Esempio n. 1
0
int main(int argc, char *argv[])
#endif
{
	fd_set rfds;
	struct timeval tv;
	int server_socket = -1;
	int bytes, retval;
	struct dhcpMessage packet;
	uint8_t *state;
	uint8_t *server_id, *requested;
	uint32_t server_id_align, requested_align;
	unsigned long timeout_end;
	struct option_set *option;
	struct dhcpOfferedAddr *lease;
	struct dhcpOfferedAddr static_lease;
	int max_sock;
	unsigned long num_ips;

	uint32_t static_lease_ip;

	memset(&server_config, 0, sizeof(struct server_config_t));
	read_config(argc < 2 ? DHCPD_CONF_FILE : argv[1]);

	/* Start the log, sanitize fd's, and write a pid file */
	start_log_and_pid("udhcpd", server_config.pidfile);

	if ((option = find_option(server_config.options, DHCP_LEASE_TIME))) {
		memcpy(&server_config.lease, option->data + 2, 4);
		server_config.lease = ntohl(server_config.lease);
	}
	else server_config.lease = LEASE_TIME;

	/* Sanity check */
	num_ips = ntohl(server_config.end) - ntohl(server_config.start) + 1;
	if (server_config.max_leases > num_ips) {
		LOG(LOG_ERR, "max_leases value (%lu) not sane, "
			"setting to %lu instead",
			server_config.max_leases, num_ips);
		server_config.max_leases = num_ips;
	}

	leases = xcalloc(server_config.max_leases, sizeof(struct dhcpOfferedAddr));
	read_leases(server_config.lease_file);

	if (read_interface(server_config.interface, &server_config.ifindex,
			   &server_config.server, server_config.arp) < 0)
		return 1;

#ifndef UDHCP_DEBUG
	background(server_config.pidfile); /* hold lock during fork. */
#endif

	/* Setup the signal pipe */
	udhcp_sp_setup();

	timeout_end = time(0) + server_config.auto_time;
	while(1) { /* loop until universe collapses */

		if (server_socket < 0)
			if ((server_socket = listen_socket(INADDR_ANY, SERVER_PORT, server_config.interface)) < 0) {
				LOG(LOG_ERR, "FATAL: couldn't create server socket, %m");
				return 2;
			}

		max_sock = udhcp_sp_fd_set(&rfds, server_socket);
		if (server_config.auto_time) {
			tv.tv_sec = timeout_end - time(0);
			tv.tv_usec = 0;
		}
		if (!server_config.auto_time || tv.tv_sec > 0) {
			retval = select(max_sock + 1, &rfds, NULL, NULL,
					server_config.auto_time ? &tv : NULL);
		} else retval = 0; /* If we already timed out, fall through */

		if (retval == 0) {
			write_leases();
			timeout_end = time(0) + server_config.auto_time;
			continue;
		} else if (retval < 0 && errno != EINTR) {
			DEBUG(LOG_INFO, "error on select");
			continue;
		}

		switch (udhcp_sp_read(&rfds)) {
		case SIGUSR1:
			LOG(LOG_INFO, "Received a SIGUSR1");
			write_leases();
			/* why not just reset the timeout, eh */
			timeout_end = time(0) + server_config.auto_time;
			continue;
		case SIGTERM:
			LOG(LOG_INFO, "Received a SIGTERM");
			return 0;
		case 0: break;		/* no signal */
		default: continue;	/* signal or error (probably EINTR) */
		}

		if ((bytes = get_packet(&packet, server_socket)) < 0) { /* this waits for a packet - idle */
			if (bytes == -1 && errno != EINTR) {
				DEBUG(LOG_INFO, "error on read, %m, reopening socket");
				close(server_socket);
				server_socket = -1;
			}
			continue;
		}

		if ((state = get_option(&packet, DHCP_MESSAGE_TYPE)) == NULL) {
			DEBUG(LOG_ERR, "couldn't get option from packet, ignoring");
			continue;
		}

		/* Look for a static lease */
		static_lease_ip = getIpByMac(server_config.static_leases, &packet.chaddr);

		if(static_lease_ip)
		{
			printf("Found static lease: %x\n", static_lease_ip);

			memcpy(&static_lease.chaddr, &packet.chaddr, 16);
			static_lease.yiaddr = static_lease_ip;
			static_lease.expires = 0;

			lease = &static_lease;

