Nmap Development mailing list archives
Re: Ncat/Nsock notification of connection reset
From: Frank Bergmann <nmap () tuxad com>
Date: Sat, 18 Mar 2017 09:39:07 +0100
On Fri, Mar 17, 2017 at 11:41:34PM -0500, Daniel Miller wrote:
I really think there ought to be some way to catch the fact that the server has killed the connection. The first step would be making sure Nsock notices this. With the default select engine [2], I don't see any indication of the event with strace. But with the epoll engine, I think I see something that looks like this: epoll_wait(3, {{EPOLLERR|EPOLLHUP, {u32=13173952, u64=13173952}}}, 128, -1) = 1
Hi Daniel, ucspi-ssl had a long time issue causing high load when the *client* connection was resetted because a fast loop of poll() (not epoll) and read() did happen. Here the issues was that on connection reset poll() delivered an "IN" event but the read() after it only delivered 0 bytes / EOF. The fix HERE was to just check for 0 bytes after IN. Erwin Hoffmann applied my proposed patch for 0.98. (I detected the issue on linux i386 and x86_64.) More information I found here: https://sourceware.org/bugzilla/show_bug.cgi?id=13660 Frank _______________________________________________ Sent through the dev mailing list https://nmap.org/mailman/listinfo/dev Archived at http://seclists.org/nmap-dev/
Current thread:
- Ncat/Nsock notification of connection reset Daniel Miller (Mar 17)
- Re: Ncat/Nsock notification of connection reset Frank Bergmann (Mar 18)
- Re: Ncat/Nsock notification of connection reset Henri Doreau (Mar 18)
- Re: Ncat/Nsock notification of connection reset Henri Doreau (Mar 21)