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.
13 /* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */
14 #define WANT_PIDFILE 1
21 static int timeout; /* = 0. Must be signed */
22 static uint32_t requested_ip; /* = 0 */
23 static uint32_t server_addr;
24 static int sockfd = -1;
27 #define LISTEN_KERNEL 1
29 static smallint listen_mode;
31 static smallint state;
33 /* struct client_config_t client_config is in bb_common_bufsiz1 */
36 /* just a little helper */
37 static void change_listen_mode(int new_mode)
39 DEBUG("entering %s listen mode",
40 new_mode ? (new_mode == 1 ? "kernel" : "raw") : "none");
45 listen_mode = new_mode;
50 static void perform_renew(void)
52 bb_info_msg("Performing a DHCP renew");
55 change_listen_mode(LISTEN_KERNEL);
58 state = RENEW_REQUESTED;
60 case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
61 udhcp_run_script(NULL, "deconfig");
64 change_listen_mode(LISTEN_RAW);
65 state = INIT_SELECTING;
73 /* perform a release */
74 static void perform_release(void)
76 char buffer[sizeof("255.255.255.255")];
77 struct in_addr temp_addr;
79 /* send release packet */
80 if (state == BOUND || state == RENEWING || state == REBINDING) {
81 temp_addr.s_addr = server_addr;
82 strcpy(buffer, inet_ntoa(temp_addr));
83 temp_addr.s_addr = requested_ip;
84 bb_info_msg("Unicasting a release of %s to %s",
85 inet_ntoa(temp_addr), buffer);
86 send_release(server_addr, requested_ip); /* unicast */
87 udhcp_run_script(NULL, "deconfig");
89 bb_info_msg("Entering released state");
91 change_listen_mode(LISTEN_NONE);
97 static void client_background(void)
100 bb_error_msg("cannot background in uclinux (yet)");
101 /* ... mainly because udhcpc calls client_background()
102 * in _the _middle _of _udhcpc _run_, not at the start!
103 * If that will be properly disabled for NOMMU, client_background()
104 * will work on NOMMU too */
107 logmode &= ~LOGMODE_STDIO;
108 /* rewrite pidfile, as our pid is different now */
109 write_pidfile(client_config.pidfile);
111 /* Do not fork again. */
112 client_config.foreground = 1;
113 client_config.background_if_no_lease = 0;
117 static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
120 int len = strlen(str);
121 if (len > 255) len = 255;
122 storage = xzalloc(len + extra + OPT_DATA);
123 storage[OPT_CODE] = code;
124 storage[OPT_LEN] = len + extra;
125 memcpy(storage + extra + OPT_DATA, str, len);
130 int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
131 int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
133 uint8_t *temp, *message;
134 char *str_c, *str_V, *str_h, *str_F, *str_r;
135 USE_FEATURE_UDHCP_PORT(char *str_P;)
136 llist_t *list_O = NULL;
137 #if ENABLE_FEATURE_UDHCPC_ARPING
140 int tryagain_timeout = 20;
141 int discover_timeout = 3;
142 int discover_retries = 3;
144 uint32_t lease_seconds = 0; /* can be given as 32-bit quantity */
146 /* t1, t2... what a wonderful names... */
147 unsigned t1 = t1; /* for gcc */
149 unsigned timestamp_got_lease = timestamp_got_lease;
155 struct in_addr temp_addr;
156 struct dhcpMessage packet;
180 #if ENABLE_FEATURE_UDHCPC_ARPING
186 #if ENABLE_GETOPT_LONG
187 static const char udhcpc_longopts[] ALIGN1 =
188 "clientid\0" Required_argument "c"
189 "clientid-none\0" No_argument "C"
190 "vendorclass\0" Required_argument "V"
191 "foreground\0" No_argument "f"
192 "background\0" No_argument "b"
193 "hostname\0" Required_argument "H"
194 "fqdn\0" Required_argument "F"
195 "interface\0" Required_argument "i"
196 "now\0" No_argument "n"
197 "pidfile\0" Required_argument "p"
198 "quit\0" No_argument "q"
199 "release\0" No_argument "R"
200 "request\0" Required_argument "r"
201 "script\0" Required_argument "s"
202 "timeout\0" Required_argument "T"
203 "version\0" No_argument "v"
204 "retries\0" Required_argument "t"
205 "tryagain\0" Required_argument "A"
206 "syslog\0" No_argument "S"
