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
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
/*
 * 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.
 */

//! record data enum variants

use std::cmp::Ordering;
#[cfg(test)]
use std::convert::From;
use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};

use super::domain::Name;
use super::rdata;
use super::rdata::{CAA, MX, NULL, OPT, SOA, SRV, TLSA, TXT};
use super::record_type::RecordType;
use error::*;
use serialize::binary::*;

#[cfg(feature = "dnssec")]
use super::dnssec::rdata::DNSSECRData;

/// Record data enum variants
///
/// [RFC 1035](https://tools.ietf.org/html/rfc1035), DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION, November 1987
///
/// ```text
/// 3.3. Standard RRs
///
/// The following RR definitions are expected to occur, at least
/// potentially, in all classes.  In particular, NS, SOA, CNAME, and PTR
/// will be used in all classes, and have the same format in all classes.
/// Because their RDATA format is known, all domain names in the RDATA
/// section of these RRs may be compressed.
///
/// <domain-name> is a domain name represented as a series of labels, and
/// terminated by a label with zero length.  <character-string> is a single
/// length octet followed by that number of characters.  <character-string>
/// is treated as binary information, and can be up to 256 characters in
/// length (including the length octet).
/// ```
#[derive(Debug, PartialEq, Clone, Eq)]
pub enum RData {
    /// ```text
    /// -- RFC 1035 -- Domain Implementation and Specification    November 1987
    ///
    /// 3.4. Internet specific RRs
    ///
    /// 3.4.1. A RDATA format
    ///
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///     |                    ADDRESS                    |
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///
    /// where:
    ///
    /// ADDRESS         A 32 bit Internet address.
    ///
    /// Hosts that have multiple Internet addresses will have multiple A
    /// records.
    ///
    /// A records cause no additional section processing.  The RDATA section of
    /// an A line in a master file is an Internet address expressed as four
    /// decimal numbers separated by dots without any imbedded spaces (e.g.,
    /// "10.2.0.52" or "192.0.5.6").
    /// ```
    A(Ipv4Addr),

    /// ```text
    /// -- RFC 1886 -- IPv6 DNS Extensions              December 1995
    ///
    /// 2.2 AAAA data format
    ///
    ///    A 128 bit IPv6 address is encoded in the data portion of an AAAA
    ///    resource record in network byte order (high-order byte first).
    /// ```
    AAAA(Ipv6Addr),

    /// ```text
    /// -- RFC 6844          Certification Authority Authorization     January 2013
    ///
    /// 5.1.  Syntax
    ///
    /// A CAA RR contains a single property entry consisting of a tag-value
    /// pair.  Each tag represents a property of the CAA record.  The value
    /// of a CAA property is that specified in the corresponding value field.
    ///
    /// A domain name MAY have multiple CAA RRs associated with it and a
    /// given property MAY be specified more than once.
    ///
    /// The CAA data field contains one property entry.  A property entry
    /// consists of the following data fields:
    ///
    /// +0-1-2-3-4-5-6-7-|0-1-2-3-4-5-6-7-|
    /// | Flags          | Tag Length = n |
    /// +----------------+----------------+...+---------------+
    /// | Tag char 0     | Tag char 1     |...| Tag char n-1  |
    /// +----------------+----------------+...+---------------+
    /// +----------------+----------------+.....+----------------+
    /// | Value byte 0   | Value byte 1   |.....| Value byte m-1 |
    /// +----------------+----------------+.....+----------------+

    /// Where n is the length specified in the Tag length field and m is the
    /// remaining octets in the Value field (m = d - n - 2) where d is the
    /// length of the RDATA section.
    /// ```
    CAA(CAA),

