Ping程序的源代码

 

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 headerunsigned int version:4; // Version of IPunsigned char tos; // Type of serviceunsigned short total_len; // total length of the packetunsigned short ident; // unique identifierunsigned short frag_and_flags; // flagsunsigned char ttl;unsigned char proto; // protocol (TCP, UDP etc)unsigned short checksum; // IP checksumunsigned 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);elsedest.sin_addr.s_addr = addr;if (hp)dest.sin_family = hp->h_addrtype;elsedest.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 locatethe 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 = bytesif (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                                       *
*                                                                                                                         *
/**************************************************************/