gopacket VS dns

I have seen pcap but not packetz, thanks. Pcap looks unfinished and packetz has not been updated in a long time, but they might be able to make a working capture program. However the popularity and features available in Go regarding packet capture makes it very hard to beat. E.g. the Google gopacket library has 5.6k stars on github and as pretty much every feature you'd want for this sort of stuff built in.

eCapture implements the feature of saving a pcapng file by eBPF TC, and supports TLS Master Secret Key capturing by eBPF Uprobe. Also, gopacket's DSB feature is supported, based on Decryption Secrets Block (DSB)

Well, there is https://github.com/google/gopacket/, you have a package that uses CGo, `pcap`, and then there is `pcapgo`, native Go implementation. Doesn't have all the features but in my case, I was able to use it and remove CGo.

I will capturing TCP packets by gopacket/pcap.

For example, gopacket uses libpcap by default for capturing the traffic. Libpcap doesn't support network namespaces and we can't ask it to listen to traffic on a different namespace. However, we can change the network namespace of the calling thread and then start libpcap to see the traffic on a different namespace.

https://pkg.go.dev/github.com/google/gopacket/routing - Linux only and not working correctly and not actively maintained

The heavylifting is done by this package: https://github.com/miekg/dns.

Apart from `dig`, clients like https://github.com/miekg/dns show the same behavior.

For the DNS i wrote a PiHole clone, which on the core it uses github.com/miekg/dns, to upstream queries and also to handle the custom entries, i've been wanting to publish that project but haven't done so cause the code is a bit messy since i did it as a PoC mostly, when comparing it to pihole it has the advantage that its really resource light mostly on the admin features, the dns resolving performs pretty much the same.

coredns uses github.com/miekg/dns under the hood

You can do the same with net.Resolver, either by just setting it's Dial function (and PreferGo=true). You can use https://pkg.go.dev/golang.org/x/net/dns/dnsmessage or https://github.com/miekg/dns to implement an in-process server, either over TCP/UDP or skipping real networking completely, just like you can do with https://golang.org/pkg/net/http/httptest

Had a similar problem a couple years ago where I needed to use alternative DNS libraries to troubleshoot issues in a company's infrastructure.

Golang's rules for what implementation to use are found here: https://golang.org/pkg/net/#hdr-Name_Resolution

A really solid alternative DNS client implementation can be found here: https://github.com/miekg/dns. Real easy to read and vet compared to a few other libraries I ran into when working on this problem.