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.
19 struct dhcpOfferedAddr *leases;
20 struct server_config_t server_config;
23 int udhcpd_main(int argc, char *argv[])
27 int server_socket = -1, bytes, retval, max_sock;
28 struct dhcpMessage packet;
29 uint8_t *state, *server_id, *requested;
30 uint32_t server_id_align, requested_align, static_lease_ip;
31 unsigned long timeout_end, num_ips;
32 struct option_set *option;
33 struct dhcpOfferedAddr *lease, static_lease;
35 read_config(argc < 2 ? DHCPD_CONF_FILE : argv[1]);
37 /* Start the log, sanitize fd's, and write a pid file */
38 udhcp_start_log_and_pid(server_config.pidfile);
40 if ((option = find_option(server_config.options, DHCP_LEASE_TIME))) {
41 memcpy(&server_config.lease, option->data + 2, 4);
42 server_config.lease = ntohl(server_config.lease);
44 else server_config.lease = LEASE_TIME;
47 num_ips = ntohl(server_config.end) - ntohl(server_config.start) + 1;
48 if (server_config.max_leases > num_ips) {
49 bb_error_msg("max_leases value (%lu) not sane, "
50 "setting to %lu instead",
51 server_config.max_leases, num_ips);
52 server_config.max_leases = num_ips;
55 leases = xzalloc(server_config.max_leases * sizeof(struct dhcpOfferedAddr));
56 read_leases(server_config.lease_file);
58 if (read_interface(server_config.interface, &server_config.ifindex,
59 &server_config.server, server_config.arp) < 0)
62 if (!ENABLE_FEATURE_UDHCP_DEBUG)
63 udhcp_background(server_config.pidfile); /* hold lock during fork. */
65 /* Setup the signal pipe */
68 timeout_end = time(0) + server_config.auto_time;
69 while (1) { /* loop until universe collapses */
71 if (server_socket < 0) {
72 server_socket = listen_socket(INADDR_ANY, SERVER_PORT, server_config.interface);
75 max_sock = udhcp_sp_fd_set(&rfds, server_socket);
76 if (server_config.auto_time) {
77 tv.tv_sec = timeout_end - time(0);
80 if (!server_config.auto_time || tv.tv_sec > 0) {
81 retval = select(max_sock + 1, &rfds, NULL, NULL,
82 server_config.auto_time ? &tv : NULL);
83 } else retval = 0; /* If we already timed out, fall through */
87 timeout_end = time(0) + server_config.auto_time;
89 } else if (retval < 0 && errno != EINTR) {
90 DEBUG("error on select");
94 switch (udhcp_sp_read(&rfds)) {
96 bb_info_msg("Received a SIGUSR1");
98 /* why not just reset the timeout, eh */
99 timeout_end = time(0) + server_config.auto_time;
102 bb_info_msg("Received a SIGTERM");
104 case 0: break; /* no signal */
105 default: continue; /* signal or error (probably EINTR) */
108 if ((bytes = udhcp_get_packet(&packet, server_socket)) < 0) { /* this waits for a packet - idle */
109 if (bytes == -1 && errno != EINTR) {
110 DEBUG("error on read, %s, reopening socket", strerror(errno));
111 close(server_socket);
117 if ((state = get_option(&packet, DHCP_MESSAGE_TYPE)) == NULL) {
118 bb_error_msg("cannot get option from packet, ignoring");
122 /* Look for a static lease */
123 static_lease_ip = getIpByMac(server_config.static_leases, &packet.chaddr);
125 if (static_lease_ip) {
126 bb_info_msg("Found static lease: %x", static_lease_ip);
128 memcpy(&static_lease.chaddr, &packet.chaddr, 16);
129 static_lease.yiaddr = static_lease_ip;
130 static_lease.expires = 0;
132 lease = &static_lease;
135 lease = find_lease_by_chaddr(packet.chaddr);
140 DEBUG("Received DISCOVER");
142 if (sendOffer(&packet) < 0) {
143 bb_error_msg("send OFFER failed");
147 DEBUG("received REQUEST");
149 requested = get_option(&packet, DHCP_REQUESTED_IP);
150 server_id = get_option(&packet, DHCP_SERVER_ID);
152 if (requested) memcpy(&requested_align, requested, 4);
153 if (server_id) memcpy(&server_id_align, server_id, 4);
157 /* SELECTING State */
158 DEBUG("server_id = %08x", ntohl(server_id_align));
159 if (server_id_align == server_config.server && requested &&
160 requested_align == lease->yiaddr) {
161 sendACK(&packet, lease->yiaddr);
165 /* INIT-REBOOT State */
166 if (lease->yiaddr == requested_align)
167 sendACK(&packet, lease->yiaddr);
168 else sendNAK(&packet);
170 /* RENEWING or REBINDING State */
171 if (lease->yiaddr == packet.ciaddr)
172 sendACK(&packet, lease->yiaddr);
174 /* don't know what to do!!!! */
180 /* what to do if we have no record of the client */
181 } else if (server_id) {
182 /* SELECTING State */
184 } else if (requested) {
185 /* INIT-REBOOT State */
186 if ((lease = find_lease_by_yiaddr(requested_align))) {
187 if (lease_expired(lease)) {
188 /* probably best if we drop this lease */
189 memset(lease->chaddr, 0, 16);
190 /* make some contention for this address */
191 } else sendNAK(&packet);
192 } else if (requested_align < server_config.start ||
193 requested_align > server_config.end) {
195 } /* else remain silent */
198 /* RENEWING or REBINDING State */
202 DEBUG("Received DECLINE");
204 memset(lease->chaddr, 0, 16);
205 lease->expires = time(0) + server_config.decline_time;
209 DEBUG("Received RELEASE");
210 if (lease) lease->expires = time(0);
213 DEBUG("Received INFORM");
214 send_inform(&packet);
217 bb_info_msg("Unsupported DHCP message (%02x) - ignoring", state[0]);