nfnl_osf — OS fingerprint loader utility

       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.

       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 .

       nfnl_osf — OS fingerprint loader utility

-ffingerprints
              Read signatures from file fingerprints.

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

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

iptables 1.8.11                                                                                      NFNL_OSF(8)

nfnl_osf-ffingerprints [ -d ]