tor_socksproto/
err.rs

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    //
28    // Note: This is not the appropriate error for cases where the
29    // client has changed its declared version
30    // between the initial message and some other message:
31    // those cases should just be `Syntax`.
32    #[error("Unrecognized SOCKS protocol version {0}")]
33    BadProtocol(u8),
34
35    /// The SOCKS client tried to use a SOCKS feature that we don't
36    /// support at all.
37    #[error("SOCKS feature ({0}) not implemented")]
38    NotImplemented(Cow<'static, str>),
39
40    /// Tried to progress the SOCKS handshake when it was already
41    /// finished.  This is a programming error.
42    #[error("SOCKS handshake was finished; no need to call this again")]
43    AlreadyFinished(tor_error::Bug),
44
45    /// The SOCKS proxy refused our authentication.
46    #[error("SOCKS Authentication failed")]
47    AuthRejected,
48
49    /// During the protocol exchange, we needed to handle a handshake bigger than our buffer
50    #[error("SOCKS protocol message size limit {limit} exceeded")]
51    MessageTooLong {
52        /// The limit in bytes
53        limit: usize,
54    },
55
56    /// Peer closed connection during SOCKS handshake
57    #[error("peer closed connection during SOCKS handshake")]
58    UnexpectedEof,
59
60    /// The peer sent payload data too early
61    ///
62    /// The peer sent data after its part of the protocol exchange,
63    /// without waiting for our side of it to complete,
64    /// in circumstances where we consider that a protocol violation by the peer.
65    ///
66    /// Returned only by
67    /// [`Finished::into_output_forbid_pipelining`](crate::Finished::into_output_forbid_pipelining).
68    #[error("SOCKS peer inappropriately pipelined (optimistically sent) payload data")]
69    ForbiddenPipelining,
70
71    /// The program (perhaps this module, perhaps Arti, perhaps the caller) is buggy
72    #[error("Bug while handling SOCKS handshake")]
73    Bug(#[from] tor_error::Bug),
74}
75
76// Note: at present, tor-socksproto isn't used in any settings where ErrorKind
77// is used.  This is provided for future-proofing, since someday we'll want to
78// have SOCKS protocol support internally as well as in the `arti` proxy.
79impl HasKind for Error {
80    fn kind(&self) -> ErrorKind {
81        use Error as E;
82        use ErrorKind as EK;
83        match self {
84            E::Decode(tor_bytes::Error::Incomplete { .. }) => {
85                // This variant should always get converted before a user can
86                // see it.
87                EK::Internal
88            }
89            E::Syntax | E::Decode(_) | E::BadProtocol(_) => EK::LocalProtocolViolation,
90            E::NotImplemented(_) => EK::NotImplemented,
91            E::AuthRejected => EK::LocalProtocolViolation,
92            E::UnexpectedEof => EK::LocalProtocolViolation,
93            E::ForbiddenPipelining => EK::LocalProtocolViolation,
94            E::MessageTooLong { .. } => EK::Internal, // We should select a buffer big enough!
95            E::AlreadyFinished(e) => e.kind(),
96            E::Bug(e) => e.kind(),
97        }
98    }
99}
tor_socksproto/err.rs

tor_socksproto/
err.rs
