From 46fa10cec7b6bf26773f5e86e7b8118d9075e807 Mon Sep 17 00:00:00 2001 From: Guus Sliepen Date: Mon, 11 Mar 2002 13:14:53 +0000 Subject: [PATCH] Try to reply to neighbor solicitation requests. --- src/route.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 74 insertions(+), 2 deletions(-) diff --git a/src/route.c b/src/route.c index f42b6a55..fc02c67f 100644 --- a/src/route.c +++ b/src/route.c @@ -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 1.1.2.29 2002/03/10 14:04:48 guus Exp $ + $Id: route.c,v 1.1.2.30 2002/03/11 13:14:53 guus Exp $ */ #include "config.h" @@ -33,6 +33,8 @@ #else #include #endif +#include +#include #include #include #include @@ -184,6 +186,71 @@ cp return subnet->owner; } +void route_neighborsol(vpn_packet_t *packet) +{ + struct ip6_hdr *hdr; + struct nd_neighbor_solicit *ns; + struct nd_opt_hdr *opt; + subnet_t *subnet; +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)); + + /* 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; + } + + /* 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(ns->nd_ns_target.s6_addr16[0]), ntohs(ns->nd_ns_target.s6_addr16[1]), ntohs(ns->nd_ns_target.s6_addr16[2]), ntohs(ns->nd_ns_target.s6_addr16[3]), + ntohs(ns->nd_ns_target.s6_addr16[4]), ntohs(ns->nd_ns_target.s6_addr16[5]), ntohs(ns->nd_ns_target.s6_addr16[6]), ntohs(ns->nd_ns_target.s6_addr16[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_type = ND_NEIGHBOR_ADVERT; + opt->nd_opt_type = ND_OPT_TARGET_LINKADDR; + + write_packet(packet); +cp +} + void route_arp(vpn_packet_t *packet) { struct ether_arp *arp; @@ -216,7 +283,7 @@ cp 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); @@ -269,6 +336,11 @@ cp break; case 0x86DD: n = route_ipv6(packet); + if(!n && packet->data[6] == 0x33 && packet->data[7] == 0x33 && packet->data[8] == 0xff) + { + route_neighborsol(packet); + return; + } break; case 0x0806: route_arp(packet); -- 2.20.1