305 }
306 }
307
308 /* Start the log, sanitize fd's, and write a pid file */
309 start_log_and_pid("udhcpc", client_config.pidfile);
310
311 if (read_interface(client_config.interface, &client_config.ifindex,
312 NULL, client_config.arp) < 0)
313 return 1;
314
315 /* if not set, and not suppressed, setup the default client ID */
316 if (!client_config.clientid && !no_clientid) {
317 client_config.clientid = xmalloc(6 + 3);
318 client_config.clientid[OPT_CODE] = DHCP_CLIENT_ID;
319 client_config.clientid[OPT_LEN] = 7;
320 client_config.clientid[OPT_DATA] = 1;
321 memcpy(client_config.clientid + 3, client_config.arp, 6);
322 }
323
324 if (!client_config.vendorclass) {
325 client_config.vendorclass = xmalloc(sizeof("udhcp "VERSION) + 2);
326 client_config.vendorclass[OPT_CODE] = DHCP_VENDOR;
327 client_config.vendorclass[OPT_LEN] = sizeof("udhcp "VERSION) - 1;
328 client_config.vendorclass[OPT_DATA] = 1;
329 memcpy(&client_config.vendorclass[OPT_DATA],
330 "udhcp "VERSION, sizeof("udhcp "VERSION) - 1);
331 }
332
333
334 /* setup the signal pipe */
335 udhcp_sp_setup();
336
337 state = INIT_SELECTING;
338 run_script(NULL, "deconfig");
339 change_mode(LISTEN_RAW);
340
341 for (;;) {
342
343 tv.tv_sec = timeout - uptime();
344 tv.tv_usec = 0;
345
346 if (listen_mode != LISTEN_NONE && fd < 0) {
347 if (listen_mode == LISTEN_KERNEL)
348 fd = listen_socket(INADDR_ANY, CLIENT_PORT, client_config.interface);
349 else
350 fd = raw_socket(client_config.ifindex);
351 if (fd < 0) {
352 LOG(LOG_ERR, "FATAL: couldn't listen on socket, %m");
353 return 0;
354 }
355 }
356 max_fd = udhcp_sp_fd_set(&rfds, fd);
357
358 if (tv.tv_sec > 0) {
359 DEBUG(LOG_INFO, "Waiting on select...");
360 retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
361 } else retval = 0; /* If we already timed out, fall through */
362
363 now = uptime();
364 if (retval == 0) {
365 /* timeout dropped to zero */
366 switch (state) {
367 case INIT_SELECTING:
368 if (packet_num < client_config.retries) {
369 if (packet_num == 0)
370 xid = random_xid();
371
372 /* send discover packet */
373 send_discover(xid, requested_ip); /* broadcast */
374
375 timeout = now + client_config.timeout;
376 packet_num++;
377 } else {
378 run_script(NULL, "leasefail");
379 if (client_config.background_if_no_lease) {
380 LOG(LOG_INFO, "No lease, forking to background.");
381 client_background();
382 } else if (client_config.abort_if_no_lease) {
383 LOG(LOG_INFO, "No lease, failing.");
384 return 1;
385 }
386 /* wait to try again */
387 packet_num = 0;
388 timeout = now + 60;
389 }
390 break;
391 case RENEW_REQUESTED:
392 case REQUESTING:
393 if (packet_num < client_config.retries) {
394 /* send request packet */
395 if (state == RENEW_REQUESTED)
396 send_renew(xid, server_addr, requested_ip); /* unicast */
397 else send_selecting(xid, server_addr, requested_ip); /* broadcast */
398
399 timeout = now + ((packet_num == 2) ? 10 : 2);
400 packet_num++;
401 } else {
402 /* timed out, go back to init state */
403 if (state == RENEW_REQUESTED) run_script(NULL, "deconfig");
404 state = INIT_SELECTING;
405 timeout = now;
406 packet_num = 0;
407 change_mode(LISTEN_RAW);
408 }
409 break;
410 case BOUND:
411 /* Lease is starting to run out, time to enter renewing state */
412 state = RENEWING;
413 change_mode(LISTEN_KERNEL);
414 DEBUG(LOG_INFO, "Entering renew state");
415 /* fall right through */
416 case RENEWING:
417 /* Either set a new T1, or enter REBINDING state */
418 if ((t2 - t1) <= (lease / 14400 + 1)) {
419 /* timed out, enter rebinding state */
420 state = REBINDING;
421 timeout = now + (t2 - t1);
422 DEBUG(LOG_INFO, "Entering rebinding state");
423 } else {
424 /* send a request packet */
425 send_renew(xid, server_addr, requested_ip); /* unicast */
426
427 t1 = (t2 - t1) / 2 + t1;
428 timeout = t1 + start;
429 }
430 break;
431 case REBINDING:
