///
 // Copyright (c) 2003, Wolver Wang, MinShan Inc. R&D Center
 // wolver@minshan-inc.com
 // All rights reserved. 
 //
 // Redistribution and use in source and binary forms, with or without 
 // modification, are permitted provided that the following conditions 
 // are met: 
 // 1. Redistributions of source code must retain the above copyright 
 //    notice, this list of conditions and the following disclaimer. 
 // 2. Redistributions in binary form must reproduce the above copyright 
 //    notice, this list of conditions and the following disclaimer in the 
 //    documentation and/or other materials provided with the distribution. 
 // 3. All advertising materials mentioning features or use of this software
 //    must display the following acknowledgement:
 //      This product includes software developed by Wolver Wang.
 // 4. The name of the author may not be used to endorse or promote
 //    products derived from this software without specific prior
 //    written permission.  
 //
 // THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
 // OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 // WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 // ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 // DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 // GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 // WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  
 ///
 

///
 // Copyright (c) 2003, Wolver Wang, MinShan Inc. R&D Center
 // wolver@minshan-inc.com
 // All rights reserved. 
 //
 // Redistribution and use in source and binary forms, with or without 
 // modification, are permitted provided that the following conditions 
 // are met: 
 // 1. Redistributions of source code must retain the above copyright 
 //    notice, this list of conditions and the following disclaimer. 
 // 2. Redistributions in binary form must reproduce the above copyright 
 //    notice, this list of conditions and the following disclaimer in the 
 //    documentation and/or other materials provided with the distribution. 
 // 3. All advertising materials mentioning features or use of this software
 //    must display the following acknowledgement:
 //      This product includes software developed by Wolver Wang.
 // 4. The name of the author may not be used to endorse or promote
 //    products derived from this software without specific prior
 //    written permission.  
 //
 // THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
 // OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 // WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 // ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 // DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 // GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 // WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  
 ///
 

///
 // 版權 2003, 王衛無，四川綿陽岷山集團有限公司--研究開發中心
 // wolver@minshan-inc.com
 // 保留一切權利
 //
 // 如果符合以下條件，則無論是以原代碼或非原代碼代碼形式，且不論是否修改，
 // 再分發和使用本軟件都是被允許的。
 // 1. 原代碼的再分發必須保留上述的版權聲明、本條件說明和以下免責聲明。
 // 2. 非原代碼形式的再分發，必須在證明文件和(或)其它一同提供的材料中重新
 //    作上述的版權聲明、本條件說明和以下免責聲明。
 // 3. 一切提及本軟件和使用的廣告材料必須顯示以下致謝：
 //    本產品包含王衛無（四川綿陽岷山集團有限公司--研究開發中心）開發的軟件。
 // 4. 如果沒有預先得到特定的書面許可，不能用作者的名字來宣傳推廣基于本軟件得到
 //    的產品。
 //
 // 免責聲明：
 // 本軟件是由某某作者提供，如果出現以下情況，作者都不承擔任何責任。
 // 1. 因作者的說明以及任何明確的或暗示的保證(包括但不限于表達某種商業性和適合某一
 //    特定目的暗示性保證)而產生的損失。
 // 2. 無論在何種情況下，對使用本軟件造成的任何直接的、間接的、偶然的、特定的、可預
 //    見性的和連帶產生的損失(包括但不限于獲取產品和服務、作用喪失、數據遺失、利益損
 //    失或商業干預)，無論這些損失是怎樣造成的，并且是以何種方式闡釋責任。
 // 3. 任何因使用本軟件而相關的合同、嚴格賠償責任和侵權行為(包含：疏忽或其它)的損失，
 //    甚至即便是可能的此類已經明示或暗示的損失。
 ///


#include "tcpip.h"

#if TCP_DHCP == 0
const UINT16 guwIpAddr[2] = {((cIpAddr1<<8)|cIpAddr2), ((cIpAddr3<<8)|cIpAddr4)};
#else
UINT16 guwIpAddr[2];
#endif

#if TCP_DHCP == 0
const UINT16 guwNetMask[2] = {((cNetMask1<<8)|cNetMask2), ((cNetMask3<<8)|cNetMask4)};
#else
UINT16 guwNetMask[2];
#endif

