Re: [PATCH net-next v2 04/12] net: tunnel: add skb_vlan_inet_prepare_reason() helper

[Alexander Lobakin]

From: Menglong Dong <menglong8.dong@xxxxxxxxx>
Date: Fri, 30 Aug 2024 09:59:53 +0800

> Introduce the function skb_vlan_inet_prepare_reason() and make
> skb_vlan_inet_prepare an inline call to it. The drop reasons of it just
> come from pskb_may_pull_reason.
> 
> Signed-off-by: Menglong Dong <dongml2@xxxxxxxxxxxxxxx>
> ---
>  include/net/ip_tunnels.h | 21 +++++++++++++++------
>  1 file changed, 15 insertions(+), 6 deletions(-)
> 
> diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h
> index 7fc2f7bf837a..90f8d1510a76 100644
> --- a/include/net/ip_tunnels.h
> +++ b/include/net/ip_tunnels.h
> @@ -465,13 +465,14 @@ static inline bool pskb_inet_may_pull(struct sk_buff *skb)
>  	return pskb_inet_may_pull_reason(skb) == SKB_NOT_DROPPED_YET;
>  }
>  
> -/* Variant of pskb_inet_may_pull().
> +/* Variant of pskb_inet_may_pull_reason().
>   */
> -static inline bool skb_vlan_inet_prepare(struct sk_buff *skb,
> -					 bool inner_proto_inherit)
> +static inline enum skb_drop_reason
> +skb_vlan_inet_prepare_reason(struct sk_buff *skb, bool inner_proto_inherit)
>  {
>  	int nhlen = 0, maclen = inner_proto_inherit ? 0 : ETH_HLEN;
>  	__be16 type = skb->protocol;
> +	enum skb_drop_reason reason;
>  
>  	/* Essentially this is skb_protocol(skb, true)
>  	 * And we get MAC len.
> @@ -492,11 +493,19 @@ static inline bool skb_vlan_inet_prepare(struct sk_buff *skb,
>  	/* For ETH_P_IPV6/ETH_P_IP we make sure to pull
>  	 * a base network header in skb->head.
>  	 */
> -	if (!pskb_may_pull(skb, maclen + nhlen))
> -		return false;
> +	reason = pskb_may_pull_reason(skb, maclen + nhlen);
> +	if (reason)
> +		return reason;
>  
>  	skb_set_network_header(skb, maclen);
> -	return true;
> +	return SKB_NOT_DROPPED_YET;

An empty newline before the return as we usually do?

> +}
> +
> +static inline bool skb_vlan_inet_prepare(struct sk_buff *skb,
> +					 bool inner_proto_inherit)
> +{
> +	return skb_vlan_inet_prepare_reason(skb, inner_proto_inherit) ==
> +		SKB_NOT_DROPPED_YET;

This line must be aligned to skb_vlan_blah, IOW you need 7 spaces, not 1
tab here.

>  }
>  
>  static inline int ip_encap_hlen(struct ip_tunnel_encap *e)

Thanks,
Olek