    /// ```text
    ///   3.3. Standard RRs
    ///
    /// The following RR definitions are expected to occur, at least
    /// potentially, in all classes.  In particular, NS, SOA, CNAME, and PTR
    /// will be used in all classes, and have the same format in all classes.
    /// Because their RDATA format is known, all domain names in the RDATA
    /// section of these RRs may be compressed.
    ///
    /// <domain-name> is a domain name represented as a series of labels, and
    /// terminated by a label with zero length.  <character-string> is a single
    /// length octet followed by that number of characters.  <character-string>
    /// is treated as binary information, and can be up to 256 characters in
    /// length (including the length octet).
    ///
    /// 3.3.1. CNAME RDATA format
    ///
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///     /                     CNAME                     /
    ///     /                                               /
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///
    /// where:
    ///
    /// CNAME           A <domain-name> which specifies the canonical or primary
    ///                 name for the owner.  The owner name is an alias.
    ///
    /// CNAME RRs cause no additional section processing, but name servers may
    /// choose to restart the query at the canonical name in certain cases.  See
    /// the description of name server logic in [RFC-1034] for details.
    /// ```
    CNAME(Name),

    /// ```text
    /// 3.3.9. MX RDATA format
    ///
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///     |                  PREFERENCE                   |
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///     /                   EXCHANGE                    /
    ///     /                                               /
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ////
    /// where:
    ///
    /// PREFERENCE      A 16 bit integer which specifies the preference given to
    ///                 this RR among others at the same owner.  Lower values
    ///                 are preferred.
    ///
    /// EXCHANGE        A <domain-name> which specifies a host willing to act as
    ///                 a mail exchange for the owner name.
    ///
    /// MX records cause type A additional section processing for the host
    /// specified by EXCHANGE.  The use of MX RRs is explained in detail in
    /// [RFC-974].
    /// ```
    MX(MX),

    /// ```text
    /// 3.3.10. NULL RDATA format (EXPERIMENTAL)
    ///
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///     /                  <anything>                   /
    ///     /                                               /
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///
    /// Anything at all may be in the RDATA field so long as it is 65535 octets
    /// or less.
    ///
    /// NULL records cause no additional section processing.  NULL RRs are not
    /// allowed in master files.  NULLs are used as placeholders in some
    /// experimental extensions of the DNS.
    /// ```
    NULL(NULL),

    /// ```text
    /// 3.3.11. NS RDATA format
    ///
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///     /                   NSDNAME                     /
    ///     /                                               /
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///
    /// where:
    ///
    /// NSDNAME         A <domain-name> which specifies a host which should be
    ///                 authoritative for the specified class and domain.
    ///
    /// NS records cause both the usual additional section processing to locate
    /// a type A record, and, when used in a referral, a special search of the
    /// zone in which they reside for glue information.
    ///
    /// The NS RR states that the named host should be expected to have a zone
    /// starting at owner name of the specified class.  Note that the class may
    /// not indicate the protocol family which should be used to communicate
    /// with the host, although it is typically a strong hint.  For example,
    /// hosts which are name servers for either Internet (IN) or Hesiod (HS)
    /// class information are normally queried using IN class protocols.
    /// ```
    NS(Name),

    /// ```text
    /// RFC 6891                   EDNS(0) Extensions                 April 2013
    /// 6.1.2.  Wire Format
    ///
    ///        +------------+--------------+------------------------------+
    ///        | Field Name | Field Type   | Description                  |
    ///        +------------+--------------+------------------------------+
    ///        | NAME       | domain name  | MUST be 0 (root domain)      |
    ///        | TYPE       | u_int16_t    | OPT (41)                     |
    ///        | CLASS      | u_int16_t    | requestor's UDP payload size |
    ///        | TTL        | u_int32_t    | extended RCODE and flags     |
    ///        | RDLEN      | u_int16_t    | length of all RDATA          |
    ///        | RDATA      | octet stream | {attribute,value} pairs      |
    ///        +------------+--------------+------------------------------+
    ///
    /// The variable part of an OPT RR may contain zero or more options in
    ///    the RDATA.  Each option MUST be treated as a bit field.  Each option
    ///    is encoded as:
    ///
    ///                   +0 (MSB)                            +1 (LSB)
    ///        +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    ///     0: |                          OPTION-CODE                          |
    ///        +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    ///     2: |                         OPTION-LENGTH                         |
    ///        +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    ///     4: |                                                               |
    ///        /                          OPTION-DATA                          /
    ///        /                                                               /
    ///        +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
    /// ```
    OPT(OPT),

