Nmap Development mailing list archives
Addressing the hang on Windows 2012 R2 w/WinPcap
From: Daniel Miller <bonsaiviking () gmail com>
Date: Sun, 20 Sep 2015 23:00:49 -0500
List, I recently pushed a change in r35259 to try to address a hang that several of our users have experienced on Windows 8.1 and 2012 R2. Specifically, Nmap hangs when multiple nmap.exe processes are run in parallel and reach the same scan phase at the same time. In debugging the issue with WinPcap's debug DLLs, we traced the problem to concurrent access to the WinPcap NPF driver. The change in r35259 introduces a global mutex to control access to the NPF driver. The locations to control were determined by working backwards from the OpenServiceA calls within WinPcap to the Packet.DLL functions that contained them. There were calls to these functions in libpcap, libdnet, and libnetutil. I am not a Windows programming expert, so I cannot be certain that this is the best approach, or that I did not do something unorthodox or inadvisable. I have CC'd some of our best Windows minds (apologies to anyone I didn't think of in the space of 10 seconds) and I'm hoping to hear their thoughts on this, or any concerns that anyone may have with this change. I intend to put this into the next (and final) BETA release this week for broader testing, so I would like a little more assurance that it is safe and sane. Dan
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Current thread:
- Addressing the hang on Windows 2012 R2 w/WinPcap Daniel Miller (Sep 20)
- Re: Addressing the hang on Windows 2012 R2 w/WinPcap 食肉大灰兔V5 (Sep 21)
- Re: Addressing the hang on Windows 2012 R2 w/WinPcap Daniel Miller (Sep 21)
- Re: Addressing the hang on Windows 2012 R2 w/WinPcap 食肉大灰兔V5 (Sep 21)