Re: capturing on both interfaces simultaneously

[abhinav narain <abhinavnarain10 () gmail com>]

> > itself, as specified by pcap_set_buffer_size()?

> > >
> > Yes, I havent user the pcap_set_buffer_size(), but in open_live() , i
> give the buffersize as BUFSIZ,
>
>
> There is no buffer size option in pcap_open_live(), so you *can't* give
> the buffer size in a pcap_open_live() call.
>
> I can't find any default buffer size in pcap,How can I know that it is
goodenough when I am doing select

> > > One way to identify a beacon frame from an 802.11n-capable AP is to look
> > > for the HT Capabilities Info field; see "7.3.2.56.2 HT Capabilities Info
> > > field" in the 802.11 spec.
> > Is this is information in the radiotap header
>
> No.
>
> > or the mac header ?
>
> No.
>
> It's in the management frame body.  See sections 7.1, 7.2, and 7.3 of the
> 802.11 standard:
>
>        http://standards.ieee.org/getieee802/download/802.11-2007.pdf
>
> and of the 802.11n standard:
>
>        http://standards.ieee.org/getieee802/download/802.11n-2009.pdf
>
> Thanks for the resources!
I am doing similar to tcpdump code to use 7.3.1.4 to detect ESS,IBSS,
PRIVACY bits on in beacon frame. The structure is in 2007 pdf.

Now, the 802.11n pdf describes the capabilty structure (2 bytes) with
totally different field !
7.3.2.56.2 show different format of Capabilities section.
I have a pointer to capabilty section, I am not sure how to check the
protocol n is advertised by the AP


> > I looked at wireshark code which is the only tool i came across giving
> some
> > information on N protocol, but its code is more complicated than
> > pcap,tcpdump,kismet,horst i went through before.
> > Is there any other tool i can see how to code it.
>
> None that I know of.
>
> > I am parsing till the 31st bit on radiotap header bitmap.
> > Any code base where I can see how they do it ?
>
> None of this is in the radiotap header!  It's in the body of a management
> frame.-
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