bin/42196: Parser for "/etc/resolv.conf" in "mdnsd" considered harmful

[tron%zhadum.org.uk@localhost]

>Number:         42196
>Category:       bin
>Synopsis:       Parser for "/etc/resolv.conf" in "mdnsd" considered harmful
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    bin-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Oct 18 12:20:00 +0000 2009
>Originator:     tron%zhadum.org.uk@localhost
>Release:        NetBSD 5.99.20
>Organization:
Matthias Scheler                                  http://zhadum.org.uk/
>Environment:
System: NetBSD lyssa.zhadum.org.uk 5.99.20 NetBSD 5.99.20 (LYSSA) #0: Fri Oct 
16 09:54:46 BST 2009 tron%lyssa.zhadum.org.uk@localhost:/src/sys/compile/LYSSA 
i386
Architecture: i386
Machine: i386
>Description:
"mdnsd" uses a home grown parser ("mDNSPosix.c", function "ParseDNSServers")
to parse "/etc/resolv.conf". This parser only understands "nameserver"
lines with IPv4 addresses in them. The DNS resolve in NetBSD's "libc"
however supports IPv6 addresses as well which makes this an viable
configuration option.

>How-To-Repeat:
Configure only IPv6 nameservers in "/etc/resolv.conf".

>Fix:
None provided but it is eventually not very difficult.
From "mDNSPosix.c":

            mDNSAddr DNSAddr;
            DNSAddr.type = mDNSAddrType_IPv4;
            DNSAddr.ip.v4.NotAnInteger = ina.s_addr;
            mDNS_AddDNSServer(m, NULL, mDNSInterface_Any, &DNSAddr, 
UnicastDNSPort);

It might be enough to call mDNS_AddDNSServer() with an IPv6 record
to fix this problem.