examples/dhcp-server.c

/*
 *
 *  Embedded Linux library
 *
 *  Copyright (C) 2020  Intel Corporation. All rights reserved.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#define _GNU_SOURCE
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <assert.h>
#include <signal.h>
#include <sys/socket.h>
#include <linux/if_arp.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include <ell/ell.h>

static void do_debug(const char *str, void *user_data)
{
	const char *prefix = user_data;

	l_info("%s%s", prefix, str);
}

static void signal_handler(uint32_t signo, void *user_data)
{
	switch (signo) {
	case SIGINT:
	case SIGTERM:
		l_info("Terminate");
		l_main_quit();
		break;
	}
}

static void destroy_handler(void *data)
{
	l_info("DHCP server destroyed");
}

static void event_handler(struct l_dhcp_server *server,
					enum l_dhcp_server_event event,
					void *userdata,
					const struct l_dhcp_lease *lease)
{
	const uint8_t *mac;
	char *ip;

	switch (event) {
	case L_DHCP_SERVER_EVENT_NEW_LEASE:
		mac = l_dhcp_lease_get_mac(lease);
		ip = l_dhcp_lease_get_address(lease);

		l_info("New lease client %02x:%02x:%02x:%02x:%02x:%02x %s",
				mac[0], mac[1], mac[2], mac[3], mac[4], mac[5],
				ip);
		l_free(ip);
		break;
	case L_DHCP_SERVER_EVENT_LEASE_EXPIRED:
		break;
	}
}

int main(int argc, char *argv[])
{
	struct l_dhcp_server *server;
	int ifindex;
	uint8_t mac[6];
	char *dns[] = { "192.168.1.1", NULL };

	if (argc < 2) {
		printf("Usage: %s <interface index>\n", argv[0]);
		exit(0);
	}

	ifindex = atoi(argv[1]);

	if (!l_net_get_mac_address(ifindex, mac)) {
		printf("Unable to get address from interface %d\n", ifindex);
		exit(0);
	}

	if (!l_main_init())
		return -1;

	l_log_set_stderr();
	l_debug_enable("*");

	server = l_dhcp_server_new(ifindex);
	l_dhcp_server_set_ip_range(server, "192.168.1.2", "192.168.1.100");
	l_dhcp_server_set_netmask(server, "255.255.255.0");
	l_dhcp_server_set_gateway(server, "192.168.1.1");
	l_dhcp_server_set_dns(server, dns);
	l_dhcp_server_set_lease_time(server, 10);
	l_dhcp_server_set_debug(server, do_debug, "[DHCP SERV] ", NULL);
	l_dhcp_server_set_event_handler(server, event_handler, NULL,
						destroy_handler);
	l_dhcp_server_start(server);

	l_main_run_with_signal(signal_handler, NULL);

	l_dhcp_server_stop(server);
	l_dhcp_server_destroy(server);
	l_main_exit();

	return 0;
}