Re: [PATCH ipsec-next v3] xfrm: Add Direction to the SA in or out

[Leon Romanovsky <leon@kernel.org>]

On Tue, Mar 12, 2024 at 08:59:29PM +0100, Antony Antony wrote:
> This patch introduces the 'dir' attribute, 'in' or 'out', to the
> xfrm_state, SA, enhancing usability by delineating the scope of values
> based on direction. An input SA will now exclusively encompass values
> pertinent to input, effectively segregating them from output-related
> values. This change aims to streamline the configuration process and
> improve the overall clarity of SA attributes.
> 
> Signed-off-by: Antony Antony <antony.antony@secunet.com>
> ---
> v2->v3:
>  - delete redundant XFRM_SA_DIR_USET
>  - use u8 for "dir"
>  - fix HW OFFLOAD DIR check
> 
> v1->v2:
>  - use .strict_start_type in struct nla_policy xfrma_policy
>  - delete redundant XFRM_SA_DIR_MAX enum
> ---
>  include/net/xfrm.h        |  1 +
>  include/uapi/linux/xfrm.h |  6 +++++
>  net/xfrm/xfrm_compat.c    |  7 ++++--
>  net/xfrm/xfrm_device.c    |  5 +++++
>  net/xfrm/xfrm_state.c     |  1 +
>  net/xfrm/xfrm_user.c      | 46 +++++++++++++++++++++++++++++++++++----
>  6 files changed, 60 insertions(+), 6 deletions(-)

<...>

> diff --git a/net/xfrm/xfrm_device.c b/net/xfrm/xfrm_device.c
> index 3784534c9185..481a374eff3b 100644
> --- a/net/xfrm/xfrm_device.c
> +++ b/net/xfrm/xfrm_device.c
> @@ -253,6 +253,11 @@ int xfrm_dev_state_add(struct net *net, struct xfrm_state *x,
>  		return -EINVAL;
>  	}
> 
> +	if (xuo->flags & XFRM_OFFLOAD_INBOUND && x->dir == XFRM_SA_DIR_OUT) {
> +		NL_SET_ERR_MSG(extack, "Mismatched SA and offload direction");
> +		return -EINVAL;
> +	}

It is only one side, the more comprehensive check should be done for
XFRM_SA_DIR_IN too.

if ((xuo->flags & XFRM_OFFLOAD_INBOUND && x->dir == XFRM_SA_DIR_OUT) ||
!((xuo->flags & XFRM_OFFLOAD_INBOUND) && x->dir == XFRM_SA_DIR_IN))
....

and IMHO, it is better to have this check in verify_newsa_info().

Thanks