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
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
//! Types and traits for converting objects to addresses which
//! Tor can connect to.

use crate::err::ErrorDetail;
use crate::StreamPrefs;
use std::fmt::Display;
use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, SocketAddrV4, SocketAddrV6};
use std::str::FromStr;
use thiserror::Error;
use tor_basic_utils::StrExt;

#[cfg(feature = "onion-service-client")]
use tor_hscrypto::pk::{HsId, HSID_ONION_SUFFIX};

/// Fake plastic imitation of some of the `tor-hs*` functionality
#[cfg(not(feature = "onion-service-client"))]
pub(crate) mod hs_dummy {
    use super::*;
    use tor_error::internal;
    use void::Void;

    /// Parsed hidden service identity - uninhabited, since not supported
    #[derive(Debug, Clone)]
    pub(crate) struct HsId(pub(crate) Void);

    impl PartialEq for HsId {
        fn eq(&self, _other: &Self) -> bool {
            void::unreachable(self.0)
        }
    }
    impl Eq for HsId {}

    /// Duplicates `tor-hscrypto::pk::HSID_ONION_SUFFIX`, ah well
    pub(crate) const HSID_ONION_SUFFIX: &str = ".onion";

    /// Must not be used other than for actual `.onion` addresses
    impl FromStr for HsId {
        type Err = ErrorDetail;

        fn from_str(s: &str) -> Result<Self, Self::Err> {
            if !s.ends_with(HSID_ONION_SUFFIX) {
                return Err(internal!("non-.onion passed to dummy HsId::from_str").into());
            }

            Err(ErrorDetail::OnionAddressNotSupported)
        }
    }
}
#[cfg(not(feature = "onion-service-client"))]
use hs_dummy::*;

// ----------------------------------------------------------------------

/// An object that can be converted to a [`TorAddr`] with a minimum of risk.
///
/// Typically, this trait will be implemented for a hostname or service name.
///
/// Don't implement this trait for IP addresses and similar types; instead,
/// implement [`DangerouslyIntoTorAddr`] for those.  (The trouble with accepting
/// IP addresses is that, in order to get an IP address, most programs will do a
/// local hostname lookup, which will leak the target address to the DNS
/// resolver. The `DangerouslyIntoTorAddr` trait provides a contract for careful
/// programs to say, "I have gotten this IP address from somewhere safe."  This
/// trait is for name-based addressing and similar, which _usually_ gets its
/// addresses from a safer source.)
///
/// [*See also: the `TorAddr` documentation.*](TorAddr)
///
/// # Design note
///
/// We use a separate trait here, instead of using `Into<TorAddr>` or
/// `TryInto<TorAddr>`, because `IntoTorAddr` implies additional guarantees
/// relating to privacy risk.  The separate trait alerts users that something
/// tricky is going on here, and encourages them to think twice before
/// implementing `IntoTorAddr` for their own types.
pub trait IntoTorAddr {
    /// Try to make a [`TorAddr`] to represent connecting to this
    /// address.
    fn into_tor_addr(self) -> Result<TorAddr, TorAddrError>;
}

/// An object that can be converted to a [`TorAddr`], but which it
/// might be risky to get in the first place if you're hoping for
/// anonymity.
///
/// For example, you can use this trait to convert a [`SocketAddr`]
/// into a [`TorAddr`], and it's safe to do that conversion.  But
/// where did you get the [`SocketAddr`] in the first place?  If it
/// comes from a local DNS lookup, then you have leaked the address
/// you were resolving to your DNS resolver, and probably your ISP.
///
/// [*See also: the `TorAddr` documentation.*](TorAddr)
pub trait DangerouslyIntoTorAddr {
    /// Try to make a [`TorAddr`] to represent connecting to `self`.
    ///
    /// By calling this function, the caller asserts that `self` was
    /// obtained from some secure, private mechanism, and **not** from a local
    /// DNS lookup or something similar.
    fn into_tor_addr_dangerously(self) -> Result<TorAddr, TorAddrError>;
}

