#include <linux/kernel.h> #include <linux/netfilter.h> #include <linux/netfilter_ipv4.h> #include <linux/netfilter_ipv6.h> __sum16 nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff, u_int8_t protocol, unsigned short family) { const struct nf_ipv6_ops *v6ops; __sum16 csum = 0; switch (family) { case AF_INET: csum = nf_ip_checksum(skb, hook, dataoff, protocol); break; case AF_INET6: v6ops = rcu_dereference(nf_ipv6_ops); if (v6ops) csum = v6ops->checksum(skb, hook, dataoff, protocol); break; } return csum; } EXPORT_SYMBOL_GPL(nf_checksum);