+extern const struct nf_afinfo *nf_afinfo[NPROTO];
+static inline const struct nf_afinfo *nf_get_afinfo(unsigned short family)
+{
+ return rcu_dereference(nf_afinfo[family]);
+}
+
+static inline __sum16
+nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff,
+ u_int8_t protocol, unsigned short family)
+{
+ const struct nf_afinfo *afinfo;
+ __sum16 csum = 0;
+
+ rcu_read_lock();
+ afinfo = nf_get_afinfo(family);
+ if (afinfo)
+ csum = afinfo->checksum(skb, hook, dataoff, protocol);
+ rcu_read_unlock();
+ return csum;
+}
+
+static inline __sum16
+nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
+ unsigned int dataoff, unsigned int len,
+ u_int8_t protocol, unsigned short family)
+{
+ const struct nf_afinfo *afinfo;
+ __sum16 csum = 0;
+
+ rcu_read_lock();
+ afinfo = nf_get_afinfo(family);
+ if (afinfo)
+ csum = afinfo->checksum_partial(skb, hook, dataoff, len,
+ protocol);
+ rcu_read_unlock();
+ return csum;
+}