client.cpp (tunnel)

/*

    client.cpp
    Tunnel client by oaktree & unh0lys0da

    compile with
    g++ -std=c++11 -Wall -Werror client.cpp -o client

*/

#include <iostream>
#include <string>
#include <vector>

#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <netinet/in.h>
#include <netdb.h>

#define DEBUG(x) printf("%s\n", x);

int start_connection(int& sockfd, const std::string& host, const int& port);

int main(int argc, char** argv) {
    int sockfd;

    if (argc != 3) {
        std::cout << "[*] Usage: ./tunnel [host] [port]" << std::endl;
    }

    if (start_connection(sockfd, std::string(argv[1]), atoi(argv[2])) != 0) {
        std::cout << "[*] Something went wrong in connecting." << std::endl;
        exit(2);
    }
}

int start_connection(int& sockfd, const std::string& host, const int& port) {

    if ((sockfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
        std::cout << "[*] Socket could not be opened." << std::endl;
        return 1;
    }

    struct hostent *server;
    if ( (server = gethostbyname( host.c_str() ) ) == nullptr) {
        std::cout << "[*] Host not found." << std::endl;
        close(sockfd);
        return 2;
    }

    struct sockaddr_in serv_addr;
    memset(&serv_addr, 0, sizeof(serv_addr));

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

    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(port);

    // if ( connect(sockfd, (struct sockaddr*)&serv_addr, sizeof(serv_addr)) < 0) {
    //  std::cout << "[*] Could not connect." << std::endl;
    //  close(sockfd);
    //  return 3;
    // }

    return 0;
}