/// An address object that you can connect to over the Tor network.
///
/// When you're making a connection with Tor, you shouldn't do your DNS
/// lookups locally: that would leak your target address to your DNS server.
/// Instead, it's better to use a combination of a hostname and a port
/// directly.
///
/// The preferred way to create a `TorAddr` is via the [`IntoTorAddr`] trait,
/// using a hostname and a port (or a string containing a hostname and a
/// port).  It's also okay to use an IP and Port there, but only if they come
/// from some source _other than_ a local DNS lookup.
///
/// In order to discourage local hostname lookups, the functions that
/// construct a [`TorAddr`] from [`IpAddr`], [`SocketAddr`], and so
/// forth are labeled as "dangerous".
///
/// # Examples
///
/// Making a `TorAddr` from various "safe" sources:
///
/// ```rust
/// # use anyhow::Result;
/// # fn main() -> Result<()> {
/// use arti_client::IntoTorAddr;
///
/// let example_from_tuple = ("example.com", 80).into_tor_addr()?;
/// let example_from_string = "example.com:80".into_tor_addr()?;
///
/// assert_eq!(example_from_tuple, example_from_string);
/// # Ok(())
/// # }
/// ```
///
/// Making a `TorAddr` from an IP address and port:
///
/// > **Warning:** This example is only safe because we're not doing a DNS lookup; rather, the
/// > intent is to connect to a hardcoded IP address.
/// > If you're using [`DangerouslyIntoTorAddr`], pay careful attention to where your IP addresses
/// > are coming from, and whether there's a risk of information leakage.
///
/// ```rust
/// # use anyhow::Result;
/// # fn main() -> Result<()> {
/// use arti_client::DangerouslyIntoTorAddr;
/// use std::net::{IpAddr, SocketAddr};
///
/// let quad_one_dns: SocketAddr = "1.1.1.1:53".parse()?;
/// let addr_from_socketaddr = quad_one_dns.into_tor_addr_dangerously()?;
///
/// let quad_one_ip: IpAddr = "1.1.1.1".parse()?;
/// let addr_from_tuple = (quad_one_ip, 53).into_tor_addr_dangerously()?;
///
/// assert_eq!(addr_from_socketaddr, addr_from_tuple);
/// # Ok(())
/// # }
/// ```
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct TorAddr {
    /// The target host.
    host: Host,
    /// The target port number.
    port: u16,
}

/// How to make a stream to this `TorAddr`?
///
/// This is a separate type, returned from `address.rs` to `client.rs`,
/// so that we can test our "how to make a connection" logic and policy,
/// in isolation, without a whole Tor client.
#[derive(Debug, PartialEq, Eq)]
pub(crate) enum StreamInstructions {
    /// Create an exit circuit suitable for port, and then make a stream to `hostname`
    Exit {
        /// Hostname
        hostname: String,
        /// Port
        port: u16,
    },
    /// Create a hidden service connection to hsid, and then make a stream to `hostname`
    ///
    /// `HsId`, and therefore this variant, is uninhabited, unless the feature is enabled
    Hs {
        /// The target hidden service
        hsid: HsId,
        /// The hostname (used for subdomains, sent to the peer)
        hostname: String,
        /// Port
        port: u16,
    },
}

/// How to resolve this Tor host address into IP address(es)
#[derive(PartialEq, Eq, Debug)]
pub(crate) enum ResolveInstructions {
    /// Create an exit circuit without port restrictions, and ask the exit
    Exit(String),
    /// Simply return this
    Return(Vec<IpAddr>),
}

impl TorAddr {
    /// Construct a TorAddr from its constituent parts, rejecting it if the
    /// port is zero.
    fn new(host: Host, port: u16) -> Result<Self, TorAddrError> {
        if port == 0 {
            Err(TorAddrError::BadPort)
        } else {
            Ok(TorAddr { host, port })
        }
    }

