作者:侯志江     单位:天津大学软件学院        E-mail :tjuhzjemail@yahoo.com.cn   日期:2005年1月1日      内容简介: 编写自己的一个ping程序,可以说是许多人迈出网络编程的第一步吧!!这个ping 程序的源代码经过我的修改和调试,基本上可以取代windows中自带的ping程序. 各个模块 后都有我的详细注释和修改日志,希望能够对大家的学习有所帮助!!/* 本程序的主要源代码来自MSDN网站, 笔者只是做了一些改进和注释! 另外需要注意 的是在Build之前,必须加入ws2_32.lib库文件,否则会提示"error LNK2001:"的错误！*/ Version 1.1 修改记录:     <1> 解决了socket阻塞的问题,从而能够正确地处理超时的请求!      <2> 增加了由用户控制发送ICMP包的数目的功能(即命令的第二个参数)     <3> 增加了对ping结果的统计功能.                                                            #pragma pack(4) #include   "winsock2.h"#include   "stdlib.h"#include   "stdio.h"#define ICMP_ECHO 8 #define ICMP_ECHOREPLY 0 #define ICMP_MIN 8 // minimum 8 byte icmp packet (just header) /* The IP header */ typedef struct iphdr { unsigned int h_len:4; // length of the header unsigned int version:4; // Version of IP unsigned char tos; // Type of service unsigned short total_len; // total length of the packet unsigned short ident; // unique identifier unsigned short frag_and_flags; // flags unsigned char ttl; unsigned char proto; // protocol (TCP, UDP etc) unsigned short checksum; // IP checksum unsigned int sourceIP; unsigned int destIP; }IpHeader; // // ICMP header // typedef struct icmphdr { BYTE i_type; BYTE i_code; /* type sub code */ USHORT i_cksum; USHORT i_id; USHORT i_seq; /* This is not the std header, but we reserve space for time */ ULONG timestamp; }IcmpHeader; #define STATUS_FAILED 0xFFFF #define DEF_PACKET_SIZE    32#define DEF_PACKET_NUMBER  4    /* 发送数据报的个数 */#define MAX_PACKET 1024 #define xmalloc(s) HeapAlloc(GetProcessHeap(),HEAP_ZERO_MEMORY,(s)) #define xfree(p) HeapFree (GetProcessHeap(),0,(p)) void fill_icmp_data(char *, int); USHORT checksum(USHORT *, int); int decode_resp(char *,int ,struct sockaddr_in *); void Usage(char *progname){ fprintf(stderr,"Usage:\n"); fprintf(stderr,"%s [number of packets] [data_size]\n",progname); fprintf(stderr,"datasize can be up to 1Kb\n"); ExitProcess(STATUS_FAILED); } int main(int argc, char **argv){ WSADATA wsaData; SOCKET sockRaw; struct sockaddr_in dest,from; struct hostent * hp; int bread,datasize,times; int fromlen = sizeof(from); int timeout = 1000;int statistic = 0;  /* 用于统计结果 */  char *dest_ip; char *icmp_data; char *recvbuf; unsigned int addr=0; USHORT seq_no = 0; if (WSAStartup(MAKEWORD(2,1),&wsaData) != 0){ fprintf(stderr,"WSAStartup failed: %d\n",GetLastError()); ExitProcess(STATUS_FAILED); } if (argc <2 ) { Usage(argv[0]); } sockRaw = WSASocket(AF_INET,SOCK_RAW,IPPROTO_ICMP,NULL, 0,WSA_FLAG_OVERLAPPED);////注：为了使用发送接收超时设置(即设置SO_RCVTIMEO, SO_SNDTIMEO)，//    必须将标志位设为WSA_FLAG_OVERLAPPED !// if (sockRaw == INVALID_SOCKET) { fprintf(stderr,"WSASocket() failed: %d\n",WSAGetLastError()); ExitProcess(STATUS_FAILED); } bread = setsockopt(sockRaw,SOL_SOCKET,SO_RCVTIMEO,(char*)&timeout, sizeof(timeout)); if(bread == SOCKET_ERROR) { fprintf(stderr,"failed to set recv timeout: %d\n",WSAGetLastError()); ExitProcess(STATUS_FAILED); } timeout = 1000; bread = setsockopt(sockRaw,SOL_SOCKET,SO_SNDTIMEO,(char*)&timeout, sizeof(timeout)); if(bread == SOCKET_ERROR) { fprintf(stderr,"failed to set send timeout: %d\n",WSAGetLastError()); ExitProcess(STATUS_FAILED); } memset(&dest,0,sizeof(dest)); hp = gethostbyname(argv[1]); if (!hp){ addr = inet_addr(argv[1]); } if ((!hp) && (addr == INADDR_NONE) ) { fprintf(stderr,"Unable to resolve %s\n",argv[1]); ExitProcess(STATUS_FAILED); } if (hp != NULL) memcpy(&(dest.sin_addr),hp->h_addr,hp->h_length); else dest.sin_addr.s_addr = addr; if (hp) dest.sin_family = hp->h_addrtype; else dest.sin_family = AF_INET; dest_ip = inet_ntoa(dest.sin_addr); // //  atoi函数原型是: int atoi( const char *string );//  The return value is 0 if the input cannot be converted to an integer !