#ifndef LTSM_H_
#define LTSM_H_

#include <netinet/ip.h>
#include <netinet/ip6.h>
#include <netinet/tcp.h>
#include "mesa_net.h"
/*
	LTSM : Light TCP State Machine.
	
*/

/* RFC标准TCP协议栈状态机定义 */
enum full_tcp_state{
	FTSM_CLOSED,
	FTSM_LISTEN,
	FTSM_SYN_SENT,
	FTSM_SYN_RCVD,
	FTSM_ESTABLISHED,
	FTSM_CLOSE_WAIT,
	FTSM_LAST_ACK,
	FTSM_FIN_WAIT1,
	FTSM_FIN_WAIT2,
	FTSM_CLOSING,
	FTSM_TIME_WAIT,
};

/* 
	轻量TCP状态机定义, 
	只有三种状态:新建连接, 传输数据, 结束连接, 
	每个流必定包括1个START和1个CLOSE状态, 可能包括0或若干个DATA状态.
*/
enum light_tcp_state{
	LTSM_START,
	LTSM_DATA,
	LTSM_CLOSE,
	LTSM_INVALID,
};


enum light_tsm_opt{
	LTSMO_THREAD_NUM,		/* 线程总数, 选项类型:uint32 */
	LTSMO_CREATE_MODE,		/* 流创建模式, 1:必须包含SYN; 2:任意数据包可触发, 选项类型:uint32 */
	LTSMO_MAX_STREAM_NUM,	/* TCP最大并发流表数, for每个线程, 选项类型:uint32 */
	LTSMO_STREAM_TIMEOUT,	/* 流超时淘汰时间, 单位:秒, 0表示不超时. 选项类型:uint32 */
};

struct ltsm_result{
	enum full_tcp_state fstate;
	enum light_tcp_state lstate;
	void *pme;
};

typedef void * ltsm_global_handle;
typedef void * ltsm_stream_handle;

/* ltsm全局句柄初始化 */
void *ltsm_init(void);

/* ltsm设置相关参数 */
int ltsm_set_opt(ltsm_global_handle pltsm, enum light_tsm_opt opt, void *value, int value_len);

/* ltsm启动 */
int ltsm_run(ltsm_global_handle pltsm);

/* IPv4包处理, 返回当前包触发的ltsm状态机结果, pme用于外部调用者存储自定义数据, 内存需自行申请或释放 */
struct ltsm_result *ltsm_proc_ip4pkt(ltsm_global_handle pltsm, int tseq, const struct ip *ip4hdr);

/* IPv4包头+TCP包头处理, 返回当前包触发的ltsm状态机结果, pme用于外部调用者存储自定义数据, 内存需自行申请或释放 */
struct ltsm_result *ltsm_proc_ip4tcppkt(ltsm_global_handle pltsm, int tseq, const struct ip *ip4hdr, const struct tcphdr *tcp_hdr);

/* IPv6包处理, 返回当前包触发的ltsm状态机结果, pme用于外部调用者存储自定义数据, 内存需自行申请或释放 */
struct ltsm_result *ltsm_proc_ip6pkt(ltsm_global_handle pltsm, int tseq, const struct ip6_hdr *ip6hdr);

/* IPv6包头+TCP包头处理, 返回当前包触发的ltsm状态机结果, pme用于外部调用者存储自定义数据, 内存需自行申请或释放 */
struct ltsm_result *ltsm_proc_ip6tcppkt(ltsm_global_handle pltsm, int tseq, const struct ip6_hdr *ip6hdr, const struct tcphdr *tcp_hdr);

uint8_t ltsm_proc_ipv4tcppkt(ltsm_stream_handle s_ltsm, const struct mesa_ip4_hdr *iphdr);

void ltsm_destroy_stream_handle(ltsm_stream_handle s_ltsm);
#endif