From: Paolo Abeni <pab...@redhat.com> Date: Wed, 7 Nov 2018 12:38:27 +0100
> This series implements GRO support for UDP sockets, as the RX counterpart > of commit bec1f6f69736 ("udp: generate gso with UDP_SEGMENT"). > The core functionality is implemented by the second patch, introducing a new > sockopt to enable UDP_GRO, while patch 3 implements support for passing the > segment size to the user space via a new cmsg. > UDP GRO performs a socket lookup for each ingress packets and aggregate > datagram > directed to UDP GRO enabled sockets with constant l4 tuple. > > UDP GRO packets can land on non GRO-enabled sockets, e.g. due to iptables NAT > rules, and that could potentially confuse existing applications. > > The solution adopted here is to de-segment the GRO packet before enqueuing > as needed. Since we must cope with packet reinsertion after de-segmentation, > the relevant code is factored-out in ipv4 and ipv6 specific helpers and > exposed > to UDP usage. > > While the current code can probably be improved, this safeguard ,implemented > in > the patches 4-7, allows future enachements to enable UDP GSO offload on more > virtual devices eventually even on forwarded packets. > > The last 4 for patches implement some performance and functional self-tests, > re-using the existing udpgso infrastructure. The problematic scenario > described > above is explicitly tested. > > This revision of the series try to address the feedback provided by Willem and > Subash on previous iteration. Series applied.