自定義IP分組發送UDP包

注意，應以管理員身份運行，否則會無效創建原始套接字！

代碼

#define _WINSOCK_DEPRECATED_NO_WARNINGS
#define _CRT_SECURE_NO_WARNINGS
#define DestPort 65432            //目的UDP端口
#define SourcePort 65433          //源UDP端口
#include "iostream"
#include "winsock2.h"
#include "string.h"
#include "ws2tcpip.h"
#pragma comment(lib,"ws2_32.lib")
using namespace std;

typedef struct _IPHeader {        //定義IP首部結構
	unsigned char iphVerLen;      //版本號和頭部長度
	unsigned char ipTOS;          //服務類型
	unsigned short ipLength;      //分組總長度
	unsigned short ipID;          //分組標識
	unsigned short ipFlags;       //標誌
	unsigned char ipTTL;          //生存時間
	unsigned char ipProtocol;     //協議
	unsigned short ipChecksum;    //校驗和
	unsigned long ipSource;       //源IP地址
	unsigned long ipDestination;  //目的IP地址
}IPHeader;

typedef struct _UDPHeader {       //定義IP首部結構
	unsigned short sourcePort;    //源端口號
	unsigned short destinationPort;//目的端口號
	unsigned short len;           //包長度
	unsigned short checksum;      //校驗和
}UDPHeader;

typedef struct tsd_hdr {          //定義UDP僞首部結構
	unsigned long saddr;          //源IP地址
	unsigned long daddr;          //目的IP地址
	char mbz;                     //填充
	char ptcl;                    //協議型
	unsigned short udpl;          //TCP長度
}PSDHEADER;

unsigned short checksum(unsigned short * buff, int size) {
	unsigned long cksum = 0;
	while (size > 1) {
		cksum += *buff++;
		size -= sizeof(unsigned short);
	}
	if (size)cksum += *(char *)buff;
	cksum = (cksum >> 16) + (cksum & 0xffff);
	cksum += (cksum >> 16);
	return (unsigned short)(~cksum);
}

int main(int argc, char **argv) {

	//加載winsock2.2
	WSADATA wsaData;
	int ret;
	if ((ret = WSAStartup(MAKEWORD(2, 2), &wsaData)) != 0) {
		cout << "初始化WinSock2.2出錯！";
		return -1;
	}

	//輸入目的IP地址或域名
	char szDestIp[256] = { 0 };
    cout << "請輸入目的地址:" << endl;
	cin.getline(szDestIp, sizeof(szDestIp));
	
	char szSourceIp[] = "192.168.0.108";    //源IP地址（本機IP地址）
	char szMsg[] = "give you a UDP package!\n";
	int nMsgLen = strlen(szMsg);
	
	SOCKET sRaw = socket(AF_INET, SOCK_RAW, IPPROTO_RAW); 
	if (sRaw == INVALID_SOCKET) {
		cout << WSAGetLastError()<<endl;
		return -1;
	}

	//綁定本地IP地址
	sockaddr_in addr;
	memset((void *)&addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_port = htons(SourcePort);
	addr.sin_addr.s_addr = htonl(INADDR_ANY);
	if (bind(sRaw, (sockaddr *)&addr, sizeof(addr)) == SOCKET_ERROR) {
		cout << "bind failed" << endl;
		WSACleanup();
		return 0;
	}
	
	int bIncl = 1;
	setsockopt(sRaw,IPPROTO_IP, IP_HDRINCL, (char *)&bIncl, sizeof(bIncl));
	
	//創建並填充IP首部
	char buff[1024] = { 0 };
	IPHeader *pIphdr = (IPHeader *)buff;
	pIphdr->iphVerLen = (4 << 4 | (sizeof(IPHeader) / sizeof(unsigned long)));
	pIphdr->ipLength = htons(sizeof(IPHeader) + sizeof(UDPHeader) + sizeof(UDPHeader) + nMsgLen);
	pIphdr->ipTTL = 128;
	pIphdr->ipProtocol = IPPROTO_UDP;
	pIphdr->ipSource = inet_addr(szSourceIp);
	pIphdr->ipDestination = inet_addr(szDestIp);
	pIphdr->ipChecksum = checksum((unsigned short *)pIphdr, sizeof(IPHeader));

	//填充UDP首部
	UDPHeader *pUdphdr = (UDPHeader *)&buff[sizeof(IPHeader)];
	pUdphdr->sourcePort = htons(SourcePort);
	pUdphdr->destinationPort = htons(DestPort);
	pUdphdr->len = htons(sizeof(UDPHeader) + nMsgLen);
	pUdphdr->checksum = 0;
	
	//填充UDP數據
	char *pData = &buff[sizeof(IPHeader) + sizeof(UDPHeader)];
	memcpy(pData, szMsg, nMsgLen);

	//填充僞首部
	PSDHEADER psdHeader;
	psdHeader.saddr = pIphdr->ipSource;
	psdHeader.daddr = pIphdr->ipDestination;
	psdHeader.mbz = 0;
	psdHeader.ptcl = IPPROTO_UDP;
	psdHeader.udpl = htons(sizeof(UDPHeader) + nMsgLen);
	char szBuff[1024];
	memcpy(szBuff, &psdHeader, sizeof(psdHeader));
	memcpy(szBuff + sizeof(psdHeader), pUdphdr, sizeof(UDPHeader));
	memcpy(szBuff + sizeof(psdHeader) + sizeof(UDPHeader), pData, nMsgLen);
	pUdphdr->checksum = checksum((unsigned short *)szBuff, sizeof(psdHeader) + sizeof(UDPHeader) + nMsgLen);

	//填充發送目的地址
	sockaddr_in destAddr = { 0 };
	destAddr.sin_family = AF_INET;
	destAddr.sin_port = htons(DestPort);
	destAddr.sin_addr.S_un.S_addr = inet_addr(szDestIp);
	
	//發送5個原始UDP數據報
	int nRet;
	for (int i = 0; i < 5; i++) {
		nRet = sendto(sRaw, buff, sizeof(IPHeader) + sizeof(UDPHeader) + nMsgLen, 0, (sockaddr *)&destAddr, sizeof(destAddr));
		if (nRet == SOCKET_ERROR) {
			cout << "send failed! 錯誤代碼: " <<GetLastError()<< endl;
			break;
		}
		else
			cout << "發送字節數: " << nRet << endl;
		Sleep(1000);
	}

	closesocket(sRaw);
	WSACleanup();
	return 0;
}