along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- $Id: route.c,v 1.1.2.30 2002/03/11 13:14:53 guus Exp $
+ $Id: route.c,v 1.1.2.34 2002/03/15 15:08:21 guus Exp $
*/
#include "config.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(struct ip6_hdr));
- opt = (struct nd_opt_hdr *)(packet->data + 14 + sizeof(struct ip6_hdr) + sizeof(struct nd_neighbor_solicit));
+ 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 */
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);
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 = checksum;
+
write_packet(packet);
cp
}
break;
case 0x86DD:
n = route_ipv6(packet);
- if(!n && packet->data[6] == 0x33 && packet->data[7] == 0x33 && packet->data[8] == 0xff)
+ if(!n && packet->data[0] == 0x33 && packet->data[1] == 0x33 && packet->data[2] == 0xff)
{
route_neighborsol(packet);
return;