locupd2.c

mobile ip 在linux下的一种实现

/* $Id: locupd2.c,v 1.7 2001/09/08 14:29:40 jm Exp $
 * Automatic location updates between two FAs using MN API
 *
 * Dynamic hierarchial IP tunnel
 * Copyright (C) 1998-2001, Dynamics group
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation. See README and COPYING for
 * more details.
 */


/* locupd2 can set the firewall entry to block traffic from a host if the
 * registration did not succeed in given time. Uncomment next line and edit
 * Makefile.am to compile this support. You will also need couple of files
 * from the ipchains package (libipfwc.h, ipfwc_kernel_headers.h, libipfwc.a)
 */
/* #define FIREWALL */

#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <sys/time.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <signal.h>

#ifdef FIREWALL
/* address to be blocked when the registration does not succeed */
#define CN_ADDRESS "192.168.10.10"
#include "asm/types.h"
#include "libipfwc.h"
#endif

#include "dyn_mnlib.h"
#include "util.h"

#define DEFAULT_API_PATH "/var/run/dynamics_mn_admin"
#define TIMEOUT 1
#define MAX_FA 16

FILE *f;
unsigned long updates = 0;


static int timerdiff(struct timeval *a, struct timeval *b)
{
	return ((b->tv_sec - a->tv_sec) * 1000000 +
		b->tv_usec - a->tv_usec);
}

static void clean_up(int sig)
{
	fprintf(f, "signal %i received - exiting\n", sig);
	fprintf(f, "%lu location updates\n", updates);
	fclose(f);
	exit(0);
}

static void locupd(int period, int fa_count, struct in_addr fa[])
{
	struct timeval goal, now;
	int diff, ret, i, pos;
#ifdef FIREWALL
	int firewall = 0;
	struct ip_fwuser fw;
	struct in_addr addr;

	inet_aton(CN_ADDRESS, &addr);

	memset(&fw, 0, sizeof(fw));
	dynamics_strlcpy(fw.label, "DENY", sizeof(fw.label));
	fw.ipfw.fw_spts[1] = 65535;
	fw.ipfw.fw_dpts[1] = 65535;
	fw.ipfw.fw_tosand = 0xff;
	memcpy(&fw.ipfw.fw_src, &addr, 4);
	memset(&fw.ipfw.fw_smsk, 0xff, 4);
#endif

	fprintf(f, "Location update every %i usec between FAs: ", period);
	for (i = 0; i < fa_count; i++)
		fprintf(f, "%s ", inet_ntoa(fa[i]));
	fprintf(f, "\n");

	gettimeofday(&goal, NULL);

	pos = 0;
	updates = 0;
	for (;;) {
		ret = dynamics_mn_force_fa(&fa[pos], TIMEOUT);
		if (ret != API_SUCCESS) {
			fprintf(f, "dynamics_mn_force_fa: %i - %s\n", ret,
				dynamics_mn_get_error_string(ret));
		}

		ret = dynamics_mn_update_location_dev_block(NULL, TIMEOUT);
		if (ret != API_SUCCESS) {
			fprintf(f, "dynamics_mn_update_location_dev_block: "
				"%i - %s\n", ret,
				dynamics_mn_get_error_string(ret));
		} else
			updates++;

		goal.tv_usec += period;
		if (goal.tv_usec > 999999) {
			goal.tv_sec += goal.tv_usec / 1000000;
			goal.tv_usec %= 1000000;
		}

		gettimeofday(&now, NULL);
		diff = timerdiff(&now, &goal);
		if (diff < 0) {
			fprintf(f, "Locupd => %s did not succeed in given "
				"time period (%i usec).\n",
				inet_ntoa(fa[pos]), diff);
			gettimeofday(&goal, NULL);
#ifdef FIREWALL
			if (!firewall) {
				fprintf(f, "\tadding firewall\n");
				if (!ipfwc_append_entry("input", &fw))
					fprintf(f, "ipfwc_append_entry failed"
						" - %s\n",
						ipfwc_strerror(errno));
				firewall = 1;
			}
#endif
		} else {
#ifdef FIREWALL
			if (firewall) {
				fprintf(f, "\removing firewall\n");
				if (!ipfwc_delete_entry("input", &fw))
					fprintf(f, "ipfwc_delete_entry "
						"failed - %s\n",
						ipfwc_strerror(errno));
				firewall = 0;
			}
#endif
			/* printf("Sleeping %i usec\n", diff); */
			usleep(diff);
		}

		pos++;
		if (pos >= fa_count)
			pos = 0;
	}
}

int main(int argc, char *argv[])
{
	int ret, period, i, path = 0, count = 0;
	struct in_addr fa[MAX_FA];

	printf("Dynamics - Automatic location updates between two FAs using "
	       "MN API\n\n");
	if (argc < 4) {
		fprintf(stderr,
			"locupd2 <locupd period (usec)> <FA1 addr> <FA2 addr>"
			" [FA3 .. FAn] [API admin file name]\n"
			"e.g. locupd2 1000000 192.168.0.1 192.168.0.2\n"
			"     locupd2 500000 192.168.0.1 192.168.0.2 "
			"/var/run/dynamics_mn_admin\n");
		return -1;
	}

	if (argc - 1 > MAX_FA) {
		fprintf(stderr, "Too many FAs\n");
		exit(1);
	}

	period = atoi(argv[1]);
	for (i = 2; i < argc; i++) {
		if (inet_aton(argv[i], &fa[i-2]) == 0) {
			if (i == argc - 1) {
				printf("Using admin file '%s'\n", argv[i]);
				path = 1;
			} else {
				fprintf(stderr, "Invalid IP address: %s\n",
					argv[i]);
				exit(1);
			}
		} else
			count++;
	}
	printf("%i FAs\n", count);

	ret = dynamics_mn_init(path ? argv[argc - 1] : DEFAULT_API_PATH);

	if (ret != API_SUCCESS) {
		fprintf(stderr, "dynamics_mn_init returned %i: %s\n",
			ret, dynamics_mn_get_error_string(ret));
		return -1;
	}

	f = fopen("locupd2.log", "a");
	if (f == NULL) {
		fprintf(stderr, "Could not open locupd2.log.\n");
		exit(1);
	}

	if (dynamics_fork_daemon() != 0) {
		fprintf(stderr, "fork failed\n");
		exit(1);
	}

	signal(SIGTERM, clean_up);
	signal(SIGINT, clean_up);

	locupd(period, count, fa);

	return 0;
}