Re: [PATCH net-next v1 2/3] net/mlx5e: Add helper for encap_info_equal for tunnels with options

[Alexander Lobakin <alexandr.lobakin@intel.com>]

From: Gavin Li <gavinl@nvidia.com>
Date: Tue, 14 Feb 2023 15:41:36 +0200

(dropping non-existent nikolay@nvidia.com)

> For tunnels with options, eg, geneve and vxlan with gbp, they share the
> same way to compare the headers and options. Extract the code as a common
> function for them
> 
> Change-Id: I3ea697293c8d5d66c0c20080dbde88f60bcbd62f
> Signed-off-by: Gavin Li <gavinl@nvidia.com>
> Reviewed-by: Roi Dayan <roid@nvidia.com>
> Reviewed-by: Maor Dickman <maord@nvidia.com>
> Acked-by: Saeed Mahameed <saeedm@nvidia.com>

[...]

> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c
> index 780224fd67a1..4df9d27a63ad 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c
> @@ -571,6 +571,35 @@ bool mlx5e_tc_tun_encap_info_equal_generic(struct mlx5e_encap_key *a,
>  		a->tc_tunnel->tunnel_type == b->tc_tunnel->tunnel_type;
>  }
>  
> +bool mlx5e_tc_tun_encap_info_equal_options(struct mlx5e_encap_key *a,
> +					   struct mlx5e_encap_key *b,
> +					   __be16 tun_flags)
> +{
> +	struct ip_tunnel_info *a_info;
> +	struct ip_tunnel_info *b_info;
> +	bool a_has_opts, b_has_opts;
> +
> +	if (!mlx5e_tc_tun_encap_info_equal_generic(a, b))
> +		return false;
> +
> +	a_has_opts = !!(a->ip_tun_key->tun_flags & tun_flags);
> +	b_has_opts = !!(b->ip_tun_key->tun_flags & tun_flags);
> +
> +	/* keys are equal when both don't have any options attached */
> +	if (!a_has_opts && !b_has_opts)
> +		return true;
> +
> +	if (a_has_opts != b_has_opts)
> +		return false;
> +
> +	/* options stored in memory next to ip_tunnel_info struct */
> +	a_info = container_of(a->ip_tun_key, struct ip_tunnel_info, key);
> +	b_info = container_of(b->ip_tun_key, struct ip_tunnel_info, key);
> +
> +	return a_info->options_len == b_info->options_len &&
> +		memcmp(a_info + 1, b_info + 1, a_info->options_len) == 0;

1. memcmp() is not aligned to the first expr (off-by-one to the right).
2. `!expr` is preferred over `expr == 0`.

> +}
> +
>  static int cmp_decap_info(struct mlx5e_decap_key *a,
>  			  struct mlx5e_decap_key *b)
>  {
[...]

Thanks,
Olek