[PATCH v9 01/25] net: Introduce direct data placement tcp offload

[Paolo Abeni]

Hi,

I'm sorry for the very late feedback.

On Tue, 2023-01-17 at 17:35 +0200, Aurelien Aptel wrote:
> diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
> index cc072d2cfcd8..c711614604a6 100644
> --- a/net/ipv4/tcp_input.c
> +++ b/net/ipv4/tcp_input.c
> @@ -5234,6 +5234,10 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root,
>  		memcpy(nskb->cb, skb->cb, sizeof(skb->cb));
>  #ifdef CONFIG_TLS_DEVICE
>  		nskb->decrypted = skb->decrypted;
> +#endif
> +#ifdef CONFIG_ULP_DDP
> +		nskb->ulp_ddp = skb->ulp_ddp;
> +		nskb->ulp_crc = skb->ulp_crc;
>  #endif
>  		TCP_SKB_CB(nskb)->seq = TCP_SKB_CB(nskb)->end_seq = start;
>  		if (list)
> @@ -5267,6 +5271,10 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root,
>  #ifdef CONFIG_TLS_DEVICE
>  				if (skb->decrypted != nskb->decrypted)
>  					goto end;
> +#endif
> +#ifdef CONFIG_ULP_DDP
> +				if (skb_is_ulp_crc(skb) != skb_is_ulp_crc(nskb))
> +					goto end;
>  #endif
>  			}
>  		}

I *think* a similar check is additionally needed in tcp_try_coalesce().
Possibly even in tcp_shift_skb_data().

Cheers,

Paolo