Well..from userspace application you need to register which subtype of frames you want to receive. This is done with netlink sockets. You can check hostapd/wpa_supplicant sources to see how this is done. http://w1.fi/wpa_supplicant/ I assume you are using newer kernel e.g. 3.0 onwards. Old kernels did not support cfg80211; also your WLAN device driver needs to support mgmt register and mgmt rx. https://www.kernel.org/doc/htmldocs/80211/API-struct-cfg80211-ops.html Thanks, Avinash On Fri, Aug 28, 2015 at 10:57 AM, Gunjan Mehta <gunjanmehta08@xxxxxxxxx> wrote: > Avinash, > > Ya m talking about the WLAN. > can you just throw some more light on cfg802.11 handlers. > > On Fri, Aug 28, 2015 at 11:24 PM, Avinash Patil <avinashapatil@xxxxxxxxx> > wrote: >> >> Hi Gunjan, >> >> Are you talking about WLAN beacon frames? If so, you can you cfg80211 >> handlers to register management frames and once frame is received >> parse frame type/subtype to check if its beacon. >> I dont think beacon frames are delievered to netdev. >> >> Thanks, >> Avinash >> >> On Fri, Aug 28, 2015 at 10:51 AM, Gunjan Mehta <gunjanmehta08@xxxxxxxxx> >> wrote: >> > Then how do i capture the beacon frames? >> > >> > On Fri, Aug 28, 2015 at 10:40 PM, Jeff Haran <Jeff.Haran@xxxxxxxxxx> >> > wrote: >> >> >> >> >> >> >> >> >> >> >> >> From: kernelnewbies-bounces@xxxxxxxxxxxxxxxxx >> >> [mailto:kernelnewbies-bounces@xxxxxxxxxxxxxxxxx] On Behalf Of Gunjan >> >> Mehta >> >> Sent: Friday, August 28, 2015 9:21 AM >> >> To: kernelnewbies; netfilter-devel@xxxxxxxxxxxxxxx >> >> Subject: Identify Beacon Frame >> >> >> >> >> >> >> >> Hi All, >> >> >> >> >> >> >> >> I am new to kernel development. I am writing a kernel module that >> >> captures >> >> packet at the netfilter pre - routing hook. >> >> >> >> >> >> >> >> I only want to capture the BEACON FRAME. >> >> >> >> >> >> >> >> I have few queries: >> >> >> >> >> >> >> >> 1>When the beacon frame comes to receiving machine do the sk_buff gets >> >> allocated? >> >> >> >> 2> How can i identify the beacon frame at the pre routing hook? >> >> >> >> 3> Beacon frame consist of a string for authentication of client with >> >> the >> >> server, can i use sk_buff pointers to get access to that string, if >> >> sk_buff >> >> is allocated? >> >> >> >> >> >> >> >> Regards >> >> >> >> Gunjan >> >> >> >> >> >> >> >> These beacon frames do not appear to be IP packets. If that is true, I >> >> don’t think you are going to see them in any netfilter hooks. >> >> >> >> >> >> >> >> Jeff Haran >> >> >> >> >> > >> > >> > >> > _______________________________________________ >> > Kernelnewbies mailing list >> > Kernelnewbies@xxxxxxxxxxxxxxxxx >> > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >> > > > _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
