Nmap Development mailing list archives
Re: OS X 10.6 diagnosis: pcap timeout and bpf device access
From: David Fifield <david () bamsoftware com>
Date: Sun, 8 Nov 2009 22:54:54 -0700
On Sat, Nov 07, 2009 at 11:01:30AM -0700, David Fifield wrote:
I have been looking into this problem, and I think I have found the cause, or rather causes, both of which appear to be Apple bugs. The first is that setting timeouts for read events doesn't work unless the timeout is at least 1000 milliseconds. The second is that opening a /dev/bpf? device in O_WRONLY mode and binding it to an interface causes all other listeners on the interface to see only outgoing traffic. I don't know of a nice quick fix for these problems. How to handle this? The O_RDWR change, while ugly, is pretty innocuous. We use a short timeout for pcap reads on OS X because you can't select on a pcap file descriptor. However, apparently poll work for pcap descriptors in 10.6, where it didn't work before. So doing some kind of configuration detection and using poll when appropriate is an option. These tests were all with a stock installation of 10.6. I'll try updating to whatever the latest version is and see if anything is different.
I committed the O_RDWR change. With that, a temporary workaround for this problem is to compile in 32-bit mode by configuring like this: ./configure CFLAGS="-m32" CXXFLAGS="-m32" LDFLAGS="-m32" I'm going to try reinstalling MacPorts under 10.6 and see if I can make a release like that. If not, I'll revert back to my 10.5 installation for the next release. David Fifield _______________________________________________ Sent through the nmap-dev mailing list http://cgi.insecure.org/mailman/listinfo/nmap-dev Archived at http://seclists.org/nmap-dev/
Current thread:
- Re: OS X 10.6 Problems with privileged scans, (continued)
- Re: OS X 10.6 Problems with privileged scans Walt Scrivens (Oct 23)
- Re: OS X 10.6 Problems with privileged scans David Fifield (Oct 23)
- Re: OS X 10.6 Problems with privileged scans Walt Scrivens (Oct 23)
- Re: OS X 10.6 Problems with privileged scans Tom Sellers (Oct 23)
- Re: OS X 10.6 Problems with privileged scans Walt Scrivens (Oct 23)
- OS X 10.6 diagnosis: pcap timeout and bpf device access David Fifield (Nov 07)
- Re: OS X 10.6 diagnosis: pcap timeout and bpf device access Walt Scrivens (Nov 07)
- Re: OS X 10.6 diagnosis: pcap timeout and bpf device access David Fifield (Nov 07)
- Re: OS X 10.6 diagnosis: pcap timeout and bpf device access David Fifield (Nov 08)
- Re: OS X 10.6 diagnosis: pcap timeout and bpf device access Walt Scrivens (Nov 09)
- Re: OS X 10.6 diagnosis: pcap timeout and bpf device access Walt Scrivens (Nov 10)
- Re: OS X 10.6 diagnosis: pcap timeout and bpf device access David Fifield (Nov 10)
- Re: OS X 10.6 diagnosis: pcap timeout and bpf device access David Fifield (Nov 10)