From: Michael Orlitzky <michael@orlitzky.com>
Date: Tue, 20 Oct 2020 22:00:52 +0000 (-0400)
Subject: Warn about IP addresses in hostname fields.
X-Git-Url: http://gitweb.michael.orlitzky.com/?p=valtz.git;a=commitdiff_plain;h=2533843a92ae5a7cb04894c815b844b02ffa4242;hp=2533843a92ae5a7cb04894c815b844b02ffa4242

Warn about IP addresses in hostname fields.

A common error is to specify an IP address as the result of an MX
lookup. The RFCs (974, 1035, 2181...) state that the result should be
a "domain name," which in this context, means "host name." This commit
adds a check on "hostname" fields that rejects a dotted-quad contained
therein. In particular, it catches the aforementioned MX record error.
---