    /// ```text
    /// 3.3.12. PTR RDATA format
    ///
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///     /                   PTRDNAME                    /
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///
    /// where:
    ///
    /// PTRDNAME        A <domain-name> which points to some location in the
    ///                 domain name space.
    ///
    /// PTR records cause no additional section processing.  These RRs are used
    /// in special domains to point to some other location in the domain space.
    /// These records are simple data, and don't imply any special processing
    /// similar to that performed by CNAME, which identifies aliases.  See the
    /// description of the IN-ADDR.ARPA domain for an example.
    /// ```
    PTR(Name),

    /// ```text
    /// 3.3.13. SOA RDATA format
    ///
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///     /                     MNAME                     /
    ///     /                                               /
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///     /                     RNAME                     /
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///     |                    SERIAL                     |
    ///     |                                               |
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///     |                    REFRESH                    |
    ///     |                                               |
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///     |                     RETRY                     |
    ///     |                                               |
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///     |                    EXPIRE                     |
    ///     |                                               |
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///     |                    MINIMUM                    |
    ///     |                                               |
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///
    /// where:
    ///
    /// MNAME           The <domain-name> of the name server that was the
    ///                 original or primary source of data for this zone.
    ///
    /// RNAME           A <domain-name> which specifies the mailbox of the
    ///                 person responsible for this zone.
    ///
    //// SERIAL          The unsigned 32 bit version number of the original copy
    ///                 of the zone.  Zone transfers preserve this value.  This
    ///                 value wraps and should be compared using sequence space
    ///                 arithmetic.
    ///
    /// REFRESH         A 32 bit time interval before the zone should be
    ///                 refreshed.
    ///
    /// RETRY           A 32 bit time interval that should elapse before a
    ///                 failed refresh should be retried.
    ///
    /// EXPIRE          A 32 bit time value that specifies the upper limit on
    ///                 the time interval that can elapse before the zone is no
    ///                 longer authoritative.
    ///
    /// MINIMUM         The unsigned 32 bit minimum TTL field that should be
    ///                 exported with any RR from this zone.
    ///
    /// SOA records cause no additional section processing.
    ///
    /// All times are in units of seconds.
    ///
    /// Most of these fields are pertinent only for name server maintenance
    /// operations.  However, MINIMUM is used in all query operations that
    /// retrieve RRs from a zone.  Whenever a RR is sent in a response to a
    /// query, the TTL field is set to the maximum of the TTL field from the RR
    /// and the MINIMUM field in the appropriate SOA.  Thus MINIMUM is a lower
    /// bound on the TTL field for all RRs in a zone.  Note that this use of
    /// MINIMUM should occur when the RRs are copied into the response and not
    /// when the zone is loaded from a master file or via a zone transfer.  The
    /// reason for this provison is to allow future dynamic update facilities to
    /// change the SOA RR with known semantics.
    /// ```
    SOA(SOA),

    /// ```text
    /// RFC 2782                       DNS SRV RR                  February 2000
    ///
    /// The format of the SRV RR
    ///
    ///  _Service._Proto.Name TTL Class SRV Priority Weight Port Target
    /// ```
    SRV(SRV),

    /// [RFC 6698, DNS-Based Authentication for TLS](https://tools.ietf.org/html/rfc6698#section-2.1)
    ///
    /// ```text
    ///                         1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3
    ///     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
    ///    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    ///    |  Cert. Usage  |   Selector    | Matching Type |               /
    ///    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+               /
    ///    /                                                               /
    ///    /                 Certificate Association Data                  /
    ///    /                                                               /
    ///    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    /// ```
    TLSA(TLSA),

    /// ```text
    /// 3.3.14. TXT RDATA format
    ///
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///     /                   TXT-DATA                    /
    ///     +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
    ///
    /// where:
    ///
    /// TXT-DATA        One or more <character-string>s.
    ///
    /// TXT RRs are used to hold descriptive text.  The semantics of the text
    /// depends on the domain where it is found.
    /// ```
    TXT(TXT),

