Support PTR records in cloaking rules?

[matoro]

Right now, according to this line, the cloaking rules ignore requests for record types other than A/AAAA: https://github.com/DNSCrypt/dnscrypt-proxy/blob/master/dnscrypt-proxy/plugin_cloak.go#L104

My network is static-IP'd, so I use cloaking rules for hardcoding names on my LAN. However, I don't have any way to add in reverse records.

Could there be a simple syntax added to the cloaking plugin to support PTR records? Thank you for all your hard work!

[jedisct1]

Maybe we don't even need a new syntax, and can synthesize PTR records for all entries that have an IP address?

The flip side is that is will double the amount of required memory, and some people have huge cloaking lists.
So, maybe we also need a switch to turn this on or off.

[matoro]

That could be tricky with multiple names that point to the same address (pick the first?)

I do also use the wildcard cloaking feature (skip those?)

[ianbashford]

@matoro
I've started to build up a PR for this feature. https://github.com/DNSCrypt/dnscrypt-proxy/pull/1958/files
If you have the ability to build this then you can test the 'work in progress' version and see if it works for you.

It should function correctly, but I do still need to build in the switch to make this optional for those with large cloaking files.

To build, simply checking out that branch, and building with something like go build -ldflags="-s -w" -v will suffice to get you a working copy to test with.

[ianbashford]

Could you give me a clue as to what the rule looks like there?

[matoro]

Does the 22 correspond to the line number? The rules look something like this:

=hostone.mydomain.com    fd02::1
=hostone.mydomain.com    192.168.2.1

=hosttwo.mydomain.com    fd02::2
=hosttwo.mydomain.com    192.168.2.2

...

*.mydomain.com    fd02::1
*.mydomain.com    192.168.2.1

=anotherhost.mydomain.com    fd03::2
=anotherhost.mydomain.com    192.168.2.1
=cloud.mydomain.com    external.cname.alias.com
=ext.mydomain.com    1.2.3.4

Then a bunch of custom tracking domain blocks in the form:

*.addomain.com    0.0.0.0

Line 22 corresponds to this line:

=anotherhost.mydomain.com    fd03::2

[ianbashford]

OK I think I've fixed it -- it works now with the entries you have given me above.
I've just pushed it and it's going through CI now...
Note that I've added the config line as well, so you'll need to add cloak_ptr = true into the main config file as well

[matoro]

It works! Thank you so much, you rock man!

[matoro]

Oh, I have got one more question - is there a way to add PTR records without a corresponding A/AAAA one? For example, as you can see I give all my devices ULA IPv6 addresses, but they also have globally addressable ones. I'd like the global addresses to reverse-resolve to the correct names, but I don't want the AAAA records for the hosts to resolve to the global addresses, as all internal communications should use the ULA ones. Is that possible?