Programs using Raw sockets (like packet capturing and filtering)

Aim: Programs using Raw sockets (like packet capturing and filtering)

Progarmming

Server

#include<stdio.h>

#include<sys/types.h>

#include<netinet/in.h>

#include<sys/socket.h>

#include<errno.h>

#define SIZE 256

int main()

{

intsrFd,CIFD,len;

structsockaddr_inserver,client;

charbuf[SIZE],buf1[SIZE];

intn,j;

FILE *fp,*fp1;

srFd=socket(AF_INET,SOCK_STREAM,0);

if(srFd<0)

{

printf(“\n Socket error”);

exit(0);

}

bzero(&server,sizeof(server));

server.sin_family=AF_INET;

server.sin_port=htons(2200);

server.sin_addr.s_addr=htons(INADDR_ANY);

if(bind(srFd,(structsockaddr *)&server,sizeof(server))<0)

{

printf(“\n server : bind error”);

close(srFd);

exit(0);

}

if(listen(srFd,1)<0)

{

printf(“\n Listen Error”);

close(CIFD);

exit(0);

}

printf(“\n Server is ready to listen\n”);

len=sizeof(client);

CIFD=accept(srFd,(structsockaddr *)&client,&len);

if(CIFD<0)

{

printf(“\n Accept error”);

close(CIFD);

close(srFd);

exit(0);

}

printf(“Client gets connected\n”);

bzero(&buf,sizeof(buf));

if((n=recv(CIFD,&buf,SIZE,0))<0)

{

printf(“\n Receive Error in Server\n”);

close(srFd);

close(CIFD);

exit(0);

}

buf[n-1]=NULL;

printf(“\n File name %s”,buf);

if((n=send(CIFD,buf,strlen(buf),0))<0)

{

printf(“\n Error”);

close(CIFD);

exit(0);

}

close(srFd);

close(CIFD);

exit(0);

}

Client

#include<stdio.h>

#include<netinet/in.h>

#include<sys/socket.h>

#include<sys/types.h>

#include<string.h>

#define SIZE 256

int main()

{

int CIFD;

structsockaddr_in client;

charbuf[SIZE];

int n;

if((CIFD=socket(AF_INET,SOCK_STREAM,0))<0)

{

printf(“\n Client Socket Error”);

exit(0);

}

bzero(&client,sizeof(client));

client.sin_family=AF_INET;

client.sin_port=htons(2200);

inet_pton(AF_INET,”127.0.0.1″,&client.sin_addr);

if(connect(CIFD,(structsockaddr *)&client,sizeof(client))<0)

{

printf(“\n connection failed”);

close(CIFD);

exit(0);

}

printf(“\n connection enabled\n”);

printf(“\n Enter source file\n”);

bzero(&buf,sizeof(buf));

if(fgets(buf,SIZE,stdin)==NULL)

{

printf(“\n Failed to get source file name in client\n”);

close(CIFD);

exit(0);

}

if(send(CIFD,buf,strlen(buf),0)<0)

{

printf(“\n Send Error\n”);

close(CIFD);

exit(0);

}

printf(“\n Client message sent\n”);

bzero(&buf,sizeof(buf));

if((n=recv(CIFD,buf,SIZE,0))<0)

{

printf(“\n File name receiver error in client from server\n”);

close(CIFD);

exit(0);

}

printf(“\n Destination file name from server %s”,buf);

buf[n]=NULL;

close(CIFD);

exit(0);

}

OUTPUT

Client[student@localhost ~]$ ./a.out

Connection Enabled

Enter Source File

Tps.c

Client Message Sent

Destination Filename From Server tps.c

Server[student@localhost ~]$ ./a.out

Server is ready to listen

Client get connected

Tps.c