nmap broken with resolver setting 'options inet6'.
Package: nmap
Version: 5.00-3
Severity: important
In an environment with IPv4 as well as IPv6 active, and with
/etc/resolv.conf containing the statement "options inet6",
the present Nmap is broken when it comes to resolving IPv4
host addresses.
This is a typical symptom that Nmap is coded using
gethostbyname(3)/gethostbyaddr(3), instead of
getaddrinfo(3)/getnameinfo(3). It is a well known task
to reimplement this for easier future maintenance.
The error is evident in this condensed information:
The host 'humbug' has an IPv4 address in 192.168.0.0/24
as well as an IPv6 address in 2001:470:x:x:x::/80.
$ nmap -v -PS humbug -p 80
....
Scanning 32.1.4.112 [1 port]
....
The problem is that "options inet6" will make gethostbyaddr(3)
will return a hostent list consisting of IPv6 addresses, which
Nmap is not prepared to evaluate during an IPv4 scan.
--
Mats Erik Andersson, fil. dr
2459 41E9 C420 3F6D F68B 2E88 F768 4541 F25B 5D41
Subscriber to: debian-mentors, debian-devel-games, debian-perl,
debian-ipv6, debian-qa
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