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by ellg 243 days ago
Even the dissector stuff feels so.. broken? unmaintained? The lua api is very annoying to use and python support was removed over a decade ago. Have not used the C API so maybe thats just what most people use and its good, but for my usecase I usually just want to quickly sketch out a view for a custom protocol that I can see in the UI.

I would absolutely love for someone to write a good alternative to wireshark.
1 comments
elevation 243 days ago
As a constant Wireshark user who's personally thanked Gerald Combs for this tool, we don't need an alternative to wireshark, just some architectural refactors. Many packet dissection fields are embarrassingly parallel, but because some of them can involve previous/future packets, wireshark does all packet dissection in a single thread. So when I scoop up 10M packets it can take 20 minutes for the GUI to load them all with a single core, while 100 other cores on the same machine sit idle.

Once loaded, you have to be super careful. One update to the filter bar, like "!icmp" and you'll have to wait another 20 minutes for all the dissectors to be re-run (for some reason.)

As a previous commenter stated, if you work with Wireshark a lot, you eventually write your own tool for your performance needs. It feels magical to have a 3-page C program sitting over libpcap giving reports in miliseconds that would take wireshark minutes.

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rhynolite 243 days ago
FWIW, Wireshark 4.6.0 ships with `sharkd`, which encapsulates all the EPAN dissectors into a simple to use server that accepts JSON-RPC requests.

It is quite easy to write specialized performance tools on top of `sharkd`, and since it has the entire power of the EPAN (including statistics, charts etc.), using `sharkd` is significantly more effective than reading straight from libpcap.

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vdm 243 days ago
https://wiki.wireshark.org/Development/sharkd
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rhynolite 242 days ago
The `sharkd` has been around for quite some while, but until recently one had to build it from source. But now it is included in Wireshark DMG, so it is easier to use.
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ellg 243 days ago
You're right, and I didnt mean to sound dismissive of the great work that has been put into wireshark. I agree with you on the refactoring comment, and if that's something that can be solved in the current codebase and something I can help contribute towards with donations I would be perfectly fine with this outcome as well.

As it stands though, using the gui bits of the wireshark family of tools is just painful, and slow (as you stated)

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colechristensen 243 days ago
>It feels magical to have a 3-page C program sitting over libpcap giving reports in miliseconds that would take wireshark minutes.

Any demos available of something like this?

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elevation 242 days ago
Sadly proprietary, but the core of it was to open a file with pcap_open_offline() [0], and then calling pcap_next() from a loop and reading a few bits out of the packet buffer. With NVMe disks, the information I needed was instantaneous for a 10M packet file.

https://manpages.debian.org/stretch/libpcap0.8-dev/pcap_open...

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