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.
14 /* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */
15 #define WANT_PIDFILE 1
22 /* Something is definitely wrong here. IPv4 addresses
23 * in variables of type long?? BTW, we use inet_ntoa()
24 * in the code. Manpage says that struct in_addr has a member of type long (!)
25 * which holds IPv4 address, and the struct is passed by value (!!)
27 static unsigned timeout;
28 static uint32_t requested_ip; /* = 0 */
29 static uint32_t server_addr;
30 static int packet_num; /* = 0 */
31 static int sockfd = -1;
34 #define LISTEN_KERNEL 1
36 static smallint listen_mode;
38 static smallint state;
40 struct client_config_t client_config;
43 /* just a little helper */
44 static void change_mode(int new_mode)
46 DEBUG("entering %s listen mode",
47 new_mode ? (new_mode == 1 ? "kernel" : "raw") : "none");
52 listen_mode = new_mode;
57 static void perform_renew(void)
59 bb_info_msg("Performing a DHCP renew");
62 change_mode(LISTEN_KERNEL);
65 state = RENEW_REQUESTED;
67 case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
68 udhcp_run_script(NULL, "deconfig");
71 change_mode(LISTEN_RAW);
72 state = INIT_SELECTING;
78 /* start things over */
81 /* Kill any timeouts because the user wants this to hurry along */
86 /* perform a release */
87 static void perform_release(void)
89 char buffer[sizeof("255.255.255.255")];
90 struct in_addr temp_addr;
92 /* send release packet */
93 if (state == BOUND || state == RENEWING || state == REBINDING) {
94 temp_addr.s_addr = server_addr;
95 strcpy(buffer, inet_ntoa(temp_addr));
96 temp_addr.s_addr = requested_ip;
97 bb_info_msg("Unicasting a release of %s to %s",
98 inet_ntoa(temp_addr), buffer);
99 send_release(server_addr, requested_ip); /* unicast */
100 udhcp_run_script(NULL, "deconfig");
102 bb_info_msg("Entering released state");
104 change_mode(LISTEN_NONE);
110 static void client_background(void)
113 bb_error_msg("cannot background in uclinux (yet)");
114 /* ... mainly because udhcpc calls client_background()
115 * in _the _middle _of _udhcpc _run_, not at the start!
116 * If that will be properly disabled for NOMMU, client_background()
117 * will work on NOMMU too */
120 logmode &= ~LOGMODE_STDIO;
121 /* rewrite pidfile, as our pid is different now */
122 write_pidfile(client_config.pidfile);
124 /* Do not fork again. */
125 client_config.foreground = 1;
126 client_config.background_if_no_lease = 0;
130 static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
133 int len = strlen(str);
134 if (len > 255) len = 255;
135 storage = xzalloc(len + extra + OPT_DATA);
136 storage[OPT_CODE] = code;
137 storage[OPT_LEN] = len + extra;
138 memcpy(storage + extra + OPT_DATA, str, len);
143 int udhcpc_main(int argc, char **argv);
144 int udhcpc_main(int argc, char **argv)
146 uint8_t *temp, *message;
147 char *str_c, *str_V, *str_h, *str_F, *str_r, *str_T, *str_t;
149 uint32_t lease = 0; /* can be given as 32-bit quantity */
150 unsigned t1 = 0, t2 = 0; /* what a wonderful names */
158 struct in_addr temp_addr;
159 struct dhcpMessage packet;
183 #if ENABLE_GETOPT_LONG
184 static const char udhcpc_longopts[] ALIGN1 =
185 "clientid\0" Required_argument "c"
186 "clientid-none\0" No_argument "C"
187 "vendorclass\0" Required_argument "V"
188 "foreground\0" No_argument "f"
189 "background\0" No_argument "b"
190 "hostname\0" Required_argument "H"
191 "hostname\0" Required_argument "h"
192 "fqdn\0" Required_argument "F"
193 "interface\0" Required_argument "i"
194 "now\0" No_argument "n"
195 "pidfile\0" Required_argument "p"
196 "quit\0" No_argument "q"
197 "release\0" No_argument "R"
198 "request\0" Required_argument "r"
199 "script\0" Required_argument "s"
200 "timeout\0" Required_argument "T"
201 "version\0" No_argument "v"
202 "retries\0" Required_argument "t"
203 "syslog\0" No_argument "S"
206 /* Default options. */
207 client_config.interface = "eth0";
208 client_config.script = DEFAULT_SCRIPT;
209 client_config.retries = 3;
210 client_config.timeout = 3;
212 /* Parse command line */
213 opt_complementary = "c--C:C--c" // mutually exclusive
214 ":hH:Hh"; // -h and -H are the same
215 #if ENABLE_GETOPT_LONG
216 applet_long_options = udhcpc_longopts;
218 opt = getopt32(argc, argv, "c:CV:fbH:h:F:i:np:qRr:s:T:t:vS",
219 &str_c, &str_V, &str_h, &str_h, &str_F,
220 &client_config.interface, &client_config.pidfile, &str_r,
221 &client_config.script, &str_T, &str_t
225 client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, str_c, 0);
228 client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0);
230 client_config.foreground = 1;
232 client_config.background_if_no_lease = 1;
234 client_config.hostname = alloc_dhcp_option(DHCP_HOST_NAME, str_h, 0);
236 client_config.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3);
238 S: 1 => Client requests Server to update A RR in DNS as well as PTR
239 O: 1 => Server indicates to client that DNS has been updated regardless
240 E: 1 => Name data is DNS format, i.e. <4>host<6>domain<4>com<0> not "host.domain.com"
241 N: 1 => Client requests Server to not update DNS
243 client_config.fqdn[OPT_DATA + 0] = 0x1;
244 /* client_config.fqdn[OPT_DATA + 1] = 0; - redundant */
245 /* client_config.fqdn[OPT_DATA + 2] = 0; - redundant */
247 // if (opt & OPT_i) client_config.interface = ...
