www.pudn.com > nat.rar > ip_conntrack.h

#ifndef _IP_CONNTRACK_H 
#define _IP_CONNTRACK_H 
 
#include "nat.h" 
 
struct tcp_hdr  
{ 
	unsigned short th_sport;	// source port  
	unsigned short th_dport;	// destination port 
	unsigned long  th_seq;		// sequence number 
	unsigned long  th_ack;		// ack number 
	unsigned char  th_off;	// header len (num of bytes << 2) 
 
	unsigned char  th_flags;	// control flags 
	#define	TH_URG	0x20	// urgent pointer is valid 
	#define	TH_ACK	0x10	// acknowledgement field is valid 
	#define	TH_PSH	0x08	// this segment requests a push 
	#define	TH_RST	0x04	// reset the connection 
	#define	TH_SYN	0x02	// synchronize sequence numbers	 
	#define	TH_FIN	0x01	// sender has reached end of its stream	 
 
	unsigned short th_wnd;		// window size(num of bytes) 
	unsigned short th_sum;	// check sum 
	unsigned short th_urgptr;	// urgent pointer 
	unsigned char  th_data[1]; // option + data 
}; 
 
struct udp_hdr  
{ 
	unsigned   short uh_sport;// src UDP port 
	unsigned   short uh_dport;// dest UDP port 
	unsigned   short uh_len;  
	unsigned   short uh_sum; 
}; 
 
struct tsd_hdr //定义TCP/UDP伪首部  
{  
	unsigned long saddr; //源地址  
	unsigned long daddr; //目的地址  
	char mbz;  
	char ptcl; //协议类型  
	unsigned short udpl; //TCP/UDP长度  
};  
 
enum tcp_conntrack { 
	TCP_CONNTRACK_NONE, 
	TCP_CONNTRACK_ESTABLISHED, 
	TCP_CONNTRACK_SYN_SENT, 
	TCP_CONNTRACK_SYN_RECV, 
	TCP_CONNTRACK_FIN_WAIT, 
	TCP_CONNTRACK_TIME_WAIT, 
	TCP_CONNTRACK_CLOSE, 
	TCP_CONNTRACK_CLOSE_WAIT, 
	TCP_CONNTRACK_LAST_ACK, 
	TCP_CONNTRACK_LISTEN, 
	TCP_CONNTRACK_MAX 
}; 
 
struct ip_ct_tcp 
{ 
	enum tcp_conntrack state; 
	unsigned long handshake_ack; 
}; 
 
struct ip_ct_icmp 
{ 
	int count; 
}; 
 
enum ip_conntrack_info 
{ 
	// 连接建立部分(两个方向)  
	IP_CT_ESTABLISHED, 
 
	// 象新的连接，但是有一个存在的相关节点，或者是ICMP错误(两个方向).  
	IP_CT_RELATED, 
 
	// 开始一个新的连接 (仅仅 IP_CT_DIR_ORIGINAL); 也可能是重传.  
	IP_CT_NEW, 
 
	// >= 表示回应方向  
	IP_CT_IS_REPLY, 
 
	// 不同的 IP_CT 类型个数 (no NEW in reply dirn).  
	IP_CT_NUMBER = IP_CT_IS_REPLY * 2 - 1 
}; 
 
// 连接状态.  
// Bitset representing status of connection.  
enum ip_conntrack_status  
{ 
	// It's an expected connection: bit 0 set.  This bit never changed  
	IPS_EXPECTED_BIT = 0, 
	IPS_EXPECTED = (1 << IPS_EXPECTED_BIT), 
 
	// We've seen packets both ways: bit 1 set.  Can be set, not unset.  
	IPS_SEEN_REPLY_BIT = 1, 
	IPS_SEEN_REPLY = (1 << IPS_SEEN_REPLY_BIT), 
 
	// Conntrack should never be early-expired. 
	IPS_ASSURED_BIT = 2, 
	IPS_ASSURED = (1 << IPS_ASSURED_BIT), 
}; 
 
#ifdef CONFIG_NF_DEBUG 
#define IP_NF_ASSERT(x)							\ 
do {									\ 
	if (!(x))							\ 
		printf("NF_IP_ASSERT: %s:%i(%s)\n",			\ 
		       __FILE__, __LINE__, __FUNCTION__);		\ 
} while(0) 
#else 
#define IP_NF_ASSERT(x) 
#endif 
 
struct ip_conntrack_expect 
{ 
	struct list_head list; 
	struct ip_conntrack_tuple tuple, mask; 
	int (*expectfn)(struct ip_conntrack *one); 
	struct ip_conntrack *expectant; 
}; 
 
struct ip_conntrack 
{ 
	// These are my tuples; original and reply 
	struct ip_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX]; 
 
	// Have we seen traffic both ways yet? (bitset) 
	volatile unsigned long status; 
 
	int count; 
	 
	// Timer function; drops refcnt when it goes off. 
	struct timer_list timeout; 
	 
	// Current number of expected connections 
	struct ip_conntrack_expect expected; 
 
	 
	// per conntrack: protocol private data 
	union  
	{ 
		// insert conntrack proto private data here  
		struct ip_ct_tcp tcp; 
		struct ip_ct_icmp icmp; 
	} proto; 
	 
};    
 
 
int ip_nat_used_tuple(const struct ip_conntrack_tuple *tuple, 
		  const struct ip_conntrack *ignored_conntrack); 
 
void checksumadjust(unsigned char *chksum, unsigned char *optr,  
					int olen, unsigned char *nptr, int nlen); 
 
struct ip_conntrack_tuple_hash * 
ip_conntrack_find(const struct ip_conntrack_tuple *tuple, 
					  const struct ip_conntrack *ignored_conntrack); 
 
struct ip_conntrack_tuple_hash * 
ip_portforward_setup(struct ip_nat_protocol * proto,  
	  	  struct ip_conntrack_tuple *tuple, 
		  const struct ip_nat_multi_range *mr, 
		  u_long lanip); 
 
struct ip_conntrack_tuple_hash * 
ip_nat_setup(struct ip_nat_protocol * proto,  
			 struct ip_conntrack_tuple *tuple, 
			 const struct ip_nat_multi_range *mr); 
 
void ip_ct_refresh(struct ip_conntrack *ct, unsigned long extra_jiffies); 
 
void conntrack_print(); 
 
#endif