5 * Russ Dill <Russ.Dill@asu.edu> July 2001
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
27 #include <sys/socket.h>
28 #include <netinet/in.h>
29 #include <arpa/inet.h>
33 #include <sys/ioctl.h>
40 #include "clientpacket.h"
46 static unsigned long requested_ip; /* = 0 */
47 static unsigned long server_addr;
48 static unsigned long timeout;
49 static int packet_num; /* = 0 */
53 #define LISTEN_KERNEL 1
55 static int listen_mode;
57 #ifdef CONFIG_INSTALL_NO_USR
58 #define DEFAULT_SCRIPT "/share/udhcpc/default.script"
60 #define DEFAULT_SCRIPT "/usr/share/udhcpc/default.script"
63 struct client_config_t client_config = {
64 /* Default options. */
68 background_if_no_lease: 0,
71 script: DEFAULT_SCRIPT,
75 arp: "\0\0\0\0\0\0", /* appease gcc-3.0 */
78 /* just a little helper */
79 static void change_mode(int new_mode)
81 DEBUG(LOG_INFO, "entering %s listen mode",
82 new_mode ? (new_mode == 1 ? "kernel" : "raw") : "none");
83 if (fd >= 0) close(fd);
85 listen_mode = new_mode;
90 static void perform_renew(void)
92 LOG(LOG_INFO, "Performing a DHCP renew");
95 change_mode(LISTEN_KERNEL);
98 state = RENEW_REQUESTED;
100 case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
101 run_script(NULL, "deconfig");
104 change_mode(LISTEN_RAW);
105 state = INIT_SELECTING;
111 /* start things over */
114 /* Kill any timeouts because the user wants this to hurry along */
119 /* perform a release */
120 static void perform_release(void)
123 struct in_addr temp_addr;
125 /* send release packet */
126 if (state == BOUND || state == RENEWING || state == REBINDING) {
127 temp_addr.s_addr = server_addr;
128 sprintf(buffer, "%s", inet_ntoa(temp_addr));
129 temp_addr.s_addr = requested_ip;
130 LOG(LOG_INFO, "Unicasting a release of %s to %s",
131 inet_ntoa(temp_addr), buffer);
132 send_release(server_addr, requested_ip); /* unicast */
133 run_script(NULL, "deconfig");
135 LOG(LOG_INFO, "Entering released state");
137 change_mode(LISTEN_NONE);
139 timeout = 0x7fffffff;
143 static void client_background(void)
145 background(client_config.pidfile);
146 client_config.foreground = 1; /* Do not fork again. */
147 client_config.background_if_no_lease = 0;
151 int udhcpc_main(int argc, char *argv[])
153 unsigned char *temp, *message;
154 unsigned long t1 = 0, t2 = 0, xid = 0;
155 unsigned long start = 0, lease;
160 struct dhcpMessage packet;
161 struct in_addr temp_addr;
166 static const struct option arg_options[] = {
167 {"clientid", required_argument, 0, 'c'},
168 {"foreground", no_argument, 0, 'f'},
169 {"background", no_argument, 0, 'b'},
170 {"hostname", required_argument, 0, 'H'},
171 {"hostname", required_argument, 0, 'h'},
172 {"interface", required_argument, 0, 'i'},
173 {"now", no_argument, 0, 'n'},
174 {"pidfile", required_argument, 0, 'p'},
175 {"quit", no_argument, 0, 'q'},
176 {"request", required_argument, 0, 'r'},
177 {"script", required_argument, 0, 's'},
178 {"version", no_argument, 0, 'v'},
184 int option_index = 0;
185 c = getopt_long(argc, argv, "c:fbH:h:i:np:qr:s:v", arg_options, &option_index);
190 len = strlen(optarg) > 255 ? 255 : strlen(optarg);
191 if (client_config.clientid) free(client_config.clientid);
192 client_config.clientid = xmalloc(len + 2);
