Reverse DNS records are broken

[siberian1967]

Reverse delegated zone example: 171.110.38.in-addr.arpa.

Records are PTR like this:

2.171.110.38.in-addr.arpa
and
2.171.110.38.in-addr.arpa.

When you 'Commit' changes dns.inc.php munges them

    if (!(preg_match("/$zone$/i", $name))) {
        if (isset($name) && $name != "") {
            $name = $name . "." . $zone;
        } else {
            $name = $zone;
        }
    }

What this does is change the above examples to:

2.171.110.38.in-addr.arpa.171.110.38.in-addr.arpa (it added the name)
and
2.171.110.38.in-addr.arpa (It stripped the period)

Change nothing and hit commit again and they become
2.171.110.38.in-addr.arpa.171.110.38.in-addr.arpa.171.110.38.in-addr.arpa (it added the name again)
and
2.171.110.38.in-addr.arpa.171.110.38.in-addr.arpa (It added the name)

And so on and so forth forever.

A quick fix for this is to change the above codeblock to ignore this munging if its an in-addr.arpa record.

Before I submitted a PR for this I wanted to me sure this was not intentional and that I was not missing a bigger picture.

Tx (this broke our network something fierce today, 2000 upset customers. sigh.).

[siberian1967]

Oh sorry, my change would look like this

if (!(preg_match("/in-addr.arpa/i", $zone)) && !(preg_match("/$zone$/i", $name))) {

in dns.inc.php: validate_input

Tested and it works as expected but I want to make sure its desirable.

[ghost]

I have seen this issue before, but can't reproduce it with the latest code. Also it's not clear how you was able to add 2.171.110.38.in-addr.arpa and 2.171.110.38.in-addr.arpa. records to 171.110.38.in-addr.arpa zone. Maybe you can provide detailed steps?

[KTamas]

I ran into this recently, really nasty when you run a production system with poweradmin...

We have partial rdns zones, and the / in them messes with the preg_match

like

$zone = "224/27.194.28.217.in-addr.arpa";
$name = "176.224/27.194.28.217.in-addr.arpa";
echo preg_match("/$zone$/i", $name);

preg_match will fail.

The fix above works.

[ghost]

@siberian1967: how you was able to add reverse zone with dot at the end from Poweradmin?

[whysyn]

I ran into this same problem, still happens even in a fresh clone from git. Above suggested solution seems to completely stop it from appending the domain name when adding or updating a record in a sub-delegated reverse zone.

The regex delimiter just needs to be changed to something other than "/" so it doesn't conflict with any "/"s in the strings.

This did the trick for me and passed internal QA:

--- dns.inc.php.orig    2014-08-18 15:22:16.492241681 -0400
+++ dns.inc.php 2014-08-18 15:21:22.716239636 -0400
@@ -46,7 +46,7 @@

     $zone = get_zone_name_from_id($zid);    // TODO check for return

-    if (!(preg_match("/$zone$/i", $name))) {
+    if (!(preg_match("!$zone$!i", $name))) {
         if (isset($name) && $name != "") {
             $name = $name . "." . $zone;
         } else {

[stbuehler]

just don't do suffix string checks (i guess that is what is supposed to do, right?) with preg hacks; see http://stackoverflow.com/questions/834303/startswith-and-endswith-functions-in-php for some "real" solutions.

[SebTM]

Merged #247 so can be closed