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Added proxy-arp support. No more ifconfig -arp needed. Works like a charm

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under FreeBSD now :).
This commit is contained in:
Guus Sliepen 2001-06-04 11:14:35 +00:00
parent 0a3c8cefd4
commit 428482d86f
1 changed files with 75 additions and 3 deletions
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78
src/route.c
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@ -17,21 +17,25 @@
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
$Id: route.c,v 1.1.2.9 2001/05/28 08:21:43 guus Exp $
$Id: route.c,v 1.1.2.10 2001/06/04 11:14:35 guus Exp $
*/
#include "config.h"
#ifdef HAVE_FREEBSD
#include <sys/param.h>
#else
#include <netinet/in.h>
#endif
#include <sys/socket.h>
#include <netinet/in.h>
#include <net/ethernet.h>
#include <netinet/if_ether.h>
#include <utils.h>
#include <xalloc.h>
#include <syslog.h>
#include "net.h"
#include "net/ethernet.h"
#include "netinet/if_ether.h"
#include "connection.h"
#include "subnet.h"
#include "route.h"
@ -133,6 +137,71 @@ cp
return NULL;
}
void route_arp(vpn_packet_t *packet)
{
struct ether_arp *arp;
subnet_t *subnet;
unsigned char ipbuf[4];
ipv4_t dest;
cp
/* This routine generates replies to ARP requests.
You don't need to set NOARP flag on the interface anymore (which is broken on FreeBSD).
Most of the code here is taken from choparp.c by Takamichi Tateoka (tree@mma.club.uec.ac.jp)
*/
arp = (struct ether_arp *)(packet->data + 14);
/* Check if this is a valid ARP request */
if(ntohs(arp->arp_hrd) != ARPHRD_ETHER ||
ntohs(arp->arp_pro) != ETHERTYPE_IP ||
(int) (arp->arp_hln) != ETHER_ADDR_LEN ||
(int) (arp->arp_pln) != 4 ||
ntohs(arp->arp_op) != ARPOP_REQUEST )
{
if(debug_lvl > DEBUG_TRAFFIC)
{
syslog(LOG_WARNING, _("Cannot route packet: received unknown type ARP request"));
}
return;
}
/* Check if the IP address exists on the VPN */
dest = ntohl(*((unsigned long*)(arp->arp_tpa)));
subnet = lookup_subnet_ipv4(&dest);
if(!subnet)
{
if(debug_lvl >= DEBUG_TRAFFIC)
{
syslog(LOG_WARNING, _("Cannot route packet: ARP request for unknown address %d.%d.%d.%d"),
arp->arp_tpa[0], arp->arp_tpa[1], arp->arp_tpa[2], arp->arp_tpa[3]);
}
return;
}
/* Check if it is for our own subnet */
if(subnet->owner == myself)
return; /* silently ignore */
memcpy(packet->data, packet->data + ETHER_ADDR_LEN, ETHER_ADDR_LEN); /* copy destination address */
packet->data[ETHER_ADDR_LEN*2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */
memcpy(ipbuf, arp->arp_tpa, 4); /* save protocol addr */
memcpy(arp->arp_tpa, arp->arp_spa, 4); /* swap destination and source protocol address */
memcpy(arp->arp_spa, ipbuf, 4); /* ... */
memcpy(arp->arp_tha, arp->arp_sha, 10); /* set target hard/proto addr */
memcpy(arp->arp_sha, packet->data + ETHER_ADDR_LEN, ETHER_ADDR_LEN); /* add fake source hard addr */
arp->arp_op = htons(ARPOP_REPLY);
accept_packet(packet);
cp
}
void route_outgoing(vpn_packet_t *packet)
{
unsigned short int type;
@ -153,6 +222,9 @@ cp
case 0x86DD:
cl = route_ipv6(packet);
break;
case 0x0806:
route_arp(packet);
return;
default:
if(debug_lvl >= DEBUG_TRAFFIC)
{