Berkeley r-commands: Difference between revisions

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| style="text-align:left" | rcp || style="text-align:left" | rshd || 514 || TCP ||

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| style="text-align:left" | {{code|rexec}} || style="text-align:left" | rexecd || 512 || TCP || <ref>{{cite book |chapter-url=https://www.ibm.com/support/knowledgecenter/en/SSLTBW_2.1.0/com.ibm.zos.v2r1.halu001/rexsyn.htm |chapter={{code|rexec}}REXEC command—Execute a command on the remote host and receive the results on your local host |title=z/OS Communications Server: IP User's Guide and Commands |orig-year=1990 |year=2013 |access-date=2018-03-04}}</ref>

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| style="text-align:left" | rlogin || style="text-align:left" | rlogind || 513 || TCP || <ref name="NAG">{{cite book |title=FreeBSD Network Administrators Guide |chapter-url=https://people.freebsd.org/~nik/nag/book.html#x-087-2-intro.tcpip.ports |chapter=More on Ports |access-date=2018-03-04}}</ref>

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| style="text-align:left" | rwho || <ref name="NAG"/><ref name="Casad-350"/>

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==Protocol==

The original Berkeley package that provides {{code|rlogin}} also features {{code|rcp}} (remote-copy, allowing files to be copied over the network) and [[Remote Shell|rsh]] (remote-shell, allowing commands to be run on a remote machine without the user logging into it). These share the {{code|hosts.equiv}} and {{code|.rhosts}} access-control scheme (although they connect to a different daemon, {{code|rshd}}).

==Authentication==

As an example, the protocol is as follows:<ref>{{Cite report |url=https://datatracker.ietf.org/doc/rfc1282/ |title=BSD Rlogin |last=Kantor |first=Brian |date=December 1991 |publisher=Internet Engineering Task Force |issue=RFC 1282}}</ref><syntaxhighlight lang="bash">

The original Berkeley package that provides {{code|rlogin}} also features {{code|rcp}} (remote-copy, allowing files to be copied over the network) and [[Remote Shell|rsh]] (remote-shell, allowing commands to be run on a remote machine without the user logging into it). These share the {{code|hosts.equiv}} and {{code|.rhosts}} access-control scheme (although they connect to a different daemon, {{code|rshd}}).

Client:

<null>

user name on the client<null>

user name on the server<null>

terminal type/terminal baud rate<null>

Server:

</syntaxhighlight>The server would check that the user should have access. If so, it returns a message with nothing in it (not even a [[null character]]), meaning the connection is established.

For example:<syntaxhighlight lang="bash">

Client:

<null>

bostic<null>

kbostic<null>

vt100/9600<null>

Server:

</syntaxhighlight>Both {{code|rlogin}} and {{code|rsh}} share the {{code|/etc/hosts.equiv}} (applies to all users on the server) and {{code|$HOME/.rhosts}} (applies to only the user that puts the file in its home folder) access-control scheme, although they connect to different daemons. {{code|rlogin}} connects to {{code|rlogind}}, while {{code|rsh}} connects to {{code|rshd}}.

{{code|hosts.equiv}} and {{code|.rhosts}} uses the same format. The following shows some aspects of the format:<ref>{{Cite web |title=.rhosts File Format for TCP/IP |url=https://www.ibm.com/docs/en/aix/7.2?topic=formats-rhosts-file-format-tcpip |access-date=2023-11-29 |website=www.ibm.com |language=en-us}}</ref><ref>{{Cite web |title=hosts.equiv File Format for TCP/IP |url=https://www.ibm.com/docs/en/aix/7.2?topic=formats-hostsequiv-file-format-tcpip |access-date=2023-11-29 |website=www.ibm.com |language=en-us}}</ref><syntaxhighlight lang="bash">

host1

host2 user_a

-host3

+@group1 -user_b

-@group2

</syntaxhighlight>This allows all users from host1 to login, user_a from host2 to login, no users from host3, all users on group1 except user_b, and no users on group2.

==Commands==