CLIENT TO RESOLVE A GIVEN HOSY NAME FROM DNS SERVER

SERVER SIDE:

#include<stdio.h>

#include<sys/socket.h>

#include<sys/types.h>

#include<arpa/inet.h>

#include<netinet/in.h>

#include<string.h>

#include<netdb.h>

#include<stdlib.h>

#include<unistd.h>

int main()

{

int a,c,clisize,size;

int sersock,newsock,n;

struct sockaddr_in seraddr,clinfo;

char str1[25],str2[100];

char host[25];

struct hostent *hp;

seraddr.sin_family=AF_INET;

seraddr.sin_port=htons(2005);

seraddr.sin_addr.s_addr=htonl(INADDR_ANY);

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

{

perror("can not creat Socket");

exit(0);

}

bind(sersock,(struct sockaddr*)&seraddr,sizeof(seraddr));

listen(sersock,5);

clisize=sizeof(clinfo);

if((newsock=accept(sersock,(struct sockaddr*)&clinfo,&size))<0)

{

perror("ACCEPT");

exit(0);

}

printf("\n connected to %s",inet_ntoa(clinfo.sin_addr));

read(newsock,host,sizeof(host));

printf("%s",host);

hp=gethostbyname(host);

inet_ntop(AF_INET,hp->h_addr,str2,sizeof(str2));

printf("%s",str2);

write(newsock,str2,strlen(str2)+1);

close(newsock);

close(sersock);

return 0;

}

CLIENT SIDE:

#include<stdio.h>

#include<sys/socket.h>

#include<sys/types.h>

#include<arpa/inet.h>

#include<netinet/in.h>

#include<unistd.h>

#include<netdb.h>

#include<stdlib.h>

#include<string.h>

int main(int argc,char *argv)

{

int len;

int sockfd,n;

struct sockaddr_in servaddr,cliaddr;

char buff[1024];

char str[1000];

sockfd=socket(AF_INET,SOCK_STREAM,0);

if(sockfd<0)

perror("can not create socket");

bzero(&servaddr,sizeof(servaddr));

servaddr.sin_port=htons(2005);

servaddr.sin_family=AF_INET;

servaddr.sin_addr.s_addr=inet_addr("20.30.1.211");

connect(sockfd,(struct sockaddr*)&servaddr,sizeof(servaddr));

{

printf("enter the domain name");

scanf("%s",buff);

n=write(sockfd,buff,1024);

n=read(sockfd,buff,1024);

printf("\n received addr\t %s",buff);

}

close(sockfd);

return 0;

}

OUTPUT:

SERVER SIDE:

"abcser.c" 45L, 1006C written

[ME04@TELNET ~]$ cc abcser.c

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

 connected to 0.0.0.0localhost127.0.0.1

CLIENT SIDE:

"abccli.c" 35L, 774C written

[ME04@TELNET ~]$ cc abccli.c

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

enter the domain name localhost

received addr   127.0.0.1