/*
 * arp.c (C) 1995-1998 Darren Reed
 *
 * See the IPFILTER.LICENCE file for details on licencing.
 */
#include <sys/types.h>
#include <sys/socket.h>
# include <sys/sockio.h>
#include <sys/ioctl.h>
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <net/if.h>
#include <netinet/if_ether.h>
# include <net/if_arp.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/tcp.h>
#include <stdio.h>
#include <errno.h>
#include <netdb.h>
#include "ipsend.h"
#include "iplang/iplang.h"


/*
 * lookup host and return
 * its IP address in address
 * (4 bytes)
 */
int     resolve(char *host, char *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);
        if ((hp = gethostbyaddr(ip, 4, AF_INET)))
# if SOLARIS && (SOLARIS2 >= 10)
                if (!(ether_hostton(hp->h_name, (struct ether_addr *)ether)))
# else
                if (!(ether_hostton(hp->h_name, ether)))
# endif
                        goto savearp;

        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);
            }

        if ((ar.arp_ha.sa_data[0] == 0) && (ar.arp_ha.sa_data[1] == 0) &&
            (ar.arp_ha.sa_data[2] == 0) && (ar.arp_ha.sa_data[3] == 0) &&
            (ar.arp_ha.sa_data[4] == 0) && (ar.arp_ha.sa_data[5] == 0)) {
                fprintf(stderr, "(%s):", inet_ntoa(sin->sin_addr));
                return (-1);
        }

        bcopy(ar.arp_ha.sa_data, ether, 6);
savearp:
        bcopy(ether, ethersave, 6);
        bcopy(ip, ipsave, 4);
        return (0);
}