1 /* vi: set sw=4 ts=4: */
5 * Copyright (C) 1999 Matthew Ramsay <matthewr@moreton.com.au>
6 * Chris Trew <ctrew@moreton.com.au>
8 * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
10 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
21 struct dyn_lease *g_leases;
22 /* struct server_config_t server_config is in bb_common_bufsiz1 */
25 int udhcpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
26 int udhcpd_main(int argc UNUSED_PARAM, char **argv)
29 int server_socket = -1, retval, max_sock;
30 struct dhcp_packet packet;
32 uint32_t static_lease_ip;
36 struct option_set *option;
37 struct dyn_lease *lease, fake_lease;
38 IF_FEATURE_UDHCP_PORT(char *str_P;)
40 #if ENABLE_FEATURE_UDHCP_PORT
45 #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
46 opt_complementary = "vv";
48 opt = getopt32(argv, "fSv"
49 IF_FEATURE_UDHCP_PORT("P:", &str_P)
50 #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
55 if (!(opt & 1)) { /* no -f */
56 bb_daemonize_or_rexec(0, argv);
57 logmode = LOGMODE_NONE;
59 if (opt & 2) { /* -S */
60 openlog(applet_name, LOG_PID, LOG_DAEMON);
61 logmode |= LOGMODE_SYSLOG;
63 #if ENABLE_FEATURE_UDHCP_PORT
64 if (opt & 4) { /* -P */
65 SERVER_PORT = xatou16(str_P);
66 CLIENT_PORT = SERVER_PORT + 1;
69 /* Would rather not do read_config before daemonization -
70 * otherwise NOMMU machines will parse config twice */
71 read_config(argv[0] ? argv[0] : DHCPD_CONF_FILE);
73 /* Make sure fd 0,1,2 are open */
75 /* Equivalent of doing a fflush after every \n */
79 write_pidfile(server_config.pidfile);
80 /* if (!..) bb_perror_msg("can't create pidfile %s", pidfile); */
82 bb_info_msg("%s (v"BB_VER") started", applet_name);
84 option = find_option(server_config.options, DHCP_LEASE_TIME);
85 server_config.max_lease_sec = LEASE_TIME;
87 move_from_unaligned32(server_config.max_lease_sec, option->data + OPT_DATA);
88 server_config.max_lease_sec = ntohl(server_config.max_lease_sec);
92 num_ips = server_config.end_ip - server_config.start_ip + 1;
93 if (server_config.max_leases > num_ips) {
94 bb_error_msg("max_leases=%u is too big, setting to %u",
95 (unsigned)server_config.max_leases, num_ips);
96 server_config.max_leases = num_ips;
99 g_leases = xzalloc(server_config.max_leases * sizeof(g_leases[0]));
100 read_leases(server_config.lease_file);
102 if (udhcp_read_interface(server_config.interface,
103 &server_config.ifindex,
104 &server_config.server_nip,
105 server_config.server_mac)
111 /* Setup the signal pipe */
114 timeout_end = monotonic_sec() + server_config.auto_time;
115 while (1) { /* loop until universe collapses */
119 if (server_socket < 0) {
120 server_socket = udhcp_listen_socket(/*INADDR_ANY,*/ SERVER_PORT,
121 server_config.interface);
124 max_sock = udhcp_sp_fd_set(&rfds, server_socket);
125 if (server_config.auto_time) {
126 tv.tv_sec = timeout_end - monotonic_sec();
130 if (!server_config.auto_time || tv.tv_sec > 0) {
131 retval = select(max_sock + 1, &rfds, NULL, NULL,
132 server_config.auto_time ? &tv : NULL);
136 timeout_end = monotonic_sec() + server_config.auto_time;
139 if (retval < 0 && errno != EINTR) {
140 log1("Error on select");
144 switch (udhcp_sp_read(&rfds)) {
146 bb_info_msg("Received a SIGUSR1");
148 /* why not just reset the timeout, eh */
149 timeout_end = monotonic_sec() + server_config.auto_time;
152 bb_info_msg("Received a SIGTERM");
154 case 0: /* no signal: read a packet */
156 default: /* signal or error (probably EINTR): back to select */
160 bytes = udhcp_recv_kernel_packet(&packet, server_socket);
162 /* bytes can also be -2 ("bad packet data") */
163 if (bytes == -1 && errno != EINTR) {
164 log1("Read error: %s, reopening socket", strerror(errno));
165 close(server_socket);
171 if (packet.hlen != 6) {
172 bb_error_msg("MAC length != 6, ignoring packet");
176 state = get_option(&packet, DHCP_MESSAGE_TYPE);
178 bb_error_msg("no message type option, ignoring packet");
182 /* Look for a static lease */
183 static_lease_ip = get_static_nip_by_mac(server_config.static_leases, &packet.chaddr);
184 if (static_lease_ip) {
185 bb_info_msg("Found static lease: %x", static_lease_ip);
187 memcpy(&fake_lease.lease_mac, &packet.chaddr, 6);
188 fake_lease.lease_nip = static_lease_ip;
189 fake_lease.expires = 0;
193 lease = find_lease_by_mac(packet.chaddr);
198 log1("Received DISCOVER");
200 if (send_offer(&packet) < 0) {
201 bb_error_msg("send OFFER failed");
205 uint8_t *server_id_opt, *requested_opt;
206 uint32_t server_id_net = server_id_net; /* for compiler */
207 uint32_t requested_nip = requested_nip; /* for compiler */
209 log1("Received REQUEST");
211 requested_opt = get_option(&packet, DHCP_REQUESTED_IP);
212 server_id_opt = get_option(&packet, DHCP_SERVER_ID);
214 move_from_unaligned32(requested_nip, requested_opt);
216 move_from_unaligned32(server_id_net, server_id_opt);
220 /* SELECTING State */
221 if (server_id_net == server_config.server_nip
223 && requested_nip == lease->lease_nip
225 send_ACK(&packet, lease->lease_nip);
227 } else if (requested_opt) {
228 /* INIT-REBOOT State */
229 if (lease->lease_nip == requested_nip)
230 send_ACK(&packet, lease->lease_nip);
233 } else if (lease->lease_nip == packet.ciaddr) {
234 /* RENEWING or REBINDING State */
235 send_ACK(&packet, lease->lease_nip);
236 } else { /* don't know what to do!!!! */
240 /* what to do if we have no record of the client */
241 } else if (server_id_opt) {
242 /* SELECTING State */
244 } else if (requested_opt) {
245 /* INIT-REBOOT State */
246 lease = find_lease_by_nip(requested_nip);
248 if (is_expired_lease(lease)) {
249 /* probably best if we drop this lease */
250 memset(lease->lease_mac, 0, sizeof(lease->lease_mac));
252 /* make some contention for this address */
256 uint32_t r = ntohl(requested_nip);
257 if (r < server_config.start_ip
258 || r > server_config.end_ip
262 /* else remain silent */
266 /* RENEWING or REBINDING State */
271 log1("Received DECLINE");
273 memset(lease->lease_mac, 0, sizeof(lease->lease_mac));
274 lease->expires = time(NULL) + server_config.decline_time;
278 log1("Received RELEASE");
280 lease->expires = time(NULL);
283 log1("Received INFORM");
284 send_inform(&packet);
287 bb_info_msg("Unsupported DHCP message (%02x) - ignoring", state[0]);
293 /*if (server_config.pidfile) - server_config.pidfile is never NULL */
294 remove_pidfile(server_config.pidfile);