		}
		else
		{
		lease = find_lease_by_chaddr(packet.chaddr);
		}

		switch (state[0]) {
		case DHCPDISCOVER:
			DEBUG(LOG_INFO,"received DISCOVER");

			if (sendOffer(&packet) < 0) {
				LOG(LOG_ERR, "send OFFER failed");
			}
			break;
 		case DHCPREQUEST:
			DEBUG(LOG_INFO, "received REQUEST");

			requested = get_option(&packet, DHCP_REQUESTED_IP);
			server_id = get_option(&packet, DHCP_SERVER_ID);

			if (requested) memcpy(&requested_align, requested, 4);
			if (server_id) memcpy(&server_id_align, server_id, 4);

			if (lease) {
				if (server_id) {
					/* SELECTING State */
					DEBUG(LOG_INFO, "server_id = %08x", ntohl(server_id_align));
					if (server_id_align == server_config.server && requested &&
					    requested_align == lease->yiaddr) {
						sendACK(&packet, lease->yiaddr);
					}
				} else {
					if (requested) {
						/* INIT-REBOOT State */
						if (lease->yiaddr == requested_align)
							sendACK(&packet, lease->yiaddr);
						else sendNAK(&packet);
					} else {
						/* RENEWING or REBINDING State */
						if (lease->yiaddr == packet.ciaddr)
							sendACK(&packet, lease->yiaddr);
						else {
							/* don't know what to do!!!! */
							sendNAK(&packet);
						}
					}
				}

			/* what to do if we have no record of the client */
			} else if (server_id) {
				/* SELECTING State */

			} else if (requested) {
				/* INIT-REBOOT State */
				if ((lease = find_lease_by_yiaddr(requested_align))) {
					if (lease_expired(lease)) {
						/* probably best if we drop this lease */
						memset(lease->chaddr, 0, 16);
					/* make some contention for this address */
					} else sendNAK(&packet);
				} else if (requested_align < server_config.start ||
					   requested_align > server_config.end) {
					sendNAK(&packet);
				} /* else remain silent */

			} else {
				 /* RENEWING or REBINDING State */
			}
			break;
		case DHCPDECLINE:
			DEBUG(LOG_INFO,"received DECLINE");
			if (lease) {
				memset(lease->chaddr, 0, 16);
				lease->expires = time(0) + server_config.decline_time;
			}
			break;
		case DHCPRELEASE:
			DEBUG(LOG_INFO,"received RELEASE");
			if (lease) lease->expires = time(0);
			break;
		case DHCPINFORM:
			DEBUG(LOG_INFO,"received INFORM");
			send_inform(&packet);
			break;
		default:
			LOG(LOG_WARNING, "unsupported DHCP message (%02x) -- ignoring", state[0]);
		}
	}

	return 0;
}
Esempio n. 2
0
static gboolean listener_event(GIOChannel *channel, GIOCondition condition,
							gpointer user_data)
{
	GDHCPServer *dhcp_server = user_data;
	struct dhcp_packet packet;
	struct dhcp_lease *lease;
	uint32_t requested_nip = 0;
	uint8_t type, *server_id_option, *request_ip_option;
	int re;

	if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
		dhcp_server->listener_watch = 0;
		return FALSE;
	}

	re = dhcp_recv_l3_packet(&packet, dhcp_server->listener_sockfd);
	if (re < 0)
		return TRUE;

	type = check_packet_type(&packet);
	if (type == 0)
		return TRUE;

	server_id_option = dhcp_get_option(&packet, DHCP_SERVER_ID);
	if (server_id_option) {
		uint32_t server_nid = get_be32(server_id_option);

		if (server_nid != dhcp_server->server_nip)
			return TRUE;
	}

	request_ip_option = dhcp_get_option(&packet, DHCP_REQUESTED_IP);
	if (request_ip_option)
		requested_nip = get_be32(request_ip_option);

	lease = find_lease_by_mac(dhcp_server, packet.chaddr);

	switch (type) {
	case DHCPDISCOVER:
		debug(dhcp_server, "Received DISCOVER");

