1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104

/*
 * Copyright (C) 2015 Benjamin Fry <benjaminfry@me.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

//! text records for storing arbitrary data

use ::serialize::txt::*;
use ::serialize::binary::*;
use ::error::*;

/// [RFC 1035, DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION, November 1987](https://tools.ietf.org/html/rfc1035)
///
/// ```text
/// 3.3.14. TXT RDATA format
///
///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
///     /                   TXT-DATA                    /
///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
///
///
/// TXT RRs are used to hold descriptive text.  The semantics of the text
/// depends on the domain where it is found.
/// ```
#[derive(Debug, PartialEq, Eq, Hash, Clone)]
pub struct TXT { txt_data: Vec<String> }

impl TXT {
  /// Creates a new TXT record data.
  ///
  /// # Arguments
  ///
  /// * `txt_data` - the set of strings which make up the txt_data.
  ///
  /// # Return value
  ///
  /// The new TXT record data.
  pub fn new(txt_data: Vec<String>) -> TXT {
    TXT { txt_data: txt_data }
  }

  /// ```text
  /// TXT-DATA        One or more <character-string>s.
  /// ```
  pub fn get_txt_data(&self) -> &[String] { &self.txt_data }
}

pub fn read(decoder: &mut BinDecoder, rdata_length: u16) -> DecodeResult<TXT> {
  let data_len = decoder.len();
  let mut strings = Vec::with_capacity(1);

  while data_len - decoder.len() < rdata_length as usize {
    strings.push(try!(decoder.read_character_data()));
  }
  Ok(TXT::new(strings))
}

pub fn emit(encoder: &mut BinEncoder, txt: &TXT) -> EncodeResult {
  for s in txt.get_txt_data() {
    try!(encoder.emit_character_data(s));
  }

  Ok(())
}

pub fn parse(tokens: &Vec<Token>) -> ParseResult<TXT> {
  let mut txt_data: Vec<String> = Vec::with_capacity(tokens.len());
  for t in tokens {
    match *t {
      Token::CharData(ref txt) => txt_data.push(txt.clone()),
      _ => return Err(ParseError::UnexpectedToken(t.clone())),
    }
  }

  Ok(TXT::new(txt_data))
}

#[test]
fn test() {
  let rdata = TXT::new(vec!["test me some".to_string(), "more please".to_string()]);

  let mut bytes = Vec::new();
  let mut encoder: BinEncoder = BinEncoder::new(&mut bytes);
  assert!(emit(&mut encoder, &rdata).is_ok());
  let bytes = encoder.as_bytes();

  println!("bytes: {:?}", bytes);

  let mut decoder: BinDecoder = BinDecoder::new(bytes);
  let read_rdata = read(&mut decoder, bytes.len() as u16);
  assert!(read_rdata.is_ok(), format!("error decoding: {:?}", read_rdata.unwrap_err()));
  assert_eq!(rdata, read_rdata.unwrap());
}