Arquivos para o texto # Rust Pills - resolvendo nomes por DNS

gistfile1.txt

[package]
name = "resolver"
version = "0.1.0"
authors = ["Paulo Henrique Rodrigues Pinheiro <paulohrpinheiro@gmail.com>"]

[dependencies]
libc = "0.2.8"

main.rs

use std::io;
use std::io::prelude::*;

use std::ffi::CString;

extern crate libc;
use libc::{c_char, hostent};

#[link(name="c")]
extern {
	fn gethostbyname(name: *mut c_char) -> *mut hostent;
}

fn get_ip(hostname :&str) -> Option<Vec<String>> {
	let name = CString::new(hostname).unwrap();
	let to_resolv = name.as_ptr() as *mut i8;

	let gethost_result :*mut hostent = unsafe { gethostbyname(to_resolv) };

	if gethost_result.is_null() {
		return None;
	}

	let mut list = unsafe { (*gethost_result ).h_addr_list };
	let mut result :Vec<String> = vec![];

	while unsafe { !(*list ).is_null() } {
		let mut octet :*const c_char = unsafe { *list };

		let mut i = 0;
		let mut formatted_ip = String::new();

		loop {
			if 0 != i { formatted_ip = format!("{}.", formatted_ip) };

			formatted_ip = format!("{}{}", formatted_ip, unsafe { (*octet  as u32)&0xff });

			if i<(unsafe { (*gethost_result).h_length-1 }) {
				octet = unsafe { octet.offset(1) };
				i += 1;
			}
			else {
				break;
			}
		}

		result.push(formatted_ip);
		list = unsafe { list.offset(1) } ;
	}

	Some(result)
}

fn main() {
	let stdin = io::stdin();

	for l in stdin.lock().lines() {
		let line = l.unwrap();
		println!("{:?} => {:?}", line, get_ip(&line));
	}
}