device_info_query.c

mobile ip 在linux下的一种实现

/* $Id: device_info_query.c,v 1.8 2001/08/04 20:55:56 jm Exp $
 * Device information query
 *
 * 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.
 */


#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <time.h>
#include <getopt.h>
#include <unistd.h>
#include <signal.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/param.h>
#include <sys/ioctl.h>
#include <linux/if.h>

#include "util.h"
#include "dyn_mnlib.h"
#include "agentapi.h"
#include "fixed_fd_zero.h"
#include "device_info.h"
#include "dyn_ip.h"

static char *default_path = DEFAULT_DEVICE_INFO_PATH;
static char *usage = "device_info_query -p <socket path>] [-d device] [-h help]\n";

static int open_socket(void)
{
	int sock, r;
	struct sockaddr_un addr;
	socklen_t addrlen;
	
	sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
	if (sock < 0)
		return sock;
	
	memset(&addr, 0, sizeof(struct sockaddr_un));
	addr.sun_family = AF_LOCAL;
	addr.sun_path[0] = '\0';
	snprintf(addr.sun_path + 1, sizeof(addr.sun_path) - 1,
		 "dynamics-%i-%li", getpid(), random());
	addrlen = sizeof(addr.sun_family) + 1 + strlen(addr.sun_path + 1);
	
	r = bind(sock, (struct sockaddr *) &addr, addrlen);
	if (r < 0) {
		fprintf(stderr, "open_socket: bind failed: %s\n",
			strerror(errno));
		return -1;
	}

	return sock;
}

static int send_query(int s, struct sockaddr_un addr, 
		      char *path, struct device_info_query *msg)
{
	int n;

	if (!path || !msg) {
		fprintf(stderr, "send_query: NULL argument\n");
		return -1;
	}

	n = sendto(s, msg, sizeof(struct device_info_query), 0, 
		   (struct sockaddr *)&addr, sizeof(addr));

	if (n != sizeof(struct device_info_query)) {
		fprintf(stderr, "send_query: sendto %d/%d bytes: %s\n",
			n, sizeof(struct device_info_query), strerror(errno));
	}

	return 0;
}

static int process_reply(int s, struct device_info_query *msg)
{
	fd_set set;
	int len, n;
	struct sockaddr_un addr;
	
	FD_ZERO(&set);
	FD_SET(s, &set);
	select(FD_SETSIZE, &set, NULL, NULL, NULL);
	if (!(FD_ISSET(s, &set)))
		return 0;
	
	len = sizeof(addr);
	n = recvfrom(s, msg, sizeof(struct device_info_query), 0,
		     (struct sockaddr *)&addr, (unsigned int *)&len);
	if (n != sizeof(struct device_info_query)) {
		fprintf(stderr, "process_reply: couldn't receive whole "
			"message %d/%d\n", 
			n, sizeof(struct device_info_query));
		return -1;
	}

	return 0;
}

int main(int argc, char *argv[])
{
	char *path = NULL;
	char *ifname = NULL;
	int c, s, r;
	struct device_info_query msg;
	struct idxmap *idx = NULL, *idxmap = NULL, *prev;
	struct sockaddr_un serv_addr;

	if (argc < 2) {
		fprintf(stderr, usage);
		exit(1);
	}

	while (1) {
		int option_index = 0;
		
		c = getopt_long (argc, argv, "hd:p:", NULL, &option_index);
		if (c == -1)
			break;
		
		switch (c) {
		case 'd':
			ifname = malloc(IFNAMSIZ);
			if (ifname == NULL) {
				fprintf(stderr, "malloc for device: %s\n",
					strerror(errno));
				exit(1);
			}
			memset(ifname, 0, IFNAMSIZ);
			dynamics_strlcpy(ifname, optarg, IFNAMSIZ);
			break;
		case 'p':
			path = malloc(MAXPATHLEN);
			if (path == NULL) {
				fprintf(stderr, "malloc for path: %s\n",
					strerror(errno));
				exit(1);
			}
			memset(path, 0, MAXPATHLEN);
			dynamics_strlcpy(path, optarg, MAXPATHLEN);
			break;
		case '?':
		case 'h':
			fprintf(stderr, usage);
			exit(1);
		default:
			printf ("?? getopt returned character code "
				"0%o ??\n", c);
		}
	}

	if (path == NULL)
		path = default_path;

	if (ifname == NULL)
		printf("Querying all interfaces\n");

	idxmap = dyn_ip_get_interface_map();
	idx = idxmap;

	s = open_socket();
	if (s < 0) {
		fprintf(stderr, "socket open failed\n");
		exit(1);
	}

	memset(&serv_addr, 0, sizeof(serv_addr));
	serv_addr.sun_family = AF_LOCAL;
	dynamics_strlcpy(serv_addr.sun_path, path,
			 sizeof(serv_addr.sun_path));

	while (idx != NULL) {
		if (ifname != NULL && strncmp(idx->name, ifname, 
					      sizeof(ifname))) {
			idx = idx->next;
			continue;
		}
		msg.device_index = idx->index;
		msg.priority = -1;
		r = send_query(s, serv_addr, path, &msg);
		if (r == 0)
			process_reply(s, &msg);
		else {
			fprintf(stderr, "send_query failed\n");
			continue;
		}
		printf("interface %s:\n", idx->name);
		if (msg.priority != -1)
			printf("\tpriority %d\n", msg.priority);
		idx = idx->next;
	}

	idx = idxmap;
	while (idx != NULL) {
		prev = idx;
		idx = idx->next;
		free(prev);
	}

	close(s);
	return 0;
}