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- /*
- * $Id: get_mac.c,v 1.1.1.1 1999/05/18 15:33:44 dugsong Exp $
- *
- * libnet
- * get_mac.c - get the MAC address of a remote host
- *
- * Copyright (c) 1998, 1999 Mike D. Schiffman <mike@infonexus.com>
- * route|daemon9 <route@infonexus.com>
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- */
-
- #if (HAVE_CONFIG_H)
- #include "../../include/config.h"
- #endif
- #include <libnet.h>
- #include <pcap.h>
-
- #define IP_UCHAR_COMP(x, y) \
- (x[0] == y[0] && x[1] == y[1] && x[2] == y[2] && x[3] == y[3])
-
-
- u_char enet_dst[6] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
-
- int libnet_do_arp(struct link_int *, u_char *, struct ether_addr *, u_long);
-
- int
- main(int argc, char *argv[])
- {
- int i, c;
- char errbuf[256];
- char *device = NULL;
- struct link_int *l;
- struct ether_addr e;
- u_long ip;
-
- while ((c = getopt(argc, argv, "i:")) != EOF)
- {
- switch (c)
- {
- case 'i':
- device = optarg;
- break;
- default:
- exit(EXIT_FAILURE);
- }
- }
-
- if (!device)
- {
- fprintf(stderr, "Specify a device\n");
- exit(EXIT_FAILURE);
- }
- if (argc > optind)
- {
- if ((ip = libnet_name_resolve(argv[optind], 1)) == -1)
- {
- fprintf(stderr, "Cannot resolve IP address\n");
- exit(EXIT_FAILURE);
- }
- }
- else
- {
- fprintf(stderr, "IP address to ARP for?\n");
- exit(EXIT_FAILURE);
- }
-
- l = libnet_open_link_interface(device, errbuf);
- if (!l)
- {
- fprintf(stderr, "libnet_open_link_interface: %s\n", errbuf);
- exit(EXIT_FAILURE);
- }
-
- c = libnet_do_arp(l, device, &e, ip);
- if (c != -1)
- {
- for (i = 0; i < 6; i++)
- {
- printf("%x", e.ether_addr_octet[i]);
- if (i != 5)
- {
- printf(":");
- }
- }
- printf("\n");
- }
- return (c == -1 ? EXIT_FAILURE : EXIT_SUCCESS);
- }
-
-
- int
- libnet_do_arp(struct link_int *l, u_char *device, struct ether_addr *e,
- u_long ip)
- {
- int n, i;
- u_char *buf, errbuf[256], *packet, *ip_p;
- struct libnet_ethernet_hdr *p;
- struct libnet_arp_hdr *a;
- u_long local_ip;
- pcap_t *pd;
- struct pcap_pkthdr pc_hdr;
-
- /*
- * Initialize a packet.
- */
- if (libnet_init_packet(ARP_H + ETH_H, &buf) == -1)
- {
- perror("libnet_init_packet memory:");
- exit(EXIT_FAILURE);
- }
-
- /*
- * Get the ethernet address of the device.
- */
- e = libnet_get_hwaddr(l, device, errbuf);
- if (e == NULL)
- {
- fprintf(stderr, "libnet_get_hwaddr: %s\n", errbuf);
- return (-1);
- }
-
- /*
- * Get the IP address of the device.
- */
- local_ip = htonl(libnet_get_ipaddr(l, device, errbuf));
- if (!local_ip)
- {
- fprintf(stderr, "libnet_get_ipaddr: %s\n", errbuf);
- return (-1);
- }
-
- /*
- * Open the pcap device.
- */
- pd = pcap_open_live(device, ARP_H + ETH_H, 1, 500, errbuf);
- if (pd == NULL)
- {
- fprintf(stderr, "pcap_open_live: %s\n", errbuf);
- return (-1);
- }
-
- /*
- * Ethernet header
- */
- libnet_build_ethernet(
- enet_dst, /* broadcast ethernet address */
- e->ether_addr_octet, /* source ethernet address */
- ETHERTYPE_ARP, /* this frame holds an ARP packet */
- NULL, /* payload */
- 0, /* payload size */
- buf); /* packet header memory */
-
- /*
- * ARP header
- */
- libnet_build_arp(
- ARPHRD_ETHER, /* hardware address type */
- ETHERTYPE_IP, /* protocol address type */
- ETHER_ADDR_LEN, /* hardware address length */
- 4, /* protocol address length */
- ARPOP_REQUEST, /* packet type - ARP request */
- e->ether_addr_octet, /* source (local) ethernet address */
- (u_char *)&local_ip, /* source (local) IP address */
- enet_dst, /* target's ethernet address (broadcast) */
- (u_char *)&ip, /* target's IP address */
- NULL, /* payload */
- 0, /* payload size */
- buf + ETH_H); /* packet header memory */
-
- n = libnet_write_link_layer(l, device, buf, ARP_H + ETH_H);
- if (n == -1)
- {
- fprintf(stderr, "libnet_write_link_layer choked\n");
- return (-1);
- }
- printf("Sent a %d byte ARP request looking for the MAC of %s.\n",
- n, host_lookup(ip, 0));
- printf("Waiting for a response...\n");
-
- for (;(packet = ((u_char *)pcap_next(pd, &pc_hdr)));)
- {
- p = (struct libnet_ethernet_hdr *)(packet);
- if (ntohs(p->ether_type) == ETHERTYPE_ARP)
- {
- a = (struct libnet_arp_hdr *)(packet + ETH_H);
- if (ntohs(a->ar_op) == ARPOP_REPLY)
- {
- ip_p = (u_char *)&ip;
- if (IP_UCHAR_COMP(a->ar_spa, ip_p))
- {
- printf("Target hardware address: ");
- for (i = 0; i < 6; i++)
- {
- printf("%x", a->ar_sha[i]);
- if (i != 5)
- {
- printf(":");
- }
- }
- printf("\n");
- }
- }
- }
- }
-
- libnet_destroy_packet(&buf);
- return (n);
- }
-
- /* EOF */
-
-