ftpchroot.5

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.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