207 #if ENABLE_FEATURE_UDHCPC_ARPING
208 "arping\0" No_argument "a"
210 "request-option\0" Required_argument "O"
211 #if ENABLE_FEATURE_UDHCP_PORT
212 "client-port\0" Required_argument "P"
216 /* Default options. */
217 #if ENABLE_FEATURE_UDHCP_PORT
221 client_config.interface = "eth0";
222 client_config.script = DEFAULT_SCRIPT;
224 /* Parse command line */
225 /* Cc: mutually exclusive; O: list; -T,-t,-A take numeric param */
226 opt_complementary = "c--C:C--c:O::T+:t+:A+";
227 #if ENABLE_GETOPT_LONG
228 applet_long_options = udhcpc_longopts;
230 opt = getopt32(argv, "c:CV:fbH:h:F:i:np:qRr:s:T:t:vSA:"
231 USE_FEATURE_UDHCPC_ARPING("aW:")
232 USE_FEATURE_UDHCP_PORT("P:")
234 , &str_c, &str_V, &str_h, &str_h, &str_F
235 , &client_config.interface, &client_config.pidfile, &str_r
236 , &client_config.script
237 , &discover_timeout, &discover_retries, &tryagain_timeout
238 USE_FEATURE_UDHCPC_ARPING(, &str_W)
239 USE_FEATURE_UDHCP_PORT(, &str_P)
244 client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, str_c, 0);
247 client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0);
249 client_config.foreground = 1;
251 client_config.background_if_no_lease = 1;
252 if (opt & (OPT_h|OPT_H))
253 client_config.hostname = alloc_dhcp_option(DHCP_HOST_NAME, str_h, 0);
255 client_config.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3);
257 S: 1 => Client requests Server to update A RR in DNS as well as PTR
258 O: 1 => Server indicates to client that DNS has been updated regardless
259 E: 1 => Name data is DNS format, i.e. <4>host<6>domain<4>com<0> not "host.domain.com"
260 N: 1 => Client requests Server to not update DNS
262 client_config.fqdn[OPT_DATA + 0] = 0x1;
263 /* client_config.fqdn[OPT_DATA + 1] = 0; - redundant */
264 /* client_config.fqdn[OPT_DATA + 2] = 0; - redundant */
266 // if (opt & OPT_i) client_config.interface = ...
268 client_config.abort_if_no_lease = 1;
269 // if (opt & OPT_p) client_config.pidfile = ...
271 client_config.quit_after_lease = 1;
273 client_config.release_on_quit = 1;
275 requested_ip = inet_addr(str_r);
276 // if (opt & OPT_s) client_config.script = ...
277 // if (opt & OPT_T) discover_timeout = xatoi_u(str_T);
278 // if (opt & OPT_t) discover_retries = xatoi_u(str_t);
279 // if (opt & OPT_A) tryagain_timeout = xatoi_u(str_A);
281 puts("version "BB_VER);
285 openlog(applet_name, LOG_PID, LOG_LOCAL0);
286 logmode |= LOGMODE_SYSLOG;
288 #if ENABLE_FEATURE_UDHCP_PORT
290 CLIENT_PORT = xatou16(str_P);
291 SERVER_PORT = CLIENT_PORT - 1;
295 int n = index_in_strings(dhcp_option_strings, list_O->data);
297 bb_error_msg_and_die("unknown option '%s'", list_O->data);
298 n = dhcp_options[n].code;
299 client_config.opt_mask[n >> 3] |= 1 << (n & 7);
300 list_O = list_O->link;
303 if (read_interface(client_config.interface, &client_config.ifindex,
304 NULL, client_config.arp))
307 /* Make sure fd 0,1,2 are open */
309 /* Equivalent of doing a fflush after every \n */
313 write_pidfile(client_config.pidfile);
314 /* if (!..) bb_perror_msg("cannot create pidfile %s", pidfile); */
316 /* Goes to stdout and possibly syslog */
317 bb_info_msg("%s (v"BB_VER") started", applet_name);
319 /* if not set, and not suppressed, setup the default client ID */
320 if (!client_config.clientid && !(opt & OPT_C)) {
321 client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7);
322 client_config.clientid[OPT_DATA] = 1;
323 memcpy(client_config.clientid + OPT_DATA+1, client_config.arp, 6);
326 if (!client_config.vendorclass)
327 client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, "udhcp "BB_VER, 0);
329 /* setup the signal pipe */
332 state = INIT_SELECTING;
333 udhcp_run_script(NULL, "deconfig");
334 change_listen_mode(LISTEN_RAW);
337 /* Main event loop. select() waits on signal pipe and possibly
339 * "continue" statements in code below jump to the top of the loop.
