rlogind.8c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 8C 代码 · 共 109 行

.\" SCCSID: @(#)rlogind.8c	8.1	9/11/90
.TH rlogind 8c
.SH Name
rlogind \- remote login server
.SH Syntax
.B /etc/rlogind
.SH Description
.NXR "rlogind server"
.NXS "remote login server" "rlogind server"
.NXAM "rlogin command" "rlogind server"
.NXR "rlogind server" "protocol"
The
.PN rlogind
server is used for the 
.MS rlogin 1c
program.  The server provides a remote login facility
with authentication based on privileged port numbers.
.PP
The
.PN rlogind
server is invoked by 
.MS inetd 8c
when it receives a connection on
the port indicated in
the login service specification.  For further information, see
.MS services 5 .
When a service request is received, the following protocol
is initiated:
.TP 4
1.
The server checks the client's source port.
If the port is not in the range 0-1023, the server
aborts the connection.
.TP 4
2.
The server checks the client's source address
and requests the corresponding host name.  If the hostname cannot
be determined, the dot-notation representation of the host address is used.
.PP
Once the source port and address have been checked, 
.PN rlogind
allocates a pseudo terminal 
and manipulates file descriptors so that the slave
half of the pseudo terminal becomes the 
.BR stdin ,
.BR stdout ,
and
.B stderr 
for a login process.
For further information, see 
.MS pty 4 ,
.PP
The login process is an instance of the
.MS login 1
program, invoked with the
.PN \-r
option.  
.NXR "rlogind server" "options"
The login process then proceeds with the authentication
process as described in 
.MS rshd 8c ,
but if automatic authentication fails, it reprompts the user
to log in on a standard terminal line.
.PP
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
.PN rlogin
program.  In normal operation, the packet protocol described
in 
.MS pty 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.  For further
information see 
.MS environ 7 .
.PP
The screen or window size of the terminal is requested from the client, and
any changes in the window size from the client are sent to the pseudo terminal.
.SH Restrictions
.NXR "rlogind server" "restricted"
The authentication procedure used here assumes the integrity
of each client machine and the connecting medium.  This is
insecure, but it is useful in an open environment.
.SH Diagnostics
All diagnostic messages are returned on the connection
associated with the
.BR stderr ,
after which any network connections are closed.
An error is indicated by a leading byte with a value of 1.
.PP
.B "Hostname for your address unknown"
.br
No entry in the host name database existed for
the client's machine.
.PP
.B "Try again"
.br
A
.I fork
by the server failed.
.PP
.B "/bin/sh: ..."
.br
The user's login shell could not be started.
.SH See Also
rlogin(1c), inetd(8c)