[Click] Help!! Madwifi Monitor Mode vs Ad-Hoc Mode... Annotations?

[Ian Rose]

Will MadWifi monitor mode even allow you to transmit at all?  That might 
be something to test - the fact that pings don't work seem to indicate 
otherwise.  It might put the interface into a receive-only mode...  I'm 
not sure about this though - I develop on FreeBSD, not Linux.

- Ian


g91d5350 at campus.ru.ac.za wrote:
> Hello again, Clickers
> 
> I need some assistance...
> 
> The click script below creates a "station" device and does very little  
> with it.  When I run this script on two nodes in Ad-Hoc mode, it works  
> fine.  When I run it in Madwifi's Monitor mode, it doesn't work...
> 
> FromHost(station, 192.168.1.2/24) // use a different IP for each node!
> -> Print("FromHost")
> -> Queue
> -> to_dev :: ToDevice (ath0);
> 
> FromDevice(ath0, PROMISC true)
> // 802.11 headers configured in MadWifi, so there's no need for PrismDecap etc
> -> Print("FromDevice")
> //-> CheckIPHeader(14)
> //-> GetIPAddress(16)
> -> ToHost(station);
> 
> Before anybody jumps on me, I know that I'm doing dubious things here.  
>   I know that under Ad-hoc mode the wireless driver will convert my  
> Ethernet frames into 802.11 frames.  Under Monitor mode, I am  
> transmitting raw Ethernet frames - which is what I want for this  
> experiment.  I know too that I should filter incoming packets to  
> differentiate between my data and other traffic (such as spurious  
> beacons and 802.11 traffic)... I'll get there...
> 
> I use PING to test whether I can communicate over the "station"  
> device.  Pings work fine in ad-hoc mode, but in monitor mode they  
> don't.  My packets appear to arrive at the recipient OK - I print them  
> after FromDevice().  But it seems like Linux loses the packets after  
> that.
> 
> I have a suspicion that Linux might be silently dropping my packets  
> because they are not correctly annotated.  On a whim, I tried adding a  
> GetIPAddress(16) - but that didn't help.
> 
> Am I missing something?  I spent until 1-o-clock this morning trying  
> to figure this stuff out.  Any help would be greatly appreciated!
> 
> Thanks!
> - Kevin
> 
> 
> 
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