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

From: Willem de Bruijn
Date: Tue Dec 26 2023 - 15:24:57 EST


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@xxxxxxxxx>

Reviewed-by: Willem de Bruijn <willemb@xxxxxxxxxx>

> ---
> 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
>