#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <netdb.h>
#include <signal.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <arpa/inet.h>
/*
 * vortex.labs.pulltheplug.org
 * port 5842
 * connect() and receive 4 unsigned integers.
 * send() back the sum to obtain level1 user/pass
 * zz
 */

#define HOST "vortex.labs.pulltheplug.org"
#define BIND_HOST "src.ip.ad.dr"
#define PORT 5842

int main( void )
{
        struct hostent *he;
        struct sockaddr_in their_addr; // connector's address information
        struct sockaddr_in vhost; // vhost struct
        int sockfd;
        if ((he=gethostbyname(HOST)) == NULL) // lazy
        {
                herror("gethostbyname");
                exit(1);
        }

        if ((sockfd = socket(PF_INET, SOCK_STREAM, 0)) == -1)
        {
                perror("socket");
                exit(1);
        }
        their_addr.sin_family = AF_INET;    // host byte order
        their_addr.sin_port = htons(PORT);  // short, network byte order
        their_addr.sin_addr = *((struct in_addr *)he->h_addr);
        vhost.sin_addr.s_addr = ( BIND_HOST ? inet_addr(BIND_HOST) : INADDR_ANY ); // set vhost addr
        memset(&(their_addr.sin_zero), '\0', 8);  // zero the rest of the struct

        if(bind(sockfd, (struct sockaddr *)&vhost, sizeof(vhost)) == -1 ) //bind to source address
        {
                perror("bind");
                exit(1);
        }

        if (connect(sockfd, (struct sockaddr *)&their_addr, sizeof(struct sockaddr)) == -1)
        {
                perror("connect");
                exit(1);
        }
        int buf=0;
        int sum=0;
        int bytesin=0;

        // get the key bytes
        while( bytesin < (sizeof(int)*4) )
        {
                bytesin+=recv(sockfd, (int*)&buf, sizeof(int), 0);
                if ( buf >= 0 )
                {
                        printf("[+] key value: %d!\n", buf);
                        sum += buf;
                }
        }

        // send answer
        printf("[+] Answer: %d\n", sum );
        send( sockfd, (int*)&sum, sizeof(int), 0 );
        printf("[+] sent answer bytes\n");


        // recv password
        int MAXDATA=1024;
        char ansbuf[MAXDATA];
        memset( ansbuf, 0, MAXDATA);
        bytesin=0;
        bytesin=recv( sockfd, ansbuf, MAXDATA-1, 0 );
        printf("[+] server response: %s", ansbuf);
        memset( ansbuf, 0, MAXDATA );
        close(sockfd);
        return 0;
}