345 if (listen_mode != LISTEN_NONE && sockfd < 0) {
346 if (listen_mode == LISTEN_KERNEL)
347 sockfd = listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_config.interface);
349 sockfd = raw_socket(client_config.ifindex);
351 max_fd = udhcp_sp_fd_set(&rfds, sockfd);
353 retval = 0; /* If we already timed out, fall through, else... */
355 DEBUG("Waiting on select...");
356 retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
360 /* EINTR? signal was caught, don't panic */
361 if (errno != EINTR) {
362 /* Else: an error occured, panic! */
363 bb_perror_msg_and_die("select");
368 /* If timeout dropped to zero, time to become active:
369 * resend discover/renew/whatever
374 if (packet_num < discover_retries) {
378 /* send discover packet */
379 send_discover(xid, requested_ip); /* broadcast */
381 timeout = discover_timeout;
385 udhcp_run_script(NULL, "leasefail");
386 if (client_config.background_if_no_lease) {
387 bb_info_msg("No lease, forking to background");
389 } else if (client_config.abort_if_no_lease) {
390 bb_info_msg("No lease, failing");
394 /* wait to try again */
395 timeout = tryagain_timeout;
398 case RENEW_REQUESTED:
400 if (packet_num < discover_retries) {
401 /* send request packet */
402 if (state == RENEW_REQUESTED)
403 send_renew(xid, server_addr, requested_ip); /* unicast */
404 else send_selecting(xid, server_addr, requested_ip); /* broadcast */
406 timeout = ((packet_num == 2) ? 10 : 2);
410 /* timed out, go back to init state */
411 if (state == RENEW_REQUESTED)
412 udhcp_run_script(NULL, "deconfig");
413 change_listen_mode(LISTEN_RAW);
414 state = INIT_SELECTING;
419 /* Lease is starting to run out, time to enter renewing state */
420 change_listen_mode(LISTEN_KERNEL);
421 DEBUG("Entering renew state");
423 /* fall right through */
425 /* Either set a new T1, or enter REBINDING state */
426 if ((t2 - t1) > (lease_seconds / (4*60*60) + 1)) {
427 /* send a request packet */
428 send_renew(xid, server_addr, requested_ip); /* unicast */
430 timeout = t1 - ((int)monotonic_sec() - timestamp_got_lease);
433 /* Timed out, enter rebinding state */
434 DEBUG("Entering rebinding state");
439 /* Lease is *really* about to run out,
440 * try to find DHCP server using broadcast */
441 if ((lease_seconds - t2) > (lease_seconds / (4*60*60) + 1)) {
442 /* send a request packet */
443 send_renew(xid, 0, requested_ip); /* broadcast */
444 t2 += (lease_seconds - t2) / 2;
445 timeout = t2 - ((int)monotonic_sec() - timestamp_got_lease);
448 /* Timed out, enter init state */
449 bb_info_msg("Lease lost, entering init state");
450 udhcp_run_script(NULL, "deconfig");
451 change_listen_mode(LISTEN_RAW);
452 state = INIT_SELECTING;
458 /* yah, I know, *you* say it would never happen */
460 continue; /* back to main loop */
463 /* select() didn't timeout, something did happen. */
464 /* Is is a packet? */
465 if (listen_mode != LISTEN_NONE && FD_ISSET(sockfd, &rfds)) {
466 /* A packet is ready, read it */
468 if (listen_mode == LISTEN_KERNEL)
469 len = udhcp_recv_packet(&packet, sockfd);
471 len = get_raw_packet(&packet, sockfd);
473 if (len == -1) { /* error is severe, reopen socket */
474 DEBUG("error on read, %s, reopening socket", strerror(errno));
