1 /* vi: set sw=4 ts=4: */
6 * Russ Dill <Russ.Dill@asu.edu> July 2001
8 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
20 /* Something is definitely wrong here. IPv4 addresses
21 * in variables of type long?? BTW, we use inet_ntoa()
22 * in the code. Manpage says that struct in_addr has a member of type long (!)
23 * which holds IPv4 address, and the struct is passed by value (!!)
25 static unsigned long timeout;
26 static unsigned long requested_ip; /* = 0 */
27 static uint32_t server_addr;
28 static int packet_num; /* = 0 */
29 static int sockfd = -1;
32 #define LISTEN_KERNEL 1
34 static smallint listen_mode;
36 static smallint state;
38 struct client_config_t client_config;
41 /* just a little helper */
42 static void change_mode(int new_mode)
44 DEBUG("entering %s listen mode",
45 new_mode ? (new_mode == 1 ? "kernel" : "raw") : "none");
50 listen_mode = new_mode;
55 static void perform_renew(void)
57 bb_info_msg("Performing a DHCP renew");
60 change_mode(LISTEN_KERNEL);
63 state = RENEW_REQUESTED;
65 case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
66 udhcp_run_script(NULL, "deconfig");
69 change_mode(LISTEN_RAW);
70 state = INIT_SELECTING;
76 /* start things over */
79 /* Kill any timeouts because the user wants this to hurry along */
84 /* perform a release */
85 static void perform_release(void)
88 struct in_addr temp_addr;
90 /* send release packet */
91 if (state == BOUND || state == RENEWING || state == REBINDING) {
92 temp_addr.s_addr = server_addr;
93 sprintf(buffer, "%s", inet_ntoa(temp_addr));
94 temp_addr.s_addr = requested_ip;
95 bb_info_msg("Unicasting a release of %s to %s",
96 inet_ntoa(temp_addr), buffer);
97 send_release(server_addr, requested_ip); /* unicast */
98 udhcp_run_script(NULL, "deconfig");
100 bb_info_msg("Entering released state");
102 change_mode(LISTEN_NONE);
104 timeout = 0x7fffffff;
108 static void client_background(void)
111 bb_error_msg("cannot background in uclinux (yet)");
112 /* ... mainly because udhcpc calls client_background()
113 * in _the _middle _of _udhcpc _run_, not at the start!
114 * If that will be properly disabled for NOMMU, client_background()
115 * will work on NOMMU too */
117 // chdir(/) is problematic. Imagine that e.g. pidfile name is RELATIVE! what will unlink do then, eh?
118 bb_daemonize(DAEMON_CHDIR_ROOT);
119 /* rewrite pidfile, as our pid is different now */
120 if (client_config.pidfile)
121 write_pidfile(client_config.pidfile);
122 logmode &= ~LOGMODE_STDIO;
124 client_config.foreground = 1; /* Do not fork again. */
125 client_config.background_if_no_lease = 0;
129 static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
132 int len = strlen(str);
133 if (len > 255) len = 255;
134 storage = xzalloc(len + extra + OPT_DATA);
135 storage[OPT_CODE] = code;
136 storage[OPT_LEN] = len + extra;
137 memcpy(storage + extra + OPT_DATA, str, len);
142 int udhcpc_main(int argc, char **argv);
143 int udhcpc_main(int argc, char **argv)
145 uint8_t *temp, *message;
146 char *str_c, *str_V, *str_h, *str_F, *str_r, *str_T, *str_t;
147 unsigned long t1 = 0, t2 = 0, xid = 0;
148 unsigned long start = 0, lease = 0;
158 struct dhcpMessage packet;
159 struct in_addr temp_addr;
181 #if ENABLE_GETOPT_LONG
182 static const struct option arg_options[] = {
183 { "clientid", required_argument, 0, 'c' },
184 { "clientid-none", no_argument, 0, 'C' },
185 { "vendorclass", required_argument, 0, 'V' },
186 { "foreground", no_argument, 0, 'f' },
187 { "background", no_argument, 0, 'b' },
188 { "hostname", required_argument, 0, 'H' },
189 { "hostname", required_argument, 0, 'h' },
190 { "fqdn", required_argument, 0, 'F' },
191 { "interface", required_argument, 0, 'i' },
192 { "now", no_argument, 0, 'n' },
193 { "pidfile", required_argument, 0, 'p' },
194 { "quit", no_argument, 0, 'q' },
195 { "release", no_argument, 0, 'R' },
196 { "request", required_argument, 0, 'r' },
197 { "script", required_argument, 0, 's' },
198 { "timeout", required_argument, 0, 'T' },