432 /* Either set a new T2, or enter INIT state */
433 if ((lease - t2) <= (lease / 14400 + 1)) {
434 /* timed out, enter init state */
435 state = INIT_SELECTING;
436 LOG(LOG_INFO, "Lease lost, entering init state");
437 run_script(NULL, "deconfig");
438 timeout = now;
439 packet_num = 0;
440 change_mode(LISTEN_RAW);
441 } else {
442 /* send a request packet */
443 send_renew(xid, 0, requested_ip); /* broadcast */
444
445 t2 = (lease - t2) / 2 + t2;
446 timeout = t2 + start;
447 }
448 break;
449 case RELEASED:
450 /* yah, I know, *you* say it would never happen */
451 timeout = 0x7fffffff;
452 break;
453 }
454 } else if (retval > 0 && listen_mode != LISTEN_NONE && FD_ISSET(fd, &rfds)) {
455 /* a packet is ready, read it */
456
457 if (listen_mode == LISTEN_KERNEL)
458 len = get_packet(&packet, fd);
459 else len = get_raw_packet(&packet, fd);
460
461 if (len == -1 && errno != EINTR) {
462 DEBUG(LOG_INFO, "error on read, %m, reopening socket");
463 change_mode(listen_mode); /* just close and reopen */
464 }
465 if (len < 0) continue;
466
467 if (packet.xid != xid) {
468 DEBUG(LOG_INFO, "Ignoring XID %lx (our xid is %lx)",
469 (unsigned long) packet.xid, xid);
470 continue;
471 }
472
473 /* Ignore packets that aren't for us */
474 if (memcmp(packet.chaddr, client_config.arp, 6)) {
475 DEBUG(LOG_INFO, "packet does not have our chaddr -- ignoring");
476 continue;
477 }
478
479 if ((message = get_option(&packet, DHCP_MESSAGE_TYPE)) == NULL) {
480 DEBUG(LOG_ERR, "couldnt get option from packet -- ignoring");
481 continue;
482 }
483
484 switch (state) {
485 case INIT_SELECTING:
486 /* Must be a DHCPOFFER to one of our xid's */
487 if (*message == DHCPOFFER) {
488 if ((temp = get_option(&packet, DHCP_SERVER_ID))) {
489 memcpy(&server_addr, temp, 4);
490 xid = packet.xid;
491 requested_ip = packet.yiaddr;
492
493 /* enter requesting state */
494 state = REQUESTING;
495 timeout = now;
496 packet_num = 0;
497 } else {
498 DEBUG(LOG_ERR, "No server ID in message");
499 }
500 }
501 break;
502 case RENEW_REQUESTED:
503 case REQUESTING:
504 case RENEWING:
505 case REBINDING:
506 if (*message == DHCPACK) {
507 if (!(temp = get_option(&packet, DHCP_LEASE_TIME))) {
508 LOG(LOG_ERR, "No lease time with ACK, using 1 hour lease");
509 lease = 60 * 60;
510 } else {
511 memcpy(&lease, temp, 4);
512 lease = ntohl(lease);
513 }
514
515 /* enter bound state */
516 t1 = lease / 2;
517
518 /* little fixed point for n * .875 */
519 t2 = (lease * 0x7) >> 3;
520 temp_addr.s_addr = packet.yiaddr;
521 LOG(LOG_INFO, "Lease of %s obtained, lease time %ld",
522 inet_ntoa(temp_addr), lease);
523 start = now;
524 timeout = t1 + start;
525 requested_ip = packet.yiaddr;
526 run_script(&packet,
527 ((state == RENEWING || state == REBINDING) ? "renew" : "bound"));
528
529 state = BOUND;
530 change_mode(LISTEN_NONE);
531 if (client_config.quit_after_lease)
532 return 0;
533 if (!client_config.foreground)
534 client_background();
535
536 } else if (*message == DHCPNAK) {
537 /* return to init state */
538 LOG(LOG_INFO, "Received DHCP NAK");
539 run_script(&packet, "nak");
540 if (state != REQUESTING)
541 run_script(NULL, "deconfig");
542 state = INIT_SELECTING;
543 timeout = now;
544 requested_ip = 0;
545 packet_num = 0;
546 change_mode(LISTEN_RAW);
547 sleep(3); /* avoid excessive network traffic */
548 }
549 break;
550 /* case BOUND, RELEASED: - ignore all packets */
551 }
552 } else if (retval > 0 && (sig = udhcp_sp_read(&rfds))) {
553 switch (sig) {
554 case SIGUSR1:
555 perform_renew();
556 break;
557 case SIGUSR2:
558 perform_release();
559 break;
560 case SIGTERM:
561 LOG(LOG_INFO, "Received SIGTERM");
562 return 0;
563 }
564 } else if (retval == -1 && errno == EINTR) {
565 /* a signal was caught */
566 } else {
567 /* An error occured */
568 DEBUG(LOG_ERR, "Error on select");
569 }
570
571 }
572 return 0;
573}