    /// A DNSSEC- or SIG(0)- specific record. See `DNSSECRData` for details.
    ///
    /// These types are in `DNSSECRData` to make them easy to disable when
    /// crypto functionality isn't needed.
    #[cfg(feature = "dnssec")]
    DNSSEC(DNSSECRData),

    /// Unknown RecordData is for record types not supported by TRust-DNS
    Unknown {
        /// RecordType code
        code: u16,
        /// RData associated to the record
        rdata: NULL,
    },

    /// This corresponds to a record type of 0, unspecified
    ZERO,
}

impl RData {
    fn to_bytes(&self) -> Vec<u8> {
        let mut buf: Vec<u8> = Vec::new();
        {
            let mut encoder: BinEncoder = BinEncoder::new(&mut buf);
            self.emit(&mut encoder).unwrap_or_else(|_| {
                warn!("could not encode RDATA: {:?}", self);
                ()
            });
        }
        buf
    }

    /// Read the RData from the given Decoder
    pub fn read(
        decoder: &mut BinDecoder,
        record_type: RecordType,
        rdata_length: Restrict<u16>,
    ) -> ProtoResult<Self> {
        let start_idx = decoder.index();

        let result = match record_type {
            RecordType::A => {
                debug!("reading A");
                rdata::a::read(decoder).map(RData::A)
            }
            RecordType::AAAA => {
                debug!("reading AAAA");
                rdata::aaaa::read(decoder).map(RData::AAAA)
            }
            rt @ RecordType::ANY | rt @ RecordType::AXFR | rt @ RecordType::IXFR => {
                return Err(ProtoErrorKind::UnknownRecordTypeValue(rt.into()).into())
            }
            RecordType::CAA => {
                debug!("reading CAA");
                rdata::caa::read(decoder, rdata_length).map(RData::CAA)
            }
            RecordType::CNAME => {
                debug!("reading CNAME");
                rdata::name::read(decoder).map(RData::CNAME)
            }
            RecordType::ZERO => {
                debug!("reading EMPTY");
                return Ok(RData::ZERO);
            }
            RecordType::MX => {
                debug!("reading MX");
                rdata::mx::read(decoder).map(RData::MX)
            }
            RecordType::NULL => {
                debug!("reading NULL");
                rdata::null::read(decoder, rdata_length).map(RData::NULL)
            }
            RecordType::NS => {
                debug!("reading NS");
                rdata::name::read(decoder).map(RData::NS)
            }
            RecordType::OPT => {
                debug!("reading OPT");
                rdata::opt::read(decoder, rdata_length).map(RData::OPT)
            }
            RecordType::PTR => {
                debug!("reading PTR");
                rdata::name::read(decoder).map(RData::PTR)
            }
            RecordType::SOA => {
                debug!("reading SOA");
                rdata::soa::read(decoder).map(RData::SOA)
            }
            RecordType::SRV => {
                debug!("reading SRV");
                rdata::srv::read(decoder).map(RData::SRV)
            }
            RecordType::TLSA => {
                debug!("reading TLSA");
                rdata::tlsa::read(decoder, rdata_length).map(RData::TLSA)
            }
            RecordType::TXT => {
                debug!("reading TXT");
                rdata::txt::read(decoder, rdata_length).map(RData::TXT)
            }
            #[cfg(feature = "dnssec")]
            RecordType::DNSSEC(record_type) => {
                DNSSECRData::read(decoder, record_type, rdata_length).map(RData::DNSSEC)
            }
            RecordType::Unknown(code) => {
                debug!("reading Unknown");
                rdata::null::read(decoder, rdata_length).map(|rdata| RData::Unknown { code, rdata })
            }
        };