		send_offer(dhcp_server, &packet, lease, requested_nip);
		break;
	case DHCPREQUEST:
		debug(dhcp_server, "Received REQUEST NIP %d",
							requested_nip);
		if (requested_nip == 0) {
			requested_nip = packet.ciaddr;
			if (requested_nip == 0)
				break;
		}

		if (!lease) {
			/* check if requested address free */
			lease = add_lease(dhcp_server, OFFER_TIME,
						packet.chaddr, htonl(requested_nip));
		}

		if (lease && requested_nip == lease->lease_nip) {
			debug(dhcp_server, "Sending ACK");
			send_ACK(dhcp_server, &packet,
				lease->lease_nip);
			break;
		}

		if (server_id_option || !lease) {
			debug(dhcp_server, "Sending NAK");
			send_NAK(dhcp_server, &packet);
		}

		break;
	case DHCPDECLINE:
		debug(dhcp_server, "Received DECLINE");

		if (!server_id_option)
			break;

		if (!request_ip_option)
			break;

		if (!lease)
			break;

		if (requested_nip == lease->lease_nip)
			remove_lease(dhcp_server, lease);

		break;
	case DHCPRELEASE:
		debug(dhcp_server, "Received RELEASE");

		if (!server_id_option)
			break;

		if (!lease)
			break;

		if (packet.ciaddr == lease->lease_nip)
			lease_set_expire(dhcp_server, lease,
					time(NULL));
		break;
	case DHCPINFORM:
		debug(dhcp_server, "Received INFORM");
		send_inform(dhcp_server, &packet);
		break;
	}

	return TRUE;
}
Esempio n. 3
0
int main(int argc, char *argv[])
#endif
{	
	fd_set rfds;
	struct timeval tv;
	int server_socket = -1;
	int bytes, retval;
	struct dhcpMessage packet;
	unsigned char *state;
	unsigned char *server_id, *requested, *hostname;
	u_int32_t server_id_align, requested_align;
	unsigned long timeout_end;
	struct option_set *option;
	struct dhcpOfferedAddr *lease;
	int pid_fd;
	int max_sock;
	int sig;

	/* DD-WRT (belanger) : ignore signals until we're ready */
	signal(SIGUSR1, SIG_IGN);
	signal(SIGUSR2, SIG_IGN);
	signal(SIGHUP, SIG_IGN);
	signal(SIGTERM, SIG_IGN);

	OPEN_LOG("udhcpd");
	LOG(LOG_INFO, "udhcp server (v%s) started", VERSION);

	memset(&server_config, 0, sizeof(struct server_config_t));

	if (argc < 2)
		read_config(DHCPD_CONF_FILE);
	else 
		read_config(argv[1]);

	pid_fd = pidfile_acquire(server_config.pidfile);
	pidfile_write_release(pid_fd);

	if ((option = find_option(server_config.options, DHCP_LEASE_TIME))) {
		memcpy(&server_config.lease, option->data + 2, 4);
		server_config.lease = ntohl(server_config.lease);
	}
	else server_config.lease = LEASE_TIME;

	leases = malloc(sizeof(struct dhcpOfferedAddr) * server_config.max_leases);
	memset(leases, 0, sizeof(struct dhcpOfferedAddr) * server_config.max_leases);
	read_leases(server_config.lease_file);
	read_statics(server_config.statics_file);

	/* DD-WRT (belanger) : write leases now */
	write_leases();

	if (read_interface(server_config.interface, &server_config.ifindex,
			   &server_config.server, server_config.arp) < 0)
		exit_server(1);

#ifndef DEBUGGING
	pid_fd = pidfile_acquire(server_config.pidfile); /* hold lock during fork. */
	if (daemon(0, 0) == -1) {
		perror("fork");
		exit_server(1);
	}
	pidfile_write_release(pid_fd);
#endif


	socketpair(AF_UNIX, SOCK_STREAM, 0, signal_pipe);
	signal(SIGUSR1, signal_handler);
	signal(SIGUSR2, signal_handler);
	signal(SIGTERM, signal_handler);
	signal(SIGHUP, signal_handler);

	timeout_end = get_time(0) + server_config.auto_time;
	while(1) { /* loop until universe collapses */

		if (server_socket < 0)
			if ((server_socket = listen_socket(INADDR_ANY, SERVER_PORT, server_config.interface)) < 0) {
				LOG(LOG_ERR, "FATAL: couldn't create server socket, %s", strerror(errno));
				exit_server(0);
			}			

