freebsd-nq/sbin/fsirand/fsirand.8
Guido van Rooij 8f89943eda Add generation number randomization. Newly created filesystems wil now
automatically have random generation numbers. The kenel way of handling those
also changed. Further it is advised to run fsirand on all your nfs exported
filesystems. the code is mostly copied from OpenBSD, with the randomization
chanegd to use /dev/urandom
Reviewed by:	Garrett
Obtained from: OpenBSD
1997-03-23 20:08:22 +00:00

110 lines
3.4 KiB
Groff

.\" Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
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.\" $OpenBSD: fsirand.8,v 1.6 1997/02/23 03:58:26 millert Exp $
.\"
.Dd January 25, 1997
.Dt FSIRAND 8
.Os
.Sh NAME
.Nm fsirand
.Nd randomize inode generation numbers
.Sh SYNOPSIS
.Nm fsirand
.Op Fl b
.Op Fl f
.Op Fl p
.Ar special
.Op Ar "special ..."
.Sh DESCRIPTION
The
.Nm fsirand
command installs random generation numbers on all the inodes for
each filesystem specified on the command line by
.Ar special .
This increases the security of NFS-exported filesystems by making
it difficult to ``guess'' filehandles.
.Pp
.Em Note:
.Xr newfs 8
now does the equivalent of
.Nm
itself so it is no longer necesary to
run
.Nm
by hand on a new filesystem. It is only used to
re-randomize or report on an existing filesystem.
.Pp
.Nm Fsirand
should only be used on an unmounted filesystem that
has been checked with
.Xr fsck 8
or a filesystem that is mounted read-only.
.Nm Fsirand
may be used on the root filesystem in single-user mode
but the system should be rebooted via ``reboot -n'' afterwards.
.Sh OPTIONS
.Bl -tag -width indent
The available options are as follows:
.It Fl b
Use the default block size (usuallyt 512 bytes) instead
of the value gleaned from the disklabel.
.It Fl f
Force
.Nm
to run even if the filesystem on
.Ar special
is not marked as clean.
.It Fl p
Print the current generation numbers for all inodes instead of
generating new ones.
.Sh CAVEATS
Since
.Nm
allocates enough memory to hold all the inodes in
a given cylinder group it is may use a large amount
of memory for large disks with few cylinder groups.
.Sh SEE ALSO
.Xr fs 5 ,
.Xr fsck 8 ,
.Xr newfs 8 .
.Sh HISTORY
The
.Nm
command appeared in SunOS 3.x.
.br
This version of
.Nm
first appeared in
.Bx Open
2.1.
.Sh AUTHOR
.nf
Todd C. Miller <Todd.Miller@courtesan.com>
.fi