編程實現(xiàn)ping命令

編程實現(xiàn)ping命令物聯(lián)網(wǎng)工程學院實驗報告課程名稱《計算機網(wǎng)絡》實驗名稱編程實現(xiàn)ping命令實驗日期2023-5-1班級計科姓名學號03040實驗報告要求1．實驗名稱2．實驗要求3．實驗環(huán)境4．實驗步驟(寫明實驗結(jié)果)5．實驗體會實驗3編程實現(xiàn)ping命令實驗截圖：實驗代碼：

#pragmapack(4)

#include

"winsock2.h"

#include

"stdlib.h"

#include

"stdio.h"

#defineICMP_ECHO8

#defineICMP_ECHOREPLY0

#defineICMP_MIN8//minimum8byteicmppacket(justheader)

/*TheIPheader*/

typedefstructiphdr{

unsignedinth_len:4;//lengthoftheheader

unsignedintversion:4;//VersionofIP

unsignedchartos;//Typeofservice

unsignedshorttotal_len;//totallengthofthepacket

unsignedshortident;//uniqueidentifier

unsignedshortfrag_and_flags;//flags

unsignedcharttl;

unsignedcharproto;//protocol(TCP,UDPetc)

unsignedshortchecksum;//IPchecksum

unsignedintsourceIP;

unsignedintdestIP;

}IpHeader;

//

//ICMPheader

//

typedefstructicmphdr{

BYTEi_type;

BYTEi_code;/*typesubcode*/

USHORTi_cksum;

USHORTi_id;

USHORTi_seq;

/*Thisisnotthestdheader,butwereservespacefortime*/

ULONGtimestamp;

}IcmpHeader;

#defineSTATUS_FAILED0xFFFF

#defineDEF_PACKET_SIZE

32

#defineDEF_PACKET_NUMBER

4

/*發(fā)送數(shù)據(jù)報的個數(shù)*/

#defineMAX_PACKET1024

#definexmalloc(s)HeapAlloc(GetProcessHeap(),HEAP_ZERO_MEMORY,(s))

#definexfree(p)HeapFree(GetProcessHeap(),0,(p))

voidfill_icmp_data(char*,int);

USHORTchecksum(USHORT*,int);

intdecode_resp(char*,int,structsockaddr_in*);

voidUsage(char*progname){

fprintf(stderr,"Usage:\n");

fprintf(stderr,"%s[numberofpackets][data_size]\n",progname);

fprintf(stderr,"datasizecanbeupto1Kb\n");

ExitProcess(STATUS_FAILED);

}

intmain(intargc,char**argv){

WSADATAwsaData;

SOCKETsockRaw;

structsockaddr_indest,from;

structhostent*hp;

intbread,datasize,times;

intfromlen=sizeof(from);

inttimeout=1000;

intstatistic=0;

/*用于統(tǒng)計結(jié)果*/

char*dest_ip;

char*icmp_data;

char*recvbuf;

unsignedintaddr=0;

USHORTseq_no=0;

if(WSAStartup(MAKEWORD(2,1),&wsaData)!=0){

fprintf(stderr,"WSAStartupfailed:%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：為了使用發(fā)送接收超時設置(即設置SO_RCVTIMEO,SO_SNDTIMEO)，

//

必須將標志位設為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,"failedtosetrecvtimeout:%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,"failedtosetsendtimeout:%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,"Unabletoresolve%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函數(shù)原型是:intatoi(constchar*string);

//

Thereturnvalueis0iftheinputcannotbeconvertedtoaninteger!

//

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)

/*用戶給出的數(shù)據(jù)包大小太大*/

{

fprintf(stderr,"WARNING:data_sizeistoolarge!\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,"HeapAllocfailed%d\n",GetLastError());

ExitProcess(STATUS_FAILED);

}

memset(icmp_data,0,MAX_PACKET);

fill_icmp_data(icmp_data,datasize);

//

//顯示提示信息

//

fprintf(stdout,"\nPinging%s....\n\n",dest_ip);

for(inti=0;i{

intbwrote;

((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,(structsockaddr*)&dest,sizeof(dest));

if(bwrote==SOCKET_ERROR){

if(WSAGetLastError()==WSAETIMEDOUT){

printf("Requesttimedout.\n");

continue;

}

fprintf(stderr,"sendtofailed:%d\n",WSAGetLastError());

ExitProcess(STATUS_FAILED);

}

if(bwrote<datasize){

fprintf(stdout,"Wrote%dbytes\n",bwrote);

}

bread=recvfrom(sockRaw,recvbuf,MAX_PACKET,0,(structsockaddr*)&from,&fromlen);

if(bread==SOCKET_ERROR){

if(WSAGetLastError()==WSAETIMEDOUT){

printf("Requesttimedout.\n");

continue;

}

fprintf(stderr,"recvfromfailed:%d\n",WSAGetLastError());

ExitProcess(STATUS_FAILED);

}

if(!decode_resp(recvbuf,bread,&from))

statistic++;/*成功接收的數(shù)目++*/

Sleep(1000);

}

/*

Displaythestatisticresult

*/

fprintf(stdout,"\nPingstatisticsfor%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();

return0;

}

/*

TheresponseisanIPpacket.WemustdecodetheIPheadertolocate

theICMPdata

*/

intdecode_resp(char*buf,intbytes,structsockaddr_in*from){

IpHeader*iphdr;

IcmpHeader*icmphdr;

unsignedshortiphdrlen;

iphdr=(IpHeader*)buf;

iphdrlen=(iphdr->h_len)*4;//numberof32-bitwords*4=bytes

if(bytes<iphdrlen+ICMP_MIN){

printf("Toofewbytesfrom%s\n",inet_ntoa(from->sin_addr));

}

icmphdr=(IcmpHeader*)(buf+iphdrlen);

if(icmphdr->i_type!=ICMP_ECHOREPLY){

fprintf(stderr,"non-echotype%drecvd\n",icmphdr->i_type);

return1;

}

if(icmphdr->i_id!=(USHORT)GetCurrentProcessId()){

fprintf(stderr,"someoneelse''spacket!\n");

return1;

}

printf("%dbytesfrom%s:",bytes,inet_ntoa(from->sin_addr));

printf("icmp_seq=%d.",icmphdr->i_seq);

printf("time:%dms",GetTickCount()-icmphdr->timestamp);

printf("\n");

return0;

}

USHORTchecksum(USHORT*buffer,intsize){

unsignedlongcksum=