    /// Construct a `TorAddr` from any object that implements
    /// [`IntoTorAddr`].
    pub fn from<A: IntoTorAddr>(addr: A) -> Result<Self, TorAddrError> {
        addr.into_tor_addr()
    }
    /// Construct a `TorAddr` from any object that implements
    /// [`DangerouslyIntoTorAddr`].
    ///
    /// See [`DangerouslyIntoTorAddr`] for an explanation of why the
    /// style of programming supported by this function is dangerous
    /// to use.
    pub fn dangerously_from<A: DangerouslyIntoTorAddr>(addr: A) -> Result<Self, TorAddrError> {
        addr.into_tor_addr_dangerously()
    }

    /// Return true if this is an IP address (rather than a hostname).
    pub fn is_ip_address(&self) -> bool {
        matches!(&self.host, Host::Ip(_))
    }

    /// Get instructions for how to make a stream to this address
    pub(crate) fn into_stream_instructions(
        self,
        cfg: &crate::config::ClientAddrConfig,
        prefs: &StreamPrefs,
    ) -> Result<StreamInstructions, ErrorDetail> {
        self.enforce_config(cfg, prefs)?;

        let port = self.port;
        Ok(match self.host {
            Host::Hostname(hostname) => StreamInstructions::Exit { hostname, port },
            Host::Ip(ip) => StreamInstructions::Exit {
                hostname: ip.to_string(),
                port,
            },
            Host::Onion(onion) => {
                // The HS is identified by the last two domain name components
                let rhs = onion
                    .rmatch_indices('.')
                    .nth(1)
                    .map(|(i, _)| i + 1)
                    .unwrap_or(0);
                let rhs = &onion[rhs..];
                let hsid = rhs.parse()?;
                StreamInstructions::Hs {
                    hsid,
                    port,
                    hostname: onion,
                }
            }
        })
    }

    /// Get instructions for how to make a stream to this address
    pub(crate) fn into_resolve_instructions(
        self,
        cfg: &crate::config::ClientAddrConfig,
        prefs: &StreamPrefs,
    ) -> Result<ResolveInstructions, ErrorDetail> {
        // We defer enforcing the config until we see if this is a .onion,
        // in which case it's always doomed and we want to return *our* error,
        // not any problem with the configuration or preferences.
        // But we must *calculate* the error now because instructions consumes self.
        let enforce_config_result = self.enforce_config(cfg, prefs);

        // This IEFE is so that any use of `return` doesn't bypass
        // checking the enforce_config result
        let instructions = (move || {
            Ok(match self.host {
                Host::Hostname(hostname) => ResolveInstructions::Exit(hostname),
                Host::Ip(ip) => ResolveInstructions::Return(vec![ip]),
                Host::Onion(_) => return Err(ErrorDetail::OnionAddressResolveRequest),
            })
        })()?;

        let () = enforce_config_result?;

        Ok(instructions)
    }

    /// Return true if the `host` in this address is local.
    fn is_local(&self) -> bool {
        self.host.is_local()
    }

    /// Give an error if this address doesn't conform to the rules set in
    /// `cfg`.
    fn enforce_config(
        &self,
        cfg: &crate::config::ClientAddrConfig,
        #[allow(unused_variables)] // will only be used in certain configurations
        prefs: &StreamPrefs,
    ) -> Result<(), ErrorDetail> {
        if !cfg.allow_local_addrs && self.is_local() {
            return Err(ErrorDetail::LocalAddress);
        }

        if let Host::Hostname(addr) = &self.host {
            if !is_valid_hostname(addr) {
                // This ought not to occur, because it violates Host's invariant
                return Err(ErrorDetail::InvalidHostname);
            }
            if addr.ends_with_ignore_ascii_case(HSID_ONION_SUFFIX) {
                // This ought not to occur, because it violates Host's invariant
                return Err(ErrorDetail::OnionAddressNotSupported);
            }
        }

        if let Host::Onion(_name) = &self.host {
            cfg_if::cfg_if! {
                if #[cfg(feature = "onion-service-client")] {
                    if !prefs.connect_to_onion_services.as_bool().unwrap_or(cfg.allow_onion_addrs) {
                        return Err(ErrorDetail::OnionAddressDisabled);
                    }
                } else {
                    return Err(ErrorDetail::OnionAddressNotSupported);
                }
            }
        }

