RLOGIND(8)						      System Manager's Manual							RLOGIND(8)

NAME

       rlogind, in.rld - remote login server

SYNOPSIS

       login stream tcp nowait root /usr/sbin/in.rld in.rld
       tcpd login /usr/sbin/in.rld

DESCRIPTION

       Rlogind	is the server for the rlogin(1) program.  The server provides a remote login facility with authentication based on privileged port
       numbers from trusted hosts.

       Rlogind listens for service requests at the port indicated in the ``login'' service specification; see services(5).  When a service request
       is received the following protocol is initiated:

       1)     The server checks the client's source port.  If the port is not in the range 0-1023, the server aborts the connection.

       2)     The  server  checks  the	client's  source  address  and	requests  the  corresponding host name (see gethostbyaddr(3), hosts(5) and
	      named(8)).  If the hostname cannot be determined, the dot-notation representation of the host address is used.

       Once the source port and address have been checked, rlogind allocates a pseudo terminal (see tty(4)), and manipulates file  descriptors	so
       that  the  slave half of the pseudo terminal becomes the stdin , stdout , and stderr for a login process.  The login process is an instance
       of the login(1) program, invoked with the -r option.  The login process then proceeds with  the	authentication	process  as  described	in
       rshd(8), but if automatic authentication fails, it reprompts the user to login as one finds on a standard terminal line.

       The  parent of the login process manipulates the master side of the pseduo terminal, operating as an intermediary between the login process
       and the client instance of the rlogin program.  In normal operation, the packet protocol described in tty(4) is invoked	to  provide  ^S/^Q
       type  facilities  and propagate interrupt signals to the remote programs.  The login process propagates the client terminal's baud rate and
       terminal type, as found in the environment variable, ``TERM''; see environ(7).  The screen or window size of the terminal is requested from
       the client, and window size changes from the client are propagated to the pseudo terminal.

SEE ALSO

       rlogin(1).

DIAGNOSTICS

       All  diagnostic	messages  are  returned  on the connection associated with the stderr, after which any network connections are closed.	An
       error is indicated by a leading byte with a value of 1.

       ``Try again.''
       A fork by the server failed.

       ``/bin/sh: ...''
       The user's login shell could not be started.

BUGS

       The authentication procedure used here assumes the integrity of each client machine and the connecting medium.  This is	insecure,  but	is
       useful in an ``open'' environment.

       A facility to allow all data exchanges to be encrypted should be present.

       A more extensible protocol should be used.

4.2 Berkeley Distribution					   May 24, 1986 							RLOGIND(8)