vc++下ping命令的实现

#include <stdio.h> #include <stdlib.h> #include <winsock.h> #pragma comment (lib, "ws2_32.lib") #define ICMP_ECHOREPLY 0 // ICMP回复应答 #define ICMP_ECHOREQ 8 // ICMP回应请求 #define REQ_DATASIZE 32 // 请求数据报大小 // 定义IP首部格式 typedef struct _IPHeader { u_char VIHL; // 版本和首部长度 u_char ToS; // 服务类型 u_short TotalLen; // 总长度 u_short ID; // 标识号 u_short Frag_Flags; // 段偏移量 u_char TTL; // 生存时间 u_char Protocol; // 协议 u_short Checksum; // 首部校验和 struct in_addr SrcIP; // 源IP地址 struct in_addr DestIP; // 目的地址 }IPHDR, *PIPHDR; // 定义ICMP首部格式 typedef struct _ICMPHeader { u_char Type; // 类型 u_char Code; // 代码 u_short Checksum; // 首部校验和 u_short ID; // 标识 u_short Seq; // 序列号 char Data; // 数据 }ICMPHDR, *PICMPHDR; // 定义ICMP回应请求 typedef struct _ECHOREQUEST { ICMPHDR icmpHdr; DWORD dwTime; char cData[REQ_DATASIZE]; }ECHOREQUEST, *PECHOREQUEST; // 定义ICMP回应答复 typedef struct _ECHOREPLY { IPHDR ipHdr; ECHOREQUEST echoRequest; char cFiller[256]; }ECHOREPLY, *PECHOREPLY; // 计算校验和 u_short checksum(u_short *buffer, int len) { register int nleft = len; register u_short *w = buffer; register u_short answer; register int sum = 0; // 使用32bit的累加器，进行16bit的反馈计算 while( nleft > 1 ) { sum += *w++; nleft -= 2; } // 补全奇数位 if( nleft == 1 ) { u_short u = 0; *(u_char *)(&u) = *(u_char *)w ; sum += u; } // 将反馈的16bit从高位移至地位 sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */ sum += (sum >> 16); /* add carry */ answer = ~sum; /* truncate to 16 bits */ return (answer); } // 发送回应请求函数 int SendEchoRequest(SOCKET s,struct sockaddr_in *lpstToAddr) { static ECHOREQUEST echoReq; static nId = 1; static nSeq = 1; int nRet; // 填充回应请求消息 echoReq.icmpHdr.Type = ICMP_ECHOREQ; echoReq.icmpHdr.Code = 0; echoReq.icmpHdr.Checksum = 0; echoReq.icmpHdr.ID = nId++; echoReq.icmpHdr.Seq = nSeq++; // 填充要发送的数据（随便填写） for (nRet = 0; nRet < REQ_DATASIZE; nRet++) echoReq.cData[nRet] = ' '+nRet; // 储存发送的时间 echoReq.dwTime = GetTickCount(); // 计算回应请求的校验和 echoReq.icmpHdr.Checksum = checksum((u_short *)&echoReq, sizeof(ECHOREQUEST)); // 发送回应请求 nRet = sendto(s, // 建立起的套接字 (LPSTR)&echoReq, // 发送的缓冲区内容 sizeof(ECHOREQUEST), 0, // 标志位 (struct sockaddr*)lpstToAddr, // 发送的目标地址 sizeof(SOCKADDR_IN)); // 地址结构长度 if (nRet == SOCKET_ERROR) { printf("sendto() error:%d\n",WSAGetLastError()); } return (nRet); } // 接收应答回复并进行解析 DWORD RecvEchoReply(SOCKET s, LPSOCKADDR_IN lpsaFrom, u_char *pTTL) { ECHOREPLY echoReply; int nRet; int nAddrLen = sizeof(struct sockaddr_in); //接收应答回复 nRet = recvfrom(s, // 接收的套接字 (LPSTR)&echoReply, // 接收的缓冲区 sizeof(ECHOREPLY), // 缓冲区长度 0, // 标识 (LPSOCKADDR)lpsaFrom, // 接收的地址 &nAddrLen); // 地址结构长度 // 检验接收结果 if (nRet == SOCKET_ERROR) { printf("recvfrom() error:%d\n",WSAGetLastError()); } // 记录返回的TTL *pTTL = echoReply.ipHdr.TTL; //返回应答时间 return(echoReply.echoRequest.dwTime); } // 等待回应答复，使用select机制 int WaitForEchoReply(SOCKET s) { struct timeval timeout; fd_set readfds; readfds.fd_count = 1; readfds.fd_array[0] = s; timeout.tv_sec = 5; timeout.tv_usec = 0; return(select(1, &readfds, NULL, NULL, &timeout)); } // Ping功能实现 void Ping(char *pstrHost) { SOCKET rawSocket; LPHOSTENT lpHost; struct sockaddr_in destIP; struct sockaddr_in srcIP; DWORD dwTimeSent; DWORD dwElapsed; u_char cTTL; int nLoop; int nRet; // 创建原始套接字，ICMP类型 rawSocket = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP); if (rawSocket == SOCKET_ERROR) { printf("socket() error:%d\n",WSAGetLastError()); return; } // 检测目标主机 lpHost = gethostbyname(pstrHost); if (lpHost == NULL) { printf("Host not found: %s\n", pstrHost); return; } // 设置目标机地址 destIP.sin_addr.s_addr = *((u_long FAR *) (lpHost->h_addr)); destIP.sin_family = AF_INET; destIP.sin_port = 0; // 提示开始进行Ping printf("\nPinging %s with %d bytes of data:\n", inet_ntoa(destIP.sin_addr), REQ_DATASIZE); // 发起多次Ping测试 for (nLoop = 0; nLoop < 4; nLoop++) { //发送ICMP回应请求 SendEchoRequest(rawSocket, &destIP); // 使用select()等待回复的数据 nRet = WaitForEchoReply(rawSocket); if (nRet == SOCKET_ERROR) { printf("select() error:%d\n",WSAGetLastError()); break; } if (!nRet) { printf("\nRequest time out"); break; } //接收回复 dwTimeSent = RecvEchoReply(rawSocket, &srcIP, &cTTL); // 计算花费的时间 dwElapsed = GetTickCount() - dwTimeSent; printf("\nReply from %s: bytes=%d time=%ldms TTL=%d", inet_ntoa(srcIP.sin_addr), REQ_DATASIZE, dwElapsed, cTTL); } printf("\n"); nRet = closesocket(rawSocket); // 关闭套接字，释放资源 if (nRet == SOCKET_ERROR) { printf("closesocket() error:%d\n",WSAGetLastError()); } } void main(int argc, char **argv) { WSADATA wsd; int nRet; // 检测输入的参数 if (argc != 2) { printf("\nUsage: ping hostname\n"); return; } // 初始化Winsock if (WSAStartup(MAKEWORD(1,1), &wsd) != 0) { printf("加载Winsock失败!\n"); } //开始Ping Ping(argv[1]); // 释放Winsock资源 WSACleanup(); }