John Hurley <john.hur...@netronome.com> wrote: > Hi Eyal, > The value of 4 is basically a revert to what it was on older kernels > when TC had a TTL value in the skb: > https://elixir.bootlin.com/linux/v3.19.8/source/include/uapi/linux/pkt_cls.h#L97
IIRC this TTL value was not used ever. > I also found with my testing that a value greater than 4 was sailing > close to the edge. > With a larger value (on my system anyway), I could still trigger a > stack overflow here. > I'm not sure on the history of why a value of 4 was selected here but > it seems to fall into line with my findings. > Is there a hard requirement for >4 recursive calls here? One alternative would be to (instead of dropping the skb), to decrement the ttl and use netif_rx() instead.
