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3daf04a4c5
As the packet traverses through OVS, offloading Tx flags must be carefully evaluated and updated which results in a bit of complexity because of a separate "outer" Tx offloading flag coming from DPDK API, and a "normal"/"inner" Tx offloading flag. On the other hand, the DPDK mbuf API specifies 4 status when it comes to IP checksums: - RTE_MBUF_F_RX_IP_CKSUM_UNKNOWN: no information about the RX IP checksum - RTE_MBUF_F_RX_IP_CKSUM_BAD: the IP checksum in the packet is wrong - RTE_MBUF_F_RX_IP_CKSUM_GOOD: the IP checksum in the packet is valid - RTE_MBUF_F_RX_IP_CKSUM_NONE: the IP checksum is not correct in the packet data, but the integrity of the IP header is verified. This patch changes OVS API so that OVS code only tracks the status of the checksum of the "current" L3 header and let the Tx flags aspect to the netdev-* implementations. With this API, the flow extraction can be cleaned up. During packet processing, OVS can simply look for the IP checksum validity (either good, or partial) before changing some IP header, and then mark the checksum as partial. In the conntrack case, when natting packets, the checksum status of the inner part (ICMP error case) must be forced temporarily as unknown to force checksum resolution. When tunneling comes into play, IP checksums status is bit-shifted for future considerations in the processing if, for example, the tunnel header gets decapsulated again, or in the netdev-* implementations that support tunnel offloading. Finally, netdev-* implementations only need to care about packets in partial status: a good checksum does not need touching, a bad checksum has been updated by kept as bad by OVS, an unknown checksum is either an IPv6 or if it was an IPv4, OVS updated it too (keeping it good or bad accordingly). Rename current API for consistency with dp_packet_(inner_)?ip_checksum_. Signed-off-by: David Marchand <david.marchand@redhat.com> Signed-off-by: Ilya Maximets <i.maximets@ovn.org>