Re: [PATCH net 4/6] netfilter: nft_payload: skbuff vlan metadata mangle support

[Paolo Abeni <pabeni@redhat.com>]

On Thu, 2024-05-23 at 01:13 +0200, Pablo Neira Ayuso wrote:
> @@ -801,21 +801,79 @@ struct nft_payload_set {
>  	u8			csum_flags;
>  };
>  
> +/* This is not struct vlan_hdr. */
> +struct nft_payload_vlan_hdr {
> +        __be16          h_vlan_proto;
> +        __be16          h_vlan_TCI;
> +};
> +
> +static bool
> +nft_payload_set_vlan(const u32 *src, struct sk_buff *skb, u8 offset, u8 len,
> +		     int *vlan_hlen)
> +{
> +	struct nft_payload_vlan_hdr *vlanh;
> +	__be16 vlan_proto;
> +	__be16 vlan_tci;
> +
> +	if (offset >= offsetof(struct vlan_ethhdr, h_vlan_encapsulated_proto)) {
> +		*vlan_hlen = VLAN_HLEN;
> +		return true;
> +	}
> +
> +	switch (offset) {
> +	case offsetof(struct vlan_ethhdr, h_vlan_proto):
> +		if (len == 2) {
> +			vlan_proto = nft_reg_load16(src);

I'm sorry but the above introduces build warning due to endianess
mismatch (host -> be)

> +			skb->vlan_proto = vlan_proto;
> +		} else if (len == 4) {
> +			vlanh = (struct nft_payload_vlan_hdr *)src;
> +			__vlan_hwaccel_put_tag(skb, vlanh->h_vlan_proto,
> +					       ntohs(vlanh->h_vlan_TCI));
> +		} else {
> +			return false;
> +		}
> +		break;
> +	case offsetof(struct vlan_ethhdr, h_vlan_TCI):
> +		if (len != 2)
> +			return false;
> +
> +		vlan_tci = ntohs(nft_reg_load16(src));

Similar things here htons() expect a be short int and is receiving a
u16, vlan_tci is 'be' and the assigned data uses host endianess.


Could you please address the above?

Thanks!

Paolo