		FD_ZERO(&rfds);
		FD_SET(server_socket, &rfds);
		FD_SET(signal_pipe[0], &rfds);
		if (server_config.auto_time) {
			tv.tv_sec = timeout_end - get_time(0);
			tv.tv_usec = 0;
		}
		if (!server_config.auto_time || tv.tv_sec > 0) {
			max_sock = server_socket > signal_pipe[0] ? server_socket : signal_pipe[0];
			retval = select(max_sock + 1, &rfds, NULL, NULL, 
					server_config.auto_time ? &tv : NULL);
		} 
		else 
			retval = 0; /* If we already timed out, fall through */

		if (retval == 0) {
			write_leases();
			timeout_end = get_time(0) + server_config.auto_time;
			continue;
		} 
		else if (retval < 0 && errno != EINTR) {
			DEBUG(LOG_INFO, "error on select");
			continue;
		}
		
		if (FD_ISSET(signal_pipe[0], &rfds)) {
			if (read(signal_pipe[0], &sig, sizeof(sig)) < 0)
				continue; /* probably just EINTR */
			switch (sig) {
			case SIGUSR1:
				LOG(LOG_INFO, "Received a SIGUSR1");
				write_leases();
				/* why not just reset the timeout, eh */
				timeout_end = get_time(0) + server_config.auto_time;
				continue;
			case SIGUSR2:
				LOG(LOG_INFO, "Received a SIGUSR2");
				delete_leases();
				continue;
			case SIGHUP:
				LOG(LOG_INFO, "Received a SIGHUP");
				read_leases(server_config.lease_file);
				read_statics(server_config.statics_file);
				continue;
			case SIGTERM:
				LOG(LOG_INFO, "Received a SIGTERM");
				exit_server(0);
			}
		}

		if ((bytes = get_packet(&packet, server_socket)) < 0) { /* this waits for a packet - idle */
			if (bytes == -1 && errno != EINTR) {
				DEBUG(LOG_INFO, "error on read, %s, reopening socket", strerror(errno));
				close(server_socket);
				server_socket = -1;
			}
			continue;
		}

		if ((state = get_option(&packet, DHCP_MESSAGE_TYPE)) == NULL) {
			DEBUG(LOG_ERR, "couldn't get option from packet, ignoring");
			continue;
		}

		hostname = get_option(&packet, DHCP_HOST_NAME);

		/* ADDME: look for a static lease */
		    
		/* If a hostname is supplied, and that hostname is a static lease, and that
		   static lease has an FF:FF:FF:FF:FF:FF MAC address, then use that entry. */
		if ( NULL == hostname ||
		     NULL == (lease = find_lease_by_hostname(hostname)) || 
		     (lease->expires != EXPIRES_NEVER) ||
		     0 != memcmp(lease->chaddr, MAC_BCAST_ADDR, strlen(MAC_BCAST_ADDR))) {
		  
		  /* Otherwise, look up the table using the supplied MAC address. */
		  lease = find_lease_by_chaddr(packet.chaddr);

		}

		switch (state[0]) {
		case DHCPDISCOVER:
			LOG(LOG_INFO,"received DISCOVER from %02x:%02x:%02x:%02x:%02x:%02x",
			    packet.chaddr[0], packet.chaddr[1], packet.chaddr[2], 
			    packet.chaddr[3], packet.chaddr[4], packet.chaddr[5]);	// modify by honor
			
			if (sendOffer(&packet, lease) < 0) {
				LOG(LOG_ERR, "send OFFER failed");
			}
			break;			
 		case DHCPREQUEST:
			requested = get_option(&packet, DHCP_REQUESTED_IP);
			server_id = get_option(&packet, DHCP_SERVER_ID);

			if (requested) memcpy(&requested_align, requested, 4);
			if (server_id) memcpy(&server_id_align, server_id, 4);
		