        Ok(())
    }
}

impl std::fmt::Display for TorAddr {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self.host {
            Host::Ip(IpAddr::V6(addr)) => write!(f, "[{}]:{}", addr, self.port),
            _ => write!(f, "{}:{}", self.host, self.port),
        }
    }
}

/// An error created while making or using a [`TorAddr`].
//
// NOTE: Unlike ErrorDetail, this is a `pub` enum: Do not make breaking changes
// to it, or expose lower-level errors in it, without careful consideration!
#[derive(Debug, Error, Clone, Eq, PartialEq)]
#[non_exhaustive]
// TODO Should implement ErrorKind
pub enum TorAddrError {
    /// Tried to parse a string that can never be interpreted as a valid host.
    #[error("String can never be a valid hostname")]
    InvalidHostname,
    /// Tried to parse a string as an `address:port`, but it had no port.
    #[error("No port found in string")]
    NoPort,
    /// Tried to parse a port that wasn't a valid nonzero `u16`.
    #[error("Could not parse port")]
    BadPort,
}

/// A host that Tor can connect to: either a hostname or an IP address.
//
// We use `String` in here, and pass that directly to (for example)
// `HsId::from_str`, or `begin_stream`.
// In theory we could use a couple of newtypes or something, but
//  * The stringly-typed `HsId::from_str` call (on a string known to end `.onion`)
//    appears precisely in `into_stream_instructions` which knows what it's doing;
//  * The stringly-typed .onion domain name must be passed in the
//    StreamInstructions so that we can send it to the HS for its vhosting.
#[derive(Clone, Debug, Eq, PartialEq)]
enum Host {
    /// A hostname.
    ///
    /// This variant should never be used if the `Ip`
    /// variant could be used instead.
    /// Ie, it must not be a stringified IP address.
    ///
    /// Likewise, this variant must *not* be used for a `.onion` address.
    /// Even if we have `.onion` support compiled out, we use the `Onion` variant for that.
    ///
    /// But, this variant might *not* be on the public internet.
    /// For example, it might be `localhost`.
    Hostname(String),
    /// An IP address.
    Ip(IpAddr),
    /// The address of a hidden service (`.onion` service).
    ///
    /// We haven't validated that the base32 makes any kind of sense, yet.
    /// We do that when we try to connect.
    Onion(String),
}

impl FromStr for Host {
    type Err = TorAddrError;
    fn from_str(s: &str) -> Result<Host, TorAddrError> {
        if s.ends_with_ignore_ascii_case(".onion") && is_valid_hostname(s) {
            Ok(Host::Onion(s.to_owned()))
        } else if let Ok(ip_addr) = s.parse() {
            Ok(Host::Ip(ip_addr))
        } else if is_valid_hostname(s) {
            // TODO(nickm): we might someday want to reject some kinds of bad
            // hostnames here, rather than when we're about to connect to them.
            // But that would be an API break, and maybe not what people want.
            // Maybe instead we should have a method to check whether a hostname
            // is "bad"? Not sure; we'll need to decide the right behavior here.
            Ok(Host::Hostname(s.to_owned()))
        } else {
            Err(TorAddrError::InvalidHostname)
        }
    }
}

impl Host {
    /// Return true if this address is one that is "internal": that is,
    /// relative to the particular host that is resolving it.
    fn is_local(&self) -> bool {
        match self {
            Host::Hostname(name) => name.eq_ignore_ascii_case("localhost"),
            // TODO: use is_global once it's stable, perhaps.
            // NOTE: Contrast this with is_sufficiently_private in tor-hsproxy,
            // which has a different purpose. Also see #1159.
            // The purpose of _this_ test is to find addresses that cannot
            // meaningfully be connected to over Tor, and that the exit
            // will not accept.
            Host::Ip(IpAddr::V4(ip)) => ip.is_loopback() || ip.is_private(),
            Host::Ip(IpAddr::V6(ip)) => ip.is_loopback(),
            Host::Onion(_) => false,
        }
    }
}

