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.
20 struct dhcpOfferedAddr *leases;
21 struct server_config_t server_config;
24 int udhcpd_main(int argc, char **argv);
25 int udhcpd_main(int argc, char **argv)
29 int server_socket = -1, bytes, retval, max_sock;
30 struct dhcpMessage packet;
31 uint8_t *state, *server_id, *requested;
32 uint32_t server_id_align, requested_align, static_lease_ip;
35 struct option_set *option;
36 struct dhcpOfferedAddr *lease, static_lease;
38 //Huh, dhcpd don't have --foreground, --syslog options?? TODO
40 if (!ENABLE_FEATURE_UDHCP_DEBUG) {
41 bb_daemonize_or_rexec(0, argv);
42 logmode &= ~LOGMODE_STDIO;
45 if (ENABLE_FEATURE_UDHCP_SYSLOG) {
46 openlog(applet_name, LOG_PID, LOG_LOCAL0);
47 logmode |= LOGMODE_SYSLOG;
50 /* Would rather not do read_config before daemonization -
51 * otherwise NOMMU machines will parse config twice */
52 read_config(argv[1] ? argv[1] : DHCPD_CONF_FILE);
54 udhcp_make_pidfile(server_config.pidfile);
56 option = find_option(server_config.options, DHCP_LEASE_TIME);
57 server_config.lease = LEASE_TIME;
59 memcpy(&server_config.lease, option->data + 2, 4);
60 server_config.lease = ntohl(server_config.lease);
64 num_ips = server_config.end_ip - server_config.start_ip + 1;
65 if (server_config.max_leases > num_ips) {
66 bb_error_msg("max_leases=%u is too big, setting to %u",
67 (unsigned)server_config.max_leases, num_ips);
68 server_config.max_leases = num_ips;
71 leases = xzalloc(server_config.max_leases * sizeof(*leases));
72 read_leases(server_config.lease_file);
74 if (read_interface(server_config.interface, &server_config.ifindex,
75 &server_config.server, server_config.arp) < 0) {
80 /* Setup the signal pipe */
83 timeout_end = monotonic_sec() + server_config.auto_time;
84 while (1) { /* loop until universe collapses */
86 if (server_socket < 0) {
87 server_socket = listen_socket(INADDR_ANY, SERVER_PORT,
88 server_config.interface);
91 max_sock = udhcp_sp_fd_set(&rfds, server_socket);
92 if (server_config.auto_time) {
93 tv.tv_sec = timeout_end - monotonic_sec();
97 if (!server_config.auto_time || tv.tv_sec > 0) {
98 retval = select(max_sock + 1, &rfds, NULL, NULL,
99 server_config.auto_time ? &tv : NULL);
103 timeout_end = monotonic_sec() + server_config.auto_time;
106 if (retval < 0 && errno != EINTR) {
107 DEBUG("error on select");
111 switch (udhcp_sp_read(&rfds)) {
113 bb_info_msg("Received a SIGUSR1");
115 /* why not just reset the timeout, eh */
116 timeout_end = monotonic_sec() + server_config.auto_time;
119 bb_info_msg("Received a SIGTERM");
121 case 0: break; /* no signal */
122 default: continue; /* signal or error (probably EINTR) */
125 bytes = udhcp_get_packet(&packet, server_socket); /* this waits for a packet - idle */
127 if (bytes == -1 && errno != EINTR) {
128 DEBUG("error on read, %s, reopening socket", strerror(errno));
129 close(server_socket);
135 state = get_option(&packet, DHCP_MESSAGE_TYPE);
137 bb_error_msg("cannot get option from packet, ignoring");
141 /* Look for a static lease */
142 static_lease_ip = getIpByMac(server_config.static_leases, &packet.chaddr);
144 if (static_lease_ip) {
145 bb_info_msg("Found static lease: %x", static_lease_ip);
147 memcpy(&static_lease.chaddr, &packet.chaddr, 16);
148 static_lease.yiaddr = static_lease_ip;
149 static_lease.expires = 0;
151 lease = &static_lease;
153 lease = find_lease_by_chaddr(packet.chaddr);
158 DEBUG("Received DISCOVER");
160 if (sendOffer(&packet) < 0) {
161 bb_error_msg("send OFFER failed");
165 DEBUG("received REQUEST");
167 requested = get_option(&packet, DHCP_REQUESTED_IP);
168 server_id = get_option(&packet, DHCP_SERVER_ID);
170 if (requested) memcpy(&requested_align, requested, 4);
171 if (server_id) memcpy(&server_id_align, server_id, 4);
175 /* SELECTING State */
176 DEBUG("server_id = %08x", ntohl(server_id_align));
177 if (server_id_align == server_config.server && requested
178 && requested_align == lease->yiaddr
180 sendACK(&packet, lease->yiaddr);
182 } else if (requested) {
183 /* INIT-REBOOT State */
184 if (lease->yiaddr == requested_align)
185 sendACK(&packet, lease->yiaddr);
188 } else if (lease->yiaddr == packet.ciaddr) {
189 /* RENEWING or REBINDING State */
190 sendACK(&packet, lease->yiaddr);
192 /* don't know what to do!!!! */
196 /* what to do if we have no record of the client */
197 } else if (server_id) {
198 /* SELECTING State */
200 } else if (requested) {
201 /* INIT-REBOOT State */
202 lease = find_lease_by_yiaddr(requested_align);
204 if (lease_expired(lease)) {
205 /* probably best if we drop this lease */
206 memset(lease->chaddr, 0, 16);
207 /* make some contention for this address */
211 uint32_t r = ntohl(requested_align);
212 if (r < server_config.start_ip
213 || r > server_config.end_ip
217 /* else remain silent */
221 /* RENEWING or REBINDING State */
225 DEBUG("Received DECLINE");
227 memset(lease->chaddr, 0, 16);
228 lease->expires = time(0) + server_config.decline_time;
232 DEBUG("Received RELEASE");
234 lease->expires = time(0);
237 DEBUG("Received INFORM");
238 send_inform(&packet);
241 bb_info_msg("Unsupported DHCP message (%02x) - ignoring", state[0]);
247 /*if (server_config.pidfile) - server_config.pidfile is never NULL */
248 remove_pidfile(server_config.pidfile);