Re: [PATCH net] ipvs: get sctphdr by sctphoff in sctp_csum_check

[Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>]

On Mon, Feb 25, 2019 at 07:27:43PM +0800, Xin Long wrote:
> sctp_csum_check() is called by sctp_s/dnat_handler() where it calls
> skb_make_writable() to ensure sctphdr to be linearized.
> 
> So there's no need to get sctphdr by calling skb_header_pointer()
> in sctp_csum_check().
> 
> Signed-off-by: Xin Long <lucien.xin@gmail.com>

Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>

> ---
>  net/netfilter/ipvs/ip_vs_proto_sctp.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/net/netfilter/ipvs/ip_vs_proto_sctp.c b/net/netfilter/ipvs/ip_vs_proto_sctp.c
> index b0cd7d0..0ecf241 100644
> --- a/net/netfilter/ipvs/ip_vs_proto_sctp.c
> +++ b/net/netfilter/ipvs/ip_vs_proto_sctp.c
> @@ -183,7 +183,7 @@ static int
>  sctp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp)
>  {
>  	unsigned int sctphoff;
> -	struct sctphdr *sh, _sctph;
> +	struct sctphdr *sh;
>  	__le32 cmp, val;
>  
>  #ifdef CONFIG_IP_VS_IPV6
> @@ -193,10 +193,7 @@ sctp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp)
>  #endif
>  		sctphoff = ip_hdrlen(skb);
>  
> -	sh = skb_header_pointer(skb, sctphoff, sizeof(_sctph), &_sctph);
> -	if (sh == NULL)
> -		return 0;
> -
> +	sh = (struct sctphdr *)(skb->data + sctphoff);
>  	cmp = sh->checksum;
>  	val = sctp_compute_cksum(skb, sctphoff);
>  
> -- 
> 2.1.0
>