impl std::fmt::Display for Host {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Host::Hostname(s) => Display::fmt(s, f),
            Host::Ip(ip) => Display::fmt(ip, f),
            Host::Onion(onion) => Display::fmt(onion, f),
        }
    }
}

impl IntoTorAddr for TorAddr {
    fn into_tor_addr(self) -> Result<TorAddr, TorAddrError> {
        Ok(self)
    }
}

impl<A: IntoTorAddr + Clone> IntoTorAddr for &A {
    fn into_tor_addr(self) -> Result<TorAddr, TorAddrError> {
        self.clone().into_tor_addr()
    }
}

impl IntoTorAddr for &str {
    fn into_tor_addr(self) -> Result<TorAddr, TorAddrError> {
        if let Ok(sa) = SocketAddr::from_str(self) {
            TorAddr::new(Host::Ip(sa.ip()), sa.port())
        } else {
            let (host, port) = self.rsplit_once(':').ok_or(TorAddrError::NoPort)?;
            let host = host.parse()?;
            let port = port.parse().map_err(|_| TorAddrError::BadPort)?;
            TorAddr::new(host, port)
        }
    }
}

impl IntoTorAddr for String {
    fn into_tor_addr(self) -> Result<TorAddr, TorAddrError> {
        self[..].into_tor_addr()
    }
}

impl FromStr for TorAddr {
    type Err = TorAddrError;
    fn from_str(s: &str) -> Result<Self, TorAddrError> {
        s.into_tor_addr()
    }
}

impl IntoTorAddr for (&str, u16) {
    fn into_tor_addr(self) -> Result<TorAddr, TorAddrError> {
        let (host, port) = self;
        let host = host.parse()?;
        TorAddr::new(host, port)
    }
}

impl IntoTorAddr for (String, u16) {
    fn into_tor_addr(self) -> Result<TorAddr, TorAddrError> {
        let (host, port) = self;
        (&host[..], port).into_tor_addr()
    }
}

impl<T: DangerouslyIntoTorAddr + Clone> DangerouslyIntoTorAddr for &T {
    fn into_tor_addr_dangerously(self) -> Result<TorAddr, TorAddrError> {
        self.clone().into_tor_addr_dangerously()
    }
}

impl DangerouslyIntoTorAddr for (IpAddr, u16) {
    fn into_tor_addr_dangerously(self) -> Result<TorAddr, TorAddrError> {
        let (addr, port) = self;
        TorAddr::new(Host::Ip(addr), port)
    }
}

impl DangerouslyIntoTorAddr for (Ipv4Addr, u16) {
    fn into_tor_addr_dangerously(self) -> Result<TorAddr, TorAddrError> {
        let (addr, port) = self;
        TorAddr::new(Host::Ip(addr.into()), port)
    }
}

impl DangerouslyIntoTorAddr for (Ipv6Addr, u16) {
    fn into_tor_addr_dangerously(self) -> Result<TorAddr, TorAddrError> {
        let (addr, port) = self;
        TorAddr::new(Host::Ip(addr.into()), port)
    }
}

impl DangerouslyIntoTorAddr for SocketAddr {
    fn into_tor_addr_dangerously(self) -> Result<TorAddr, TorAddrError> {
        let (addr, port) = (self.ip(), self.port());
        (addr, port).into_tor_addr_dangerously()
    }
}

impl DangerouslyIntoTorAddr for SocketAddrV4 {
    fn into_tor_addr_dangerously(self) -> Result<TorAddr, TorAddrError> {
        let (addr, port) = (self.ip(), self.port());
        (*addr, port).into_tor_addr_dangerously()
    }
}

impl DangerouslyIntoTorAddr for SocketAddrV6 {
    fn into_tor_addr_dangerously(self) -> Result<TorAddr, TorAddrError> {
        let (addr, port) = (self.ip(), self.port());
        (*addr, port).into_tor_addr_dangerously()
    }
}

/// Check whether `hostname` is a valid hostname or not.
///
/// (Note that IPv6 addresses don't follow these rules.)
fn is_valid_hostname(hostname: &str) -> bool {
    hostname_validator::is_valid(hostname)
}

