Nmap Development mailing list archives
Re: nmap.bind to set NSE socket source address
From: Tom Sellers <nmap () fadedcode net>
Date: Thu, 15 Oct 2009 18:04:01 -0500
David Fifield wrote:
Take a look at the attached .pcap file -- I did DHCPINFORM, which worked fine with the changes, then I did DHCPDISCOVER, which didn't.Do you know if there's any way to receive broadcast packets without a pcap?The DHCP server in my router sends back a unicast DHCP offer in response to DHCPDISCOVER, so it must not be every server that does that. I think what you would normally do is make a socket bound to 255.255.255.255:67 and try to receive on it. In Python this works: import socket s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP) s.bind("255.255.255.255", 67) print s.recv() But that currently won't work in NSE, because the socket descriptor isn't created until a connection is attempted. There's no way to create a socket without also connecting it. Something about the connection keeps the receive from working. This is what I tried: s = nmap.new_socket() assert(s:bind("255.255.255.255", 67)) assert(s:connect(host.ip, 68, "udp")) status, data = s:receive() So we would have to rearchitect part of Nsock to allocate a socket on nsi_new, which I think is pretty reasonable. David Fifield
I have never used them, but would nmap.pcap_open [1] and nmap.pcap_receive be useful for this? It looks like some work, but it looks like pcap_open will take a filter expression that could limit the amount of data you have to process. Tom 1. http://nmap.org/nsedoc/lib/nmap.html#pcap_open _______________________________________________ Sent through the nmap-dev mailing list http://cgi.insecure.org/mailman/listinfo/nmap-dev Archived at http://SecLists.Org
Current thread:
- nmap.bind to set NSE socket source address David Fifield (Oct 11)
- Re: nmap.bind to set NSE socket source address Ron (Oct 11)
- Re: nmap.bind to set NSE socket source address Ron (Oct 11)
- Re: nmap.bind to set NSE socket source address David Fifield (Oct 15)
- Re: nmap.bind to set NSE socket source address Patrick Donnelly (Oct 15)
- Re: nmap.bind to set NSE socket source address Tom Sellers (Oct 15)
- Re: nmap.bind to set NSE socket source address Ron (Oct 15)
- Re: nmap.bind to set NSE socket source address David Fifield (Oct 15)