Re: [PATCH 2/4] netfilter: nft_flow_offload: skip dst neigh lookup for ppp devices

[Pablo Neira Ayuso <pablo@netfilter.org>]

Series LGTM.

Would you repost adding Fixes: tag and target nf tree?

Thanks.

On Fri, May 06, 2022 at 03:18:39PM +0200, Felix Fietkau wrote:
> The dst entry does not contain a valid hardware address, so skip the lookup
> in order to avoid running into errors here.
> The proper hardware address is filled in from nft_dev_path_info
> 
> Signed-off-by: Felix Fietkau <nbd@nbd.name>
> ---
>  net/netfilter/nft_flow_offload.c | 22 +++++++++++++---------
>  1 file changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
> index 900d48c810a1..d88de26aad75 100644
> --- a/net/netfilter/nft_flow_offload.c
> +++ b/net/netfilter/nft_flow_offload.c
> @@ -36,6 +36,15 @@ static void nft_default_forward_path(struct nf_flow_route *route,
>  	route->tuple[dir].xmit_type	= nft_xmit_type(dst_cache);
>  }
>  
> +static bool nft_is_valid_ether_device(const struct net_device *dev)
> +{
> +	if (!dev || (dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
> +	    dev->addr_len != ETH_ALEN || !is_valid_ether_addr(dev->dev_addr))
> +		return false;
> +
> +	return true;
> +}
> +
>  static int nft_dev_fill_forward_path(const struct nf_flow_route *route,
>  				     const struct dst_entry *dst_cache,
>  				     const struct nf_conn *ct,
> @@ -47,6 +56,9 @@ static int nft_dev_fill_forward_path(const struct nf_flow_route *route,
>  	struct neighbour *n;
>  	u8 nud_state;
>  
> +	if (!nft_is_valid_ether_device(dev))
> +		goto out;
> +
>  	n = dst_neigh_lookup(dst_cache, daddr);
>  	if (!n)
>  		return -1;
> @@ -60,6 +72,7 @@ static int nft_dev_fill_forward_path(const struct nf_flow_route *route,
>  	if (!(nud_state & NUD_VALID))
>  		return -1;
>  
> +out:
>  	return dev_fill_forward_path(dev, ha, stack);
>  }
>  
> @@ -78,15 +91,6 @@ struct nft_forward_info {
>  	enum flow_offload_xmit_type xmit_type;
>  };
>  
> -static bool nft_is_valid_ether_device(const struct net_device *dev)
> -{
> -	if (!dev || (dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
> -	    dev->addr_len != ETH_ALEN || !is_valid_ether_addr(dev->dev_addr))
> -		return false;
> -
> -	return true;
> -}
> -
>  static void nft_dev_path_info(const struct net_device_path_stack *stack,
>  			      struct nft_forward_info *info,
>  			      unsigned char *ha, struct nf_flowtable *flowtable)
> -- 
> 2.35.1
>