Messages in this thread | | | From | Hiroshi Shimamoto <> | Subject | RE: [E1000-devel] [PATCH 1/2] if_link: Add VF multicast promiscuous mode control | Date | Wed, 21 Jan 2015 12:18:23 +0000 |
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> Subject: RE: [E1000-devel] [PATCH 1/2] if_link: Add VF multicast promiscuous mode control > > From: Hiroshi Shimamoto > > My concern is what is the real issue that VF multicast promiscuous mode can cause. > > I think there is the 4k entries to filter multicast address, and the current ixgbe/ixgbevf > > can turn all bits on from VM. That is almost same as enabling multicast promiscuous mode. > > I mean that we can receive all multicast addresses by an onerous operation in untrusted VM. > > I think we should clarify what is real security issue in this context. > > If you are worried about passing un-enabled multicasts to users then > what about doing a software hash of received multicasts and checking > against an actual list of multicasts enabled for that hash entry. > Under normal conditions there is likely to be only a single address to check. > > It may (or may not) be best to use the same hash as any hashing hardware > filter uses.
thanks for the comment. But I don't think that is the point.
I guess, introducing VF multicast promiscuous mode seems to add new privilege to peek every multicast packet in VM and that doesn't look good. On the other hand, I think that there has been the same privilege in the current ixgbe/ixgbevf implementation already. Or I'm reading the code wrongly. I'd like to clarify what is the issue of allowing to receive all multicast packets.
thanks, Hiroshi
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