Add EDNS and DNSSEC awareness to DNS protocol plugin

[McStork]

Hello,
I would like to implement the DNS protocol missing features. I already forked and the TCP part is on its way.

[andrewkroh]

@McStork I am happy to hear TCP support is being worked. If you have any questions let us know. Also feel free to open up a pull request for your branch even in incomplete form if you would like to get some early feedback.

Regarding EDNS and DNSSEC, I was considering switching from using gopacket to miekg/dns since miekg/dns already has support for these. However I haven't looked to see how easy or difficult it would be to switch.

[andrewkroh]

I am updating the title to reflect the fact that support for monitoring DNS traffic over TCP has been added.

[andrewkroh]

So that status here is that Packetbeat now uses miekg/dns for parsing. The work remaining is to update Packetbeat to use the library to get the data from the EDNS and DNSSEC records. @McStork Is that correct? Thanks

[McStork]

@andrewkroh Correct. FYI my schedule requires it to be implemented in two months at the latest. But I might work on it sooner than that.

[McStork]

#1292 closes this.
The DNS protocol in Packetbeat could still use some work (grep TODO in dns package), but as far as TCP, EDNS and DNSSEC are concerned, it's done with.