#[cfg(test)]
mod test {
    // @@ begin test lint list maintained by maint/add_warning @@
    #![allow(clippy::bool_assert_comparison)]
    #![allow(clippy::clone_on_copy)]
    #![allow(clippy::dbg_macro)]
    #![allow(clippy::mixed_attributes_style)]
    #![allow(clippy::print_stderr)]
    #![allow(clippy::print_stdout)]
    #![allow(clippy::single_char_pattern)]
    #![allow(clippy::unwrap_used)]
    #![allow(clippy::unchecked_duration_subtraction)]
    #![allow(clippy::useless_vec)]
    #![allow(clippy::needless_pass_by_value)]
    //! <!-- @@ end test lint list maintained by maint/add_warning @@ -->
    use super::*;

    /// Make a `StreamPrefs` with `.onion` enabled, if cfg-enabled
    fn mk_stream_prefs() -> StreamPrefs {
        let prefs = crate::StreamPrefs::default();

        #[cfg(feature = "onion-service-client")]
        let prefs = {
            let mut prefs = prefs;
            prefs.connect_to_onion_services(tor_config::BoolOrAuto::Explicit(true));
            prefs
        };

        prefs
    }

    #[test]
    fn validate_hostname() {
        // Valid hostname tests
        assert!(is_valid_hostname("torproject.org"));
        assert!(is_valid_hostname("Tor-Project.org"));
        assert!(is_valid_hostname("example.onion"));
        assert!(is_valid_hostname("some.example.onion"));

        // Invalid hostname tests
        assert!(!is_valid_hostname("-torproject.org"));
        assert!(!is_valid_hostname("_torproject.org"));
        assert!(!is_valid_hostname("tor_project1.org"));
        assert!(!is_valid_hostname("iwanna$money.org"));
    }

    #[test]
    fn validate_addr() {
        use crate::err::ErrorDetail;
        fn val<A: IntoTorAddr>(addr: A) -> Result<TorAddr, ErrorDetail> {
            let toraddr = addr.into_tor_addr()?;
            toraddr.enforce_config(&Default::default(), &mk_stream_prefs())?;
            Ok(toraddr)
        }

        assert!(val("[2001:db8::42]:20").is_ok());
        assert!(val(("2001:db8::42", 20)).is_ok());
        assert!(val(("198.151.100.42", 443)).is_ok());
        assert!(val("198.151.100.42:443").is_ok());
        assert!(val("www.torproject.org:443").is_ok());
        assert!(val(("www.torproject.org", 443)).is_ok());

        // When HS disabled, tested elsewhere, see: stream_instructions, prefs_onion_services
        #[cfg(feature = "onion-service-client")]
        {
            assert!(val("example.onion:80").is_ok());
            assert!(val(("example.onion", 80)).is_ok());

            match val("eweiibe6tdjsdprb4px6rqrzzcsi22m4koia44kc5pcjr7nec2rlxyad.onion:443") {
                Ok(TorAddr {
                    host: Host::Onion(_),
                    ..
                }) => {}
                x => panic!("{x:?}"),
            }
        }

        assert!(matches!(
            val("-foobar.net:443"),
            Err(ErrorDetail::InvalidHostname)
        ));
        assert!(matches!(
            val("www.torproject.org"),
            Err(ErrorDetail::Address(TorAddrError::NoPort))
        ));

        assert!(matches!(
            val("192.168.0.1:80"),
            Err(ErrorDetail::LocalAddress)
        ));
        assert!(matches!(
            val(TorAddr::new(Host::Hostname("foo@bar".to_owned()), 553).unwrap()),
            Err(ErrorDetail::InvalidHostname)
        ));
        assert!(matches!(
            val(TorAddr::new(Host::Hostname("foo.onion".to_owned()), 80).unwrap()),
            Err(ErrorDetail::OnionAddressNotSupported)
        ));
    }

