NFNL_OSF(8)

🌸 NFNL_OSF(8) 🌸

okay so bestie, this is the manual page for nfnl_osf, the OS fingerprint loader utility 💅✨

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✨ NAME ✨

nfnl_osf — OS fingerprint loader utility 🧚

💖 SYNOPSIS 💖

nfnl_osf -f fingerprints [ -d ]

🦋 DESCRIPTION 🦋

okay so the nfnl_osf utility lets you load a whole set of operating system signatures into the kernel 🔥 once they're in there, you can match against them later with iptables' osf match. it's giving organized, no cap 😭

🎀 OPTIONS 🎀

• -f fingerprints — read the signatures from the file fingerprints 📄
• -d — instead of adding the signatures from fingerprints into the kernel, this one removes them 🙈

💀 EXIT STATUS 💀

so the exit status is 0 if the command succeeded ✨ if it didn't, you get a negative return code telling you what kind of oopsie happened:

• -1 — illegal arguments were passed, the fingerprints file isn't readable, or the netlink communication failed 😭
• -ENOENT — the fingerprints file wasn't specified 🫠
• -EINVAL — the netlink handle couldn't be initialized, or the fingerprints file format is invalid 💅

🌈 FILES 🌈

you can grab an up to date set of operating system signatures from http://www.openbsd.org/cgi-bin/cvsweb/src/etc/pf.os 🍓 (it's a download link, not a file on your machine, so don't go hunting for it locally, periodt)

🧚 SEE ALSO 🧚

the description of the osf match in iptables-extensions(8) has more info on the whole topic, plus example nfnl_osf invocations. go check it out, it's iconic 👑

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iykyk, this page is from iptables 1.8.11 ✨ thanks for reading, bestie, you're literally the best 🫶💜