193 client_config.clientid[OPT_CODE] = DHCP_CLIENT_ID;
194 client_config.clientid[OPT_LEN] = len;
195 client_config.clientid[OPT_DATA] = '\0';
196 strncpy(client_config.clientid + OPT_DATA, optarg, len);
199 client_config.foreground = 1;
202 client_config.background_if_no_lease = 1;
206 len = strlen(optarg) > 255 ? 255 : strlen(optarg);
207 if (client_config.hostname) free(client_config.hostname);
208 client_config.hostname = xmalloc(len + 2);
209 client_config.hostname[OPT_CODE] = DHCP_HOST_NAME;
210 client_config.hostname[OPT_LEN] = len;
211 strncpy(client_config.hostname + 2, optarg, len);
214 client_config.interface = optarg;
217 client_config.abort_if_no_lease = 1;
220 client_config.pidfile = optarg;
223 client_config.quit_after_lease = 1;
226 requested_ip = inet_addr(optarg);
229 client_config.script = optarg;
232 bb_error_msg("version %s\n", VERSION);
241 if (read_interface(client_config.interface, &client_config.ifindex,
242 NULL, client_config.arp) < 0)
245 if (!client_config.clientid) {
246 client_config.clientid = xmalloc(6 + 3);
247 client_config.clientid[OPT_CODE] = DHCP_CLIENT_ID;
248 client_config.clientid[OPT_LEN] = 7;
249 client_config.clientid[OPT_DATA] = 1;
250 memcpy(client_config.clientid + 3, client_config.arp, 6);
253 /* setup signal handlers */
254 udhcp_set_signal_pipe(SIGUSR2);
256 state = INIT_SELECTING;
257 run_script(NULL, "deconfig");
258 change_mode(LISTEN_RAW);
262 tv.tv_sec = timeout - time(0);
266 if (listen_mode != LISTEN_NONE && fd < 0) {
267 if (listen_mode == LISTEN_KERNEL)
268 fd = listen_socket(INADDR_ANY, CLIENT_PORT, client_config.interface);
270 fd = raw_socket(client_config.ifindex);
272 LOG(LOG_ERR, "FATAL: couldn't listen on socket, %m");
276 if (fd >= 0) FD_SET(fd, &rfds);
277 FD_SET(udhcp_signal_pipe[0], &rfds);
280 DEBUG(LOG_INFO, "Waiting on select...\n");
281 max_fd = udhcp_signal_pipe[0] > fd ? udhcp_signal_pipe[0] : fd;
282 retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
283 } else retval = 0; /* If we already timed out, fall through */
287 /* timeout dropped to zero */
290 if (packet_num < 3) {
294 /* send discover packet */
295 send_discover(xid, requested_ip); /* broadcast */
297 timeout = now + ((packet_num == 2) ? 4 : 2);
300 if (client_config.background_if_no_lease) {
301 LOG(LOG_INFO, "No lease, forking to background.");
303 } else if (client_config.abort_if_no_lease) {
304 LOG(LOG_INFO, "No lease, failing.");
307 /* wait to try again */
312 case RENEW_REQUESTED:
314 if (packet_num < 3) {
315 /* send request packet */
316 if (state == RENEW_REQUESTED)
317 send_renew(xid, server_addr, requested_ip); /* unicast */
318 else send_selecting(xid, server_addr, requested_ip); /* broadcast */
320 timeout = now + ((packet_num == 2) ? 10 : 2);
323 /* timed out, go back to init state */
324 if (state == RENEW_REQUESTED) run_script(NULL, "deconfig");
325 state = INIT_SELECTING;
328 change_mode(LISTEN_RAW);
332 /* Lease is starting to run out, time to enter renewing state */
334 change_mode(LISTEN_KERNEL);
335 DEBUG(LOG_INFO, "Entering renew state");
336 /* fall right through */
338 /* Either set a new T1, or enter REBINDING state */
339 if ((t2 - t1) <= (lease / 14400 + 1)) {
