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Neighbor solicitation requests now work (I think).

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This commit is contained in:
Guus Sliepen 2002-03-15 14:41:57 +00:00
parent 4b3aef9e69
commit e1de9ca990
1 changed files with 40 additions and 49 deletions
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89
src/route.c
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@ -17,7 +17,7 @@
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
$Id: route.c,v 1.1.2.32 2002/03/12 14:25:04 guus Exp $
$Id: route.c,v 1.1.2.33 2002/03/15 14:41:57 guus Exp $
*/
#include "config.h"
@ -33,10 +33,8 @@
#else
#include <net/ethernet.h>
#endif
#ifdef NEIGHBORSOL
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#endif
#include <netinet/if_ether.h>
#include <utils.h>
#include <xalloc.h>
@ -188,14 +186,17 @@ cp
return subnet->owner;
}
#ifdef NEIGHBORSOL
unsigned short int ipv6_cksum(short int *data, int len, unsigned short int cksum)
unsigned short int inet_checksum(unsigned short int *data, int len, unsigned short int prevsum)
{
unsigned long int checksum = prevsum ^ 0xFFFF;
while(len--)
{
cksum += ntohs(*data++);
}
return cksum;
checksum += ntohs(*data++);
while(checksum >> 16)
checksum = (checksum & 0xFFFF) + (checksum >> 16);
return checksum ^ 0xFFFF;
}
void route_neighborsol(vpn_packet_t *packet)
@ -204,7 +205,7 @@ void route_neighborsol(vpn_packet_t *packet)
struct nd_neighbor_solicit *ns;
struct nd_opt_hdr *opt;
subnet_t *subnet;
short int cksum;
short unsigned int checksum;
struct {
struct in6_addr ip6_src; /* source address */
@ -215,8 +216,8 @@ void route_neighborsol(vpn_packet_t *packet)
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 */
@ -234,8 +235,28 @@ cp
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 */
#if 0
subnet = lookup_subnet_ipv6((ipv6_t *)&ns->nd_ns_target);
if(!subnet)
@ -254,35 +275,8 @@ cp
if(subnet->owner == myself)
return; /* silently ignore */
#endif
syslog(LOG_DEBUG, "Neighbor solicitation request with checksum %hx", ntohs(ns->nd_ns_hdr.icmp6_cksum));
/* Create pseudo header */
memcpy(&pseudo.ip6_src, &hdr->ip6_src, 16);
memcpy(&pseudo.ip6_dst, &hdr->ip6_dst, 16);
pseudo.length = htonl(sizeof(*ns));
pseudo.junk[0] = pseudo.junk[1] = pseudo.junk[2] = 0;
pseudo.junk[3] = IPPROTO_ICMPV6;
/* Generate checksum */
ns->nd_ns_hdr.icmp6_cksum = 0;
cksum = ipv6_cksum((short int *)&pseudo, sizeof(pseudo)/2, 0);
syslog(LOG_DEBUG, "Our checksum %hx", cksum);
cksum = ipv6_cksum((short int *)ns, sizeof(*ns)/2, cksum);
syslog(LOG_DEBUG, "Our checksum %hx", cksum);
cksum = ipv6_cksum((short int *)opt, sizeof(*opt)/2, cksum);
syslog(LOG_DEBUG, "Our checksum %hx", cksum);
/* Create neighbor advertation reply */
/* 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 */
@ -294,27 +288,26 @@ cp
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(struct icmp6_hdr));
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 */
cksum = ipv6_cksum((short int *)&pseudo, sizeof(pseudo)/2, 0);
cksum = ipv6_cksum((short int *)ns, sizeof(*ns)/2, cksum);
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(cksum);
write_packet(packet);
cp
}
#endif
void route_arp(vpn_packet_t *packet)
{
@ -401,13 +394,11 @@ cp
break;
case 0x86DD:
n = route_ipv6(packet);
#ifdef NEIGHBORSOL
if(!n && packet->data[0] == 0x33 && packet->data[1] == 0x33 && packet->data[2] == 0xff)
{
route_neighborsol(packet);
return;
}
#endif
break;
case 0x0806:
route_arp(packet);