Hi Ivan,
> -----Original Message----- > You would be right... if the PMDs did not transparently strip the CRC in > software when hardware CRC stripping is disabled at port configuration (as > described above). > See for instance how the function ixgbe_recv_pkts_lro() in file > drivers/net/ixgbe/ixgbe_rxtx.c deals with crc_len. Yeah, I see. However, I wonder what's the utility of the hw_strip_crc feature if finally it is completely masked to the mbuf user. However, to my understanding, looking at that ixgbe code, I think that what I wrote before: uint32_t crc = *(rte_pktmbuf_mtod_offset (mymbuf, uint32_t*, mymbuf->pkt_len)) ; should work, since the pkt_len and data_len has the "crc_len" removed, but the CRC itself should be there. I know it is kind of an hack, but at least for ixgbe that sounds like a possible (temporary) solution for me.... > Considering your need, I think now that PMDs should keep the CRC that are > stored in received packets when hardware CRC stripping is disabled by the > application, so that the application can access it as needed. > Yes, that would be very useful. > Note that this would impose that the input packet processing of such DPDK > applications be aware of the CRC presence (+4 in the packet length , for > instance). Or perhaps, to maintain backward compatibility, just a flag inside the mbuf could be set that informs the user that at the end of the mbuf packet, you can find 4 bytes with the CRC. > > Let's see what others, if any, that might care think about such a change into > the CRC stripping semantics. Thanks! Francesco
