Hi, I'm trying to understand when pktio implementation should set the L4 offset. In point of view, if there is a known L3 header than the L4 offset should be set to the L3-offset + L3 header length. I noticed that Linux generic implementation is not as above. E.g. if there is only IP header and payload, than L4 offset is set to 'ODP_PACKET_OFFSET_INVALID'. Is the above is the real intention? The API is documented as foolowed: /** * Layer 4 start offset * * Returns offset to the start of the layer 4 header. The offset is calculated * from the current odp_packet_data() position in bytes. * * User is responsible to update the offset when modifying the packet data * pointer position. * * @param pkt Packet handle * * @return Layer 4 start offset * @retval ODP_PACKET_OFFSET_INVALID packet does not contain a valid L4 header * * @see odp_packet_l4_offset_set(), odp_packet_has_l4() */ uint32_t odp_packet_l4_offset(odp_packet_t pkt);
What is the meaning of a valid L4 header? A payload is a valid L4? Maybe you should remove the 'header' and just mention that there is a L4 layer. In order to calculate IP checksum, the IP-Header-length is needed and in absence of this exact value, the L4 offset can be used to calculate it. Regards, Liron