199 { "version", no_argument, 0, 'v' },
200 { "retries", required_argument, 0, 't' },
204 /* Default options. */
205 client_config.interface = "eth0";
206 client_config.script = DEFAULT_SCRIPT;
207 client_config.retries = 3;
208 client_config.timeout = 3;
210 /* Parse command line */
211 opt_complementary = "?:c--C:C--c" // mutually exclusive
212 ":hH:Hh"; // -h and -H are the same
213 #if ENABLE_GETOPT_LONG
214 applet_long_options = arg_options;
216 opt = getopt32(argc, argv, "c:CV:fbH:h:F:i:np:qRr:s:T:t:v",
217 &str_c, &str_V, &str_h, &str_h, &str_F,
218 &client_config.interface, &client_config.pidfile, &str_r,
219 &client_config.script, &str_T, &str_t
223 client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, str_c, 0);
227 client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0);
229 client_config.foreground = 1;
231 client_config.background_if_no_lease = 1;
233 client_config.hostname = alloc_dhcp_option(DHCP_HOST_NAME, str_h, 0);
235 client_config.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3);
237 S: 1 => Client requests Server to update A RR in DNS as well as PTR
238 O: 1 => Server indicates to client that DNS has been updated regardless
239 E: 1 => Name data is DNS format, i.e. <4>host<6>domain<4>com<0> not "host.domain.com"
240 N: 1 => Client requests Server to not update DNS
242 client_config.fqdn[OPT_DATA + 0] = 0x1;
243 /* client_config.fqdn[OPT_DATA + 1] = 0; - redundant */
244 /* client_config.fqdn[OPT_DATA + 2] = 0; - redundant */
246 // if (opt & OPT_i) client_config.interface = ...
248 client_config.abort_if_no_lease = 1;
249 // if (opt & OPT_p) client_config.pidfile = ...
251 client_config.quit_after_lease = 1;
253 client_config.release_on_quit = 1;
255 requested_ip = inet_addr(str_r);
256 // if (opt & OPT_s) client_config.script = ...
258 client_config.timeout = xatoi_u(str_T);
260 client_config.retries = xatoi_u(str_t);
262 printf("version %s\n\n", BB_VER);
266 if (ENABLE_FEATURE_UDHCP_SYSLOG) {
267 openlog(applet_name, LOG_PID, LOG_LOCAL0);
268 logmode |= LOGMODE_SYSLOG;
271 if (read_interface(client_config.interface, &client_config.ifindex,
272 NULL, client_config.arp) < 0)
275 /* Sanitize fd's and write pidfile */
276 udhcp_make_pidfile(client_config.pidfile);
278 /* if not set, and not suppressed, setup the default client ID */
279 if (!client_config.clientid && !no_clientid) {
280 client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7);
281 client_config.clientid[OPT_DATA] = 1;
282 memcpy(client_config.clientid + OPT_DATA+1, client_config.arp, 6);
285 if (!client_config.vendorclass)
286 client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, "udhcp "BB_VER, 0);
288 /* setup the signal pipe */
291 state = INIT_SELECTING;
292 udhcp_run_script(NULL, "deconfig");
293 change_mode(LISTEN_RAW);
296 tv.tv_sec = timeout - uptime();
299 if (listen_mode != LISTEN_NONE && sockfd < 0) {
300 if (listen_mode == LISTEN_KERNEL)
301 sockfd = listen_socket(INADDR_ANY, CLIENT_PORT, client_config.interface);
303 sockfd = raw_socket(client_config.ifindex);
305 max_fd = udhcp_sp_fd_set(&rfds, sockfd);
308 DEBUG("Waiting on select...");
309 retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
310 } else retval = 0; /* If we already timed out, fall through */
314 /* timeout dropped to zero */
317 if (packet_num < client_config.retries) {
321 /* send discover packet */
322 send_discover(xid, requested_ip); /* broadcast */
324 timeout = now + client_config.timeout;
327 udhcp_run_script(NULL, "leasefail");
328 if (client_config.background_if_no_lease) {
329 bb_info_msg("No lease, forking to background");
331 } else if (client_config.abort_if_no_lease) {
332 bb_info_msg("No lease, failing");
336 /* wait to try again */
341 case RENEW_REQUESTED:
343 if (packet_num < client_config.retries) {
344 /* send request packet */
345 if (state == RENEW_REQUESTED)
346 send_renew(xid, server_addr, requested_ip); /* unicast */
347 else send_selecting(xid, server_addr, requested_ip); /* broadcast */
