On 5/2/18 5:13 AM, Jesper Dangaard Brouer wrote: > > On Sun, 29 Apr 2018 11:07:52 -0700 David Ahern <dsah...@gmail.com> wrote: > >> + /* verify egress index has xdp support */ >> + // TO-DO bpf_map_lookup_elem(&tx_port, &key) fails with >> + // cannot pass map_type 14 into func bpf_map_lookup_elem#1: > > I just want to point out that I/we are aware of this "usability" > problem with the sample program, but I don't want to block the FIB > helper going upstream, we can fix this problem later. > > The problem is that if you load this bpf/xdp prog, then all incoming > traffic (on that interface), will be forward using XDP, regardless > whether the egress ifindex support XDP or not. And if not supported, > then packets are dropped hard (only detectable via tracepoints). > > If the bpf prog could tell/know that the egress ifindex doesn't > support XDP xmit, then it could simply return XDP_PASS to fallback to > the normal network stack. >
That's what the above lookup is intending but DEVMAP type does not handle lookups from xdp programs. Any chance of fixing that?
