Re: [PATCH net-next 1/3] net: gso: add HBH extension header offload support

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

Richard Gobert wrote:
> This commit adds net_offload to IPv6 Hop-by-Hop extension headers (as it
> is done for routing and dstopts) since it is supported in GSO and GRO.
> This allows to remove specific HBH conditionals in GSO and GRO when
> pulling and parsing an incoming packet.
> 
> Signed-off-by: Richard Gobert <richardbgobert@gmail.com>

Reviewed-by: Willem de Bruijn <willemb@google.com>

> ---
>  net/ipv6/exthdrs_offload.c | 11 +++++++++++
>  net/ipv6/ip6_offload.c     | 25 +++++++++++--------------
>  2 files changed, 22 insertions(+), 14 deletions(-)
> 
> diff --git a/net/ipv6/exthdrs_offload.c b/net/ipv6/exthdrs_offload.c
> index 06750d65d480..4c00398f4dca 100644
> --- a/net/ipv6/exthdrs_offload.c
> +++ b/net/ipv6/exthdrs_offload.c
> @@ -16,6 +16,10 @@ static const struct net_offload dstopt_offload = {
>  	.flags		=	INET6_PROTO_GSO_EXTHDR,
>  };
>  
> +static const struct net_offload hbh_offload = {
> +	.flags		=	INET6_PROTO_GSO_EXTHDR,
> +};
> +
>  int __init ipv6_exthdrs_offload_init(void)
>  {
>  	int ret;
> @@ -28,9 +32,16 @@ int __init ipv6_exthdrs_offload_init(void)
>  	if (ret)
>  		goto out_rt;
>  
> +	ret = inet6_add_offload(&hbh_offload, IPPROTO_HOPOPTS);
> +	if (ret)
> +		goto out_dstopts;
> +
>  out:
>  	return ret;
>  
> +out_dstopts:
> +	inet6_del_offload(&dstopt_offload, IPPROTO_DSTOPTS);
> +
>  out_rt:
>  	inet6_del_offload(&rthdr_offload, IPPROTO_ROUTING);
>  	goto out;
> diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
> index d6314287338d..0e0b5fed0995 100644
> --- a/net/ipv6/ip6_offload.c
> +++ b/net/ipv6/ip6_offload.c
> @@ -45,15 +45,13 @@ static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto)
>  		struct ipv6_opt_hdr *opth;
>  		int len;
>  
> -		if (proto != NEXTHDR_HOP) {
> -			ops = rcu_dereference(inet6_offloads[proto]);
> +		ops = rcu_dereference(inet6_offloads[proto]);
>  
> -			if (unlikely(!ops))
> -				break;
> +		if (unlikely(!ops))
> +			break;
>  
> -			if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
> -				break;
> -		}
> +		if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))
> +			break;
>  
>  		if (unlikely(!pskb_may_pull(skb, 8)))
>  			break;
> @@ -171,13 +169,12 @@ static int ipv6_exthdrs_len(struct ipv6hdr *iph,
>  
>  	proto = iph->nexthdr;
>  	for (;;) {
> -		if (proto != NEXTHDR_HOP) {
> -			*opps = rcu_dereference(inet6_offloads[proto]);
> -			if (unlikely(!(*opps)))
> -				break;
> -			if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR))
> -				break;
> -		}
> +		*opps = rcu_dereference(inet6_offloads[proto]);
> +		if (unlikely(!(*opps)))
> +			break;
> +		if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR))
> +			break;
> +
>  		opth = (void *)opth + optlen;
>  		optlen = ipv6_optlen(opth);
>  		len += optlen;
> -- 
> 2.36.1
>