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/*
* author: Darren Bounds <dbounds@intrusense.com>
* copyright: Copyright (C) 2002 by Darren Bounds
* license: This software is under GPL version 2 of license
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* packit official page at http://packit.sourceforge.net
*/
#include "shape_arp_hdr.h"
libnet_t *
shape_arp_hdr(libnet_t *pkt_d)
{
u_int32_t i, s_paddr, r_paddr;
u_int8_t s_neaddr[6];
u_int8_t r_neaddr[6];
struct libnet_ether_addr *hw_addr;
#ifdef DEBUG
fprintf(stdout, "DEBUG: shape_arp_hdr()\n");
#endif
hw_addr = malloc(sizeof(struct libnet_ether_addr));
memset(hw_addr, 0, sizeof(struct libnet_ether_addr));
s_paddr = r_paddr = 0;
if(ahdr_o.rand_s_paddr)
ahdr_o.s_paddr = retrieve_rand_ipv4_addr(ahdr_o.s_paddr);
if(ahdr_o.rand_r_paddr)
ahdr_o.r_paddr = retrieve_rand_ipv4_addr(ahdr_o.r_paddr);
if(ahdr_o.rand_s_eaddr)
ahdr_o.s_eaddr = retrieve_rand_ethernet_addr(ahdr_o.s_eaddr);
if(ahdr_o.rand_r_eaddr)
ahdr_o.r_eaddr = retrieve_rand_ethernet_addr(ahdr_o.r_eaddr);
if(ahdr_o.s_paddr == NULL)
{
switch(ahdr_o.op_type)
{
case ARPOP_REQUEST: case ARPOP_REVREQUEST:
if((s_paddr = libnet_get_ipaddr4(pkt_d)) == -1)
fatal_error("Unable to retrieve local IP address: %s", libnet_geterror(pkt_d));
ahdr_o.s_paddr = libnet_addr2name4(s_paddr, 0);
break;
default:
ahdr_o.s_paddr = IPV4_DEFAULT;
break;
}
}
if((s_paddr = libnet_name2addr4(pkt_d, ahdr_o.s_paddr, 0)) == -1)
fatal_error("Invalid sender protocol address: %s", ahdr_o.s_paddr);
if(ahdr_o.s_eaddr == NULL)
{
switch(ahdr_o.op_type)
{
case ARPOP_REQUEST: case ARPOP_REVREQUEST:
if((hw_addr = libnet_get_hwaddr(pkt_d)) == NULL)
fatal_error("Unable to determine ethernet address: %s", libnet_geterror(pkt_d));
for(i = 0; i < 6; i++)
s_neaddr[i] = hw_addr->ether_addr_octet[i];
break;
default:
ahdr_o.s_eaddr = ETH_DEFAULT;
break;
}
}
if(format_ethernet_addr(ahdr_o.s_eaddr, s_neaddr) == 0)
fatal_error("Invalid sender ethernet address");
snprintf(ahdr_o.shw_addr, 18, "%0X:%0X:%0X:%0X:%0X:%0X",
s_neaddr[0], s_neaddr[1], s_neaddr[2], s_neaddr[3], s_neaddr[4], s_neaddr[5]);
if(ahdr_o.r_paddr == NULL)
{
switch(ahdr_o.op_type)
{
case ARPOP_REPLY: case ARPOP_REQUEST:
if((r_paddr = libnet_get_ipaddr4(pkt_d)) == -1)
fatal_error("Unable to retrieve local IP address: %s", libnet_geterror(pkt_d));
ahdr_o.r_paddr = libnet_addr2name4(r_paddr, 0);
break;
default:
ahdr_o.r_paddr = IPV4_DEFAULT;
break;
}
}
if((r_paddr = libnet_name2addr4(pkt_d, ahdr_o.r_paddr, 0)) == -1)
fatal_error("Invalid receiver protocol address: %s", ahdr_o.r_paddr);
if(ahdr_o.r_eaddr == NULL)
{
switch(ahdr_o.op_type)
{
case ARPOP_REPLY: case ARPOP_REVREPLY:
if((hw_addr = libnet_get_hwaddr(pkt_d)) == NULL)
fatal_error("Unable to determine ethernet address: %s", libnet_geterror(pkt_d));
for(i = 0; i < 6; i++)
r_neaddr[i] = hw_addr->ether_addr_octet[i];
break;
default:
ahdr_o.r_eaddr = ETH_DEFAULT;
break;
}
}
if(format_ethernet_addr(ahdr_o.r_eaddr, r_neaddr) == 0)
fatal_error("Invalid receiver ethernet address");
snprintf(ahdr_o.rhw_addr, 18, "%0X:%0X:%0X:%0X:%0X:%0X",
r_neaddr[0], r_neaddr[1], r_neaddr[2], r_neaddr[3], r_neaddr[4], r_neaddr[5]);
if(libnet_build_arp(
ARPHRD_ETHER,
ETHERTYPE_IP,
6,
4,
ahdr_o.op_type,
s_neaddr,
(u_int8_t *)&s_paddr,
r_neaddr,
(u_int8_t *)&r_paddr,
payload,
payload_len,
pkt_d,
0) == -1)
{
fatal_error("Unable to build ARP header: %s", libnet_geterror(pkt_d));
}
return pkt_d;
}
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