[REBOL] Re: Binding server ports to specific host IPs
From: gscottjones:mchsi at: 10-Aug-2002 10:53
Hi, Brian,
From: "Brian Hawley"
> My computer has several IP channels available to it: The ethernet card,
> localhost, and a couple VMware virtual networks. If I am setting up a
> server, how do I bind a listen port to just one or some of them, not all?
> I would like to set up local services that I would prefer not to be
> accessible to the outside world. I haven't found anything like this in
> the docs - they all seem to assume that all network channels are alike.
>
> For that matter, is there some way to set a net-mask or a list of IPs to
> limit who can connect to my service somewhere in the port settings, rather
> than manually checking every connection? I'm looking for speed and
security
> here...
I think I know one way to accomplish your task. This works on my home
network.
If the hypothetical tiny-server IP is 192.168.1.100, then the following sets
up a "tiny server" that only answers if the connection-port comes from the
IP indicated in the code below:
server-port: open/lines tcp://:4321
forever [
connection-port: first server-port
until [
wait connection-port
either find [192.168.1.100] connection-port/host [
error? try [do first connection-port]
][
probe reduce join "intrusion from " connection-port/host
]
]
close connection-port
]
close server-port
I can connect and use from the machine on IP 192.168.1.100 using:
server: open/lines tcp://192.168.1.100:4321
until [error? try [insert server ask "R> "]]
;close server
But from my wife's machine on 192.168.1.101 or by localhost, I the server
only reports an intrusion attempt. More accepted IP's can be added to the
block:
...
either find [192.168.1.100 192.168.1.101] connection-port/host [
...
*****
Warning: This code has not been thoroughly tested and is likely to ruin your
computer, your business and your life. I suspect that even a 2 month old
infant hacker could easily circumvent this server. It is meant to be a
comical satire of a real computer ip filter and is meant for pleasure
reading only at a distance no closer than 4000 meters from any computer.
*****
Hope that this is more useful than my last posts.
--Scott Jones
