Nmap Development mailing list archives
Re: [ncat] Listening Unix domain socket and UDP dies on Connect
From: John Schwarz <jschwarz () redhat com>
Date: Mon, 3 Nov 2014 16:52:30 +0200
Daniel, Thanks a lot for responding. Answers inline.
On Oct28, 2014, at 01:34, Daniel Miller <bonsaiviking () gmail com> wrote: John, I'm sorry it has taken so long to get back to you on this. Unfortunately, I'm not able to reproduce the error. Is it still affecting you?
I tried working on this feature again a few weeks back and still encountered the same problem. It will probably take me a while to rewrite the code as I reworked it (into a dummy python code which runs the server instead of ncat) :(
On Sun, Sep 21, 2014 at 12:00 PM, John Schwarz <jschwarz () redhat com> wrote:Hi guys, I'm encountering a really weird problem with the latest ncat version taken from your SVN sources, and hopefully you guys could help me (or otherwise confirm this is a bug?) I have an haproxy process which is configured to send logs to a specific unix domain socket located at some path at the HD. Prior to running the haproxy, I start a ncat process like so: ncat --unixsock <path> --output /tmp/logs --listen --unix -vvvI'm assuming you meant --udp and not --unix here
Yeps. Sorry :)
Once haproxy starts and sends the first log message, though, ncat quits and the printout in [1] is given. Using GDB, I've tracked the "connect: Invalid argument" to a call to Connect in ncat_listen.c:818 (function name: ncat_listen_dgram) which produce EINVAL. Furthermore, commenting out the Connect call and recompiling produces actual log messages being read by the ncat process. Do you guys have any ideas what am I doing wrong here? Much appreciated, [1]: http://pastebin.com/5xwdWZAE -- John Schwarz, Software Engineer, Red Hat.In order to better solve your problem, will you please provide some information about your platform? I don't see EINVAL as a documented error from connect in the Linux man pages, but I'd assume you are running Red Hat. What kernel version are you using?
I’m running Fedora 20, x86_64, kernel version 3.15.10-200.fc20.x86_64. Netcat’s version is taken from upstream (6.47SVN is what was running during the last attempt). What else can I provide you with?
Can you reproduce the bug using ncat as the client as well, or is the crash specific to the haproxy connection?
Surprisingly, using netcat as a client as well as the server doesn’t cause the server to crash at all. How odd.
Of note, I am running across a bug where I can't send more than a couple messages to a listening unixsock+udp ncat before it stops receiving data. I'll continue to look into it.
Sounds very similar to what I’m experiencing.
Dan
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Current thread:
- Re: [ncat] Listening Unix domain socket and UDP dies on Connect Daniel Miller (Oct 27)
- Re: [ncat] Listening Unix domain socket and UDP dies on Connect John Schwarz (Nov 03)