			if (requested) {
			  struct in_addr addr;
			  addr.s_addr = requested_align;
			  LOG(LOG_INFO, "received REQUEST for %s from %02x:%02x:%02x:%02x:%02x:%02x",
			      inet_ntoa(addr),
			      packet.chaddr[0], packet.chaddr[1], packet.chaddr[2], 
			      packet.chaddr[3], packet.chaddr[4], packet.chaddr[5]);
			}
			else {
			  LOG(LOG_INFO, "received REQUEST from %02x:%02x:%02x:%02x:%02x:%02x",
			      packet.chaddr[0], packet.chaddr[1], packet.chaddr[2], 
			      packet.chaddr[3], packet.chaddr[4], packet.chaddr[5]);
			}

			if (lease) { /*ADDME: or static lease */
				if (server_id) {
					/* SELECTING State */
					DEBUG(LOG_INFO, "server_id = %08x", ntohl(server_id_align));
					if (server_id_align == server_config.server && requested && 
					    requested_align == lease->yiaddr) {
						sendACK(&packet, lease->yiaddr);
					}
					else
						sendNAK(&packet); //Sveasoft - shouldn't we let them know we don't like the request?
				} 
				else {
					if (requested) {
						/* INIT-REBOOT State */
						if (lease->yiaddr == requested_align)
							sendACK(&packet, lease->yiaddr);
						else 
							sendNAK(&packet);
					} else {
						/* RENEWING or REBINDING State */
						if (lease->yiaddr == packet.ciaddr)
							sendACK(&packet, lease->yiaddr);
//						else if (!packet.ciaddr)
							/* Accept an invalid request in RENEWING state,
							   where the ciaddr should be set, but is not. */
							/* e.g. Linksys Print Server */
//							sendACK(&packet, lease->yiaddr); //note: let's not support broken stuff - Sveasoft 2005-01-19
						else {
							/* don't know what to do!!!! */
							sendNAK(&packet);
						}
					}						
				}
				if (lease->expires != EXPIRES_NEVER) {
					/* Don't change hostname of static leases */
					if (hostname) {
						bytes = hostname[-1];
						if (bytes >= (int) sizeof(lease->hostname))
							bytes = sizeof(lease->hostname) - 1;
						strncpy(lease->hostname, hostname, bytes);
							lease->hostname[bytes] = '\0';
					} else
						lease->hostname[0] = '\0';
				}
			
			/* what to do if we have no record of the client */
			} 
			else if (server_id) {
				/* SELECTING State */
				sendNAK(&packet);       // by honor

			} 
			else if (requested) {
				/* INIT-REBOOT State */
				if ((lease = find_lease_by_yiaddr(requested_align))) {
					if (lease_expired(lease)) {
						/* probably best if we drop this lease */
						memset(lease->chaddr, 0, 16);
					/* make some contention for this address */
					} 
					else 
						sendNAK(&packet);
				} 
				else if (requested_align < server_config.start || 
					 requested_align > server_config.end) {
					sendNAK(&packet);
				} 
				else {
					sendNAK(&packet);
				}

			} 
			else if (packet.ciaddr) {

				/* RENEWING or REBINDING State */
				sendNAK(&packet);
			}
			break;
		case DHCPDECLINE:
			LOG(LOG_INFO,"received DECLINE from %02x:%02x:%02x:%02x:%02x:%02x",
			    packet.chaddr[0], packet.chaddr[1], packet.chaddr[2], 
			    packet.chaddr[3], packet.chaddr[4], packet.chaddr[5]);	// modify by honor
			if (lease && lease->expires != EXPIRES_NEVER) {
				memset(lease->chaddr, 0, 16);
				lease->expires = get_time(0) + server_config.decline_time;
			}			
			break;
		case DHCPRELEASE:
			LOG(LOG_INFO,"received RELEASE from %02x:%02x:%02x:%02x:%02x:%02x",
			    packet.chaddr[0], packet.chaddr[1], packet.chaddr[2], 
			    packet.chaddr[3], packet.chaddr[4], packet.chaddr[5]);	// modify by honor
			if (lease && lease->expires != EXPIRES_NEVER) 
				lease->expires = get_time(0);
			break;
		case DHCPINFORM:
			LOG(LOG_INFO,"received INFORM from %02x:%02x:%02x:%02x:%02x:%02x",
			    packet.chaddr[0], packet.chaddr[1], packet.chaddr[2], 
			    packet.chaddr[3], packet.chaddr[4], packet.chaddr[5]);	// modify by honor
			send_inform(&packet);
			break;	
		default:
			LOG(LOG_WARNING, "unsupported DHCP message (%02x) -- ignoring", state[0]);
		}
	}

	return 0;
}
Esempio n. 4
0
int main(int argc, char *argv[])
#endif
{	
	fd_set rfds;
	struct timeval tv;
	int server_socket = -1;
	int bytes, retval;
	struct dhcpMessage packet;
	unsigned char *state;
	unsigned char *server_id, *requested, *hostname;
	u_int32_t server_id_align, requested_align;
	unsigned long timeout_end;
	struct option_set *option;
	struct dhcpOfferedAddr *lease;
	int pid_fd;
	int max_sock;
	int sig;
	