    #[test]
    fn local_addrs() {
        fn is_local_hostname(s: &str) -> bool {
            let h: Host = s.parse().unwrap();
            h.is_local()
        }

        assert!(is_local_hostname("localhost"));
        assert!(is_local_hostname("loCALHOST"));
        assert!(is_local_hostname("127.0.0.1"));
        assert!(is_local_hostname("::1"));
        assert!(is_local_hostname("192.168.0.1"));

        assert!(!is_local_hostname("www.example.com"));
    }

    #[test]
    fn is_ip_address() {
        fn ip(s: &str) -> bool {
            TorAddr::from(s).unwrap().is_ip_address()
        }

        assert!(ip("192.168.0.1:80"));
        assert!(ip("[::1]:80"));
        assert!(ip("[2001:db8::42]:65535"));
        assert!(!ip("example.com:80"));
        assert!(!ip("example.onion:80"));
    }

    #[test]
    fn stream_instructions() {
        use StreamInstructions as SI;

        fn sap(s: &str) -> Result<StreamInstructions, ErrorDetail> {
            TorAddr::from(s)
                .unwrap()
                .into_stream_instructions(&Default::default(), &mk_stream_prefs())
        }

        assert_eq!(
            sap("[2001:db8::42]:9001").unwrap(),
            SI::Exit {
                hostname: "2001:db8::42".to_owned(),
                port: 9001
            },
        );
        assert_eq!(
            sap("example.com:80").unwrap(),
            SI::Exit {
                hostname: "example.com".to_owned(),
                port: 80
            },
        );

        {
            let b32 = "eweiibe6tdjsdprb4px6rqrzzcsi22m4koia44kc5pcjr7nec2rlxyad";
            let onion = format!("sss1234.www.{}.onion", b32);
            let got = sap(&format!("{}:443", onion));

            #[cfg(feature = "onion-service-client")]
            assert_eq!(
                got.unwrap(),
                SI::Hs {
                    hsid: format!("{}.onion", b32).parse().unwrap(),
                    hostname: onion,
                    port: 443,
                }
            );

            #[cfg(not(feature = "onion-service-client"))]
            assert!(matches!(got, Err(ErrorDetail::OnionAddressNotSupported)));
        }
    }

    #[test]
    fn resolve_instructions() {
        use ResolveInstructions as RI;

        fn sap(s: &str) -> Result<ResolveInstructions, ErrorDetail> {
            TorAddr::from(s)
                .unwrap()
                .into_resolve_instructions(&Default::default(), &Default::default())
        }

        assert_eq!(
            sap("[2001:db8::42]:9001").unwrap(),
            RI::Return(vec!["2001:db8::42".parse().unwrap()]),
        );
        assert_eq!(
            sap("example.com:80").unwrap(),
            RI::Exit("example.com".to_owned()),
        );
        assert!(matches!(
            sap("example.onion:80"),
            Err(ErrorDetail::OnionAddressResolveRequest),
        ));
    }

    #[test]
    fn bad_ports() {
        assert_eq!(
            TorAddr::from("www.example.com:squirrel"),
            Err(TorAddrError::BadPort)
        );
        assert_eq!(
            TorAddr::from("www.example.com:0"),
            Err(TorAddrError::BadPort)
        );
    }

    #[test]
    fn prefs_onion_services() {
        use crate::err::ErrorDetailDiscriminants;
        use tor_error::{ErrorKind, HasKind as _};
        use ErrorDetailDiscriminants as EDD;
        use ErrorKind as EK;

        #[allow(clippy::redundant_closure)] // for symmetry with prefs_of, below, and clarity
        let prefs_def = || StreamPrefs::default();

        let addr: TorAddr = "eweiibe6tdjsdprb4px6rqrzzcsi22m4koia44kc5pcjr7nec2rlxyad.onion:443"
            .parse()
            .unwrap();

        fn map(
            got: Result<impl Sized, ErrorDetail>,
        ) -> Result<(), (ErrorDetailDiscriminants, ErrorKind)> {
            got.map(|_| ())
                .map_err(|e| (ErrorDetailDiscriminants::from(&e), e.kind()))
        }

