xref: /freebsd/libexec/ftpd/ftpchroot.5 (revision fa9896e082a1046ff4fbc75fcba4d18d1f2efc19)

.\" Copyright (c) 2003 FreeBSD Project
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.Dd January 26, 2003
.Dt FTPCHROOT 5
.Os
.Sh NAME
.Nm ftpchroot
.Nd "list users and groups subject to FTP access restrictions"
.Sh DESCRIPTION
The file
.Nm
is read by
.Xr ftpd 8
at the beginning of an FTP session, after having authenticated the user.
Each line in
.Nm
corresponds to a user or group.
If a line in
.Nm
matches the current user or a group he is a member of,
access restrictions will be applied to this
session by changing its root directory with
.Xr chroot 2
to that specified on the line or to the user's login directory.
.Pp
The order of records in
.Nm
is important because the first match will be used.
Fields on each line are separated by tabs or spaces.
.Pp
The first field specifies a user or group name.
If it is prefixed by an
.Dq at
sign,
.Ql @ ,
it specifies a group name;
the line will match each user who is a member of this group.
As a special case, a single
.Ql @
in this field will match any user.
A username is specified otherwise.
.Pp
The optional second field describes the directory for the user
or each member of the group to be locked up in using
.Xr chroot 2 .
Be it omitted, the user's login directory will be used.
If it is not an absolute pathname, then it will be relative
to the user's login directory.
If it contains the
.Pa /./
separator,
.Xr ftpd 8
will treat its left-hand side as the name of the directory to do
.Xr chroot 2
to, and its right-hand side to change the current directory to afterwards.
.Sh FILES
.Bl -tag -width ".Pa /etc/ftpchroot" -compact
.It Pa /etc/ftpchroot
.El
.Sh EXAMPLES
These lines in
.Nm
will lock up the user
.Dq Li webuser
and each member of the group
.Dq Li hostee
in their respective login directories:
.Bd -literal -offset indent
webuser
@hostee
.Ed
.Pp
And this line will tell
.Xr ftpd 8
to lock up the user
.Dq Li joe
in
.Pa /var/spool/ftp
and then to change the current directory to
.Pa /joe ,
which is relative to the session's new root:
.Pp
.Dl "joe	/var/spool/ftp/./joe"
.Pp
And finally the following line will lock up every user connecting
through FTP in his respective
.Pa ~/public_html ,
thus lowering possible impact on the system
from intrinsic insecurity of FTP:
.Pp
.Dl "@	public_html"
.Sh SEE ALSO
.Xr chroot 2 ,
.Xr group 5 ,
.Xr passwd 5 ,
.Xr ftpd 8