tor_socksproto/
err.rs

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1//! Declare an error type for tor_socksproto
2use std::borrow::Cow;
3
4use thiserror::Error;
5
6use tor_error::{ErrorKind, HasKind};
7
8/// An error that occurs while negotiating a SOCKS handshake.
9#[derive(Clone, Error, Debug)]
10#[non_exhaustive]
11pub enum Error {
12    /// The SOCKS client didn't implement SOCKS correctly.
13    ///
14    /// (Or, more likely, we didn't account for its behavior.)
15    #[error("SOCKS protocol syntax violation")]
16    Syntax,
17
18    /// Failed to decode a SOCKS message.
19    #[error("Error decoding SOCKS message")]
20    Decode(#[from] tor_bytes::Error),
21
22    /// The SOCKS client declared a SOCKS version number that isn't
23    /// one we support.
24    ///
25    /// In all likelihood, this is somebody trying to use the port for
26    /// some protocol other than SOCKS.
27    #[error("Unrecognized SOCKS protocol version {0}")]
28    BadProtocol(u8),
29
30    /// The SOCKS client tried to use a SOCKS feature that we don't
31    /// support at all.
32    #[error("SOCKS feature ({0}) not implemented")]
33    NotImplemented(Cow<'static, str>),
34
35    /// Tried to progress the SOCKS handshake when it was already
36    /// finished.  This is a programming error.
37    #[error("SOCKS handshake was finished; no need to call this again")]
38    AlreadyFinished(tor_error::Bug),
39
40    /// The SOCKS proxy refused our authentication.
41    #[error("SOCKS Authentication failed")]
42    AuthRejected,
43
44    /// During the protocol exchange, we needed to handle a handshake bigger than our buffer
45    #[error("SOCKS protocol message size limit {limit} exceeded")]
46    MessageTooLong {
47        /// The limit in bytes
48        limit: usize,
49    },
50
51    /// Peer closed connection during SOCKS handshake
52    #[error("peer closed connection during SOCKS handshake")]
53    UnexpectedEof,
54
55    /// The peer sent payload data too early
56    ///
57    /// The peer sent data after its part of the protocol exchange,
58    /// without waiting for our side of it to complete,
59    /// in circumstances where we consider that a protocol violation by the peer.
60    ///
61    /// Returned only by
62    /// [`Finished::into_output_forbid_pipelining`](crate::Finished::into_output_forbid_pipelining).
63    #[error("SOCKS peer inappropriately pipelined (optimistically sent) payload data")]
64    ForbiddenPipelining,
65
66    /// The program (perhaps this module, perhaps Arti, perhaps the caller) is buggy
67    #[error("Bug while handling SOCKS handshake")]
68    Bug(#[from] tor_error::Bug),
69}
70
71// Note: at present, tor-socksproto isn't used in any settings where ErrorKind
72// is used.  This is provided for future-proofing, since someday we'll want to
73// have SOCKS protocol support internally as well as in the `arti` proxy.
74impl HasKind for Error {
75    fn kind(&self) -> ErrorKind {
76        use Error as E;
77        use ErrorKind as EK;
78        match self {
79            E::Decode(tor_bytes::Error::Incomplete { .. }) => {
80                // This variant should always get converted before a user can
81                // see it.
82                EK::Internal
83            }
84            E::Syntax | E::Decode(_) | E::BadProtocol(_) => EK::LocalProtocolViolation,
85            E::NotImplemented(_) => EK::NotImplemented,
86            E::AuthRejected => EK::LocalProtocolViolation,
87            E::UnexpectedEof => EK::LocalProtocolViolation,
88            E::ForbiddenPipelining => EK::LocalProtocolViolation,
89            E::MessageTooLong { .. } => EK::Internal, // We should select a buffer big enough!
90            E::AlreadyFinished(e) => e.kind(),
91            E::Bug(e) => e.kind(),
92        }
93    }
94}
tor_socksproto/err.rs

tor_socksproto/
err.rs
