Issue 28431: socket gethostbyaddr returns IPv6 names for 127.0.0.1 (original) (raw)

socket.gethostbyaddr seems to be equating loopback addresses regardless of IP protocol version.

In both versions tested (2.7.5 and 3.4.3) the ordering of the entries in my /etc/hosts file determines the result I get, rather than what address I'm querying for.

For example:

/etc/hosts:

::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4

result:

import socket socket.gethostbyaddr("127.0.0.1") ('localhost', ['localhost.localdomain', 'localhost6', 'localhost6.localdomain6'], ['127.0.0.1'])

Then if I change the ordering of the entries in /etc/hosts as follows:

127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6

result:

import socket socket.gethostbyaddr("127.0.0.1") ('localhost', ['localhost.localdomain', 'localhost4', 'localhost4.localdomain4'], ['127.0.0.1'])

I would expect gethostbyaddr to return only the hostnames associated with the given address regardless of the ordering of the entries in /etc/hosts.