Re: supporting extend 'open live capture' parametes

["Paolo Abeni" <paolo.abeni () gmail com>]

Guy Harris wrote:

> Paolo Abeni wrote:
>
> > I thought that such things (pcap API to ask for supported parameters)
> > could be implemented adding dedicated fields into the pcap struct (on in
> > a pcap_t sub structure), which must be set by the platform specific
> > pcap_activate().
>
> That would mean you couldn't ask for supported parameters until
> pcap_activate() is called; however, an application such as Wireshark
> would want to query whether monitor mode is available *before* activating.

Perhaps I'm missing the point, but I think a similar situation
currently happens in the pcap_findalldevs() function, which ultimately
calls pcap_open_live()/pcap_close() for each discovered device. We can
implement the pcap_is_monitor_mode_available(char* device_name) API
[perhaps with a shorter name :-) ] in a similar fashion; something
like:

handle = pcap_create()
pcap_set_device(handle, device_name);
pcap_activate(handle);
ret = pcap_get_monitor_mode_availability(handle);
pcap_close(handle)
return ret;

This is quite time inefficient, but I think that this way the
implementation of the various pcap_get_property() api is very easy.
Moreover, I hope/think that they don't have any time constraint. What
do you think ?

cheers,

Paolo
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