[v3] net/cksum: compute raw cksum for several segments

[Thomas Monjalon]

Hello,

04/08/2025 05:54, Su Sai:
> The rte_raw_cksum_mbuf function is used to compute
> the raw checksum of a packet.
> If the packet payload stored in multi mbuf, the function
> will goto the hard case. In hard case,
> the variable 'tmp' is a type of uint32_t,
> so rte_bswap16 will drop high 16 bit.
> Meanwhile, the variable 'sum' is a type of uint32_t,
> so 'sum += tmp' will drop the carry when overflow.
> Both drop will make cksum incorrect.
> This commit fixes the above bug.

Thank you for the fix and the associated test.

Please could describe the exact condition to get a wrong checksum?
Does it happen with all multiseg packets?
3 segments is a minimum? Any other constraint to reproduce?