1
//! Declare dirclient-specific errors.
2

            
3
use std::sync::Arc;
4

            
5
use thiserror::Error;
6
use tor_error::{Bug, ErrorKind, HasKind};
7
use tor_linkspec::OwnedChanTarget;
8
use tor_rtcompat::TimeoutError;
9

            
10
use crate::SourceInfo;
11

            
12
/// An error originating from the tor-dirclient crate.
13
#[derive(Error, Debug, Clone)]
14
#[non_exhaustive]
15
#[allow(clippy::large_enum_variant)] // TODO(nickm) worth fixing as we do #587
16
pub enum Error {
17
    /// Error while getting a circuit
18
    #[error("Error while getting a circuit")]
19
    CircMgr(#[from] tor_circmgr::Error),
20

            
21
    /// An error that has occurred after we have contacted a directory cache and made a circuit to it.
22
    #[error("Error fetching directory information")]
23
    RequestFailed(#[from] RequestFailedError),
24

            
25
    /// We ran into a problem that is probably due to a programming issue.
26
    #[error("Internal error")]
27
    Bug(#[from] Bug),
28
}
29

            
30
/// An error that has occurred after we have contacted a directory cache and made a circuit to it.
31
#[derive(Error, Debug, Clone)]
32
#[allow(clippy::exhaustive_structs)] // TODO should not be exhaustive
33
#[error("Request failed{}", FromSource(.source))]
34
pub struct RequestFailedError {
35
    /// The source that gave us this error.
36
    pub source: Option<SourceInfo>,
37

            
38
    /// The underlying error that occurred.
39
    #[source]
40
    pub error: RequestError,
41
}
42

            
43
/// Helper type to display an optional source of directory information.
44
struct FromSource<'a>(&'a Option<SourceInfo>);
45

            
46
impl std::fmt::Display for FromSource<'_> {
47
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
48
        if let Some(si) = self.0 {
49
            write!(f, " from {}", si)
50
        } else {
51
            Ok(())
52
        }
53
    }
54
}
55

            
56
/// An error originating from the tor-dirclient crate.
57
#[derive(Error, Debug, Clone)]
58
#[non_exhaustive]
59
pub enum RequestError {
60
    /// The directory cache took too long to reply to us.
61
    #[error("directory timed out")]
62
    DirTimeout,
63

            
64
    /// We got an EOF before we were done with the headers.
65
    #[error("truncated HTTP headers")]
66
    TruncatedHeaders,
67

            
68
    /// Received a response that was longer than we expected.
69
    #[error("response too long; gave up after {0} bytes")]
70
    ResponseTooLong(usize),
71

            
72
    /// Received too many bytes in our headers.
73
    #[error("headers too long; gave up after {0} bytes")]
74
    HeadersTooLong(usize),
75

            
76
    /// Data received was not UTF-8 encoded.
77
    #[error("Couldn't decode data as UTF-8.")]
78
    Utf8Encoding(#[from] std::string::FromUtf8Error),
79

            
80
    /// Io error while reading on connection
81
    #[error("IO error")]
82
    IoError(#[source] Arc<std::io::Error>),
83

            
84
    /// A protocol error while launching a stream
85
    #[error("Protocol error while launching a stream")]
86
    Proto(#[from] tor_proto::Error),
87

            
88
    /// A protocol error while launching a stream
89
    #[error("Tunnel error")]
90
    Tunnel(#[from] tor_circmgr::Error),
91

            
92
    /// Error when parsing http
93
    #[error("Couldn't parse HTTP headers")]
94
    HttparseError(#[from] httparse::Error),
95

            
96
    /// Error while creating http request
97
    //
98
    // TODO this should be abolished, in favour of a `Bug` variant,
99
    // so that we get a stack trace, as per the notes for EK::Internal.
100
    // We could convert via into_internal!, or a custom `From` impl.
101
    #[error("Couldn't create HTTP request")]
102
    HttpError(#[source] Arc<http::Error>),
103

            
104
    /// Unrecognized content-encoding
105
    #[error("Unrecognized content encoding: {0:?}")]
106
    ContentEncoding(String),
107

            
108
    /// Too much clock skew between us and the directory.
109
    ///
110
    /// (We've giving up on this request early, since any directory that it
111
    /// believes in, we would reject as untimely.)
112
    #[error("Too much clock skew with directory cache")]
113
    TooMuchClockSkew,
114

            
115
    /// We tried to launch a request without any requested objects.
116
    ///
117
    /// This can happen if (for example) we request an empty list of
118
    /// microdescriptors or certificates.
119
    #[error("We didn't have any objects to request")]
120
    EmptyRequest,
121

            
122
    /// HTTP status code indicates a not completely successful request
123
    #[error("HTTP status code {0}: {1:?}")]
124
    HttpStatus(u16, String),
125
}
126

            
127
impl From<TimeoutError> for RequestError {
128
    fn from(_: TimeoutError) -> Self {
129
        RequestError::DirTimeout
130
    }
131
}
132

            
133
impl From<std::io::Error> for RequestError {
134
630
    fn from(err: std::io::Error) -> Self {
135
630
        Self::IoError(Arc::new(err))
136
630
    }
137
}
138

