#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/types.h>
#include <netdb.h>
#include <fcntl.h>


/*
getshell6.c is provided by 0x4D722E20446F6E
This code is ripped and modified from Joonbok Lee
Presentation about IPv6 Socket Programming
*/

int main(int argc, char *argv[]){
 fd_set fd_read;
 char buff[2048];
 int n, s, c, retval, addrlen;
 struct addrinfo Hints, *AddrInfo, *AI;

 if(argc!=3){
   printf("Usage : %s <IPv6 address> <Port>\n", argv[0]);
   exit(0);
 }

 if(strstr(argv[1],":")==NULL){
   printf("ERR : You dont enter valid IPv6 address!\n");
   exit(0);
 }

 memset(&Hints,0,sizeof(Hints));
 Hints.ai_family = AF_UNSPEC;
 Hints.ai_socktype = SOCK_STREAM;

 retval = getaddrinfo(argv[1],argv[2], &Hints, &AddrInfo);
 if(retval!=0){
  printf("Cannot resolve requested address\n");
  exit(0);
 }

 for(AI=AddrInfo;AI!=NULL;AI=AI->ai_next){
  if(AI->ai_family==AF_INET6){
   if((s=socket(AI->ai_family,AI->ai_socktype,AI->ai_protocol))<0){
    printf("can't create socket\n");
    exit(0);
   }
   c=connect(s,AI->ai_addr,AI->ai_addrlen);
  }else{
    printf("%s is not IPv6 family\n",argv[1]);
  }
  freeaddrinfo(AddrInfo);
 }

 FD_ZERO(&fd_read);
 FD_SET(s, &fd_read);
 FD_SET(0, &fd_read);

 while(1) {
  FD_SET(s,&fd_read);
  FD_SET(0,&fd_read);

  if (select(FD_SETSIZE, &fd_read, NULL, NULL, NULL) < 0 ) break;

  if (FD_ISSET(s, &fd_read)) {
    if((n = recv(s, buff, sizeof(buff), 0)) < 0){
      fprintf(stderr, "EOF\n");
      exit(2);
    }
    if (write(1, buff, n) < 0) break;
  }

  if (FD_ISSET(0, &fd_read)) {
    if((n = read(0, buff, sizeof(buff))) < 0){
      fprintf(stderr, "EOF\n");
      exit(2);
    }
    if (send(s, buff, n, 0) < 0) break;
  }

  usleep(10);
 }
 fprintf(stderr, "Connection lost.\n\n");
 exit(0);
}