Re: [PATCH net-next 11/11] tcp: increase tcp_rmem[2] to 32 MB

[Jakub Kicinski <kuba@kernel.org>]

On Wed, 14 May 2025 14:20:05 -0700 Kuniyuki Iwashima wrote:
> > It seems ACK was not handled by BPF at tc hook on lo.
> > 
> > ACK was not sent or tcp_load_headers() failed to parse it ?
> > both sounds unlikely though.
> > 
> > Will try to reproduce it.  
> 
> I hard-coded the expected TCPOPT_WINDOW to be 7, and this
> series bumps it to 10, so SYN was dropped as invalid.
> 
> This fixes the failure, and I think it's not a blocker.
> 
> ---8<---
> diff --git a/tools/testing/selftests/bpf/progs/test_tcp_custom_syncookie.c b/tools/testing/selftests/bpf/progs/test_tcp_custom_syncookie.c
> index eb5cca1fce16..7d5293de1952 100644
> --- a/tools/testing/selftests/bpf/progs/test_tcp_custom_syncookie.c
> +++ b/tools/testing/selftests/bpf/progs/test_tcp_custom_syncookie.c
> @@ -294,7 +294,9 @@ static int tcp_validate_sysctl(struct tcp_syncookie *ctx)
>  	    (ctx->ipv6 && ctx->attrs.mss != MSS_LOCAL_IPV6))
>  		goto err;
>  
> -	if (!ctx->attrs.wscale_ok || ctx->attrs.snd_wscale != 7)
> +	if (!ctx->attrs.wscale_ok ||
> +	    !ctx->attrs.snd_wscale ||
> +	    ctx->attrs.snd_wscale >= BPF_SYNCOOKIE_WSCALE_MASK)
>  		goto err;
>  
>  	if (!ctx->attrs.tstamp_ok)

Awesome, could you submit officially? As soon as your fix is in
patchwork I can return Eric's series into the testing branch.