From: Gerrit Hoetzel (gt_at_hzhome.mine.nu)
Date: Mon 30 Dec 2002 - 15:39:04 GMT
Hi!
I've already requested your help a few days ago, but got no answers.
As I consider this topic too important to be totally ignored, I simply
assume nobody could understand my bad English.
If otherwise my question is utterly stupid: please let me known why.
So here we go:
I recently stumbled over southDebugger by Jens Bruhn (available at
http://www.jensbruhn.de/products/southDebugger/southdebugger.html).
It is written in java and works togehter with POSE (Palm OS Emulator) as
a debugger for Palm OS programs.
When it starts up it wants to connect to POSE and asks for the IP.
Regardless of the IP you enter and with or without POSE running it'll
try to connect to 127.0.0.1 and listens on 127.0.0.1 for answers.
Additionally southDebugger listens on 0.0.0.0.
A netstat -tan gives:
tcp 0 0 0.0.0.0:36113 0.0.0.0:* LISTEN
tcp 0 1 127.0.0.1:36114 127.0.0.1:36113 SYN_SENT
Any other vserver may now successfully connect to port 36113.
That looks very strange to me!
I thought a vserver is not allowed to bind to 0.0.0.0 if IPROOT is set
to some other IP (ie 192.168.1.1 for me).
I was able to produce a similar effect using netcat.
Running "netcat -l 1234" results in a netcat bound to 0.0.0.0 listening
to some (random) port.
I tested all this using a 2.4.19-ctx-15 kernel but got the same results
for netcat on a 2.4.18-ctx-10 kernel.
I understand that a program may not change its listening IP to something
other than the one(s) specified by chbind. Right?
Anyway, southDebugger cannot connect to POSE which is listening on
192.168.1.1.
What have I missed or can this be called a "bug" in ipv4root ?
Happy new year!
-- Gerrit Hoetzel