ipvs: get sctphdr by sctphoff in sctp_csum_check

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>
Acked-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/ipvs/ip_vs_proto_sctp.c b/net/netfilter/ipvs/ip_vs_proto_sctp.c
index bc3d1625ecc85156f3f6256f3bee9f9471cdf575..b58ddb7dffd1521ddab2b43a7c396731405b96ba 100644 (file)
--- a/net/netfilter/ipvs/ip_vs_proto_sctp.c
+++ b/net/netfilter/ipvs/ip_vs_proto_sctp.c
@@ -186,7 +186,7 @@ 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
@@ -196,10 +196,7 @@ 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);