


      RRRRLLLLOOOOGGGGIIIINNNNDDDD((((1111))))                  ((((bbbbssssdddd 4444....2222))))                  RRRRLLLLOOOOGGGGIIIINNNNDDDD((((1111))))



      NNNNAAAAMMMMEEEE
           rlogind - remote login server

      SSSSYYYYNNNNTTTTAAAAXXXX
           ////eeeettttcccc////rrrrllllooooggggiiiinnnndddd [ ----dddd ]

      DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
           _R_l_o_g_i_n_d is the server for the _r_l_o_g_i_n(1) program.  The server
           provides a remote login facility with authentication based
           on privileged port numbers.

           _R_l_o_g_i_n_d listens for service requests at the port indicated
           in the ``login'' service specification; see _s_e_r_v_i_c_e_s(4).
           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.  If the
                address is associated with a host for which no
                corresponding entry exists in the host name data base
                (see _h_o_s_t_s(4)), the server aborts the connection.

           Once the source port and address have been checked, _r_l_o_g_i_n_d
           allocates a pseudo terminal (see _p_t_y(7)), and manipulates
           file descriptors so that the slave half of the pseudo
           terminal becomes the ssssttttddddiiiinnnn, ssssttttddddoooouuuutttt, and ssssttttddddeeeerrrrrrrr for a login
           process.  The login process is an instance of the _l_o_g_i_n(1)
           program, invoked with the ----RRRR option.  The login process then
           proceeds with the authentication process as described in
           _r_s_h_d(1), 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 _r_l_o_g_i_n
           program.  In normal operation, the packet protocol described
           in _p_t_y(4) is invoked to provide ^S/^Q type facilities and
           propagate interrupt signals to the remote programs.

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

           ````````HHHHoooossssttttnnnnaaaammmmeeee ffffoooorrrr yyyyoooouuuurrrr aaaaddddddddrrrreeeessssssss uuuunnnnkkkknnnnoooowwwwnnnn....''''''''
           No entry in the host name database existed for the client's
           machine.




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      RRRRLLLLOOOOGGGGIIIINNNNDDDD((((1111))))                  ((((bbbbssssdddd 4444....2222))))                  RRRRLLLLOOOOGGGGIIIINNNNDDDD((((1111))))



           ````````TTTTrrrryyyy aaaaggggaaaaiiiinnnn....''''''''
           A _f_o_r_k by the server failed.

           ````````////bbbbiiiinnnn////sssshhhh:::: ............''''''''
           The user's login shell could not be started.

      BBBBUUUUGGGGSSSS
           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.










































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