349 timeout = now + ((packet_num == 2) ? 10 : 2);
352 /* timed out, go back to init state */
353 if (state == RENEW_REQUESTED)
354 udhcp_run_script(NULL, "deconfig");
355 state = INIT_SELECTING;
358 change_mode(LISTEN_RAW);
362 /* Lease is starting to run out, time to enter renewing state */
364 change_mode(LISTEN_KERNEL);
365 DEBUG("Entering renew state");
366 /* fall right through */
368 /* Either set a new T1, or enter REBINDING state */
369 if ((t2 - t1) <= (lease / 14400 + 1)) {
370 /* timed out, enter rebinding state */
372 timeout = now + (t2 - t1);
373 DEBUG("Entering rebinding state");
375 /* send a request packet */
376 send_renew(xid, server_addr, requested_ip); /* unicast */
378 t1 = (t2 - t1) / 2 + t1;
379 timeout = t1 + start;
383 /* Either set a new T2, or enter INIT state */
384 if ((lease - t2) <= (lease / 14400 + 1)) {
385 /* timed out, enter init state */
386 state = INIT_SELECTING;
387 bb_info_msg("Lease lost, entering init state");
388 udhcp_run_script(NULL, "deconfig");
391 change_mode(LISTEN_RAW);
393 /* send a request packet */
394 send_renew(xid, 0, requested_ip); /* broadcast */
396 t2 = (lease - t2) / 2 + t2;
397 timeout = t2 + start;
401 /* yah, I know, *you* say it would never happen */
402 timeout = 0x7fffffff;
405 } else if (retval > 0 && listen_mode != LISTEN_NONE && FD_ISSET(sockfd, &rfds)) {
406 /* a packet is ready, read it */
408 if (listen_mode == LISTEN_KERNEL)
409 len = udhcp_get_packet(&packet, sockfd);
410 else len = get_raw_packet(&packet, sockfd);
412 if (len == -1 && errno != EINTR) {
413 DEBUG("error on read, %s, reopening socket", strerror(errno));
414 change_mode(listen_mode); /* just close and reopen */
416 if (len < 0) continue;
418 if (packet.xid != xid) {
419 DEBUG("Ignoring XID %lx (our xid is %lx)",
420 (unsigned long) packet.xid, xid);
424 /* Ignore packets that aren't for us */
425 if (memcmp(packet.chaddr, client_config.arp, 6)) {
426 DEBUG("Packet does not have our chaddr - ignoring");
430 message = get_option(&packet, DHCP_MESSAGE_TYPE);
431 if (message == NULL) {
432 bb_error_msg("cannot get option from packet - ignoring");
438 /* Must be a DHCPOFFER to one of our xid's */
439 if (*message == DHCPOFFER) {
440 temp = get_option(&packet, DHCP_SERVER_ID);
442 /* can be misaligned, thus memcpy */
443 memcpy(&server_addr, temp, 4);
445 requested_ip = packet.yiaddr;
447 /* enter requesting state */
452 bb_error_msg("no server ID in message");
456 case RENEW_REQUESTED:
460 if (*message == DHCPACK) {
461 temp = get_option(&packet, DHCP_LEASE_TIME);
463 bb_error_msg("no lease time with ACK, using 1 hour lease");
466 /* can be misaligned, thus memcpy */
467 memcpy(&lease, temp, 4);
468 lease = ntohl(lease);
471 /* enter bound state */
474 /* little fixed point for n * .875 */
475 t2 = (lease * 0x7) >> 3;
476 temp_addr.s_addr = packet.yiaddr;
477 bb_info_msg("Lease of %s obtained, lease time %ld",
478 inet_ntoa(temp_addr), lease);
480 timeout = t1 + start;
481 requested_ip = packet.yiaddr;
482 udhcp_run_script(&packet,
483 ((state == RENEWING || state == REBINDING) ? "renew" : "bound"));
486 change_mode(LISTEN_NONE);
487 if (client_config.quit_after_lease) {
488 if (client_config.release_on_quit)
492 if (!client_config.foreground)
495 } else if (*message == DHCPNAK) {
496 /* return to init state */
497 bb_info_msg("Received DHCP NAK");
498 udhcp_run_script(&packet, "nak");
499 if (state != REQUESTING)
500 udhcp_run_script(NULL, "deconfig");
501 state = INIT_SELECTING;
505 change_mode(LISTEN_RAW);
506 sleep(3); /* avoid excessive network traffic */
509 /* case BOUND, RELEASED: - ignore all packets */
511 } else if (retval > 0 && (sig = udhcp_sp_read(&rfds))) {
520 bb_info_msg("Received SIGTERM");
521 if (client_config.release_on_quit)
525 } else if (retval == -1 && errno == EINTR) {
526 /* a signal was caught */
528 /* An error occured */
529 bb_perror_msg("select");
535 if (client_config.pidfile)
536 remove_pidfile(client_config.pidfile);