along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: route.c,v 1.1.2.28 2002/03/01 14:33:48 guus Exp $
+ $Id: route.c,v 1.1.2.37 2002/03/19 00:08:23 guus Exp $
*/
#include "config.h"
#else
#include <net/ethernet.h>
#endif
+#include <netinet/ip6.h>
+#include <netinet/icmp6.h>
#include <netinet/if_ether.h>
#include <utils.h>
#include <xalloc.h>
return subnet->owner;
}
+unsigned short int inet_checksum(unsigned short int *data, int len, unsigned short int prevsum)
+{
+ unsigned long int checksum = prevsum ^ 0xFFFF;
+
+ while(len--)
+ checksum += ntohs(*data++);
+
+ while(checksum >> 16)
+ checksum = (checksum & 0xFFFF) + (checksum >> 16);
+
+ return checksum ^ 0xFFFF;
+}
+
+void route_neighborsol(vpn_packet_t *packet)
+{
+ struct ip6_hdr *hdr;
+ struct nd_neighbor_solicit *ns;
+ struct nd_opt_hdr *opt;
+ subnet_t *subnet;
+ short unsigned int checksum;
+
+ struct {
+ struct in6_addr ip6_src; /* source address */
+ struct in6_addr ip6_dst; /* destination address */
+ uint32_t length;
+ uint8_t junk[4];
+ } pseudo;
+
+cp
+ hdr = (struct ip6_hdr *)(packet->data + 14);
+ ns = (struct nd_neighbor_solicit *)(packet->data + 14 + sizeof(*hdr));
+ opt = (struct nd_opt_hdr *)(packet->data + 14 + sizeof(*hdr) + sizeof(*ns));
+
+ /* First, snatch the source address from the neighbor solicitation packet */
+
+ memcpy(mymac.net.mac.address.x, packet->data + 6, 6);
+
+ /* Check if this is a valid neighbor solicitation request */
+
+ if(ns->nd_ns_hdr.icmp6_type != ND_NEIGHBOR_SOLICIT ||
+ opt->nd_opt_type != ND_OPT_SOURCE_LINKADDR)
+ {
+ if(debug_lvl > DEBUG_TRAFFIC)
+ {
+ syslog(LOG_WARNING, _("Cannot route packet: received unknown type neighbor solicitation request"));
+ }
+ return;
+ }
+
+ /* Create pseudo header */
+
+ memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16);
+ memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16);
+ pseudo.length = htonl(sizeof(*ns) + sizeof(*opt) + 6);
+ pseudo.junk[0] = pseudo.junk[1] = pseudo.junk[2] = 0;
+ pseudo.junk[3] = IPPROTO_ICMPV6;
+
+ /* Generate checksum */
+
+ checksum = inet_checksum((unsigned short int *)&pseudo, sizeof(pseudo)/2, ~0);
+ checksum = inet_checksum((unsigned short int *)ns, sizeof(*ns)/2 + 4, checksum);
+
+ if(checksum)
+ {
+ if(debug_lvl >= DEBUG_TRAFFIC)
+ syslog(LOG_WARNING, _("Cannot route packet: checksum error for neighbor solicitation request"));
+ return;
+ }
+
+ /* Check if the IPv6 address exists on the VPN */
+
+ subnet = lookup_subnet_ipv6((ipv6_t *)&ns->nd_ns_target);
+
+ if(!subnet)
+ {
+ if(debug_lvl >= DEBUG_TRAFFIC)
+ {
+ syslog(LOG_WARNING, _("Cannot route packet: neighbor solicitation request for unknown address %hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx"),
+ ntohs(((uint16_t *)&ns->nd_ns_target)[0]), ntohs(((uint16_t *)&ns->nd_ns_target)[1]), ntohs(((uint16_t *)&ns->nd_ns_target)[2]), ntohs(((uint16_t *)&ns->nd_ns_target)[3]),
+ ntohs(((uint16_t *)&ns->nd_ns_target)[4]), ntohs(((uint16_t *)&ns->nd_ns_target)[5]), ntohs(((uint16_t *)&ns->nd_ns_target)[6]), ntohs(((uint16_t *)&ns->nd_ns_target)[7]));
+ }
+
+ return;
+ }
+
+ /* Check if it is for our own subnet */
+
+ if(subnet->owner == myself)
+ return; /* silently ignore */
+
+ /* Create neighbor advertation reply */
+
+ 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(&hdr->ip6_dst, &hdr->ip6_src, 16); /* swap destination and source protocol address */
+ memcpy(&hdr->ip6_src, &ns->nd_ns_target, 16); /* ... */
+
+ memcpy((char *)opt + sizeof(*opt), packet->data + ETHER_ADDR_LEN, 6); /* add fake source hard addr */
+
+ ns->nd_ns_hdr.icmp6_cksum = 0;
+ ns->nd_ns_hdr.icmp6_type = ND_NEIGHBOR_ADVERT;
+ ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[0] = 0x40; /* Set solicited flag */
+ ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[1] = ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[2] = ns->nd_ns_hdr.icmp6_dataun.icmp6_un_data8[3] = 0;
+ opt->nd_opt_type = ND_OPT_TARGET_LINKADDR;
+
+ /* Create pseudo header */
+
+ memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16);
+ memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16);
+ pseudo.length = htonl(sizeof(*ns) + sizeof(*opt) + 6);
+ pseudo.junk[0] = pseudo.junk[1] = pseudo.junk[2] = 0;
+ pseudo.junk[3] = IPPROTO_ICMPV6;
+
+ /* Generate checksum */
+
+ checksum = inet_checksum((unsigned short int *)&pseudo, sizeof(pseudo)/2, ~0);
+ checksum = inet_checksum((unsigned short int *)ns, sizeof(*ns)/2 + 4, checksum);
+
+ ns->nd_ns_hdr.icmp6_cksum = htons(checksum);
+
+ write_packet(packet);
+cp
+}
+
void route_arp(vpn_packet_t *packet)
{
struct ether_arp *arp;
return;
}
- /* Check if the IP address exists on the VPN */
+ /* Check if the IPv4 address exists on the VPN */
subnet = lookup_subnet_ipv4((ipv4_t *)arp->arp_tpa);
void route_outgoing(vpn_packet_t *packet)
{
unsigned short int type;
- node_t *n;
+ node_t *n = NULL;
cp
/* FIXME: multicast? */
n = route_ipv4(packet);
break;
case 0x86DD:
+ if(packet->data[20] == IPPROTO_ICMPV6 && packet->data[54] == ND_NEIGHBOR_SOLICIT)
+ {
+ route_neighborsol(packet);
+ return;
+ }
n = route_ipv6(packet);
break;
case 0x0806:
{
case RMODE_ROUTER:
{
- node_t *n;
+ node_t *n = NULL;
+ unsigned short int type;
- n = route_ipv4(packet);
+ type = ntohs(*((unsigned short*)(&packet->data[12])));
+ switch(type)
+ {
+ case 0x0800:
+ n = route_ipv4(packet);
+ break;
+ case 0x86DD:
+ n = route_ipv6(packet);
+ break;
+ default:
+ n = myself;
+ break;
+ }
if(n)
{