259 lines
6.8 KiB
C
259 lines
6.8 KiB
C
/*
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route.c -- routing
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Copyright (C) 2000,2001 Ivo Timmermans <itimmermans@bigfoot.com>,
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2000,2001 Guus Sliepen <guus@sliepen.warande.net>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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$Id: route.c,v 1.1.2.11 2001/06/05 16:09:55 guus Exp $
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*/
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#include "config.h"
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#ifdef HAVE_FREEBSD
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#include <sys/param.h>
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#endif
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <net/ethernet.h>
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#include <netinet/if_ether.h>
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#include <utils.h>
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#include <xalloc.h>
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#include <syslog.h>
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#include "net.h"
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#include "net/ethernet.h"
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#include "netinet/if_ether.h"
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#include "connection.h"
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#include "subnet.h"
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#include "route.h"
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#include "system.h"
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int routing_mode = RMODE_ROUTER;
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subnet_t mymac;
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void learn_mac(connection_t *source, mac_t *address)
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{
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subnet_t *subnet;
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cp
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subnet = lookup_subnet_mac(address);
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if(!subnet)
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{
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subnet = new_subnet();
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subnet->type = SUBNET_MAC;
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// subnet->lasttime = gettimeofday();
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memcpy(&subnet->net.mac.address, address, sizeof(mac_t));
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subnet_add(source, subnet);
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if(debug_lvl >= DEBUG_TRAFFIC)
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{
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syslog(LOG_DEBUG, _("Learned new MAC address %x:%x:%x:%x:%x:%x from %s (%s)"),
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address->x[0],
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address->x[1],
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address->x[2],
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address->x[3],
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address->x[4],
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address->x[5],
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source->name, source->hostname);
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}
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}
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}
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connection_t *route_mac(connection_t *source, vpn_packet_t *packet)
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{
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subnet_t *subnet;
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cp
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/* Learn source address */
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learn_mac(source, (mac_t *)(&packet->data[6]));
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/* Lookup destination address */
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subnet = lookup_subnet_mac((mac_t *)(&packet->data[0]));
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if(subnet)
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return subnet->owner;
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else
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return NULL;
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}
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connection_t *route_ipv4(vpn_packet_t *packet)
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{
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ipv4_t dest;
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subnet_t *subnet;
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cp
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dest = ntohl(*((unsigned long*)(&packet->data[30])));
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subnet = lookup_subnet_ipv4(&dest);
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if(!subnet)
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{
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if(debug_lvl >= DEBUG_TRAFFIC)
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{
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syslog(LOG_WARNING, _("Cannot route packet: unknown destination address %d.%d.%d.%d"),
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packet->data[30], packet->data[31], packet->data[32], packet->data[33]);
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}
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return NULL;
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}
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cp
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return subnet->owner;
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}
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connection_t *route_ipv6(vpn_packet_t *packet)
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{
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cp
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if(debug_lvl > DEBUG_NOTHING)
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{
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syslog(LOG_WARNING, _("Cannot route packet: IPv6 routing not yet implemented"));
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}
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cp
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return NULL;
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}
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void route_arp(vpn_packet_t *packet)
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{
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struct ether_arp *arp;
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subnet_t *subnet;
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unsigned char ipbuf[4];
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ipv4_t dest;
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cp
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/* This routine generates replies to ARP requests.
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You don't need to set NOARP flag on the interface anymore (which is broken on FreeBSD).
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Most of the code here is taken from choparp.c by Takamichi Tateoka (tree@mma.club.uec.ac.jp)
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*/
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arp = (struct ether_arp *)(packet->data + 14);
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/* Check if this is a valid ARP request */
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if(ntohs(arp->arp_hrd) != ARPHRD_ETHER ||
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ntohs(arp->arp_pro) != ETHERTYPE_IP ||
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(int) (arp->arp_hln) != ETHER_ADDR_LEN ||
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(int) (arp->arp_pln) != 4 ||
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ntohs(arp->arp_op) != ARPOP_REQUEST )
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{
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if(debug_lvl > DEBUG_TRAFFIC)
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{
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syslog(LOG_WARNING, _("Cannot route packet: received unknown type ARP request"));
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}
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return;
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}
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/* Check if the IP address exists on the VPN */
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dest = ntohl(*((unsigned long*)(arp->arp_tpa)));
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subnet = lookup_subnet_ipv4(&dest);
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if(!subnet)
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{
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if(debug_lvl >= DEBUG_TRAFFIC)
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{
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syslog(LOG_WARNING, _("Cannot route packet: ARP request for unknown address %d.%d.%d.%d"),
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arp->arp_tpa[0], arp->arp_tpa[1], arp->arp_tpa[2], arp->arp_tpa[3]);
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}
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return;
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}
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/* Check if it is for our own subnet */
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if(subnet->owner == myself)
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return; /* silently ignore */
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memcpy(packet->data, packet->data + ETHER_ADDR_LEN, ETHER_ADDR_LEN); /* copy destination address */
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packet->data[ETHER_ADDR_LEN*2 - 1] ^= 0xFF; /* mangle source address so it looks like it's not from us */
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memcpy(ipbuf, arp->arp_tpa, 4); /* save protocol addr */
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memcpy(arp->arp_tpa, arp->arp_spa, 4); /* swap destination and source protocol address */
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memcpy(arp->arp_spa, ipbuf, 4); /* ... */
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memcpy(arp->arp_tha, arp->arp_sha, 10); /* set target hard/proto addr */
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memcpy(arp->arp_sha, packet->data + ETHER_ADDR_LEN, ETHER_ADDR_LEN); /* add fake source hard addr */
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arp->arp_op = htons(ARPOP_REPLY);
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accept_packet(packet);
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cp
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}
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void route_outgoing(vpn_packet_t *packet)
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{
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unsigned short int type;
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connection_t *cl;
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cp
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/* FIXME: multicast? */
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switch(routing_mode)
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{
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case RMODE_ROUTER:
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type = ntohs(*((unsigned short*)(&packet->data[12])));
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switch(type)
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{
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case 0x0800:
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cl = route_ipv4(packet);
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break;
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case 0x86DD:
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cl = route_ipv6(packet);
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break;
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case 0x0806:
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route_arp(packet);
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return;
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default:
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if(debug_lvl >= DEBUG_TRAFFIC)
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{
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syslog(LOG_WARNING, _("Cannot route packet: unknown type %hx"), type);
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}
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return;
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}
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if(cl)
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send_packet(cl, packet);
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break;
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case RMODE_SWITCH:
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cl = route_mac(myself, packet);
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if(cl)
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send_packet(cl, packet);
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else
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broadcast_packet(myself, packet);
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break;
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case RMODE_HUB:
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broadcast_packet(myself, packet);
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break;
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}
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}
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void route_incoming(connection_t *source, vpn_packet_t *packet)
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{
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switch(routing_mode)
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{
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case RMODE_ROUTER:
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memcpy(packet->data, mymac.net.mac.address.x, 6); /* Override destination address to make the kernel accept it */
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break;
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case RMODE_SWITCH:
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if((packet->data[0] & packet->data[1]) == 0xFF) /* Broadcast? */
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broadcast_packet(source, packet); /* If yes, spread it on */
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else
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learn_mac(source, (mac_t *)(&packet->data[6]));
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break;
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case RMODE_HUB:
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broadcast_packet(source,packet); /* Spread it on */
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break;
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}
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accept_packet(packet);
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}
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