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

// conn_expr/addr.rs
// Copyright 2022 Matti Hänninen
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.

use std::{fmt, net, str};

use super::parser::{ConnectionExprLanguage, Pair, Parser, Rule};

#[derive(Clone, Debug, PartialEq)]
pub enum Addr {
  Domain(String),
  IP(net::IpAddr),
}

impl fmt::Display for Addr {
  fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
    match self {
      Addr::Domain(domain) => domain.fmt(fmt),
      Addr::IP(ip) => ip.fmt(fmt),
    }
  }
}

impl<'a> TryFrom<Pair<'a, Rule>> for Addr {
  type Error = ConversionError;

  fn try_from(pair: Pair<'a, Rule>) -> Result<Self, Self::Error> {
    if matches!(pair.as_rule(), Rule::addr) {
      let addr = pair
        .into_inner()
        .next()
        .expect("grammar guarantees specific inner address");
      Ok(match addr.as_rule() {
        Rule::ipv4_addr => Addr::IP(
          addr
            .as_str()
            .parse::<net::Ipv4Addr>()
            .expect("grammar guarantees legal IPv4 address")
            .into(),
        ),
        Rule::ipv6_addr => Addr::IP(
          addr
            .as_str()
            .parse::<net::Ipv6Addr>()
            .expect("grammar guarantees legal IPv6 address")
            .into(),
        ),
        Rule::domain_addr => {
          let domain = addr.as_str().to_owned();
          if addr.as_str().len() > 253
            || addr.into_inner().any(|l| l.as_str().len() > 63)
          {
            return Err(ConversionError);
          }
          Addr::Domain(domain)
        }
        _ => unreachable!("grammar guarantees IPv6, IPv4, or domain address"),
      })
    } else {
      Err(ConversionError)
    }
  }
}

#[derive(Clone, Copy, Debug, PartialEq, thiserror::Error)]
#[error("failed to convert into address")]
pub struct ConversionError;

impl str::FromStr for Addr {
  type Err = ParseError;

  fn from_str(s: &str) -> Result<Self, Self::Err> {
    ConnectionExprLanguage::parse(Rule::addr_expr, s)
      .map_err(|_| ParseError)?
      .next()
      .expect("grammar guaranteed addr_expr")
      .into_inner()
      .next()
      .expect("grammar guarantees addr")
      .try_into()
      .map_err(|_| ParseError)
  }
}

#[derive(Clone, Copy, Debug, PartialEq, thiserror::Error)]
#[error("failed to parse address")]
pub struct ParseError;

#[cfg(test)]
mod test {

  use super::*;

  #[test]
  fn parse_domain_name() {
    let d = |s: &str| Ok(Addr::Domain(s.to_string()));
    assert_eq!("localhost".parse(), d("localhost"));
    assert_eq!("localhost.".parse(), d("localhost."));
    assert_eq!("a.b.c.d".parse(), d("a.b.c.d"));
    assert_eq!("a1.b-2.c--3.d---4".parse(), d("a1.b-2.c--3.d---4"));
  }

  #[test]
  fn parse_ipv4_address() {
    let ip4 = |a, b, c, d| Ok(Addr::IP(net::Ipv4Addr::new(a, b, c, d).into()));
    assert_eq!("0.0.0.0".parse(), ip4(0, 0, 0, 0));
    assert_eq!("1.2.3.4".parse(), ip4(1, 2, 3, 4));
    assert_eq!("255.255.255.255".parse(), ip4(255, 255, 255, 255));
  }

  #[test]
  fn parse_ipv6_address() {
    let ip6 = |a, b, c, d, e, f, g, h| {
      Ok(Addr::IP(net::Ipv6Addr::new(a, b, c, d, e, f, g, h).into()))
    };
    assert_eq!("[::]".parse(), ip6(0, 0, 0, 0, 0, 0, 0, 0));
    assert_eq!("[::1]".parse(), ip6(0, 0, 0, 0, 0, 0, 0, 1));
    assert_eq!("[1::]".parse(), ip6(1, 0, 0, 0, 0, 0, 0, 0));
    assert_eq!("[::0.0.0.0]".parse(), ip6(0, 0, 0, 0, 0, 0, 0, 0));
    assert_eq!(
      "[DEAD::BEEF]".parse(),
      ip6(0xDEAD, 0, 0, 0, 0, 0, 0, 0xBEEF)
    );
    assert_eq!(
      "[dead::beef]".parse(),
      ip6(0xDEAD, 0, 0, 0, 0, 0, 0, 0xBEEF)
    );
    assert_eq!(
      "[1:23:456:789a::127.0.0.1]".parse(),
      ip6(0x0001, 0x0023, 0x0456, 0x789A, 0, 0, 0x7F00, 1),
    );
  }

  #[test]
  fn parse_bad_address() {
    let err = Err(ParseError);
    assert_eq!(" 1.2.3.4".parse::<Addr>(), err);
    assert_eq!("".parse::<Addr>(), err);
    assert_eq!(".".parse::<Addr>(), err);
    assert_eq!("01.2.3.4".parse::<Addr>(), err);
    assert_eq!("1. 2.3.4".parse::<Addr>(), err);
    assert_eq!("1.2.3.04".parse::<Addr>(), err);
    assert_eq!("1.2.3.256".parse::<Addr>(), err);
    assert_eq!("1.2.3.4 ".parse::<Addr>(), err);
    assert_eq!("1.2.3.4.com".parse::<Addr>(), err);
    assert_eq!("1.com".parse::<Addr>(), err);
    assert_eq!("[ ::]".parse::<Addr>(), err);
    assert_eq!("[:: ]".parse::<Addr>(), err);
    assert_eq!("[]".parse::<Addr>(), err);
    assert_eq!("dash-.com".parse::<Addr>(), err);
    assert_eq!("tyre.8bar.com".parse::<Addr>(), err);
    // XXX(soija) These are actually legal IP addresses but ¯\_(ツ)_/¯
    assert_eq!("1".parse(), err);
    assert_eq!("1.2".parse(), err);
    assert_eq!("1.2.3".parse(), err);
  }
}