340 /* timed out, enter rebinding state */
342 timeout = now + (t2 - t1);
343 DEBUG(LOG_INFO, "Entering rebinding state");
345 /* send a request packet */
346 send_renew(xid, server_addr, requested_ip); /* unicast */
348 t1 = (t2 - t1) / 2 + t1;
349 timeout = t1 + start;
353 /* Either set a new T2, or enter INIT state */
354 if ((lease - t2) <= (lease / 14400 + 1)) {
355 /* timed out, enter init state */
356 state = INIT_SELECTING;
357 LOG(LOG_INFO, "Lease lost, entering init state");
358 run_script(NULL, "deconfig");
361 change_mode(LISTEN_RAW);
363 /* send a request packet */
364 send_renew(xid, 0, requested_ip); /* broadcast */
366 t2 = (lease - t2) / 2 + t2;
367 timeout = t2 + start;
371 /* yah, I know, *you* say it would never happen */
372 timeout = 0x7fffffff;
375 } else if (retval > 0 && listen_mode != LISTEN_NONE && FD_ISSET(fd, &rfds)) {
376 /* a packet is ready, read it */
378 if (listen_mode == LISTEN_KERNEL)
379 len = get_packet(&packet, fd);
380 else len = get_raw_packet(&packet, fd);
382 if (len == -1 && errno != EINTR) {
383 DEBUG(LOG_INFO, "error on read, %m, reopening socket");
384 change_mode(listen_mode); /* just close and reopen */
386 if (len < 0) continue;
388 if (packet.xid != xid) {
389 DEBUG(LOG_INFO, "Ignoring XID %lx (our xid is %lx)",
390 (unsigned long) packet.xid, xid);
394 if ((message = get_option(&packet, DHCP_MESSAGE_TYPE)) == NULL) {
395 DEBUG(LOG_ERR, "couldnt get option from packet -- ignoring");
401 /* Must be a DHCPOFFER to one of our xid's */
402 if (*message == DHCPOFFER) {
403 if ((temp = get_option(&packet, DHCP_SERVER_ID))) {
404 memcpy(&server_addr, temp, 4);
406 requested_ip = packet.yiaddr;
408 /* enter requesting state */
413 DEBUG(LOG_ERR, "No server ID in message");
417 case RENEW_REQUESTED:
421 if (*message == DHCPACK) {
422 if (!(temp = get_option(&packet, DHCP_LEASE_TIME))) {
423 LOG(LOG_ERR, "No lease time with ACK, using 1 hour lease");
426 memcpy(&lease, temp, 4);
427 lease = ntohl(lease);
430 /* enter bound state */
433 /* little fixed point for n * .875 */
434 t2 = (lease * 0x7) >> 3;
435 temp_addr.s_addr = packet.yiaddr;
436 LOG(LOG_INFO, "Lease of %s obtained, lease time %ld",
437 inet_ntoa(temp_addr), lease);
439 timeout = t1 + start;
440 requested_ip = packet.yiaddr;
442 ((state == RENEWING || state == REBINDING) ? "renew" : "bound"));
445 change_mode(LISTEN_NONE);
446 if (client_config.quit_after_lease)
448 if (!client_config.foreground)
451 } else if (*message == DHCPNAK) {
452 /* return to init state */
453 LOG(LOG_INFO, "Received DHCP NAK");
454 run_script(&packet, "nak");
455 if (state != REQUESTING)
456 run_script(NULL, "deconfig");
457 state = INIT_SELECTING;
461 change_mode(LISTEN_RAW);
462 sleep(3); /* avoid excessive network traffic */
465 /* case BOUND, RELEASED: - ignore all packets */
467 } else if (retval > 0 && FD_ISSET(udhcp_signal_pipe[0], &rfds)) {
468 if (read(udhcp_signal_pipe[0], &sig, sizeof(sig)) < 0) {
469 DEBUG(LOG_ERR, "Could not read signal: %m");
470 continue; /* probably just EINTR */
480 LOG(LOG_INFO, "Received SIGTERM");
483 } else if (retval == -1 && errno == EINTR) {
484 /* a signal was caught */
486 /* An error occured */
487 DEBUG(LOG_ERR, "Error on select");