.TH RTELNET 8
.SH NAME
rtelnet \- Annex reverse TELNET daemon
.\"To "rtelnet " "Annex reverse TELNET daemon"
.SH SYNOPSIS
.B rtelnet
[
.B \-bdfhmrtD
]
.I annex
.I port
.I device-name
.SH ARGUMENTS
.TP 6n
.B \-b
requests that
.I rtelnet
negotiate
.SM TELNET
binary mode
when communicating with the Annex.
This is for devices like laser printers which use binary data
that might be scrambled by
.SM TELNET's
CR/LF conventions.  (See also -t option below.)
.TP
.B \-d
turns on socket-level debugging.
.TP
.B \-f
enables the \fIconnect on the fly\fP mode.
The \fB-m\fP switch should also be used with this mode,
to ensure that
.I rtelnet
will drop the connection when the slave device is not in use.
.TP
.B \-h
tells
.I rtelnet
to send a \fBreset port\fP RPC to the Annex port when the slave pseudo device
is closed. This must be used in conjuction with the \fB-m\fP switch. This uses
the same
.SM NETADM
protocol used by \fBna\fP. This will currently only work on Annexes without
an \fBannex_password\fP parameter set.
.TP
.B \-m
tells
.I rtelnet
to momentarily drop the network connection to the
Annex port whenever the slave pseudo device is closed.
This causes the Annex to drop
.SM DTR,
which can be used to cause a dial-out modem to
hang up when a program like tip exits.
.TP
.B \-r
directs
.I rtelnet
to remove the device
.I device-name
if it already exists.  Without
.BR \-r ,
.I rtelnet
will exit with an error message if
.I device-name
already exists.
.TP
.B \-t
causes
.I rtelnet
to use a transparent TCP connection to the indicated Annex.
This will cause the connection to be made through Annex ports
in the 7000 range, rather than the 5000 range, and no
.SM TELNET
option negotiation or CR/LF mapping will be used.  Use this option
to create a fast, completely transparent data path.
.TP
.B \-D
turns on verbose debugging output.
.I Rtelnet
does not fork off a daemon in this case;
instead, it displays TELNET option negotiation
and all received data on the terminal where
.I rtelnet
was started.
.TP
.I annex
The hostname or Internet address
(in standard Internet dot separated notation)
of the Annex.
.TP
.I port
The serial port number on the Annex.
.TP
.I device-name
name of psuedo device to create (usually in the /dev directory).
.SH DESCRIPTION
.I Rtelnet
is a modified version of the 4BSD telnetd program.
Its purpose is to create a pseudo-tty device
that is connected to an Annex serial port.
This allows UNIX programs such as tip and uucp to
access serial devices attached to Annex ports.
.I Rtelnet
works like a telnet daemon program (telnetd)
except in a reverse fashion.
Instead of accepting telnet connections from other network machines,
.I rtelnet
makes telnet connections to Annex ports.
.I Rtelnet
creates a new file-like device (in /dev)
that programs can open and use like a normal tty.
.PP
Normally,
.I rtelnet
makes the connection to the Annex immediately.
This ties the Annex port to exactly one host.
This is useful for dedicated devices.
On the otherhand, this will not interact correctly with a port set to the
.B adaptive
mode, which would normally be used for a dial-in/dial-out modem.
Such a configuration should use the \fIconnect on the fly\fP option.
In that case,
.I rtelnet
will not make the connection immediately,
but will instead wait until another process opens the slave device.
When that happens,
.I rtelnet
will attempt to make the network connection.
When the connection is up, data will flow as normal.
If the connection cannot be made,
.I rtelnet
will try again using an exponential backoff.
.PP
.I Rtelnet
should run as-is on any 4BSD-based system.
To run on other systems may require some code modification.
In particular, some systems name their psuedo-terminals differently.
The source code has rudimentary support for some such systems.
.PP
Example usage:
.RS +5
A dial-out modem is attached to
port 15 of an Annex named "modem-annex".
To enable its use via \fItip\fP on a 4BSD host:
.IP 1.
Configure port 15 using \fIna\fP to:
.sp
		"control_lines: modem_control"
		"         mode: slave"
.IP 2.
Start up \fIrtelnet\fP to create the pseudo-device:
.sp
		rtelnet -rbm modem-annex 15 /dev/modem1
.sp
Normally, this would be added to the system startup file
(/etc/rc).
.IP 3.
Create new system definition in /etc/remote specifying /dev/modem1
as the device.
.sp
.SH FILES
.nf
.ta \w'/dev/pty[p-s][0-9a-f]   'u
/dev/pty[p-s][0-9a-f]	default list of master pseudo-terminals
/dev/tty[p-s][0-9a-f]	default list of slave pseudo-terminals
.fi
.SH SEE ALSO
Annex Network Administrator's Guide
.SH DIAGNOSTICS
Messages should be self-explanatory.