SOCKET APPLICATION PROGRAM FOR ARP AND RARP

SERVER SIDE:

#include<stdio.h>

#include<netdb.h>

#include<netinet/in.h>

#include<sys/types.h>

#include<sys/socket.h>

#include<errno.h>

int main(int argc,char **argv)

{

struct sockaddr_in saddr,caddr;

struct hostent *server;

int n,i,len,ssid,csid,pid,pi;

char wbuffer[1024],rbuffer[1024];

char a[20][20]={"12312","23211","43211","32122","23122"};

char b[20][20]={"12.12.12.12","33.22.22.22","45.34.22.33","23.33.11.22","64.45.3

2.54"};

float c;

if(argc<2)

fprintf(stderr,"port number not specified \n");

ssid=socket(AF_INET,SOCK_STREAM,0);

if(csid<0)

perror("socket failed \n");

bzero((char *) & saddr,sizeof(saddr));

saddr.sin_family=AF_INET;

saddr.sin_port=htons(atoi(argv[1]));

saddr.sin_addr.s_addr=INADDR_ANY;

if(bind(ssid,(struct sockaddr*)&saddr,sizeof(saddr))<0)

perror("socket bind \n");

listen(ssid,5);

len= sizeof (caddr);

while(1)

{

csid=accept(ssid,(struct sockaddr*)&caddr,&len);

if(csid<0)

perror("socket accept");

fprintf(stdout,"type message to client: \n");

pid=fork();

if(pid==0)

{

close(ssid);

bzero(rbuffer,1024);

n=read(csid,rbuffer,1024);

if(n==0)

perror("socket read \n");

else

fprintf(stdout,"message from client %s\n",rbuffer);

for(i=0;i<5;i++)

{

if(!strncmp(a[i],rbuffer,5))

{

n=write(csid,b[i],1024);

break;

}

else if(!strncmp(b[i],rbuffer,5))

{

n=write(csid,a[i],5);

break;

}

else if(strncmp(b[i],rbuffer,5))

{

n=write(csid,"invalid no",10);

break;

}

}

exit(0);

}

else

close(csid);

}

}

CLIENT SIDE:

#iinclude<stdio.h>

#include<netdb.h>

#include<netinet/in.h>

#include<sys/types.h>

#include<sys/socket.h>

#include<errno.h>

int main(int argc,char **argv)

{

struct sockaddr_in saddr;

struct hostent *server;

int n,ssid,csid,pid,pi;

char wbuffer[1024],rbuffer[1024];

char str[15];

if(argc<3)

fprintf(stderr,"parameter inadiquate \n");

csid=socket(AF_INET,SOCK_STREAM,0);

if(csid<0)

perror("socket failed \n");

bzero((char*)&saddr,sizeof(saddr));

server=gethostbyname(argv[1]);

saddr.sin_family=AF_INET;

saddr.sin_port=htons(atoi(argv[2]));

bcopy((char*)server->h_addr,(char*)&saddr.sin_addr.s_addr,server->h_length);

ssid=connect(csid,(struct sockaddr *)&saddr,sizeof(saddr));

if(ssid<0)

perror("socket connected \n");

fprintf(stdout,"ENTER MESSAGE TO SERVER:\n");

bzero(wbuffer,1024);

fgets(wbuffer,1024,stdin);

n=write(csid,wbuffer,sizeof(wbuffer));

if(n==0)

perror("socket write");

bzero(rbuffer,1024);

n=read(csid,str,15);

if(n==0)

perror("socket read \n");

else

fprintf(stdout,"MESSAGE FROM SERVER:%s\n",str);

return(0);

OUTPUT:

SERVER SIDE:

[ME04@TELNET ~]$ cc arpser.c

[ME04@TELNET ~]$ ./a.out 9987

type message to client:

message from client 12.12.12.12

CLIENT SIDE:

[ME04@TELNET ~]$ cc arpcli.c

[ME04@TELNET ~]$ ./a.out 20.30.1.211 9987

ENTER MESSAGE TO SERVER:

12.12.12.12

MESSAGE FROM SERVER:12312☺