        let check_stream = |prefs, expected| {
            let got = addr
                .clone()
                .into_stream_instructions(&Default::default(), &prefs);
            assert_eq!(map(got), expected, "{prefs:?}");
        };
        let check_resolve = |prefs| {
            let got = addr
                .clone()
                .into_resolve_instructions(&Default::default(), &prefs);
            // This should be OnionAddressResolveRequest no matter if .onion is compiled in or enabled.
            // Since compiling it in, or enabling it, won't help.
            let expected = Err((EDD::OnionAddressResolveRequest, EK::NotImplemented));
            assert_eq!(map(got), expected, "{prefs:?}");
        };

        cfg_if::cfg_if! {
            if #[cfg(feature = "onion-service-client")] {
                use tor_config::BoolOrAuto as B;
                let prefs_of = |yn| {
                    let mut prefs = StreamPrefs::default();
                    prefs.connect_to_onion_services(yn);
                    prefs
                };
                check_stream(prefs_def(), Err((EDD::OnionAddressDisabled, EK::ForbiddenStreamTarget)));
                check_stream(prefs_of(B::Auto), Err((EDD::OnionAddressDisabled, EK::ForbiddenStreamTarget)));
                check_stream(prefs_of(B::Explicit(true)), Ok(()));
                check_stream(prefs_of(B::Explicit(false)), Err((EDD::OnionAddressDisabled, EK::ForbiddenStreamTarget)));

                check_resolve(prefs_def());
                check_resolve(prefs_of(B::Auto));
                check_resolve(prefs_of(B::Explicit(true)));
                check_resolve(prefs_of(B::Explicit(false)));
            } else {
                check_stream(prefs_def(), Err((EDD::OnionAddressNotSupported, EK::FeatureDisabled)));

                check_resolve(prefs_def());
            }
        }
    }

    #[test]
    fn convert_safe() {
        fn check<A: IntoTorAddr>(a: A, s: &str) {
            let a1 = TorAddr::from(a).unwrap();
            let a2 = s.parse().unwrap();
            assert_eq!(a1, a2);
            assert_eq!(&a1.to_string(), s);
        }

        check(("www.example.com", 8000), "www.example.com:8000");
        check(
            TorAddr::from(("www.example.com", 8000)).unwrap(),
            "www.example.com:8000",
        );
        check(
            TorAddr::from(("www.example.com", 8000)).unwrap(),
            "www.example.com:8000",
        );
        let addr = "[2001:db8::0042]:9001".to_owned();
        check(&addr, "[2001:db8::42]:9001");
        check(addr, "[2001:db8::42]:9001");
        check(("2001:db8::0042".to_owned(), 9001), "[2001:db8::42]:9001");
        check(("example.onion", 80), "example.onion:80");
    }

    #[test]
    fn convert_dangerous() {
        fn check<A: DangerouslyIntoTorAddr>(a: A, s: &str) {
            let a1 = TorAddr::dangerously_from(a).unwrap();
            let a2 = TorAddr::from(s).unwrap();
            assert_eq!(a1, a2);
            assert_eq!(&a1.to_string(), s);
        }

        let ip: IpAddr = "203.0.133.6".parse().unwrap();
        let ip4: Ipv4Addr = "203.0.133.7".parse().unwrap();
        let ip6: Ipv6Addr = "2001:db8::42".parse().unwrap();
        let sa: SocketAddr = "203.0.133.8:80".parse().unwrap();
        let sa4: SocketAddrV4 = "203.0.133.8:81".parse().unwrap();
        let sa6: SocketAddrV6 = "[2001:db8::43]:82".parse().unwrap();

        // This tests impl DangerouslyIntoTorAddr for &T
        #[allow(clippy::needless_borrow)]
        #[allow(clippy::needless_borrows_for_generic_args)]
        check(&(ip, 443), "203.0.133.6:443");
        check((ip, 443), "203.0.133.6:443");
        check((ip4, 444), "203.0.133.7:444");
        check((ip6, 445), "[2001:db8::42]:445");
        check(sa, "203.0.133.8:80");
        check(sa4, "203.0.133.8:81");
        check(sa6, "[2001:db8::43]:82");
    }
}