475 change_listen_mode(listen_mode); /* just close and reopen */
477 if (len < 0) continue;
479 if (packet.xid != xid) {
480 DEBUG("Ignoring XID %x (our xid is %x)",
481 (unsigned)packet.xid, (unsigned)xid);
485 /* Ignore packets that aren't for us */
486 if (memcmp(packet.chaddr, client_config.arp, 6)) {
487 DEBUG("Packet does not have our chaddr - ignoring");
491 message = get_option(&packet, DHCP_MESSAGE_TYPE);
492 if (message == NULL) {
493 bb_error_msg("cannot get message type from packet - ignoring");
499 /* Must be a DHCPOFFER to one of our xid's */
500 if (*message == DHCPOFFER) {
501 /* TODO: why we don't just fetch server's IP from IP header? */
502 temp = get_option(&packet, DHCP_SERVER_ID);
504 bb_error_msg("no server ID in message");
506 /* still selecting - this server looks bad */
508 /* can be misaligned, thus memcpy */
509 memcpy(&server_addr, temp, 4);
511 requested_ip = packet.yiaddr;
513 /* enter requesting state */
519 case RENEW_REQUESTED:
523 if (*message == DHCPACK) {
524 temp = get_option(&packet, DHCP_LEASE_TIME);
526 bb_error_msg("no lease time with ACK, using 1 hour lease");
527 lease_seconds = 60 * 60;
529 /* can be misaligned, thus memcpy */
530 memcpy(&lease_seconds, temp, 4);
531 lease_seconds = ntohl(lease_seconds);
533 #if ENABLE_FEATURE_UDHCPC_ARPING
535 if (!arpping(packet.yiaddr,
538 client_config.interface)
540 bb_info_msg("offered address is in use "
541 "(got ARP reply), declining");
542 send_decline(xid, server_addr, packet.yiaddr);
544 if (state != REQUESTING)
545 udhcp_run_script(NULL, "deconfig");
546 change_listen_mode(LISTEN_RAW);
547 state = INIT_SELECTING;
549 timeout = tryagain_timeout;
551 continue; /* back to main loop */
555 /* enter bound state */
556 t1 = lease_seconds / 2;
558 /* little fixed point for n * .875 */
559 t2 = (lease_seconds * 7) >> 3;
560 temp_addr.s_addr = packet.yiaddr;
561 bb_info_msg("Lease of %s obtained, lease time %u",
562 inet_ntoa(temp_addr), (unsigned)lease_seconds);
563 timestamp_got_lease = monotonic_sec();
565 requested_ip = packet.yiaddr;
566 udhcp_run_script(&packet,
567 ((state == RENEWING || state == REBINDING) ? "renew" : "bound"));
570 change_listen_mode(LISTEN_NONE);
571 if (client_config.quit_after_lease) {
572 if (client_config.release_on_quit)
576 if (!client_config.foreground)
579 continue; /* back to main loop */
581 if (*message == DHCPNAK) {
582 /* return to init state */
583 bb_info_msg("Received DHCP NAK");
584 udhcp_run_script(&packet, "nak");
585 if (state != REQUESTING)
586 udhcp_run_script(NULL, "deconfig");
587 change_listen_mode(LISTEN_RAW);
588 sleep(3); /* avoid excessive network traffic */
589 state = INIT_SELECTING;
595 /* case BOUND, RELEASED: - ignore all packets */
597 continue; /* back to main loop */
600 /* select() didn't timeout, something did happen.
601 * But it wasn't a packet. It's a signal pipe then. */
603 int signo = udhcp_sp_read(&rfds);
607 /* start things over */
609 /* Kill any timeouts because the user wants this to hurry along */
616 bb_info_msg("Received SIGTERM");
617 if (client_config.release_on_quit)
622 } /* for (;;) - main loop ends */
627 /*if (client_config.pidfile) - remove_pidfile has it's own check */
628 remove_pidfile(client_config.pidfile);