X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Froute.c;h=dcf43e41e712c5a845a3f6727fda456ca0ec60d9;hp=fc02c67fbca30be25fdf766ba9b4fffb22f6be44;hb=5c2d74de86d1acb3774a20357ad815d000f8a7f6;hpb=46fa10cec7b6bf26773f5e86e7b8118d9075e807

diff --git a/src/route.c b/src/route.c
index fc02c67f..dcf43e41 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 1.1.2.30 2002/03/11 13:14:53 guus Exp $
+    $Id: route.c,v 1.1.2.37 2002/03/19 00:08:23 guus Exp $
 */
 
 #include "config.h"
@@ -186,16 +186,38 @@ cp
   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 */
 
@@ -213,6 +235,26 @@ 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 */
 
   subnet = lookup_subnet_ipv6((ipv6_t *)&ns->nd_ns_target);
@@ -222,8 +264,8 @@ cp
       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]));
+                 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;
@@ -244,9 +286,27 @@ cp
 
   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
 }
@@ -335,12 +395,12 @@ cp
               n = route_ipv4(packet);
               break;
             case 0x86DD:
-              n = route_ipv6(packet);
-	      if(!n && packet->data[6] == 0x33 && packet->data[7] == 0x33 && packet->data[8] == 0xff)
+              if(packet->data[20] == IPPROTO_ICMPV6 && packet->data[54] == ND_NEIGHBOR_SOLICIT)
 	        {
 	          route_neighborsol(packet);
 		  return;
 		}
+              n = route_ipv6(packet);
               break;
             case 0x0806:
               route_arp(packet);