On Wed, Jan 4, 2017 at 9:44 AM, Sowmini Varadhan <sowmini.varadhan@xxxxxxxxxx> wrote: > On (01/04/17 09:30), Willem de Bruijn wrote: >> >> The common and simpler solution to this problem is to open the socket >> with protocol 0 to reject all packets, add the BPF filter and only then bind >> with sll_ifindex set to lo. That way no false positives can arrive. > > Yes, I thought of that too (and I've seen that done in one commercial > implementation), but given that tpacket nicely returns the incoming > interface, I figured, why not use the test prog to use this (thus > verifying it, and also showing how to use it) This approach is less restrictive. It still allows incorrect packets to be enqueued in the time between the socket call and attaching the bpf filter. Also, if packets are restricted to a single packet, using bind with sll_ifindex is simpler. -- To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
