From: Guus Sliepen <guus@tinc-vpn.org>
Date: Tue, 12 Mar 2002 14:25:04 +0000 (+0000)
Subject: Put #ifdef NEIGHBORSOL around corresponding code.
X-Git-Tag: import-tinc-1.1~785^2~351
X-Git-Url: https://git.meshlink.io/?a=commitdiff_plain;h=f219f156cf13fd30369d7cd4632c406ffd6ff628;p=meshlink

Put #ifdef NEIGHBORSOL around corresponding code.
---

diff --git a/src/route.c b/src/route.c
index bd4341da..0799c48c 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 1.1.2.31 2002/03/11 13:56:00 guus Exp $
+    $Id: route.c,v 1.1.2.32 2002/03/12 14:25:04 guus Exp $
 */
 
 #include "config.h"
@@ -33,8 +33,10 @@
 #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>
@@ -57,10 +59,6 @@ int priorityinheritance = 0;
 int macexpire = 600;
 subnet_t mymac;
 
-#ifdef HAVE_FREEBSD
-#define s6_addr16 __u6_addr.__u6_addr16
-#endif
-
 void learn_mac(mac_t *address)
 {
   subnet_t *subnet;
@@ -190,14 +188,35 @@ cp
   return subnet->owner;  
 }
 
-node_t *route_neighborsol(vpn_packet_t *packet)
+#ifdef NEIGHBORSOL
+unsigned short int ipv6_cksum(short int *data, int len, unsigned short int cksum)
+{
+  while(len--)
+    {
+      cksum += ntohs(*data++);
+    }
+  return cksum;
+}
+
+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 int cksum;
+  
+  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));
 
   /* First, snatch the source address from the neighbor solicitation packet */
 
@@ -205,7 +224,8 @@ cp
 
   /* Check if this is a valid neighbor solicitation request */
   
-  if(ns->nd_ns_hdr.icmp6_type != ND_NEIGHBOR_SOLICIT)
+  if(ns->nd_ns_hdr.icmp6_type != ND_NEIGHBOR_SOLICIT ||
+     opt->nd_opt_type != ND_OPT_SOURCE_LINKADDR)
     {
       if(debug_lvl > DEBUG_TRAFFIC)
         {
@@ -215,7 +235,7 @@ cp
     }
 
   /* Check if the IPv6 address exists on the VPN */
-
+#if 0
   subnet = lookup_subnet_ipv6((ipv6_t *)&ns->nd_ns_target);
 
   if(!subnet)
@@ -227,19 +247,74 @@ cp
                  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 NULL;
+      return;
     }
 
   /* Check if it is for our own subnet */
   
   if(subnet->owner == myself)
-    return NULL;	/* silently ignore */
+    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);
 
-  /* Forward to destination */
+  cksum = ipv6_cksum((short int *)ns, sizeof(*ns)/2, cksum);
 
-  return subnet->owner;
+  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 */
+
+  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;
+  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.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);
+
+  ns->nd_ns_hdr.icmp6_cksum = htons(cksum);
+  
+  write_packet(packet);
 cp
 }
+#endif
 
 void route_arp(vpn_packet_t *packet)
 {
@@ -326,8 +401,13 @@ cp
               break;
             case 0x86DD:
               n = route_ipv6(packet);
+#ifdef NEIGHBORSOL
 	      if(!n && packet->data[0] == 0x33 && packet->data[1] == 0x33 && packet->data[2] == 0xff)
-	        n = route_neighborsol(packet);
+	        {
+	          route_neighborsol(packet);
+		  return;
+		}
+#endif
               break;
             case 0x0806:
               route_arp(packet);