        // we should have read rdata_length, but we did not
        let read = decoder.index() - start_idx;
        rdata_length
            .map(|u| u as usize)
            .verify_unwrap(|rdata_length| read == *rdata_length)
            .map_err(|rdata_length| {
                ProtoError::from(ProtoErrorKind::IncorrectRDataLengthRead {
                    read,
                    len: rdata_length,
                })
            })?;

        result
    }

    /// [RFC 4034](https://tools.ietf.org/html/rfc4034#section-6), DNSSEC Resource Records, March 2005
    ///
    /// ```text
    /// 6.2.  Canonical RR Form
    ///
    ///    For the purposes of DNS security, the canonical form of an RR is the
    ///    wire format of the RR where:
    ///
    ///    ...
    ///
    ///    3.  if the type of the RR is NS, MD, MF, CNAME, SOA, MB, MG, MR, PTR,
    ///        HINFO, MINFO, MX, HINFO, RP, AFSDB, RT, SIG, PX, NXT, NAPTR, KX,
    ///        SRV, DNAME, A6, RRSIG, or (rfc6840 removes NSEC), all uppercase
    ///        US-ASCII letters in the DNS names contained within the RDATA are replaced
    ///        by the corresponding lowercase US-ASCII letters;
    /// ```
    pub fn emit(&self, encoder: &mut BinEncoder) -> ProtoResult<()> {
        match *self {
            RData::A(ref address) => rdata::a::emit(encoder, address),
            RData::AAAA(ref address) => rdata::aaaa::emit(encoder, address),
            RData::CAA(ref caa) => rdata::caa::emit(encoder, caa),
            // to_lowercase for rfc4034 and rfc6840
            RData::CNAME(ref name) | RData::NS(ref name) | RData::PTR(ref name) => {
                rdata::name::emit(encoder, name)
            }
            RData::ZERO => Ok(()),
            // to_lowercase for rfc4034 and rfc6840
            RData::MX(ref mx) => rdata::mx::emit(encoder, mx),
            RData::NULL(ref null) => rdata::null::emit(encoder, null),
            RData::OPT(ref opt) => rdata::opt::emit(encoder, opt),
            // to_lowercase for rfc4034 and rfc6840
            RData::SOA(ref soa) => rdata::soa::emit(encoder, soa),
            // to_lowercase for rfc4034 and rfc6840
            RData::SRV(ref srv) => rdata::srv::emit(encoder, srv),
            RData::TLSA(ref tlsa) => rdata::tlsa::emit(encoder, tlsa),
            RData::TXT(ref txt) => rdata::txt::emit(encoder, txt),
            #[cfg(feature = "dnssec")]
            RData::DNSSEC(ref rdata) => rdata.emit(encoder),
            RData::Unknown { ref rdata, .. } => rdata::null::emit(encoder, rdata),
        }
    }

    /// Converts this to a Recordtype
    pub fn to_record_type(&self) -> RecordType {
        match *self {
            RData::A(..) => RecordType::A,
            RData::AAAA(..) => RecordType::AAAA,
            RData::CAA(..) => RecordType::CAA,
            RData::CNAME(..) => RecordType::CNAME,
            RData::MX(..) => RecordType::MX,
            RData::NS(..) => RecordType::NS,
            RData::NULL(..) => RecordType::NULL,
            RData::OPT(..) => RecordType::OPT,
            RData::PTR(..) => RecordType::PTR,
            RData::SOA(..) => RecordType::SOA,
            RData::SRV(..) => RecordType::SRV,
            RData::TLSA(..) => RecordType::TLSA,
            RData::TXT(..) => RecordType::TXT,
            #[cfg(feature = "dnssec")]
            RData::DNSSEC(ref rdata) => RecordType::DNSSEC(DNSSECRData::to_record_type(rdata)),
            RData::Unknown { code, .. } => RecordType::Unknown(code),
            RData::ZERO => RecordType::ZERO,
        }
    }

    /// If this is an A or AAAA record type, then an IpAddr will be returned
    pub fn to_ip_addr(&self) -> Option<IpAddr> {
        match *self {
            RData::A(a) => Some(IpAddr::from(a)),
            RData::AAAA(aaaa) => Some(IpAddr::from(aaaa)),
            _ => None,
        }
    }
}

impl PartialOrd<RData> for RData {
    fn partial_cmp(&self, other: &RData) -> Option<Ordering> {
        Some(self.cmp(other))
    }
}

