[NET]: Move netfilter checksum helpers to net/core/utils.c

This allows to get rid of the CONFIG_NETFILTER dependency of NET_ACT_NAT.
This patch redefines the old names to keep the noise low, the next patch
converts all users.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 45 insertions, 37 deletions

diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 25fc12260340..e2bf6d2ffb6c 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -298,27 +298,10 @@ extern void nf_invalidate_cache(int pf);
    Returns true or false. */
 extern int skb_make_writable(struct sk_buff *skb, unsigned int writable_len);
 
-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);
-}
+#define nf_csum_replace4        csum_replace4
+#define nf_csum_replace2        csum_replace2
+#define nf_proto_csum_replace4  inet_proto_csum_replace4
+#define nf_proto_csum_replace2  inet_proto_csum_replace2
 
 struct nf_afinfo {
         unsigned short  family;
diff --git a/include/net/checksum.h b/include/net/checksum.h
index 124246172a88..07602b7fa218 100644
--- a/include/net/checksum.h
+++ b/include/net/checksum.h
@@ -93,4 +93,29 @@ static inline __wsum csum_unfold(__sum16 n)
 }
 
 #define CSUM_MANGLED_0 ((__force __sum16)0xffff)
+
+static inline void 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 csum_replace2(__sum16 *sum, __be16 from, __be16 to)
+{
+        csum_replace4(sum, (__force __be32)from, (__force __be32)to);
+}
+
+struct sk_buff;
+extern void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
+                                     __be32 from, __be32 to, int pseudohdr);
+
+static inline void inet_proto_csum_replace2(__sum16 *sum, struct sk_buff *skb,
+                                            __be16 from, __be16 to,
+                                            int pseudohdr)
+{
+        inet_proto_csum_replace4(sum, skb, (__force __be32)from,
+                                 (__force __be32)to, pseudohdr);
+}
+
 #endif
diff --git a/net/core/utils.c b/net/core/utils.c
index 0bf17da40d52..34459c4c740c 100644
--- a/net/core/utils.c
+++ b/net/core/utils.c
@@ -293,3 +293,19 @@ out:
 }
 
 EXPORT_SYMBOL(in6_pton);
+
+void inet_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
+                              __be32 from, __be32 to, int pseudohdr)
+{
+        __be32 diff[] = { ~from, to };
+        if (skb->ip_summed != CHECKSUM_PARTIAL) {
+                *sum = csum_fold(csum_partial(diff, sizeof(diff),
+                                ~csum_unfold(*sum)));
+                if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
+                        skb->csum = ~csum_partial(diff, sizeof(diff),
+                                                ~skb->csum);
+        } else if (pseudohdr)
+                *sum = ~csum_fold(csum_partial(diff, sizeof(diff),
+                                csum_unfold(*sum)));
+}
+EXPORT_SYMBOL(inet_proto_csum_replace4);
diff --git a/net/netfilter/core.c b/net/netfilter/core.c
index bed9ba01e8ec..631d26948314 100644
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c
@@ -217,22 +217,6 @@ int skb_make_writable(struct sk_buff *skb, unsigned int writable_len)
 }
 EXPORT_SYMBOL(skb_make_writable);
 
-void nf_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
-                            __be32 from, __be32 to, int pseudohdr)
-{
-        __be32 diff[] = { ~from, to };
-        if (skb->ip_summed != CHECKSUM_PARTIAL) {
-                *sum = csum_fold(csum_partial(diff, sizeof(diff),
-                                ~csum_unfold(*sum)));
-                if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
-                        skb->csum = ~csum_partial(diff, sizeof(diff),
-                                                ~skb->csum);
-        } else if (pseudohdr)
-                *sum = ~csum_fold(csum_partial(diff, sizeof(diff),
-                                csum_unfold(*sum)));
-}
-EXPORT_SYMBOL(nf_proto_csum_replace4);
-
 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
 /* This does not belong here, but locally generated errors need it if connection
    tracking in use: without this, connection may not be in hash table, and hence