4.3BSD-Reno/share/man/cat8/sliplogin.0

SLIPLOGIN(8)		      1990		     SLIPLOGIN(8)



NNAAMMEE
     sliplogin - attach a serial line network interface

SSYYNNOOPPSSIISS
     sslliippllooggiinn [ _l_o_g_i_n_n_a_m_e ]

DDEESSCCRRIIPPTTIIOONN
     sslliippllooggiinn is used to turn the terminal line on standard
     input into a Serial Line IP (SLIP) link to a remote host.
     To do this, the program searches the file //eettcc//sslliipp..hhoossttss
     for an entry matching _l_o_g_i_n_n_a_m_e (which defaults to the
     current login name if omitted).  If a matching entry is
     found, the line is configured appropriately for slip (8-bit
     transparent i/o) and converted to SLIP line discipline.
     Then a shell script is invoked to initialize the slip inter-
     face with the appropriate local and remote IP address, net-
     mask, etc.

     The usual initialization script is //eettcc//sslliipp..llooggiinn but, if
     particular hosts need special initialization, the file
     //eettcc//sslliipp..llooggiinn.._l_o_g_i_n_n_a_m_e will be executed instead if it
     exists.  The script is invoked with the parameters

     _s_l_i_p_u_n_i_t
	  The unit number of the slip interface assigned to this
	  line.  E.g., 00 for ssll00.

     _s_p_e_e_d
	  The speed of the line.

     _a_r_g_s The arguments from the //eettcc//sslliipp..hhoossttss entry, in order
	  starting with _l_o_g_i_n_n_a_m_e.

     Only the super-user may attach a network interface.  The
     interface is automatically detached when the other end hangs
     up or the sslliippllooggiinn process dies.	If the kernel slip module
     has been configured for it, all routes through that inter-
     face will also disappear at the same time.  If there is
     other processing a site would like done on hangup, the file
     //eettcc//sslliipp..llooggoouutt or //eettcc//sslliipp..llooggoouutt.._l_o_g_i_n_n_a_m_e is executed
     if it exists.  It is given the same arguments as the login
     script.

     FFoorrmmaatt ooff //eettcc//sslliipp..hhoossttss
     Comments (lines starting with a `#') and blank lines are
     ignored.  Other lines must start with a _l_o_g_i_n_n_a_m_e but the
     remaining arguments can be whatever is appropriate for the
     sslliipp..llooggiinn file that will be executed for that name.  Argu-
     ments are separated by white space and follow normal sshh(1)
     quoting conventions (however, _l_o_g_i_n_n_a_m_e cannot be quoted).
     Usually, lines have the form
	  _l_o_g_i_n_n_a_m_e _l_o_c_a_l-_a_d_d_r_e_s_s _r_e_m_o_t_e-_a_d_d_r_e_s_s _n_e_t_m_a_s_k _o_p_t-_a_r_g_s



Printed 7/27/90               July				1






SLIPLOGIN(8)		      1990		     SLIPLOGIN(8)



     where _l_o_c_a_l-_a_d_d_r_e_s_s and _r_e_m_o_t_e-_a_d_d_r_e_s_s are the IP host names
     or addresses of the local and remote ends of the slip line
     and _n_e_t_m_a_s_k is the appropriate IP netmask.  These arguments
     are passed directly to iiffccoonnffiigg(8).  _O_p_t-_a_r_g_s are optional
     arguments used to configure the line.

EEXXAAMMPPLLEE
     The normal use of sslliippllooggiinn is to create a //eettcc//ppaasssswwdd entry
     for each legal, remote slip site with sslliippllooggiinn as the shell
     for that entry.  E.g.,
	  Sfoo:ikhuy6:2010:1:slip line to foo:/tmp:/etc/sliplogin
     (Our convention is to name the account used by remote host
     _h_o_s_t_n_a_m_e as _S_h_o_s_t_n_a_m_e.) Then an entry is added to sslliipp..hhoossttss
     that looks like:
	  Sfoo `hostname`     foo  netmask
     where `_h_o_s_t_n_a_m_e` will be evaluated by sshh to the local host
     name and _n_e_t_m_a_s_k is the local host IP netmask.

     Note that sslliippllooggiinn must be setuid to root and, while not a
     security hole, moral defectives can use it to place terminal
     lines in an unusable state and/or deny access to legitimate
     users of a remote slip line.  To prevent this, a site can
     create a group, say _s_l_i_p, that only the slip login accounts
     are put in then make sure that //eettcc//sslliippllooggiinn is in group
     _s_l_i_p and mode 4550 (setuid root, only group _s_l_i_p can execute
     binary).

DDIIAAGGNNOOSSTTIICCSS
     sslliippllooggiinn logs various information to the system log daemon,
     ssyyssllooggdd(8), with a facility code of ddaaeemmoonn.  The messages
     are listed here, grouped by severity level.

     EErrrr SSeevveerriittyy

     iiooccttll ((TTCCGGEETTSS)):: _r_e_a_s_o_n
	  A iiooccttll to get the line parameters failed.

     iiooccttll ((TTCCSSEETTSS)):: _r_e_a_s_o_n
	  A iiooccttll to set the line parameters failed.

     //eettcc//sslliipp..hhoossttss:: _r_e_a_s_o_n
	  The //eettcc//sslliipp..hhoossttss file could not be opened.

     aacccceessss ddeenniieedd ffoorr _u_s_e_r
	  No entry for _u_s_e_r was found in //eettcc//sslliipp..hhoossttss.

     NNoottiiccee SSeevveerriittyy

     aattttaacchhiinngg sslliipp uunniitt _u_n_i_t ffoorr _l_o_g_i_n_n_a_m_e
	  SLIP unit _u_n_i_t was successfully attached.





Printed 7/27/90               July				2






SLIPLOGIN(8)		      1990		     SLIPLOGIN(8)



SSEEEE AALLSSOO
     ssllaattttaacchh(8), ssyyssllooggdd(8)





















































Printed 7/27/90               July				3