impl Ord for RData {
    // RFC 4034                DNSSEC Resource Records               March 2005
    //
    // 6.3.  Canonical RR Ordering within an RRset
    //
    //    For the purposes of DNS security, RRs with the same owner name,
    //    class, and type are sorted by treating the RDATA portion of the
    //    canonical form of each RR as a left-justified unsigned octet sequence
    //    in which the absence of an octet sorts before a zero octet.
    //
    //    [RFC2181] specifies that an RRset is not allowed to contain duplicate
    //    records (multiple RRs with the same owner name, class, type, and
    //    RDATA).  Therefore, if an implementation detects duplicate RRs when
    //    putting the RRset in canonical form, it MUST treat this as a protocol
    //    error.  If the implementation chooses to handle this protocol error
    //    in the spirit of the robustness principle (being liberal in what it
    //    accepts), it MUST remove all but one of the duplicate RR(s) for the
    //    purposes of calculating the canonical form of the RRset.
    fn cmp(&self, other: &Self) -> Ordering {
        // TODO: how about we just store the bytes with the decoded data?
        //  the decoded data is useful for queries, the encoded data is needed for transfers, signing
        //  and ordering.
        self.to_bytes().cmp(&other.to_bytes())
    }
}

#[cfg(test)]
mod tests {
    use std::net::Ipv4Addr;
    use std::net::Ipv6Addr;
    use std::str::FromStr;

    use super::*;
    use rr::domain::Name;
    use rr::rdata::{MX, SOA, SRV, TXT};
    use serialize::binary::bin_tests::test_emit_data_set;
    #[allow(unused)]
    use serialize::binary::*;

    fn get_data() -> Vec<(RData, Vec<u8>)> {
        vec![
            (
                RData::CNAME(Name::from_str("www.example.com").unwrap()),
                vec![
                    3, b'w', b'w', b'w', 7, b'e', b'x', b'a', b'm', b'p', b'l', b'e', 3, b'c',
                    b'o', b'm', 0,
                ],
            ),
            (
                RData::MX(MX::new(256, Name::from_str("n").unwrap())),
                vec![1, 0, 1, b'n', 0],
            ),
            (
                RData::NS(Name::from_str("www.example.com").unwrap()),
                vec![
                    3, b'w', b'w', b'w', 7, b'e', b'x', b'a', b'm', b'p', b'l', b'e', 3, b'c',
                    b'o', b'm', 0,
                ],
            ),
            (
                RData::PTR(Name::from_str("www.example.com").unwrap()),
                vec![
                    3, b'w', b'w', b'w', 7, b'e', b'x', b'a', b'm', b'p', b'l', b'e', 3, b'c',
                    b'o', b'm', 0,
                ],
            ),
            (
                RData::SOA(SOA::new(
                    Name::from_str("www.example.com").unwrap(),
                    Name::from_str("xxx.example.com").unwrap(),
                    u32::max_value(),
                    -1 as i32,
                    -1 as i32,
                    -1 as i32,
                    u32::max_value(),
                )),
                vec![
                    3, b'w', b'w', b'w', 7, b'e', b'x', b'a', b'm', b'p', b'l', b'e', 3, b'c',
                    b'o', b'm', 0, 3, b'x', b'x', b'x', 0xC0, 0x04, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
                    0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
                    0xFF, 0xFF,
                ],
            ),
            (
                RData::TXT(TXT::new(vec![
                    "abcdef".to_string(),
                    "ghi".to_string(),
                    "".to_string(),
                    "j".to_string(),
                ])),
                vec![
                    6, b'a', b'b', b'c', b'd', b'e', b'f', 3, b'g', b'h', b'i', 0, 1, b'j',
                ],
            ),
            (
                RData::A(Ipv4Addr::from_str("0.0.0.0").unwrap()),
                vec![0, 0, 0, 0],
            ),
            (
                RData::AAAA(Ipv6Addr::from_str("::").unwrap()),
                vec![0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
            ),
            (
                RData::SRV(SRV::new(
                    1,
                    2,
                    3,
                    Name::from_str("www.example.com").unwrap(),
                )),
                vec![
                    0x00, 0x01, 0x00, 0x02, 0x00, 0x03, 3, b'w', b'w', b'w', 7, b'e', b'x', b'a',
                    b'm', b'p', b'l', b'e', 3, b'c', b'o', b'm', 0,
                ],
            ),
        ]
    }