249 client_config.abort_if_no_lease = 1;
250 // if (opt & OPT_p) client_config.pidfile = ...
252 client_config.quit_after_lease = 1;
254 client_config.release_on_quit = 1;
256 requested_ip = inet_addr(str_r);
257 // if (opt & OPT_s) client_config.script = ...
259 client_config.timeout = xatoi_u(str_T);
261 client_config.retries = xatoi_u(str_t);
263 printf("version %s\n", BB_VER);
268 openlog(applet_name, LOG_PID, LOG_LOCAL0);
269 logmode |= LOGMODE_SYSLOG;
272 if (read_interface(client_config.interface, &client_config.ifindex,
273 NULL, client_config.arp))
276 /* Make sure fd 0,1,2 are open */
278 /* Equivalent of doing a fflush after every \n */
282 write_pidfile(client_config.pidfile);
283 /* if (!..) bb_perror_msg("cannot create pidfile %s", pidfile); */
285 /* Goes to stdout and possibly syslog */
286 bb_info_msg("%s (v%s) started", applet_name, BB_VER);
288 /* if not set, and not suppressed, setup the default client ID */
289 if (!client_config.clientid && !(opt & OPT_C)) {
290 client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7);
291 client_config.clientid[OPT_DATA] = 1;
292 memcpy(client_config.clientid + OPT_DATA+1, client_config.arp, 6);
295 if (!client_config.vendorclass)
296 client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, "udhcp "BB_VER, 0);
298 /* setup the signal pipe */
301 state = INIT_SELECTING;
302 udhcp_run_script(NULL, "deconfig");
303 change_mode(LISTEN_RAW);
308 tv.tv_sec = timeout - monotonic_sec();
312 if (listen_mode != LISTEN_NONE && sockfd < 0) {
313 if (listen_mode == LISTEN_KERNEL)
314 sockfd = listen_socket(INADDR_ANY, CLIENT_PORT, client_config.interface);
316 sockfd = raw_socket(client_config.ifindex);
318 max_fd = udhcp_sp_fd_set(&rfds, sockfd);
320 retval = 0; /* If we already timed out, fall through, else... */
322 DEBUG("Waiting on select...");
323 retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
326 now = monotonic_sec();
328 /* EINTR? signal was caught, don't panic */
329 if (errno != EINTR) {
330 /* Else: an error occured, panic! */
331 bb_perror_msg_and_die("select");
333 } else if (retval == 0) {
334 /* timeout dropped to zero */
337 if (packet_num < client_config.retries) {
341 /* send discover packet */
342 send_discover(xid, requested_ip); /* broadcast */
344 timeout = now + client_config.timeout;
347 udhcp_run_script(NULL, "leasefail");
348 if (client_config.background_if_no_lease) {
349 bb_info_msg("No lease, forking to background");
351 } else if (client_config.abort_if_no_lease) {
352 bb_info_msg("No lease, failing");
356 /* wait to try again */
361 case RENEW_REQUESTED:
363 if (packet_num < client_config.retries) {
364 /* send request packet */
365 if (state == RENEW_REQUESTED)
366 send_renew(xid, server_addr, requested_ip); /* unicast */
367 else send_selecting(xid, server_addr, requested_ip); /* broadcast */
369 timeout = now + ((packet_num == 2) ? 10 : 2);
372 /* timed out, go back to init state */
373 if (state == RENEW_REQUESTED)
374 udhcp_run_script(NULL, "deconfig");
375 state = INIT_SELECTING;
378 change_mode(LISTEN_RAW);
382 /* Lease is starting to run out, time to enter renewing state */
384 change_mode(LISTEN_KERNEL);
385 DEBUG("Entering renew state");
386 /* fall right through */
388 /* Either set a new T1, or enter REBINDING state */
389 if ((t2 - t1) <= (lease / 14400 + 1)) {