#if TCP_DHCP == 0
const UINT16 guwDR_IpAddr[2] = {((cDR_IpAddr1<<8)|cDR_IpAddr2), ((cDR_IpAddr3<<8)|cDR_IpAddr4)};
#else
UINT16 guwDR_IpAddr[2];
#endif

const UINT16 guwEthAddr[3] = {((cEthAddr1<<8)|cEthAddr2), ((cEthAddr3<<8)|cEthAddr4), ((cEthAddr5<<8)|cEthAddr6)};



// 最大允許的以太包緩沖區
UINT16 guwEthBuf[cEthBufSize];

// 正在處理包的字節長度。這個值隨處理層的不同而改變！
volatile UINT16 guwEthLen = 0;

// 分配ARP表的內寸
ArpEntries_Stru		gstArpTab[cArpTabSize];

// 記錄本地IP序號
volatile UINT16 guwIpId;

// TCP 本地初始32位序號
volatile UINT16 guwISN[2];

// 記錄TCP本地端口號
UINT16 guwListenPorts[cMaxListenPorts];

// TCP最大聯接事務記錄表
Conn_Stru			gstConns[cMaxConnetions];

// 當前TCP事務聯接指針
Conn_Stru *gptConn;

// TCP/IP協議棧和應用程序間通訊的變量
volatile UINT16 guwFlags;

//--------------------------------------------------------------------------------------
void msip_Init(void){
	UINT16 index;

	// Initialize ArpEntries
	for (index = 0; index < cArpTabSize; index++){
		gstArpTab[index].IpAddr[0] = 0;
		gstArpTab[index].IpAddr[1] = 0;
	}

	// Initialize Listen Ports
	for (index = 0; index < cMaxListenPorts; index++)
		guwListenPorts[index] = 0;
	
	// Initialize Listen Ports
	for (index = 0; index < cMaxConnetions; index++){
		gstConns[index].TcpStateFlags = cTCP_CLOSED;
		gstConns[index].PollTime = 0;
	}
		
}

//--------------------------------------------------------------------------------------
void msip_Arp_Time(){
	ArpEntries_Stru *pARP;

	for (pARP = cptArpTabStart; pARP < cptArpTabEnd; pARP++){
		if (((pARP->IpAddr[0] | pARP->IpAddr[1]) != 0) && ((guwTime2 - pARP->Time2) > 2*cArpMaxAge)){
			pARP->IpAddr[0] = 0;
			pARP->IpAddr[1] = 0;
		}
	}

	guwMsg_Route &= ~cM_ARP_TIME;	// 清除ARP表老化處理事件
}

//--------------------------------------------------------------------------------------
ArpEntries_Stru *msip_Arp_Update(UINT16 *uwIpAddr, UINT16 *uwEthAddr){
	ArpEntries_Stru *pARPTAB, *pARPTAB1;
	UINT16 maxtime,cmptime;

	// 如果接收包的源地址與本地相同，說明是DDoS攻擊！！！
	if ((uwIpAddr[0] == guwIpAddr[0]) && (uwIpAddr[1] == guwIpAddr[1])){
		return cptArpTabEnd;
	}

	// 如果找到匹配的IP，就更新MAC 
	for (pARPTAB = cptArpTabStart; pARPTAB < cptArpTabEnd; pARPTAB++){
		if((pARPTAB->IpAddr[0] == uwIpAddr[0]) && (pARPTAB->IpAddr[1] == uwIpAddr[1])){
			goto Arp_Update_Exit2;	// 更新 MAC/Time
		}
	}

	// 沒有找到匹配IP，找個空記錄來更新
	for (pARPTAB = cptArpTabStart; pARPTAB < cptArpTabEnd; pARPTAB++){
		if((pARPTAB->IpAddr[0] | pARPTAB->IpAddr[1]) == 0){
			goto Arp_Update_Exit1;	// 更新 IP/MAC/Time
		}
	}

	// 既沒有匹配IP，又沒有空記錄！把時間最長的記錄更新
	maxtime = 0;
	for (pARPTAB1 = cptArpTabStart; pARPTAB1 < cptArpTabEnd; pARPTAB1++){
		cmptime = guwTime2 - pARPTAB1->Time2;	// 計算記錄存放時間
		if(cmptime > maxtime){
			maxtime = cmptime;			// 記錄最大時間
			pARPTAB = pARPTAB1;				// 記錄ARP表指針
		}
	}
	
