On Mon, Mar 01, 2021 at 05:26:53PM +0100, Markus Blöchl wrote: > The main problem here could also just be that almost everybody _thinks_ > that promiscuity means receiving all frames and no one is aware of the > standards definition. > In fact, I can't blame them, as the standard is hard to come by and not > enjoyable to read, imho. And all secondary documentation I could find > on the internet explain promiscuous mode as a "mode of operation" in which > "the card accepts every Ethernet packet sent on the network" or similar. > Even libpcap, which I consider the reference on network sniffing, thinks > that "Promiscuous mode [...] sniffs all traffic on the wire." > > Thus I still think that this issue is also fixable by proper > documentation of promiscuity. > At least the meaning and guarantees of IFF_PROMISC in this kernel should > be clearly defined - in one way or the other - such that users with > different expectations can be directed there and drivers with different > behavior can be fixed with that definition as justification.
If Jakub and/or David give us the ACK, I will go ahead and update the documentation (probably Documentation/networking/netdevices.rst) to mention what does IFF_PROMISC cover, _separate_ from this series.
