[PATCH] net/af_packet: add capture direction option

[Frank Dressler]

On 10/4/26 17:10, Stephen Hemminger wrote:

 > The AF_PACKET PMD is special case really intended for monitoring
 > applications, not for general use. You are probably better off using 
AF_XDP
 > for general use.

I agree there are cases in which AF_XDP is better, but it redirects 
packets from the host stack and needs bpf()/XDP. The AF_PACKET approach 
allows for passive monitoring without taking the traffic and works even 
when there is already an XDP program attached or bpf() not allowed.

 > The kernel does have flags to filter by direction, so you could
 > avoid having it be done in the PMD.

Thanks for the hint. It made me find the PACKET_IGNORE_OUTGOING sockopt 
(Linux 4.20+, fa788d986a3a). v2 drops the capture_dir=<in|out|inout> in 
favor of ignore_outgoing=<0|1>.