rlogind(1M)                      (TCP/IP)                       rlogind(1M)


   NAME
         rlogind - remote login server

   SYNOPSIS
         in.rlogind host.port

   DESCRIPTION
         rlogind is the server for the rlogin(1) program.  The server provides
         a remote login facility with authentication based on privileged port
         numbers.

         rlogind is invoked by inetd(1M) when a remote login connection is
         established, and executes the following protocol:

         1)    The server checks the client's source port.  If the port is not
               in the range 0-1023, the server aborts the connection.  The
               client's address and port number are passed as arguments to
               rlogind by inetd in the form host.port with host in hexadecimal
               and port in decimal.

         2)    The server checks the client's source address.  If an entry for
               the client exists is both /etc/hosts and /etc/hosts.equiv, a
               user logging in from the client is not prompted for a password.
               If the address is associated with a host for which no
               corresponding entry exists in /etc/hosts, the user is prompted
               for a password, regardless of whether or not an entry for the
               client is present in /etc/hosts.equiv [see hosts(4) and
               hosts.equiv(4)].

         Once the source port and address have been checked, rlogind allocates
         a pseudo-terminal 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(1M), 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
         pseudo-terminal, operating as an intermediary between the login
         process and the client instance of the rlogin program.  In normal
         operation, a packet protocol is invoked to provide Ctrl-S / Ctrl-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(4).

   SEE ALSO
         inetd(1M), hosts(4), hosts.equiv(4).




   8/91                                                                 Page 1

   rlogind(1M)                      (TCP/IP)                       rlogind(1M)


   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.

         Hostname for your address unknown.
               No entry in the host name database existed for the client's
               machine.

         Try again.
               A fork by the server failed.

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

   NOTES
         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.































   Page 2                                                                 8/91