trust-dns 0.11.0

TRust-DNS is a safe and secure DNS library. This is the Client library with DNSec support. DNSSec with NSEC validation for negative records, is complete. The client supports dynamic DNS with SIG0 authenticated requests, implementing easy to use high level funtions. TRust-DNS is based on the Tokio and Futures libraries, which means it should be easily integrated into other software that also use those libraries.
Documentation
/*
 * 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.
 */

//! Query struct for looking up resource records

use rr::domain::Name;
use rr::record_type::RecordType;
use rr::dns_class::DNSClass;
use ::serialize::binary::*;
use ::error::*;

/// Query struct for looking up resource records, basically a resource record without RDATA.
///
/// [RFC 1035, DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION, November 1987](https://tools.ietf.org/html/rfc1035)
///
/// ```text
/// 4.1.2. Question section format
///
/// The question section is used to carry the "question" in most queries,
/// i.e., the parameters that define what is being asked.  The section
/// contains QDCOUNT (usually 1) entries, each of the following format:
///
///                                     1  1  1  1  1  1
///       0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
///     |                                               |
///     /                     QNAME / ZNAME             /
///     /                                               /
///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
///     |                     QTYPE / ZTYPE             |
///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
///     |                     QCLASS / ZCLASS           |
///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
///
/// ```
#[derive(Clone, Debug, Eq, Hash, PartialEq)]
pub struct Query {
    name: Name,
    query_type: RecordType,
    query_class: DNSClass,
}

impl Query {
    /// return a default query with an empty name and A, IN for the query_type and query_class
    pub fn new() -> Self {
        Query {
            name: Name::new(),
            query_type: RecordType::A,
            query_class: DNSClass::IN,
        }
    }

    /// replaces name with the new name
    pub fn set_name(&mut self, name: Name) -> &mut Self {
        self.name = name;
        self
    }

    /// Specify the RecordType being queried
    pub fn set_query_type(&mut self, query_type: RecordType) -> &mut Self {
        self.query_type = query_type;
        self
    }

    /// Specify√∑ the DNS class of the Query, almost always IN
    pub fn set_query_class(&mut self, query_class: DNSClass) -> &mut Self {
        self.query_class = query_class;
        self
    }

    /// ```text
    /// QNAME           a domain name represented as a sequence of labels, where
    ///                 each label consists of a length octet followed by that
    ///                 number of octets.  The domain name terminates with the
    ///                 zero length octet for the null label of the root.  Note
    ///                 that this field may be an odd number of octets; no
    ///                 padding is used.
    /// ```
    pub fn name(&self) -> &Name {
        &self.name
    }

    /// ```text
    /// QTYPE           a two octet code which specifies the type of the query.
    ///                 The values for this field include all codes valid for a
    ///                 TYPE field, together with some more general codes which
    ///                 can match more than one type of RR.
    /// ```
    pub fn query_type(&self) -> RecordType {
        self.query_type
    }

    /// ```text
    /// QCLASS          a two octet code that specifies the class of the query.
    ///                 For example, the QCLASS field is IN for the Internet.
    /// ```
    pub fn query_class(&self) -> DNSClass {
        self.query_class
    }
}

impl BinSerializable<Query> for Query {
    fn read(decoder: &mut BinDecoder) -> DecodeResult<Self> {
        let name = try!(Name::read(decoder));
        let query_type = try!(RecordType::read(decoder));
        let query_class = try!(DNSClass::read(decoder));

        Ok(Query {
            name: name,
            query_type: query_type,
            query_class: query_class,
        })
    }

    fn emit(&self, encoder: &mut BinEncoder) -> EncodeResult {
        try!(self.name.emit(encoder));
        try!(self.query_type.emit(encoder));
        try!(self.query_class.emit(encoder));

        Ok(())
    }
}

#[test]
fn test_read_and_emit() {
    let expect = Query {
        name: Name::from_labels(vec!["WWW", "example", "com"]),
        query_type: RecordType::AAAA,
        query_class: DNSClass::IN,
    };

    let mut byte_vec: Vec<u8> = Vec::with_capacity(512);
    {
        let mut encoder = BinEncoder::new(&mut byte_vec);
        expect.emit(&mut encoder).unwrap();
    }

    let mut decoder = BinDecoder::new(&byte_vec);
    let got = Query::read(&mut decoder).unwrap();
    assert_eq!(got, expect);
}