nl-pktloc-lookup(8)

✨ nl-pktloc-lookup ✨

okay bestie, welcome to the System Manager's Manual section for nl-pktloc-lookup — yes she's a section 8 girlie, system manager vibes only 💅

🌸 NAME 🌸

nl-pktloc-lookup — Lookup packet location definitions

🦋 SYNOPSIS 🦋

nl-pktloc-lookup name
nl-pktloc-lookup --list

💖 DESCRIPTION 💖

So basically nl-pktloc-lookup goes rummaging through the packet location database looking for a matching entry 🔍✨

It's the one you call when you need to resolve packet location aliases into their actual definition, which means: the alignment, the layer, the offset, and the mask. Like, the whole glow-up from cute little nickname to full spec, no cap 🫶

🎀 OPTIONS 🎀

• -h, --help — prints the help text to the console and then dips. exit, stage left 💅
• -v, --version — prints versioning info to the console and exits. cute little resume moment ✨
• -l, --list — lists all the packet location definitions. the full roster, everybody's here 👑
• --u32=VALUE — prints the packet location definition in a special format that iproute2's u32 selector parser understands. It'll output a u32 selector that compares the value you gave with the value specified by the packet location. iconic behavior fr fr 🔥

okay so listen: due to the limitation of u32, it is not possible to use packet locations based on the link layer. nl-pktloc-lookup will print an error message in that case. not a bug, just the rules bestie 😭

Example:

selector=$(nl-pktloc-lookup --u32 22 tcp.sport)
tc filter add [...] u32 match $(selector) flowid 1:2

🗂️ FILES 🗂️

• /etc/libnl/pktloc

👑 AUTHOR 👑

Thomas Graf is the original author and current maintainer of libnl and libnl tools. Many people have contributed to it since. the whole squad ate, periodt 🌈💖

k that's the whole page bestie, go forth and resolve those packet locations ✨

this was nl-pktloc-lookup, part of libnl, dated 27 October 2010 — mwah, love u, bye 🎀💜