Re: [PATCH nf-next 5/6] netfilter: use nf_ip6_check_hbh_len in nf_ct_skb_network_trim

[Aaron Conole <aconole@redhat.com>]

Xin Long <lucien.xin@gmail.com> writes:

> For IPv6 Jumbo packets, the ipv6_hdr(skb)->payload_len is always 0,
> and its real payload_len ( > 65535) is saved in hbh exthdr. With 0
> length for the jumbo packets, all data and exthdr will be trimmed
> in nf_ct_skb_network_trim().
>
> This patch is to call nf_ip6_check_hbh_len() to get real pkt_len
> of the IPv6 packet, similar to br_validate_ipv6().
>
> Signed-off-by: Xin Long <lucien.xin@gmail.com>
> ---

Reviewed-by: Aaron Conole <aconole@redhat.com>

>  net/netfilter/nf_conntrack_ovs.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/net/netfilter/nf_conntrack_ovs.c b/net/netfilter/nf_conntrack_ovs.c
> index 52b776bdf526..2016a3b05f86 100644
> --- a/net/netfilter/nf_conntrack_ovs.c
> +++ b/net/netfilter/nf_conntrack_ovs.c
> @@ -6,6 +6,7 @@
>  #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
>  #include <net/ipv6_frag.h>
>  #include <net/ip.h>
> +#include <linux/netfilter_ipv6.h>
>  
>  /* 'skb' should already be pulled to nh_ofs. */
>  int nf_ct_helper(struct sk_buff *skb, struct nf_conn *ct,
> @@ -114,14 +115,20 @@ EXPORT_SYMBOL_GPL(nf_ct_add_helper);
>  int nf_ct_skb_network_trim(struct sk_buff *skb, int family)
>  {
>  	unsigned int len;
> +	int err;
>  
>  	switch (family) {
>  	case NFPROTO_IPV4:
>  		len = skb_ip_totlen(skb);
>  		break;
>  	case NFPROTO_IPV6:
> -		len = sizeof(struct ipv6hdr)
> -			+ ntohs(ipv6_hdr(skb)->payload_len);
> +		len = ntohs(ipv6_hdr(skb)->payload_len);
> +		if (ipv6_hdr(skb)->nexthdr == NEXTHDR_HOP) {
> +			err = nf_ip6_check_hbh_len(skb, &len);
> +			if (err)
> +				return err;
> +		}
> +		len += sizeof(struct ipv6hdr);
>  		break;
>  	default:
>  		len = skb->len;