-1
Illegal arguments passed, fingerprints file not readable or failure in netlink communication.
Os fingerprint loader utility
nfnl_osf -f
fingerprints
[-d]
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.
-f fingerprintsRead signatures from file fingerprints.
-d
Instead of adding the signatures from fingerprints into the kernel, remove them.
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.
An up to date set of operating system signatures can be downloaded from http://www.openbsd.org/cgi-bin/cvsweb/src/etc/pf.os .
7 releases since Debian 8 (Jessie); the text changed 5 times.
-d since Debian 10 (Buster).