//if(argc>2){times=atoi(argv[2]);if(times == 0)  times=DEF_PACKET_NUMBER;}else    times=DEF_PACKET_NUMBER;if (argc >3) { datasize = atoi(argv[3]);     if (datasize == 0)         datasize = DEF_PACKET_SIZE;if (datasize >1024)   /* 用户给出的数据包大小太大 */{  fprintf(stderr,"WARNING : data_size is too large !\n");  datasize = DEF_PACKET_SIZE; }} else     datasize = DEF_PACKET_SIZE; datasize += sizeof(IcmpHeader); icmp_data = (char*)xmalloc(MAX_PACKET); recvbuf = (char*)xmalloc(MAX_PACKET); if (!icmp_data) { fprintf(stderr,"HeapAlloc failed %d\n",GetLastError()); ExitProcess(STATUS_FAILED); } memset(icmp_data,0,MAX_PACKET); fill_icmp_data(icmp_data,datasize); ////显示提示信息//fprintf(stdout,"\nPinging %s ....\n\n",dest_ip);for(int i=0;i{ int bwrote; ((IcmpHeader*)icmp_data)->i_cksum = 0; ((IcmpHeader*)icmp_data)->timestamp = GetTickCount(); ((IcmpHeader*)icmp_data)->i_seq = seq_no++; ((IcmpHeader*)icmp_data)->i_cksum = checksum((USHORT*)icmp_data,datasize);bwrote = sendto(sockRaw,icmp_data,datasize,0,(struct sockaddr*)&dest,sizeof(dest)); if (bwrote == SOCKET_ERROR){ if (WSAGetLastError() == WSAETIMEDOUT) { printf("Request timed out.\n"); continue; } fprintf(stderr,"sendto failed: %d\n",WSAGetLastError()); ExitProcess(STATUS_FAILED); } if (bwrote < datasize ) { fprintf(stdout,"Wrote %d bytes\n",bwrote); } bread = recvfrom(sockRaw,recvbuf,MAX_PACKET,0,(struct sockaddr*)&from,&fromlen); if (bread == SOCKET_ERROR){ if (WSAGetLastError() == WSAETIMEDOUT) { printf("Request timed out.\n"); continue; } fprintf(stderr,"recvfrom failed: %d\n",WSAGetLastError()); ExitProcess(STATUS_FAILED); } if(!decode_resp(recvbuf,bread,&from))statistic++; /* 成功接收的数目++ */Sleep(1000); }/*Display the statistic result*/fprintf(stdout,"\nPing statistics for %s \n",dest_ip);fprintf(stdout,"    Packets: Sent = %d,Received = %d, Lost = %d (%2.0f%% loss)\n",times,     statistic,(times-statistic),(float)(times-statistic)/times*100);WSACleanup();return 0; } /* The response is an IP packet. We must decode the IP header to locate the ICMP data */ int decode_resp(char *buf, int bytes,struct sockaddr_in *from) { IpHeader *iphdr; IcmpHeader *icmphdr; unsigned short iphdrlen; iphdr = (IpHeader *)buf; iphdrlen = (iphdr->h_len) * 4 ; // number of 32-bit words *4 = bytes if (bytes < iphdrlen + ICMP_MIN) { printf("Too few bytes from %s\n",inet_ntoa(from->sin_addr)); } icmphdr = (IcmpHeader*)(buf + iphdrlen); if (icmphdr->i_type != ICMP_ECHOREPLY) { fprintf(stderr,"non-echo type %d recvd\n",icmphdr->i_type); return 1; } if (icmphdr->i_id != (USHORT)GetCurrentProcessId()) { fprintf(stderr,"someone else''s packet!\n"); return 1; } printf("%d bytes from %s:",bytes, inet_ntoa(from->sin_addr)); printf(" icmp_seq = %d. ",icmphdr->i_seq); printf(" time: %d ms ",GetTickCount()-icmphdr->timestamp); printf("\n");return 0; } USHORT checksum(USHORT *buffer, int size) { unsigned long cksum=0; while(size >1) { cksum+=*buffer++; size -=sizeof(USHORT); } if(size) { cksum += *(UCHAR*)buffer; } cksum = (cksum >> 16) + (cksum & 0xffff); cksum += (cksum >>16); return (USHORT)(~cksum); } /* Helper function to fill in various stuff in our ICMP request. */ void fill_icmp_data(char * icmp_data, int datasize){ IcmpHeader *icmp_hdr; char *datapart; icmp_hdr = (IcmpHeader*)icmp_data; icmp_hdr->i_type = ICMP_ECHO; icmp_hdr->i_code = 0; icmp_hdr->i_id = (USHORT)GetCurrentProcessId(); icmp_hdr->i_cksum = 0; icmp_hdr->i_seq = 0; datapart = icmp_data + sizeof(IcmpHeader); // // Place some junk in the buffer. // memset(datapart,''E'', datasize - sizeof(IcmpHeader)); } /******************* 附: ping命令执行时显示的画面 ****************\*  C:\Documents and settings\houzhijiang>ping   236.56.54.12                              * *                                                                                                                          **  Pinging 236.56.54.12 with 32 bytes of data:                                                      **                                                                                                                          * *  Request timed out.                                                                                            **  Request timed out.                                                                                            **  Request timed out.                                                                                            **  Request timed out.                                                                                            * *                                                                                                                          **  Ping statistics for 236.56.54.12:                                                                        **     Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),                                **                                                                                                                         *\**************************************************************//**************************************************************\*  C:\Documents and Settings\houzhijiang>ping 127.0.0.1                                    **                                                                                                                         **  Pinging 127.0.0.1 with 32 bytes of data:                                                           **                                                                                                                         **  Reply from 127.0.0.1: bytes=32 time<1ms TTL=128                                      **  Reply from 127.0.0.1: bytes=32 time<1ms TTL=128                                      **  Reply from 127.0.0.1: bytes=32 time<1ms TTL=128                                      **  Reply from 127.0.0.1: bytes=32 time<1ms TTL=128                                      **                                                                                                                         **  Ping statistics for 127.0.0.1:                                                                             **     Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),                                   **  Approximate round trip times in milli-seconds:                                                  **     Minimum = 0ms, Maximum = 0ms, Average = 0ms                                       **                                                                                                                         *\**************************************************************/本栏文章均来自于互联网，版权归原作者和各发布网站所有，本站收集这些文章仅供学习参考之用。任何人都不能将这些文章用于商业或者其他目的。(  

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