[unix-history] / usr / man / man8 / rlogind.8c

.TH RLOGIND 8C "4 March 1983"
.UC 4
.SH NAME
rlogind \- remote login server
.SH SYNOPSIS
.B /etc/rlogind
[
.B \-d
]
.SH DESCRIPTION
.I Rlogind
is the server for the 
.IR rlogin (1C)
program.  The server provides a remote login facility
with authentication based on privileged port numbers.
.PP
.I Rlogind
listens for service requests at the port indicated in
the ``login'' service specification; see
.IR services (5).
When a service request is received the following protocol
is initiated:
.IP 1)
The server checks the client's source port.
If the port is not in the range 0-1023, the server
aborts the connection.
.IP 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
.IR hosts (5)),
the server aborts the connection.
.PP
Once the source port and address have been checked, 
.I rlogind
allocates a pseudo terminal (see 
.IR pty (4)),
and manipulates file descriptors so that the slave
half of the pseudo terminal becomes the 
.B stdin ,
.B stdout ,
and
.B stderr 
for a login process.
The login process is an instance of the
.IR login (1)
program, invoked with the
.B \-r
option.  The login process then proceeds with the authentication
process as described in
.IR rshd (8C),
but if automatic authentication fails, it reprompts the user
to login as one finds on a standard terminal line.
.PP
The parent of the login process manipulates the master side of
the pseduo terminal, operating as an intermediary
between the login process and the client instance of the
.I rlogin
program.  In normal operation, the packet protocol described
in
.IR 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''; see
.IR environ (7).
.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 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.
.PP
A facility to allow all data exchanges to be encrypted should be
present.
Commit	Line	Data
8d07919b C	1	.TH RLOGIND 8C "4 March 1983"
	2	.UC 4
	3	.SH NAME
	4	rlogind \- remote login server
	5	.SH SYNOPSIS
	6	.B /etc/rlogind
	7	[
	8	.B \-d
	9	]
	10	.SH DESCRIPTION
	11	.I Rlogind
	12	is the server for the
	13	.IR rlogin (1C)
	14	program. The server provides a remote login facility
	15	with authentication based on privileged port numbers.
	16	.PP
	17	.I Rlogind
	18	listens for service requests at the port indicated in
	19	the ``login'' service specification; see
	20	.IR services (5).
	21	When a service request is received the following protocol
	22	is initiated:
	23	.IP 1)
	24	The server checks the client's source port.
	25	If the port is not in the range 0-1023, the server
	26	aborts the connection.
	27	.IP 2)
	28	The server checks the client's source address.
	29	If the address is associated with a host for which no
	30	corresponding entry exists in the host name data base (see
	31	.IR hosts (5)),
	32	the server aborts the connection.
	33	.PP
	34	Once the source port and address have been checked,
	35	.I rlogind
	36	allocates a pseudo terminal (see
	37	.IR pty (4)),
	38	and manipulates file descriptors so that the slave
	39	half of the pseudo terminal becomes the
	40	.B stdin ,
	41	.B stdout ,
	42	and
	43	.B stderr
	44	for a login process.
	45	The login process is an instance of the
	46	.IR login (1)
	47	program, invoked with the
	48	.B \-r
	49	option. The login process then proceeds with the authentication
	50	process as described in
	51	.IR rshd (8C),
	52	but if automatic authentication fails, it reprompts the user
	53	to login as one finds on a standard terminal line.
	54	.PP
	55	The parent of the login process manipulates the master side of
	56	the pseduo terminal, operating as an intermediary
	57	between the login process and the client instance of the
	58	.I rlogin
	59	program. In normal operation, the packet protocol described
	60	in
	61	.IR pty (4)
	62	is invoked to provide ^S/^Q type facilities and propagate
	63	interrupt signals to the remote programs. The login process
	64	propagates the client terminal's baud rate and terminal type,
65	as found in the environment variable, ``TERM''; see
66	.IR environ (7).
67	.SH DIAGNOSTICS
68	All diagnostic messages are returned on the connection
69	associated with the
70	.BR stderr ,
71	after which any network connections are closed.
72	An error is indicated by a leading byte with a value of 1.
73	.PP
74	.B ``Hostname for your address unknown.''
75	.br
76	No entry in the host name database existed for
77	the client's machine.
78	.PP
79	.B ``Try again.''
80	.br
81	A
82	.I fork
83	by the server failed.
84	.PP
85	.B ``/bin/sh: ...''
86	.br
87	The user's login shell could not be started.
88	.SH BUGS
89	The authentication procedure used here assumes the integrity
90	of each client machine and the connecting medium. This is
91	insecure, but is useful in an ``open'' environment.
92	.PP
93	A facility to allow all data exchanges to be encrypted should be
94	present.