    // TODO this test kinda sucks, shows the problem with not storing the binary parts
    #[test]
    fn test_order() {
        let ordered: Vec<RData> = vec![
            RData::A(Ipv4Addr::from_str("0.0.0.0").unwrap()),
            RData::AAAA(Ipv6Addr::from_str("::").unwrap()),
            RData::SRV(SRV::new(
                1,
                2,
                3,
                Name::from_str("www.example.com").unwrap(),
            )),
            RData::MX(MX::new(256, Name::from_str("n").unwrap())),
            RData::CNAME(Name::from_str("www.example.com").unwrap()),
            RData::PTR(Name::from_str("www.example.com").unwrap()),
            RData::NS(Name::from_str("www.example.com").unwrap()),
            RData::SOA(SOA::new(
                Name::from_str("www.example.com").unwrap(),
                Name::from_str("xxx.example.com").unwrap(),
                u32::max_value(),
                -1 as i32,
                -1 as i32,
                -1 as i32,
                u32::max_value(),
            )),
            RData::TXT(TXT::new(vec![
                "abcdef".to_string(),
                "ghi".to_string(),
                "".to_string(),
                "j".to_string(),
            ])),
        ];
        let mut unordered = vec![
            RData::CNAME(Name::from_str("www.example.com").unwrap()),
            RData::MX(MX::new(256, Name::from_str("n").unwrap())),
            RData::PTR(Name::from_str("www.example.com").unwrap()),
            RData::NS(Name::from_str("www.example.com").unwrap()),
            RData::SOA(SOA::new(
                Name::from_str("www.example.com").unwrap(),
                Name::from_str("xxx.example.com").unwrap(),
                u32::max_value(),
                -1 as i32,
                -1 as i32,
                -1 as i32,
                u32::max_value(),
            )),
            RData::TXT(TXT::new(vec![
                "abcdef".to_string(),
                "ghi".to_string(),
                "".to_string(),
                "j".to_string(),
            ])),
            RData::A(Ipv4Addr::from_str("0.0.0.0").unwrap()),
            RData::AAAA(Ipv6Addr::from_str("::").unwrap()),
            RData::SRV(SRV::new(
                1,
                2,
                3,
                Name::from_str("www.example.com").unwrap(),
            )),
        ];

        unordered.sort();
        assert_eq!(ordered, unordered);
    }

    #[test]
    fn test_read() {
        let mut test_pass = 0;
        for (expect, binary) in get_data() {
            test_pass += 1;
            println!("test {}: {:?}", test_pass, binary);
            let length = binary.len() as u16; // pre exclusive borrow
            let mut decoder = BinDecoder::new(&binary);

            assert_eq!(
                RData::read(&mut decoder, record_type_from_rdata(&expect), Restrict::new(length)).unwrap(),
                expect
            );
        }
    }

    // TODO: this is kinda broken right now since it can't cover all types.
    fn record_type_from_rdata(rdata: &RData) -> ::rr::record_type::RecordType {
        match *rdata {
            RData::A(..) => RecordType::A,
            RData::AAAA(..) => RecordType::AAAA,
            RData::CAA(..) => RecordType::CAA,
            RData::CNAME(..) => RecordType::CNAME,
            RData::MX(..) => RecordType::MX,
            RData::NS(..) => RecordType::NS,
            RData::NULL(..) => RecordType::NULL,
            RData::OPT(..) => RecordType::OPT,
            RData::PTR(..) => RecordType::PTR,
            RData::SOA(..) => RecordType::SOA,
            RData::SRV(..) => RecordType::SRV,
            RData::TLSA(..) => RecordType::TLSA,
            RData::TXT(..) => RecordType::TXT,
            #[cfg(feature = "dnssec")]
            RData::DNSSEC(ref rdata) => RecordType::DNSSEC(rdata.to_record_type()),
            RData::Unknown { code, .. } => RecordType::Unknown(code),
            RData::ZERO => RecordType::ZERO,
        }
    }

    #[test]
    fn test_write_to() {
        test_emit_data_set(get_data(), |e, d| d.emit(e));
    }
}