[Dnsmasq-discuss] Reverse IPv6 domain issue

Paul Maddock Paul at whitefall.co.uk
Sat Jun 9 00:47:59 BST 2018


Hi,

I think I've come across a bug with how the domain is determined for reverse 
lookups for IPv6 addresses. Having set a domain config with my domain name and 
IPv6 prefix I was correctly seeing the domain passed to the clients via DHCPv6, 
but DNS lookups on the IPv6 returned my fallback domain.

Having checked the source code I think the problem is in the read_leases 
function. For IPv6 is appears to be trying to find the domain based on the 
hwaddr instead of the IPv6 address. I've recompiled with the below patch and 
I'm now getting the expected domain.

Please review and apply the fix as necessary.


--- dnsmasq/src/lease.c 2018-06-08 22:32:29.486011028 +0000
+++ dnsmasq/src/lease.c 2018-06-08 22:33:31.118012520 +0000
@@ -87,7 +87,7 @@
            if ((lease = lease6_allocate(&addr.addr.addr6, lease_type)))
              {
                lease_set_iaid(lease, strtoul(s, NULL, 10));
-               domain = get_domain6((struct in6_addr *)lease->hwaddr);
+               domain = get_domain6(&lease->addr6);
              }
          }
 #endif


Regards,

Paul




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