rlogind(8)                          CLIX                          rlogind(8)



  NAME

    rlogind - Runs a remote login server

  SYNOPSIS

    /usr/ip32/tcpip/rlogind

  DESCRIPTION

    The rlogind command is the server for the rlogin command.  The rlogind
    server provides a remote login facility with authentication based on
    selected port numbers supplied by certain hosts.

    The rlogind command listens for service requests at the port indicated in
    the login service specification (see services(4)).  When a service request
    is received, the following protocol is initiated:

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

    2.  The server checks the client source address and requests the
        corresponding hostname (see gethostbyaddr(3) and hosts(4)).  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, the rlogind command
    allocates a pseudo terminal (see pty(7)) and manipulates the file
    descriptors so that the slave half of the pseudo terminal mimics the
    stdin, stdout, and stderr functions for the login process.  The login
    process is an instance of the login command.

    The parent of the login process manipulates the master side of the pseudo
    terminal, operating as an intermediary between the login process and the
    client instance of the rlogin command.  In normal operation, the packet
    protocol described in pty(7) is invoked to provide <Ctrl-S> and <Ctrl-Q>
    facilities, and to 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(4)).

  EXAMPLES

    The rlogind server is spawned by the inetd daemon when an rlogin
    connection is requested by the user (on the client side).

  FILES

    /etc/services      Service name database.

    /etc/reslov.conf   Domain Name System (DNS) client configuration file.
                       DNS is the preferred method for host address



  2/94 - Intergraph Corporation                                              1

  rlogind(8)                          CLIX                          rlogind(8)



                       resolution.

    /etc/hosts         Hostname database.

  NOTES

    The authentication procedure used here assumes the integrity of each
    client machine and the connecting medium.  This is not secure 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.

  DIAGNOSTICS

    All diagnostic messages are returned on the connection associated with
    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() function call by the server failed.

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

    Error messages are displayed to stderr using the perror() function.  The
    messages are prepended with rlogind:.


  EXIT VALUES

    The rlogind server exits with a value of 0 if successful.  If
    unsuccessful, it exits with a nonzero value.

  RELATED INFORMATION

    Commands:  inetd(8), login(1), rlogin(1)

    Functions:  fork(2), gethostbyaddr(3)

    Files:  services(4), hosts(4), environ(4), pty(7)












  2                                              Intergraph Corporation - 2/94