#ifndef _IP_CONNTRACK_CORE_H#define _IP_CONNTRACK_CORE_H#include <linux/netfilter_ipv4/lockhelp.h>/* This header is used to share core functionality between the   standalone connection tracking module, and the compatibility layer's use   of connection tracking. */extern unsigned int ip_conntrack_in(unsigned int hooknum,				    struct sk_buff **pskb,				    const struct net_device *in,				    const struct net_device *out,				    int (*okfn)(struct sk_buff *));extern int ip_conntrack_init(void);extern void ip_conntrack_cleanup(void);struct ip_conntrack_protocol;extern struct ip_conntrack_protocol *ip_ct_find_proto(u_int8_t protocol);/* Like above, but you already have conntrack read lock. */extern struct ip_conntrack_protocol *__ip_ct_find_proto(u_int8_t protocol);extern struct list_head protocol_list;/* Returns conntrack if it dealt with ICMP, and filled in skb->nfct */extern struct ip_conntrack *icmp_error_track(struct sk_buff *skb,					     enum ip_conntrack_info *ctinfo,					     unsigned int hooknum);extern int get_tuple(const struct iphdr *iph, size_t len,		     struct ip_conntrack_tuple *tuple,		     struct ip_conntrack_protocol *protocol);/* Find a connection corresponding to a tuple. */struct ip_conntrack_tuple_hash *ip_conntrack_find_get(const struct ip_conntrack_tuple *tuple,		      const struct ip_conntrack *ignored_conntrack);extern int __ip_conntrack_confirm(struct nf_ct_info *nfct);/* Confirm a connection: returns NF_DROP if packet must be dropped. */static inline int ip_conntrack_confirm(struct sk_buff *skb){	if (skb->nfct	    && !is_confirmed((struct ip_conntrack *)skb->nfct->master))		return __ip_conntrack_confirm(skb->nfct);	return NF_ACCEPT;}extern struct list_head *ip_conntrack_hash;extern struct list_head ip_conntrack_expect_list;DECLARE_RWLOCK_EXTERN(ip_conntrack_lock);#endif /* _IP_CONNTRACK_CORE_H */