gopacket VS libpcap

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

As long as your custom service used the rpcap protocol I'd expect it to be possible. You may find this GitHub page informative, since it includes some rpcap source code and one of the main Wireshark developers appears to be a contributor there.

mitmproxy can be used to find the HTTP request with the needed data in addition browser dev tools. At some point, I'll explore tcpdump and wireshark to reverse engineer websites for web scraping and share the learnings with you.

(Of course, this consideration should be appropriately downweighted by YAGNI, as threading memory management through prototype or internal utility code can by itself easily force it into very non-prototype amounts of effort.)

[1] https://github.com/the-tcpdump-group/libpcap/blob/2180b6e56a...

I am working with libpcap, a library that parses packets captured from tcpdump, which I have cIncluded from Zig.

Nmap and Wireshark, tcpdump tools can be used to scan networks and packets.

Also definitely start looking at tcpdump and wireshark. These are invaluable tools for the non-network engineer that is perhaps a sysadmin or analyst to use for network troubleshooting.

For future reference, libpcap is a library that Wireshark and many other network analysis tools use to record network traffic. It has its own file format that it can use to save the recorded network traffic to disk.

A lot is covered here and here, sar might be useful, getfacl and tcpdump and probably hundred more tools I am not even aware of. The easiest to learn those is to have a problem and identify and solve it with those tools, but to do that you need to know roughly what those tools can do.

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.