390 /* timed out, enter rebinding state */
392 timeout = now + (t2 - t1);
393 DEBUG("Entering rebinding state");
395 /* send a request packet */
396 send_renew(xid, server_addr, requested_ip); /* unicast */
397 t1 = (t2 - t1) / 2 + t1;
398 timeout = start + t1;
402 /* Either set a new T2, or enter INIT state */
403 if ((lease - t2) <= (lease / 14400 + 1)) {
404 /* timed out, enter init state */
405 state = INIT_SELECTING;
406 bb_info_msg("Lease lost, entering init state");
407 udhcp_run_script(NULL, "deconfig");
410 change_mode(LISTEN_RAW);
412 /* send a request packet */
413 send_renew(xid, 0, requested_ip); /* broadcast */
414 t2 = (lease - t2) / 2 + t2;
415 timeout = start + t2;
419 /* yah, I know, *you* say it would never happen */
423 } else if (listen_mode != LISTEN_NONE && FD_ISSET(sockfd, &rfds)) {
424 /* a packet is ready, read it */
426 if (listen_mode == LISTEN_KERNEL)
427 len = udhcp_get_packet(&packet, sockfd);
428 else len = get_raw_packet(&packet, sockfd);
430 if (len == -1 && errno != EINTR) {
431 DEBUG("error on read, %s, reopening socket", strerror(errno));
432 change_mode(listen_mode); /* just close and reopen */
434 if (len < 0) continue;
436 if (packet.xid != xid) {
437 DEBUG("Ignoring XID %x (our xid is %x)",
438 (unsigned)packet.xid, (unsigned)xid);
442 /* Ignore packets that aren't for us */
443 if (memcmp(packet.chaddr, client_config.arp, 6)) {
444 DEBUG("Packet does not have our chaddr - ignoring");
448 message = get_option(&packet, DHCP_MESSAGE_TYPE);
449 if (message == NULL) {
450 bb_error_msg("cannot get option from packet - ignoring");
456 /* Must be a DHCPOFFER to one of our xid's */
457 if (*message == DHCPOFFER) {
458 temp = get_option(&packet, DHCP_SERVER_ID);
460 /* can be misaligned, thus memcpy */
461 memcpy(&server_addr, temp, 4);
463 requested_ip = packet.yiaddr;
465 /* enter requesting state */
470 bb_error_msg("no server ID in message");
474 case RENEW_REQUESTED:
478 if (*message == DHCPACK) {
479 temp = get_option(&packet, DHCP_LEASE_TIME);
481 bb_error_msg("no lease time with ACK, using 1 hour lease");
484 /* can be misaligned, thus memcpy */
485 memcpy(&lease, temp, 4);
486 lease = ntohl(lease);
489 /* enter bound state */
492 /* little fixed point for n * .875 */
493 t2 = (lease * 7) >> 3;
494 temp_addr.s_addr = packet.yiaddr;
495 bb_info_msg("Lease of %s obtained, lease time %u",
496 inet_ntoa(temp_addr), (unsigned)lease);
498 timeout = start + t1;
499 requested_ip = packet.yiaddr;
500 udhcp_run_script(&packet,
501 ((state == RENEWING || state == REBINDING) ? "renew" : "bound"));
504 change_mode(LISTEN_NONE);
505 if (client_config.quit_after_lease) {
506 if (client_config.release_on_quit)
510 if (!client_config.foreground)
513 } else if (*message == DHCPNAK) {
514 /* return to init state */
515 bb_info_msg("Received DHCP NAK");
516 udhcp_run_script(&packet, "nak");
517 if (state != REQUESTING)
518 udhcp_run_script(NULL, "deconfig");
519 state = INIT_SELECTING;
523 change_mode(LISTEN_RAW);
524 sleep(3); /* avoid excessive network traffic */
527 /* case BOUND, RELEASED: - ignore all packets */
530 int signo = udhcp_sp_read(&rfds);
539 bb_info_msg("Received SIGTERM");
540 if (client_config.release_on_quit)
549 /*if (client_config.pidfile) - remove_pidfile has it's own check */
550 remove_pidfile(client_config.pidfile);