RLOGIND(1M) Domain/OS SysV RLOGIND(1M)
NAME
rlogind - remote login server
SYNOPSIS
/etc/rlogind [ -d ]
DESCRIPTION
rlogind is the server for the rlogin(1C) program. The server provides a
remote login facility with authentication based on privileged port
numbers from trusted hosts.
rlogind 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'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 and requests the
corresponding host name (see gethostbyaddr(3N), hosts(4) and
named(1M)). 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, rlogind allocates a
pseudoterminal (see pty(7)), and manipulates file descriptors so that the
slave half of the pseudoterminal 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 log in as one
finds on a standard terminal line.
The parent of the login process manipulates the master side of the
pseudoterminal, operating as an intermediary between the login process
and the client instance of the rlogin program. In normal operation, the
packet protocol described in pty(7) is invoked to provide CTRL/S and
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(5). The screen or window size of the terminal is requested from
the client, and window size changes from the client are propagated to the
pseudoterminal.
RLOGIND(1M) Domain/OS SysV 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.
Try again.
A fork by the server failed.
/bin/sh: ...
The user's login shell could not be started.
BUGS
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.
A more extensible protocol should be used.