tor_dirclient/
err.rs

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1//! Declare dirclient-specific errors.
2
3use std::sync::Arc;
4
5use thiserror::Error;
6use tor_error::{Bug, ErrorKind, HasKind};
7use tor_linkspec::OwnedChanTarget;
8use tor_rtcompat::TimeoutError;
9
10use 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
16pub 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))]
34pub 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.
44struct FromSource<'a>(&'a Option<SourceInfo>);
45
46impl 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]
59pub 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    /// Error when parsing http
89    #[error("Couldn't parse HTTP headers")]
90    HttparseError(#[from] httparse::Error),
91
92    /// Error while creating http request
93    //
94    // TODO this should be abolished, in favour of a `Bug` variant,
95    // so that we get a stack trace, as per the notes for EK::Internal.
96    // We could convert via into_internal!, or a custom `From` impl.
97    #[error("Couldn't create HTTP request")]
98    HttpError(#[source] Arc<http::Error>),
99
100    /// Unrecognized content-encoding
101    #[error("Unrecognized content encoding: {0:?}")]
102    ContentEncoding(String),
103
104    /// Too much clock skew between us and the directory.
105    ///
106    /// (We've giving up on this request early, since any directory that it
107    /// believes in, we would reject as untimely.)
108    #[error("Too much clock skew with directory cache")]
109    TooMuchClockSkew,
110
111    /// We tried to launch a request without any requested objects.
112    ///
113    /// This can happen if (for example) we request an empty list of
114    /// microdescriptors or certificates.
115    #[error("We didn't have any objects to request")]
116    EmptyRequest,
117
118    /// HTTP status code indicates a not completely successful request
119    #[error("HTTP status code {0}: {1:?}")]
120    HttpStatus(u16, String),
121}
122
123impl From<TimeoutError> for RequestError {
124    fn from(_: TimeoutError) -> Self {
125        RequestError::DirTimeout
126    }
127}
128
129impl From<std::io::Error> for RequestError {
130    fn from(err: std::io::Error) -> Self {
131        Self::IoError(Arc::new(err))
132    }
133}
134
135impl From<http::Error> for RequestError {
136    fn from(err: http::Error) -> Self {
137        Self::HttpError(Arc::new(err))
138    }
139}
140
141impl Error {
142    /// Return true if this error means that the circuit shouldn't be used
143    /// for any more directory requests.
144    pub fn should_retire_circ(&self) -> bool {
145        // TODO: probably this is too aggressive, and we should
146        // actually _not_ dump the circuit under all circumstances.
147        match self {
148            Error::CircMgr(_) => true, // should be unreachable.
149            Error::RequestFailed(RequestFailedError { error, .. }) => error.should_retire_circ(),
150            Error::Bug(_) => true,
151        }
152    }
153
154    /// Return the peer or peers that are to be blamed for the error.
155    ///
156    /// (This can return multiple peers if the request failed because multiple
157    /// circuit attempts all failed.)
158    pub fn cache_ids(&self) -> Vec<&OwnedChanTarget> {
159        match &self {
160            Error::CircMgr(e) => e.peers(),
161            Error::RequestFailed(RequestFailedError {
162                source: Some(source),
163                ..
164            }) => vec![source.cache_id()],
165            _ => Vec::new(),
166        }
167    }
168}
169
170impl RequestError {
171    /// Return true if this error means that the circuit shouldn't be used
172    /// for any more directory requests.
173    pub fn should_retire_circ(&self) -> bool {
174        // TODO: probably this is too aggressive, and we should
175        // actually _not_ dump the circuit under all circumstances.
176        true
177    }
178}
179
180impl HasKind for RequestError {
181    fn kind(&self) -> ErrorKind {
182        use ErrorKind as EK;
183        use RequestError as E;
184        match self {
185            E::DirTimeout => EK::TorNetworkTimeout,
186            E::TruncatedHeaders => EK::TorProtocolViolation,
187            E::ResponseTooLong(_) => EK::TorProtocolViolation,
188            E::HeadersTooLong(_) => EK::TorProtocolViolation,
189            E::Utf8Encoding(_) => EK::TorProtocolViolation,
190            // TODO: it would be good to get more information out of the IoError
191            // in this case, but that would require a bunch of gnarly
192            // downcasting.
193            E::IoError(_) => EK::TorDirectoryError,
194            E::Proto(e) => e.kind(),
195            E::HttparseError(_) => EK::TorProtocolViolation,
196            E::HttpError(_) => EK::Internal,
197            E::ContentEncoding(_) => EK::TorProtocolViolation,
198            E::TooMuchClockSkew => EK::TorDirectoryError,
199            E::EmptyRequest => EK::Internal,
200            E::HttpStatus(_, _) => EK::TorDirectoryError,
201        }
202    }
203}
204
205impl HasKind for RequestFailedError {
206    fn kind(&self) -> ErrorKind {
207        self.error.kind()
208    }
209}
210
211impl HasKind for Error {
212    fn kind(&self) -> ErrorKind {
213        use Error as E;
214        match self {
215            E::CircMgr(e) => e.kind(),
216            E::RequestFailed(e) => e.kind(),
217            E::Bug(e) => e.kind(),
218        }
219    }
220}
221
222#[cfg(any(feature = "hs-client", feature = "hs-service"))]
223impl Error {
224    /// Return true if this error is one that we should report as a suspicious event,
225    /// along with the dirserver and description of the relevant document,
226    /// if the request was made anonymously.
227    pub fn should_report_as_suspicious_if_anon(&self) -> bool {
228        use Error as E;
229        match self {
230            E::CircMgr(_) => false,
231            E::RequestFailed(e) => e.error.should_report_as_suspicious_if_anon(),
232            E::Bug(_) => false,
233        }
234    }
235}
236#[cfg(any(feature = "hs-client", feature = "hs-service"))]
237impl RequestError {
238    /// Return true if this error is one that we should report as a suspicious event,
239    /// along with the dirserver and description of the relevant document,
240    /// if the request was made anonymously.
241    pub fn should_report_as_suspicious_if_anon(&self) -> bool {
242        use tor_proto::Error as PE;
243        match self {
244            RequestError::ResponseTooLong(_) => true,
245            RequestError::HeadersTooLong(_) => true,
246            RequestError::Proto(PE::ExcessInboundCells) => true,
247            RequestError::Proto(_) => false,
248            RequestError::DirTimeout => false,
249            RequestError::TruncatedHeaders => false,
250            RequestError::Utf8Encoding(_) => false,
251            RequestError::IoError(_) => false,
252            RequestError::HttparseError(_) => false,
253            RequestError::HttpError(_) => false,
254            RequestError::ContentEncoding(_) => false,
255            RequestError::TooMuchClockSkew => false,
256            RequestError::EmptyRequest => false,
257            RequestError::HttpStatus(_, _) => false,
258        }
259    }
260}
tor_dirclient/err.rs

tor_dirclient/
err.rs