            
139
impl From<http::Error> for RequestError {
140
    fn from(err: http::Error) -> Self {
141
        Self::HttpError(Arc::new(err))
142
    }
143
}
144

            
145
impl Error {
146
    /// Return true if this error means that the circuit shouldn't be used
147
    /// for any more directory requests.
148
2
    pub fn should_retire_circ(&self) -> bool {
149
2
        // TODO: probably this is too aggressive, and we should
150
2
        // actually _not_ dump the circuit under all circumstances.
151
2
        match self {
152
            Error::CircMgr(_) => true, // should be unreachable.
153
2
            Error::RequestFailed(RequestFailedError { error, .. }) => error.should_retire_circ(),
154
            Error::Bug(_) => true,
155
        }
156
2
    }
157

            
158
    /// Return the peer or peers that are to be blamed for the error.
159
    ///
160
    /// (This can return multiple peers if the request failed because multiple
161
    /// circuit attempts all failed.)
162
    pub fn cache_ids(&self) -> Vec<&OwnedChanTarget> {
163
        match &self {
164
            Error::CircMgr(e) => e.peers(),
165
            Error::RequestFailed(RequestFailedError {
166
                source: Some(source),
167
                ..
168
            }) => vec![source.cache_id()],
169
            _ => Vec::new(),
170
        }
171
    }
172
}
173

            
174
impl RequestError {
175
    /// Return true if this error means that the circuit shouldn't be used
176
    /// for any more directory requests.
177
2
    pub fn should_retire_circ(&self) -> bool {
178
2
        // TODO: probably this is too aggressive, and we should
179
2
        // actually _not_ dump the circuit under all circumstances.
180
2
        true
181
2
    }
182
}
183

            
184
impl HasKind for RequestError {
185
    fn kind(&self) -> ErrorKind {
186
        use ErrorKind as EK;
187
        use RequestError as E;
188
        match self {
189
            E::DirTimeout => EK::TorNetworkTimeout,
190
            E::TruncatedHeaders => EK::TorProtocolViolation,
191
            E::ResponseTooLong(_) => EK::TorProtocolViolation,
192
            E::HeadersTooLong(_) => EK::TorProtocolViolation,
193
            E::Utf8Encoding(_) => EK::TorProtocolViolation,
194
            // TODO: it would be good to get more information out of the IoError
195
            // in this case, but that would require a bunch of gnarly
196
            // downcasting.
197
            E::IoError(_) => EK::TorDirectoryError,
198
            E::Proto(e) => e.kind(),
199
            E::HttparseError(_) => EK::TorProtocolViolation,
200
            E::HttpError(_) => EK::Internal,
201
            E::ContentEncoding(_) => EK::TorProtocolViolation,
202
            E::TooMuchClockSkew => EK::TorDirectoryError,
203
            E::EmptyRequest => EK::Internal,
204
            E::HttpStatus(_, _) => EK::TorDirectoryError,
205
            E::Tunnel(e) => e.kind(),
206
        }
207
    }
208
}
209

            
210
impl HasKind for RequestFailedError {
211
    fn kind(&self) -> ErrorKind {
212
        self.error.kind()
213
    }
214
}
215

            
216
impl HasKind for Error {
217
    fn kind(&self) -> ErrorKind {
218
        use Error as E;
219
        match self {
220
            E::CircMgr(e) => e.kind(),
221
            E::RequestFailed(e) => e.kind(),
222
            E::Bug(e) => e.kind(),
223
        }
224
    }
225
}
226

            
227
#[cfg(any(feature = "hs-client", feature = "hs-service"))]
228
impl Error {
229
    /// Return true if this error is one that we should report as a suspicious event,
230
    /// along with the dirserver and description of the relevant document,
231
    /// if the request was made anonymously.
232
    pub fn should_report_as_suspicious_if_anon(&self) -> bool {
233
        use Error as E;
234
        match self {
235
            E::CircMgr(_) => false,
236
            E::RequestFailed(e) => e.error.should_report_as_suspicious_if_anon(),
237
            E::Bug(_) => false,
238
        }
239
    }
240
}
241
#[cfg(any(feature = "hs-client", feature = "hs-service"))]
242
impl RequestError {
243
    /// Return true if this error is one that we should report as a suspicious event,
244
    /// along with the dirserver and description of the relevant document,
245
    /// if the request was made anonymously.
246
1248
    pub fn should_report_as_suspicious_if_anon(&self) -> bool {
247
        use tor_proto::Error as PE;
248
        match self {
249
            RequestError::ResponseTooLong(_) => true,
250
            RequestError::HeadersTooLong(_) => true,
251
            RequestError::Proto(PE::ExcessInboundCells) => true,
252
            RequestError::Proto(_) => false,
253
            RequestError::DirTimeout => false,
254
            RequestError::TruncatedHeaders => false,
255
            RequestError::Utf8Encoding(_) => false,
256
624
            RequestError::IoError(_) => false,
257
            RequestError::HttparseError(_) => false,
258
            RequestError::HttpError(_) => false,
259
            RequestError::ContentEncoding(_) => false,
260
            RequestError::TooMuchClockSkew => false,
261
            RequestError::EmptyRequest => false,
262
624
            RequestError::HttpStatus(_, _) => false,
263
            RequestError::Tunnel(_) => false,
264
        }
265
1248
    }
266
}