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

use crate::codec::{SendError, UserError};
use crate::frame::StreamId;
use crate::proto::{self, Initiator};

use bytes::Bytes;
use std::{error, fmt, io};

pub use crate::frame::Reason;

/// Represents HTTP/2 operation errors.
///
/// `Error` covers error cases raised by protocol errors caused by the
/// peer, I/O (transport) errors, and errors caused by the user of the library.
///
/// If the error was caused by the remote peer, then it will contain a
/// [`Reason`] which can be obtained with the [`reason`] function.
///
/// [`Reason`]: struct.Reason.html
/// [`reason`]: #method.reason
#[derive(Debug)]
pub struct Error {
    kind: Kind,
}

#[derive(Debug)]
enum Kind {
    /// A RST_STREAM frame was received or sent.
    Reset(StreamId, Reason, Initiator),

    /// A GO_AWAY frame was received or sent.
    GoAway(Bytes, Reason, Initiator),

    /// The user created an error from a bare Reason.
    Reason(Reason),

    /// An error resulting from an invalid action taken by the user of this
    /// library.
    User(UserError),

    /// An `io::Error` occurred while trying to read or write.
    Io(io::Error),
}

// ===== impl Error =====

impl Error {
    /// If the error was caused by the remote peer, the error reason.
    ///
    /// This is either an error received by the peer or caused by an invalid
    /// action taken by the peer (i.e. a protocol error).
    pub fn reason(&self) -> Option<Reason> {
        match self.kind {
            Kind::Reset(_, reason, _) | Kind::GoAway(_, reason, _) | Kind::Reason(reason) => {
                Some(reason)
            }
            _ => None,
        }
    }

    /// Returns the true if the error is an io::Error
    pub fn is_io(&self) -> bool {
        match self.kind {
            Kind::Io(_) => true,
            _ => false,
        }
    }

    /// Returns the error if the error is an io::Error
    pub fn get_io(&self) -> Option<&io::Error> {
        match self.kind {
            Kind::Io(ref e) => Some(e),
            _ => None,
        }
    }

    /// Returns the error if the error is an io::Error
    pub fn into_io(self) -> Option<io::Error> {
        match self.kind {
            Kind::Io(e) => Some(e),
            _ => None,
        }
    }

    pub(crate) fn from_io(err: io::Error) -> Self {
        Error {
            kind: Kind::Io(err),
        }
    }
}

impl From<proto::Error> for Error {
    fn from(src: proto::Error) -> Error {
        use crate::proto::Error::*;

        Error {
            kind: match src {
                Reset(stream_id, reason, initiator) => Kind::Reset(stream_id, reason, initiator),
                GoAway(debug_data, reason, initiator) => {
                    Kind::GoAway(debug_data, reason, initiator)
                }
                Io(kind, inner) => {
                    Kind::Io(inner.map_or_else(|| kind.into(), |inner| io::Error::new(kind, inner)))
                }
            },
        }
    }
}

impl From<Reason> for Error {
    fn from(src: Reason) -> Error {
        Error {
            kind: Kind::Reason(src),
        }
    }
}

impl From<SendError> for Error {
    fn from(src: SendError) -> Error {
        match src {
            SendError::User(e) => e.into(),
            SendError::Connection(e) => e.into(),
        }
    }
}

impl From<UserError> for Error {
    fn from(src: UserError) -> Error {
        Error {
            kind: Kind::User(src),
        }
    }
}

impl fmt::Display for Error {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        let debug_data = match self.kind {
            Kind::Reset(_, reason, Initiator::User) => {
                return write!(fmt, "stream error sent by user: {}", reason)
            }
            Kind::Reset(_, reason, Initiator::Library) => {
                return write!(fmt, "stream error detected: {}", reason)
            }
            Kind::Reset(_, reason, Initiator::Remote) => {
                return write!(fmt, "stream error received: {}", reason)
            }
            Kind::GoAway(ref debug_data, reason, Initiator::User) => {
                write!(fmt, "connection error sent by user: {}", reason)?;
                debug_data
            }
            Kind::GoAway(ref debug_data, reason, Initiator::Library) => {
                write!(fmt, "connection error detected: {}", reason)?;
                debug_data
            }
            Kind::GoAway(ref debug_data, reason, Initiator::Remote) => {
                write!(fmt, "connection error received: {}", reason)?;
                debug_data
            }
            Kind::Reason(reason) => return write!(fmt, "protocol error: {}", reason),
            Kind::User(ref e) => return write!(fmt, "user error: {}", e),
            Kind::Io(ref e) => return e.fmt(fmt),
        };

        if !debug_data.is_empty() {
            write!(fmt, " ({:?})", debug_data)?;
        }

        Ok(())
    }
}

impl error::Error for Error {}

#[cfg(test)]
mod tests {
    use super::Error;
    use crate::Reason;

    #[test]
    fn error_from_reason() {
        let err = Error::from(Reason::HTTP_1_1_REQUIRED);
        assert_eq!(err.reason(), Some(Reason::HTTP_1_1_REQUIRED));
    }
}