Arp_Update_Exit1:
	pARPTAB->IpAddr[0] = uwIpAddr[0];
	pARPTAB->IpAddr[1] = uwIpAddr[1];

Arp_Update_Exit2:
	pARPTAB->EthAddr[0] = uwEthAddr[0];
	pARPTAB->EthAddr[1] = uwEthAddr[1];
	pARPTAB->EthAddr[2] = uwEthAddr[2];
	pARPTAB->Time2 = guwTime2;
	
	return pARPTAB;
}

//--------------------------------------------------------------------------------------
void msip_Arp_In(void){
	
	// 如果接收包的源地址與本地相同，說明是DDoS攻擊！！！
	if ((cptArpHdrBuf->SndIpAddr[0] == guwIpAddr[0]) &&
		(cptArpHdrBuf->SndIpAddr[1] == guwIpAddr[1])){
		goto arp_in_exit;
	}

	// 如果不是請求本地，就退出！
	if ((cptArpHdrBuf->RcvIpAddr[0] != guwIpAddr[0]) || 
		(cptArpHdrBuf->RcvIpAddr[1] != guwIpAddr[1])){
		goto arp_in_exit;
	}

	switch (cptArpHdrBuf->OpCode){
	case cArpRequest:
	// 如果是ARP請求，就構造ARP回應
		cptEthHdrBuf->DestEthAddr[0] = cptArpHdrBuf->SndEthAddr[0];
		cptArpHdrBuf->RcvEthAddr[0] = cptArpHdrBuf->SndEthAddr[0];
			
		cptEthHdrBuf->DestEthAddr[1] = cptArpHdrBuf->SndEthAddr[1];
		cptArpHdrBuf->RcvEthAddr[1] = cptArpHdrBuf->SndEthAddr[1];
		
		cptEthHdrBuf->DestEthAddr[2] = cptArpHdrBuf->SndEthAddr[2];
		cptArpHdrBuf->RcvEthAddr[2] = cptArpHdrBuf->SndEthAddr[2];
			
		cptEthHdrBuf->SrcEthAddr[0] = guwEthAddr[0];
		cptArpHdrBuf->SndEthAddr[0] = guwEthAddr[0];
			
		cptEthHdrBuf->SrcEthAddr[1] = guwEthAddr[1];
		cptArpHdrBuf->SndEthAddr[1] = guwEthAddr[1];
		
		cptEthHdrBuf->SrcEthAddr[2] = guwEthAddr[2];
		cptArpHdrBuf->SndEthAddr[2] = guwEthAddr[2];
			
		cptArpHdrBuf->RcvIpAddr[0] = cptArpHdrBuf->SndIpAddr[0];
		cptArpHdrBuf->RcvIpAddr[1] = cptArpHdrBuf->SndIpAddr[1];
		cptArpHdrBuf->SndIpAddr[0] = guwIpAddr[0];
		cptArpHdrBuf->SndIpAddr[1] = guwIpAddr[1];

		cptArpHdrBuf->OpCode = cArpReply;
		// cptEthHdrBuf->EthType: is unchanged
		// cptArpHdrBuf->HwType: is unchanged
		// cptArpHdrBuf->ProtoType: is unchanged
		// cptArpHdrBuf->HwLen8Proto8:  is unchanged
			
		// 發送以太包
		guwEthLen = 60;
		ether_Send();
		break;
	case cArpReply:
	// 如果是ARP回應，就更新ARP表
		msip_Arp_Update(cptArpHdrBuf->SndIpAddr, cptArpHdrBuf->SndEthAddr);
	}

arp_in_exit:

	// 釋放緩沖區
	guwEthLen = 0;
}


//--------------------------------------------------------------------------------------
void msip_Arp_Out(ArpEntries_Stru *pARPTAB){

	// 如果指針是否在ARP表范圍內，就構造以太頭
	if ((pARPTAB >= cptArpTabStart) && (pARPTAB < cptArpTabEnd)){
		goto build_eth;
	}
	
