h2/frame/
reason.rs

1use std::fmt;
2
3/// HTTP/2 error codes.
4///
5/// Error codes are used in `RST_STREAM` and `GOAWAY` frames to convey the
6/// reasons for the stream or connection error. For example,
7/// [`SendStream::send_reset`] takes a `Reason` argument. Also, the `Error` type
8/// may contain a `Reason`.
9///
10/// Error codes share a common code space. Some error codes apply only to
11/// streams, others apply only to connections, and others may apply to either.
12/// See [RFC 7540] for more information.
13///
14/// See [Error Codes in the spec][spec].
15///
16/// [spec]: http://httpwg.org/specs/rfc7540.html#ErrorCodes
17/// [`SendStream::send_reset`]: struct.SendStream.html#method.send_reset
18#[derive(PartialEq, Eq, Clone, Copy)]
19pub struct Reason(u32);
20
21impl Reason {
22    /// The associated condition is not a result of an error.
23    ///
24    /// For example, a GOAWAY might include this code to indicate graceful
25    /// shutdown of a connection.
26    pub const NO_ERROR: Reason = Reason(0);
27    /// The endpoint detected an unspecific protocol error.
28    ///
29    /// This error is for use when a more specific error code is not available.
30    pub const PROTOCOL_ERROR: Reason = Reason(1);
31    /// The endpoint encountered an unexpected internal error.
32    pub const INTERNAL_ERROR: Reason = Reason(2);
33    /// The endpoint detected that its peer violated the flow-control protocol.
34    pub const FLOW_CONTROL_ERROR: Reason = Reason(3);
35    /// The endpoint sent a SETTINGS frame but did not receive a response in
36    /// a timely manner.
37    pub const SETTINGS_TIMEOUT: Reason = Reason(4);
38    /// The endpoint received a frame after a stream was half-closed.
39    pub const STREAM_CLOSED: Reason = Reason(5);
40    /// The endpoint received a frame with an invalid size.
41    pub const FRAME_SIZE_ERROR: Reason = Reason(6);
42    /// The endpoint refused the stream prior to performing any application
43    /// processing.
44    pub const REFUSED_STREAM: Reason = Reason(7);
45    /// Used by the endpoint to indicate that the stream is no longer needed.
46    pub const CANCEL: Reason = Reason(8);
47    /// The endpoint is unable to maintain the header compression context for
48    /// the connection.
49    pub const COMPRESSION_ERROR: Reason = Reason(9);
50    /// The connection established in response to a CONNECT request was reset
51    /// or abnormally closed.
52    pub const CONNECT_ERROR: Reason = Reason(10);
53    /// The endpoint detected that its peer is exhibiting a behavior that might
54    /// be generating excessive load.
55    pub const ENHANCE_YOUR_CALM: Reason = Reason(11);
56    /// The underlying transport has properties that do not meet minimum
57    /// security requirements.
58    pub const INADEQUATE_SECURITY: Reason = Reason(12);
59    /// The endpoint requires that HTTP/1.1 be used instead of HTTP/2.
60    pub const HTTP_1_1_REQUIRED: Reason = Reason(13);
61
62    /// Get a string description of the error code.
63    pub fn description(&self) -> &str {
64        match self.0 {
65            0 => "not a result of an error",
66            1 => "unspecific protocol error detected",
67            2 => "unexpected internal error encountered",
68            3 => "flow-control protocol violated",
69            4 => "settings ACK not received in timely manner",
70            5 => "received frame when stream half-closed",
71            6 => "frame with invalid size",
72            7 => "refused stream before processing any application logic",
73            8 => "stream no longer needed",
74            9 => "unable to maintain the header compression context",
75            10 => {
76                "connection established in response to a CONNECT request was reset or abnormally \
77                 closed"
78            }
79            11 => "detected excessive load generating behavior",
80            12 => "security properties do not meet minimum requirements",
81            13 => "endpoint requires HTTP/1.1",
82            _ => "unknown reason",
83        }
84    }
85}
86
87impl From<u32> for Reason {
88    fn from(src: u32) -> Reason {
89        Reason(src)
90    }
91}
92
93impl From<Reason> for u32 {
94    fn from(src: Reason) -> u32 {
95        src.0
96    }
97}
98
99impl fmt::Debug for Reason {
100    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
101        let name = match self.0 {
102            0 => "NO_ERROR",
103            1 => "PROTOCOL_ERROR",
104            2 => "INTERNAL_ERROR",
105            3 => "FLOW_CONTROL_ERROR",
106            4 => "SETTINGS_TIMEOUT",
107            5 => "STREAM_CLOSED",
108            6 => "FRAME_SIZE_ERROR",
109            7 => "REFUSED_STREAM",
110            8 => "CANCEL",
111            9 => "COMPRESSION_ERROR",
112            10 => "CONNECT_ERROR",
113            11 => "ENHANCE_YOUR_CALM",
114            12 => "INADEQUATE_SECURITY",
115            13 => "HTTP_1_1_REQUIRED",
116            other => return f.debug_tuple("Reason").field(&Hex(other)).finish(),
117        };
118        f.write_str(name)
119    }
120}
121
122struct Hex(u32);
123
124impl fmt::Debug for Hex {
125    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
126        fmt::LowerHex::fmt(&self.0, f)
127    }
128}
129
130impl fmt::Display for Reason {
131    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
132        write!(fmt, "{}", self.description())
133    }
134}
h2/frame/reason.rs

h2/frame/
reason.rs
