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. |