	OPEN_LOG("udhcpd");
	LOG(LOG_INFO, "udhcp server (v%s) started", VERSION);

	memset(&server_config, 0, sizeof(struct server_config_t));
	
	if (argc < 2)
		read_config(DHCPD_CONF_FILE);
	else read_config(argv[1]);

	pid_fd = pidfile_acquire(server_config.pidfile);
	pidfile_write_release(pid_fd);

	if ((option = find_option(server_config.options, DHCP_LEASE_TIME))) {
		memcpy(&server_config.lease, option->data + 2, 4);
		server_config.lease = ntohl(server_config.lease);
	}
	else server_config.lease = LEASE_TIME;
	
	leases = malloc(sizeof(struct dhcpOfferedAddr) * server_config.max_leases);
	memset(leases, 0, sizeof(struct dhcpOfferedAddr) * server_config.max_leases);

	// Added by Joey to load static lease
	if (argc>=3)
	{
		load_leases(argv[2]);
	}

	read_leases(server_config.lease_file);

	if (read_interface(server_config.interface, &server_config.ifindex,
			   &server_config.server, server_config.arp) < 0)
		exit_server(1);

#ifndef DEBUGGING
	pid_fd = pidfile_acquire(server_config.pidfile); /* hold lock during fork. */
	if (daemon(0, 0) == -1) {
		perror("fork");
		exit_server(1);
	}
	pidfile_write_release(pid_fd);
#endif

	/* ensure that stdin/stdout/stderr are never returned by pipe() */
	if (fcntl(STDIN_FILENO, F_GETFL) == -1)
		(void) open("/dev/null", O_RDONLY);
	if (fcntl(STDOUT_FILENO, F_GETFL) == -1)
		(void) open("/dev/null", O_WRONLY);
	if (fcntl(STDERR_FILENO, F_GETFL) == -1)
		(void) open("/dev/null", O_WRONLY);

	/* setup signal handlers */
	pipe(signal_pipe);
	signal(SIGUSR1, signal_handler);
	signal(SIGTERM, signal_handler);

	timeout_end = uptime() + server_config.auto_time;
	while(1) { /* loop until universe collapses */

		if (server_socket < 0)
			if ((server_socket = listen_socket(INADDR_ANY, SERVER_PORT, server_config.interface)) < 0) {
				LOG(LOG_ERR, "FATAL: couldn't create server socket, %s", strerror(errno));
				exit_server(0);
			}			

		FD_ZERO(&rfds);
		FD_SET(server_socket, &rfds);
		FD_SET(signal_pipe[0], &rfds);
		if (server_config.auto_time) {
			tv.tv_sec = timeout_end - uptime();
			tv.tv_usec = 0;
		}
		if (!server_config.auto_time || tv.tv_sec > 0) {
			max_sock = server_socket > signal_pipe[0] ? server_socket : signal_pipe[0];
			retval = select(max_sock + 1, &rfds, NULL, NULL, 
					server_config.auto_time ? &tv : NULL);
		} else retval = 0; /* If we already timed out, fall through */

		if (retval == 0) {
			write_leases();
			timeout_end = uptime() + server_config.auto_time;
			continue;
		} else if (retval < 0 && errno != EINTR) {
			DEBUG(LOG_INFO, "error on select");
			continue;
		}
		
		if (FD_ISSET(signal_pipe[0], &rfds)) {
			if (read(signal_pipe[0], &sig, sizeof(sig)) < 0)
				continue; /* probably just EINTR */
			switch (sig) {
			case SIGUSR1:
				LOG(LOG_INFO, "Received a SIGUSR1");
				write_leases();
				/* why not just reset the timeout, eh */
				timeout_end = uptime() + server_config.auto_time;
				continue;
			case SIGTERM:
				LOG(LOG_INFO, "Received a SIGTERM");
				exit_server(0);
			}
		}

