131 lines
2.8 KiB
C
131 lines
2.8 KiB
C
/* $NetBSD: arp.c,v 1.1.1.1 1999/12/11 22:24:07 veego Exp $ */
|
|
|
|
/*
|
|
* arp.c (C) 1995-1998 Darren Reed
|
|
*
|
|
* Redistribution and use in source and binary forms are permitted
|
|
* provided that this notice is preserved and due credit is given
|
|
* to the original author and the contributors.
|
|
*/
|
|
#if !defined(lint)
|
|
static const char sccsid[] = "@(#)arp.c 1.4 1/11/96 (C)1995 Darren Reed";
|
|
static const char rcsid[] = "@(#)Id: arp.c,v 2.1 1999/08/04 17:31:03 darrenr Exp";
|
|
#endif
|
|
#include <stdio.h>
|
|
#include <errno.h>
|
|
#include <sys/types.h>
|
|
#include <sys/socket.h>
|
|
#if !defined(ultrix) && !defined(hpux)
|
|
#include <sys/sockio.h>
|
|
#endif
|
|
#include <sys/ioctl.h>
|
|
#include <netdb.h>
|
|
#include <netinet/in.h>
|
|
#include <net/if.h>
|
|
#include <netinet/if_ether.h>
|
|
#ifndef ultrix
|
|
#include <net/if_arp.h>
|
|
#endif
|
|
#include <netinet/in.h>
|
|
#include <netinet/ip_var.h>
|
|
#include <netinet/tcp.h>
|
|
#include "ipsend.h"
|
|
#include "iplang/iplang.h"
|
|
|
|
|
|
/*
|
|
* lookup host and return
|
|
* its IP address in address
|
|
* (4 bytes)
|
|
*/
|
|
int resolve(host, address)
|
|
char *host, *address;
|
|
{
|
|
struct hostent *hp;
|
|
u_long add;
|
|
|
|
add = inet_addr(host);
|
|
if (add == -1)
|
|
{
|
|
if (!(hp = gethostbyname(host)))
|
|
{
|
|
fprintf(stderr, "unknown host: %s\n", host);
|
|
return -1;
|
|
}
|
|
bcopy((char *)hp->h_addr, (char *)address, 4);
|
|
return 0;
|
|
}
|
|
bcopy((char*)&add, address, 4);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* ARP for the MAC address corresponding
|
|
* to the IP address. This taken from
|
|
* some BSD program, I cant remember which.
|
|
*/
|
|
int arp(ip, ether)
|
|
char *ip;
|
|
char *ether;
|
|
{
|
|
static int sfd = -1;
|
|
static char ethersave[6], ipsave[4];
|
|
struct arpreq ar;
|
|
struct sockaddr_in *sin, san;
|
|
struct hostent *hp;
|
|
int fd;
|
|
|
|
#ifdef IPSEND
|
|
if (arp_getipv4(ip, ether) == 0)
|
|
return 0;
|
|
#endif
|
|
if (!bcmp(ipsave, ip, 4)) {
|
|
bcopy(ethersave, ether, 6);
|
|
return 0;
|
|
}
|
|
fd = -1;
|
|
bzero((char *)&ar, sizeof(ar));
|
|
sin = (struct sockaddr_in *)&ar.arp_pa;
|
|
sin->sin_family = AF_INET;
|
|
bcopy(ip, (char *)&sin->sin_addr.s_addr, 4);
|
|
#ifndef hpux
|
|
if ((hp = gethostbyaddr(ip, 4, AF_INET)))
|
|
if (!(ether_hostton(hp->h_name, ether)))
|
|
goto savearp;
|
|
#endif
|
|
|
|
if (sfd == -1)
|
|
if ((sfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
|
|
{
|
|
perror("arp: socket");
|
|
return -1;
|
|
}
|
|
tryagain:
|
|
if (ioctl(sfd, SIOCGARP, (caddr_t)&ar) == -1)
|
|
{
|
|
if (fd == -1)
|
|
{
|
|
bzero((char *)&san, sizeof(san));
|
|
san.sin_family = AF_INET;
|
|
san.sin_port = htons(1);
|
|
bcopy(ip, &san.sin_addr.s_addr, 4);
|
|
fd = socket(AF_INET, SOCK_DGRAM, 0);
|
|
(void) sendto(fd, ip, 4, 0,
|
|
(struct sockaddr *)&san, sizeof(san));
|
|
sleep(1);
|
|
(void) close(fd);
|
|
goto tryagain;
|
|
}
|
|
fprintf(stderr, "(%s):", inet_ntoa(sin->sin_addr));
|
|
if (errno != ENXIO)
|
|
perror("SIOCGARP");
|
|
return -1;
|
|
}
|
|
|
|
bcopy(ar.arp_ha.sa_data, ether, 6);
|
|
savearp:
|
|
bcopy(ether, ethersave, 6);
|
|
bcopy(ip, ipsave, 4);
|
|
return 0;
|
|
}
|