Subject: Re: [PATCH net-next 5/6] selftests: drv-net: gro: test ip6ip6

From: Willem de Bruijn <[email-masked]>
Date: Wed, 01 Apr 2026 20:20:09 -0400

Jakub Kicinski wrote:
> We explicitly test ipip encap. Let's add ip6ip6, too. Having
> just ipip seems like favoring IPv4 which we should not do :)
> Testing all combinations is left for future work, not sure
> it's actually worth it.
> 
> Signed-off-by: Jakub Kicinski <[email-masked]>
> ---
>  tools/testing/selftests/net/lib/gro.c      | 29 ++++++++++++++++------
>  tools/testing/selftests/drivers/net/gro.py | 19 ++++++++------
>  2 files changed, 34 insertions(+), 14 deletions(-)
> 
> diff --git a/tools/testing/selftests/net/lib/gro.c b/tools/testing/selftests/net/lib/gro.c
> index 57080ecc3df8..762e88932ed2 100644
> --- a/tools/testing/selftests/net/lib/gro.c
> +++ b/tools/testing/selftests/net/lib/gro.c
> @@ -94,11 +94,14 @@
>  #define START_SEQ 100
>  #define START_ACK 100
>  #define ETH_P_NONE 0
> -#define TOTAL_HDR_LEN (ETH_HLEN + sizeof(struct ipv6hdr) + sizeof(struct tcphdr))
> +#define TOTAL_HDR_LEN \
> +	(ETH_HLEN + sizeof(struct ipv6hdr) * 2 + sizeof(struct tcphdr))
>  #define MSS (4096 - sizeof(struct tcphdr) - sizeof(struct ipv6hdr))
> -#define MAX_PAYLOAD (IP_MAXPACKET - sizeof(struct tcphdr) - sizeof(struct ipv6hdr))
> +#define MAX_PAYLOAD \
> +	(IP_MAXPACKET - sizeof(struct tcphdr) - sizeof(struct ipv6hdr))
>  #define NUM_LARGE_PKT (MAX_PAYLOAD / MSS)
> -#define MAX_HDR_LEN (ETH_HLEN + sizeof(struct ipv6hdr) + sizeof(struct tcphdr))
> +#define MAX_HDR_LEN \
> +	(ETH_HLEN + sizeof(struct ipv6hdr) * 2 + sizeof(struct tcphdr))

Not something that needs to be addressed here (or at all), but
TOTAL_HDR_LEN and MAX_HDR_LEN seem to be the same.