RE: [PATCH v4] lib/net: fix tcp/udp cksum with padding data

["Morten Brørup" <mb@smartsharesystems.com>]

> From: Kaiwen Deng [mailto:kaiwenx.deng@intel.com]
> Sent: Wednesday, 13 December 2023 05.38
> 
> IEEE 802 packets may have a minimum size limit. The data fields
> should be padded when necessary. In some cases, the padding data
> is not zero.
> 
> In 'rte_ipv4_udptcp_cksum_mbuf()', as payload length
> "mbuf->pkt_len - l4_off" is used, which includes padding and if
> padding is not zero it will end up producing wrong checksum.
> 
> This patch will use IP header to get the payload size to calculate
> tcp/udp checksum.
> 
> Fixes: d178f693bbfe ("net: add UDP/TCP checksum in mbuf segments")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Kaiwen Deng <kaiwenx.deng@intel.com>

Please fix indentation, refer to the Coding Style:
https://doc.dpdk.org/guides/contributing/coding_style.html#c-indentation

Note that line length up to 100 characters is acceptable:
https://doc.dpdk.org/guides/contributing/coding_style.html#general-guidelines

To some degree, indentation is a matter of taste. Just stay within the boundaries of the Coding Style.

> ---
>  lib/net/rte_ip.h | 17 +++++++++++------
>  1 file changed, 11 insertions(+), 6 deletions(-)
> 
> diff --git a/lib/net/rte_ip.h b/lib/net/rte_ip.h
> index 6fa98a5a0f..bcdce723a5 100644
> --- a/lib/net/rte_ip.h
> +++ b/lib/net/rte_ip.h
> @@ -419,11 +419,15 @@ __rte_ipv4_udptcp_cksum_mbuf(const struct
> rte_mbuf *m,
>  {
>  	uint16_t raw_cksum;
>  	uint32_t cksum;
> +	uint16_t len;
> 
> -	if (l4_off > m->pkt_len)
> -		return 0;
> +	if (unlikely(l4_off > m->pkt_len))
> +		return 0; /* invalid params, return a dummy value */
> +
> +	len = rte_be_to_cpu_16(ipv4_hdr->total_length) -
> +				(uint16_t)rte_ipv4_hdr_len(ipv4_hdr);

Please fix indentation of this continuation line.

> 
> -	if (rte_raw_cksum_mbuf(m, l4_off, m->pkt_len - l4_off,
> &raw_cksum))
> +	if (rte_raw_cksum_mbuf(m, l4_off, len, &raw_cksum))
>  		return 0;
> 
>  	cksum = raw_cksum + rte_ipv4_phdr_cksum(ipv4_hdr, 0);
> @@ -663,10 +667,11 @@ __rte_ipv6_udptcp_cksum_mbuf(const struct
> rte_mbuf *m,
>  	uint16_t raw_cksum;
>  	uint32_t cksum;
> 
> -	if (l4_off > m->pkt_len)
> -		return 0;
> +	if (unlikely(l4_off > m->pkt_len))
> +		return 0; /* invalid params, return a dummy value */
> 
> -	if (rte_raw_cksum_mbuf(m, l4_off, m->pkt_len - l4_off,
> &raw_cksum))
> +	if (rte_raw_cksum_mbuf(m, l4_off,
> +		rte_be_to_cpu_16(ipv6_hdr->payload_len), &raw_cksum))

Please fix indentation of this continuation line.

>  		return 0;
> 
>  	cksum = raw_cksum + rte_ipv6_phdr_cksum(ipv6_hdr, 0);
> --
> 2.34.1

With indentation fixed,

Reviewed-by: Morten Brørup <mb@smartsharesystems.com>