trust_dns_proto/op/
op_code.rs

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1// Copyright 2015-2021 Benjamin Fry <benjaminfry@me.com>
2//
3// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
4// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
5// http://opensource.org/licenses/MIT>, at your option. This file may not be
6// copied, modified, or distributed except according to those terms.
7
8//! Operation code for queries, updates, and responses
9
10use std::{convert::From, fmt};
11
12use crate::error::*;
13
14/// Operation code for queries, updates, and responses
15///
16/// [RFC 1035, DOMAIN NAMES - IMPLEMENTATION AND SPECIFICATION, November 1987](https://tools.ietf.org/html/rfc1035)
17///
18/// ```text
19/// OPCODE          A four bit field that specifies kind of query in this
20///                 message.  This value is set by the originator of a query
21///                 and copied into the response.  The values are:
22///
23///                 0               a standard query (QUERY)
24///
25///                 1               an inverse query (IQUERY)
26///
27///                 2               a server status request (STATUS)
28///
29///                 3-15            reserved for future use
30/// ```
31#[derive(Debug, PartialEq, Eq, PartialOrd, Copy, Clone, Hash)]
32#[allow(dead_code)]
33pub enum OpCode {
34    /// Query request [RFC 1035](https://tools.ietf.org/html/rfc1035)
35    Query,
36
37    /// Status message [RFC 1035](https://tools.ietf.org/html/rfc1035)
38    Status,
39
40    /// Notify of change [RFC 1996](https://tools.ietf.org/html/rfc1996)
41    Notify,
42
43    /// Update message [RFC 2136](https://tools.ietf.org/html/rfc2136)
44    Update,
45}
46
47impl fmt::Display for OpCode {
48    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
49        let s = match self {
50            Self::Query => "QUERY",
51            Self::Status => "STATUS",
52            Self::Notify => "NOTIFY",
53            Self::Update => "UPDATE",
54        };
55
56        f.write_str(s)
57    }
58}
59
60/// Convert from `OpCode` to `u8`
61///
62/// ```
63/// use std::convert::From;
64/// use trust_dns_proto::op::op_code::OpCode;
65///
66/// let var: u8 = From::from(OpCode::Query);
67/// assert_eq!(0, var);
68///
69/// let var: u8 = OpCode::Query.into();
70/// assert_eq!(0, var);
71/// ```
72impl From<OpCode> for u8 {
73    fn from(rt: OpCode) -> Self {
74        match rt {
75            OpCode::Query => 0,
76            // 1	IQuery (Inverse Query, OBSOLETE)	[RFC3425]
77            OpCode::Status => 2,
78            // 3	Unassigned
79            OpCode::Notify => 4,
80            OpCode::Update => 5,
81            // 6-15	Unassigned
82        }
83    }
84}
85
86/// Convert from `u8` to `OpCode`
87///
88/// ```
89/// use std::convert::From;
90/// use trust_dns_proto::op::op_code::OpCode;
91///
92/// let var: OpCode = OpCode::from_u8(0).unwrap();
93/// assert_eq!(OpCode::Query, var);
94/// ```
95impl OpCode {
96    /// Decodes the binary value of the OpCode
97    pub fn from_u8(value: u8) -> ProtoResult<Self> {
98        match value {
99            0 => Ok(Self::Query),
100            2 => Ok(Self::Status),
101            4 => Ok(Self::Notify),
102            5 => Ok(Self::Update),
103            _ => Err(format!("unknown OpCode: {}", value).into()),
104        }
105    }
106}
trust_dns_proto/op/op_code.rs

trust_dns_proto/op/
op_code.rs