	// 指針不在ARP范圍，檢查遠端IP是否在本地網內，以決定ARP請求的遠端IP地址
	if (((cptIpHdrBuf->DestIpAddr[0] & guwNetMask[0]) == (guwIpAddr[0] & guwNetMask[0])) &&
		((cptIpHdrBuf->DestIpAddr[1] & guwNetMask[1]) == (guwIpAddr[1] & guwNetMask[1]))){
		// IP在本地網內，在ARP表里查找對應遠端IP地址的表指針
		for (pARPTAB = cptArpTabStart; pARPTAB < cptArpTabEnd; pARPTAB++){
		
			if((pARPTAB->IpAddr[0] == cptIpHdrBuf->DestIpAddr[0]) &&
				(pARPTAB->IpAddr[1] == cptIpHdrBuf->DestIpAddr[1])){
				
				goto build_eth;
			}
		}

		goto request_local;

	} else {
		// 遠端IP不在本地網內，在ARP表里查找網關IP地址的表指針
		for (pARPTAB = cptArpTabStart; pARPTAB < cptArpTabEnd; pARPTAB++){

			if((pARPTAB->IpAddr[0] == guwDR_IpAddr[0]) && (pARPTAB->IpAddr[1] == guwDR_IpAddr[1])){

				goto build_eth;
			}
		}
		
		//goto request_gateway;
	}


// 如果到這里，表明在ARP表里找不到相應的IP記錄！所以構造需要的ARP請求包
request_gateway:
	cptArpHdrBuf->RcvIpAddr[0] = guwDR_IpAddr[0];
	cptArpHdrBuf->RcvIpAddr[1] = guwDR_IpAddr[1];
	goto build_arp;

request_local:
	cptArpHdrBuf->RcvIpAddr[0] = cptIpHdrBuf->DestIpAddr[0];
	cptArpHdrBuf->RcvIpAddr[1] = cptIpHdrBuf->DestIpAddr[1];

build_arp:
	cptArpHdrBuf->SndIpAddr[0] = guwIpAddr[0];
	cptArpHdrBuf->SndIpAddr[1] = guwIpAddr[1];

	cptEthHdrBuf->DestEthAddr[0] = 0xffff;
	cptEthHdrBuf->DestEthAddr[1] = 0xffff;
	cptEthHdrBuf->DestEthAddr[2] = 0xffff;

	cptArpHdrBuf->RcvEthAddr[0] = 0x0000;
	cptArpHdrBuf->RcvEthAddr[1] = 0x0000;
	cptArpHdrBuf->RcvEthAddr[2]	= 0x0000;

	cptEthHdrBuf->SrcEthAddr[0] = guwEthAddr[0];
	cptArpHdrBuf->SndEthAddr[0] = guwEthAddr[0];
	
	cptEthHdrBuf->SrcEthAddr[1] = guwEthAddr[1];
	cptArpHdrBuf->SndEthAddr[1] = guwEthAddr[1];
	
	cptEthHdrBuf->SrcEthAddr[2] = guwEthAddr[2];
	cptArpHdrBuf->SndEthAddr[2] = guwEthAddr[2];

	cptEthHdrBuf->EthType = cEthType_Arp;
	cptArpHdrBuf->HwType = cHwType_Eth;
	cptArpHdrBuf->ProtoType = cEthType_Ip;
	cptArpHdrBuf->Hw8Proto8 = c_vIP4;
	cptArpHdrBuf->OpCode = cArpRequest;
		
	guwEthLen = 60;
	goto send_eth;	// 跳到發送以太包處理

build_eth:
	// 構造需要的以太頭
	cptEthHdrBuf->DestEthAddr[0] = pARPTAB->EthAddr[0];
	cptEthHdrBuf->DestEthAddr[1] = pARPTAB->EthAddr[1];
	cptEthHdrBuf->DestEthAddr[2] = pARPTAB->EthAddr[2];
	cptEthHdrBuf->SrcEthAddr[0] = guwEthAddr[0];
	cptEthHdrBuf->SrcEthAddr[1] = guwEthAddr[1];
	cptEthHdrBuf->SrcEthAddr[2] = guwEthAddr[2];