[NET]: netfilter checksum annotations

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 23 insertions, 7 deletions

diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 707bb2e53c4e..6ab5e2d6133e 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -282,11 +282,27 @@ extern void nf_invalidate_cache(int pf);
    Returns true or false. */
 extern int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len);
 
-extern u_int16_t nf_csum_update(u_int32_t oldval, u_int32_t newval,
-                                u_int32_t csum);
-extern u_int16_t nf_proto_csum_update(struct sk_buff *skb,
-                                      u_int32_t oldval, u_int32_t newval,
-                                      u_int16_t csum, int pseudohdr);
+static inline void nf_csum_replace4(__sum16 *sum, __be32 from, __be32 to)
+{
+        __be32 diff[] = { ~from, to };
+
+        *sum = csum_fold(csum_partial((char *)diff, sizeof(diff), ~csum_unfold(*sum)));
+}
+
+static inline void nf_csum_replace2(__sum16 *sum, __be16 from, __be16 to)
+{
+        nf_csum_replace4(sum, (__force __be32)from, (__force __be32)to);
+}
+
+extern void nf_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
+                                      __be32 from, __be32 to, int pseudohdr);
+
+static inline void nf_proto_csum_replace2(__sum16 *sum, struct sk_buff *skb,
+                                      __be16 from, __be16 to, int pseudohdr)
+{
+        nf_proto_csum_replace4(sum, skb, (__force __be32)from,
+                                (__force __be32)to, pseudohdr);
+}
 
 struct nf_afinfo {
         unsigned short  family;
diff --git a/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h b/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h
index 1d853aa873eb..e371e0fc1672 100644
--- a/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h
+++ b/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h
@@ -102,11 +102,11 @@ static inline __be32 *gre_key(struct gre_hdr *greh)
 }
 
 /* get pointer ot gre csum, if present */
-static inline u_int16_t *gre_csum(struct gre_hdr *greh)
+static inline __sum16 *gre_csum(struct gre_hdr *greh)
 {
         if (!greh->csum)
                 return NULL;
-        return (u_int16_t *) (greh+sizeof(*greh));
+        return (__sum16 *) (greh+sizeof(*greh));
 }
 
 #endif /* __KERNEL__ */