NFNL_OSF(8)

NAME
nfnl_osf — OS fingerprint loader utility

SYNOPSIS
nfnl_osf -f fingerprints [ -d ]

DESCRIPTION
The nfnl_osf utility allows one to load a set of operating system signatures into the kernel for later matching against using iptables' osf match.

OPTIONS

-f fingerprints
    Read signatures from file fingerprints.

-d  Instead of adding the signatures from fingerprints into the kernel, remove them.

EXIT STATUS
Exit status is 0 if command succeeded, otherwise a negative return code indicates the type of error which happened:

-1  Illegal arguments passed, fingerprints file not readable or failure in netlink communication.

-ENOENT
    Fingerprints file not specified.

-EINVAL
    Netlink handle initialization failed or fingerprints file format invalid.

FILES
An up to date set of operating system signatures can be downloaded from http://www.openbsd.org/cgi-bin/cvsweb/src/etc/pf.os .

SEE ALSO
The description of osf match in iptables-extensions(8) contains further information about the topic as well as example nfnl_osf invocations.