aund.8

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.Dd December 07, 2010
.Dt AUND 8
.Os
.Sh NAME
.Nm aund
.Nd Acorn-compatible
.No Econet/ Ns Tn AUN
fileserver
.Sh SYNOPSIS
.Nm Op Fl dDfsS
.Op Fl c Ar config
.Op Fl p Ar pidfile
.Sh DESCRIPTION
.Nm
is a fileserver for Acorn clients, either real ones over
.Tn AUN
or emulated ones over BeebEm's virtual Econet.
.Nm
runs as a single process under a single user-ID, even when presenting
multiple user accounts to clients.
.Pp
The following options can be used:
.Bl -tag -width Fl
.It Fl c Ar config
Use
.Ar config
as a configuration file instead of
.Pa /etc/aund.conf .
.It Fl d
Run in debugging mode, with debugging messages going to standard output.
Implies
.Fl f .
.It Fl D
Disable debugging mode, even if it's specified in the configuration file.
.It Fl f
Run in the foreground rather than becoming a daemon.
.It Fl p Ar pidfile
Set the file in which
.Nm
should write its process-ID at startup.  Defaults to
.Pa /var/run/aund.pid .
.It Fl s
Use
.Xr syslog 3
for logging even if it's disabled in the configuration file.
.It Fl S
Do not log using
.Xr syslog 3 .
.El
.Ss Metadata
By default,
.Nm
stores the Acorn load and execute addresses for each file in a sub-directory
called
.Pa .Acorn
of the file's parent directory, in a symbolic link with the same name as
the file.
.Nm
can also generate
.Tn RISC OS
file types for files based on rules in
.Xr aund.conf 5 .
Files can also be named with the
.Tn RISC OS
type in hexadecimal at the end of their names, separated by a comma.
The file type will be removed when the file is seen from
.Tn RISC OS ,
so
.Pa TextFile,fff
appears as a text (type 0xfff) file called
.Pa TextFile .
.Ss "*\ Commands"
.Nm
implements a selection of operating system commands (known as
.Qq *\ Commands )
that can be used by clients.
Many of these are shadowed by built-in commands on newer clients.
Only the versions implemented by
.Nm
are documented here.
.Bl -tag -width Ic
.It Ic *BYE
Logs off the file server, closing all open files.
.It Ic *CAT Op Ar directory
Displays a catalogue listing of the specified
.Ar directory ,
or of the current directory if none is specified.
.It Ic *CDIR Ar name
Creates a directory called
.Ar name .
.It Ic *DELETE Ar name
Deletes the file or directory called
.Ar name .
.It Ic *DIR Op Ar dir
Sets the current directory to the specified
.Ar directory
or to the user root directory if none is specified.
.It Ic *FSOPT Li INFOFMT RISCOS | SJ
Sets the format of responses to
.Ql *INFO .
.Ql RISCOS
chooses the format specified by the
.Tn RISC OS
Programmer's Reference Manual, similar to that produced by Acorn fileservers.
.Ql SJ
chooses a format more akin to that produced by SJ Research fileservers.
This setting persists for the current session.
.It Ic *FSOPT Li SAFEHANDLES ON | OFF
Controls whether
.Nm
restricts the file handles it issues for compatibility with older 8-bit
clients.
Client systems up to at least NFS 3.60 require that the file server only
issue file handles that are powers of two.  This restricts such clients
to at most eight open files.  Later clients support more open files, but
have no way to indicate this to the file server.  If this option is set
to
.Ql ON ,
.Nm
will issue only handles compatible with older systems, while
.Ql OFF
will allow it to issue all possible handles.
The default setting is specified in
.Xr aund.conf 5
.It Ic *INFO Op Ar name
Displays detailed information about the object called
.Ar name
or the current directory if none is specified.
.It Ic "*I AM" Oo Ar station Oc Ar user Op Ar password
Log onto the file server as
.Ar user
whose password is
.Ar password .
If
.Ar password
is not specified it is treated as empty.
If
.Ar station
is specified and starts with a digit, it is ignored.
.It Ic *LIB Op Ar library
Sets the current library to
.Ar library
or to the default library if none is specified.
.It Ic *LOAD Ar file Op Ar addr
Load the specified
.Ar file
into the client's memory at
.Ar addr .
If
.Ar addr
is not specified, the load address of the file is used.
.It Ic *ACCESS Ar file Ar permission
Change the 
.Ar permission
of a
.Ar file .
Current permissions
accepted are LWR/WR, with owner permission to the left
of the slash. You must own the directory to change the
.Ar permission 
on a file.
.It Ic *LOGOFF
A synonym for
.Ic *BYE .
.It Ic *PASS Ar oldpw newpw
Change the password of the logged-on user from
.Ar oldpw
to
.Ar newpw .
.It Ic *RENAME Ar old new
Change the name of the object currently called
.Ar old
to
.Ar new .
.It Ic *SAVE Ar file start end Op Ar exec
Save a section of client memory to
.Ar file .
The memory runs from
.Ar start
(inclusive) to
.Ar end
(exclusive).
If
.Ar exec
is specified, the file's execution address is set to that.
Otherwise it is set to
.Ar start .
.It Ic *SDISC Ar disc
Reset the user environment (current directory and current library) as
though the user had logged in again.
The argument
.Ar disc
is ignored.
.It Ic *NEWUSER Op Ar Group.User Ar User
Creates a new user in the password file, and creates the home directory.
The argument
.Ar User
is used for the username, and to create the users home directory relative
to the filestore root directory,
.Ar Group.User
is allowed.
.It Ic *REMUSER Ar User
Removes an existing user from the password file, preventing the user from
logging into the file server.
The 
.Ar User
directory and files will not be removed by this command.
.El
.Ss Security Considerations
The Acorn fileserver protocol is inherently insecure.  It passes both 
login and file data over the network unencrypted, so it is trivial
for an attacker with access to the network to intercept them.
The protocol also has no authentication of individual requests other
than by source address, so it is trivial for an attacker to inject
requests that appear to be from a logged-in client.
.Sh FILES
.Bl -tag -width Pa
.It Pa /etc/aund.conf
Default configuration file location.
.It Pa /var/run/aund.pid
Default process-ID file.
.El
.Sh SEE ALSO
.Xr beebem 1 ,
.Xr aund.conf 5 ,
.Xr aund.passwd 5
.Sh BUGS
.Nm
is full of them.  Beware, and send patches to
.Aq bjh21@bjh21.me.uk .
.Sh AUTHORS
.Nm
was written by Ben Harris and Simon Tatham.