		if ((bytes = get_packet(&packet, server_socket)) < 0) { /* this waits for a packet - idle */
			if (bytes == -1 && errno != EINTR) {
				DEBUG(LOG_INFO, "error on read, %s, reopening socket", strerror(errno));
				close(server_socket);
				server_socket = -1;
			}
			continue;
		}

		if ((state = get_option(&packet, DHCP_MESSAGE_TYPE)) == NULL) {
			DEBUG(LOG_ERR, "couldn't get option from packet, ignoring");
			continue;
		}
		
		server_id = get_option(&packet, DHCP_SERVER_ID);
		if (server_id) {
			memcpy(&server_id_align, server_id, 4);
			if (server_id_align != server_config.server) {
				/* client talks to somebody else */
				DEBUG(LOG_INFO,"server ID %08x doesn't match, ignoring", ntohl(server_id_align));
				continue;
			}
		}

		/* ADDME: look for a static lease */
		lease = find_lease_by_chaddr(packet.chaddr);
		switch (state[0]) {
		case DHCPDISCOVER:
			DEBUG(LOG_INFO,"received DISCOVER");
			
			if (sendOffer(&packet) < 0) {
				LOG(LOG_ERR, "send OFFER failed");
			}
			break;			
 		case DHCPREQUEST:
			DEBUG(LOG_INFO, "received REQUEST");

			requested = get_option(&packet, DHCP_REQUESTED_IP);
			hostname = get_option(&packet, DHCP_HOST_NAME);

			if (requested) memcpy(&requested_align, requested, 4);
		
			if (lease) { /*ADDME: or static lease */
				if (server_id) {
					/* SELECTING State */
					if (requested && 
					    requested_align == lease->yiaddr) {
						sendACK(&packet, lease->yiaddr);
					}
				} else {
					if (requested) {
						/* INIT-REBOOT State */
						if (lease->yiaddr == requested_align)
							sendACK(&packet, lease->yiaddr);
						else sendNAK(&packet);
					} else {
						/* RENEWING or REBINDING State */
						if (lease->yiaddr == packet.ciaddr)
							sendACK(&packet, lease->yiaddr);
						else {
							/* don't know what to do!!!! */
							sendNAK(&packet);
						}
					}						
				}
				if (hostname) {
					bytes = hostname[-1];
					if (bytes >= (int) sizeof(lease->hostname))
						bytes = sizeof(lease->hostname) - 1;
					strncpy(lease->hostname, hostname, bytes);
					lease->hostname[bytes] = '\0';

					if (!is_valid_hostname(lease->hostname))
						lease->hostname[0] = '\0';

				} else
					lease->hostname[0] = '\0';
			
			/* what to do if we have no record of the client */
			} else if (server_id) {
				/* SELECTING State */
				if (requested)
					sendNAK(&packet);

			} else if (requested) {
				/* INIT-REBOOT State */
				if ((lease = find_lease_by_yiaddr(requested_align))) {
					if (lease_expired(lease)) {
						/* probably best if we drop this lease */
						memset(lease->chaddr, 0, 16);
					/* make some contention for this address */
					} else sendNAK(&packet);
				} else if (requested_align < server_config.start || 
					   requested_align > server_config.end) {
					sendNAK(&packet);
				} else {
					sendNAK(&packet);
				}
			} else if (packet.ciaddr) {
				/* RENEWING or REBINDING State */
				sendNAK(&packet);
			}
			break;
		case DHCPDECLINE:
			DEBUG(LOG_INFO,"received DECLINE");
			if (lease) {
				memset(lease->chaddr, 0, 16);
				lease->expires = uptime() + server_config.decline_time;
			}			
			break;
		case DHCPRELEASE:
			DEBUG(LOG_INFO,"received RELEASE");
			if (lease) lease->expires = uptime();
			break;
		case DHCPINFORM:
			DEBUG(LOG_INFO,"received INFORM");
			send_inform(&packet);
			break;	
		default:
			LOG(LOG_WARNING, "unsupported DHCP message (%02x) -- ignoring", state[0]);
		}
	}

	return 0;
}