On Aug 7, 2011, at 2:00 PM, Stig Bjørlykke wrote:
> * "Capture all in promiscuous mode" can be checked even if not all
> interfaces have this.
There is no API in libpcap to inquire whether an interface supports promiscuous mode; before Michael and Irene's changes, "Capture in promiscuous mode" could be checked regardless of whether promiscuous mode actually works.
Few OSes support asking whether a network interface supports promiscuous mode (an interface can be told to go into promiscuous mode, and the drivers generally just ignore the request if it makes no sense, e.g. on a PPP interface); at best, libpcap/WinPcap could:
assume that any interface on a network that supports broadcasting (most if not all 802.*, FDDI) supports it;
assume that most if not all others don't (e.g., PPP);
assume the "any" device doesn't or does, based on what Linux actually supports;
for devices where we're not at the mercy of the OS and drivers, provide a method to query that.
I.e., that's an interesting enhancement to consider, but there's no regression from the old code.