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

// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.

use deno_core::error::AnyError;
use std::net::SocketAddr;
use std::net::ToSocketAddrs;
use tokio::net::lookup_host;

/// Resolve network address *asynchronously*.
pub async fn resolve_addr(
  hostname: &str,
  port: u16,
) -> Result<impl Iterator<Item = SocketAddr> + '_, AnyError> {
  let addr_port_pair = make_addr_port_pair(hostname, port);
  let result = lookup_host(addr_port_pair).await?;
  Ok(result)
}

/// Resolve network address *synchronously*.
pub fn resolve_addr_sync(
  hostname: &str,
  port: u16,
) -> Result<impl Iterator<Item = SocketAddr>, AnyError> {
  let addr_port_pair = make_addr_port_pair(hostname, port);
  let result = addr_port_pair.to_socket_addrs()?;
  Ok(result)
}

fn make_addr_port_pair(hostname: &str, port: u16) -> (&str, u16) {
  // Default to localhost if given just the port. Example: ":80"
  if hostname.is_empty() {
    return ("0.0.0.0", port);
  }

  // If this looks like an ipv6 IP address. Example: "[2001:db8::1]"
  // Then we remove the brackets.
  let addr = hostname.trim_start_matches('[').trim_end_matches(']');
  (addr, port)
}

#[cfg(test)]
mod tests {
  use super::*;
  use std::net::Ipv4Addr;
  use std::net::Ipv6Addr;
  use std::net::SocketAddrV4;
  use std::net::SocketAddrV6;

  #[tokio::test]
  async fn resolve_addr1() {
    let expected = vec![SocketAddr::V4(SocketAddrV4::new(
      Ipv4Addr::new(127, 0, 0, 1),
      80,
    ))];
    let actual = resolve_addr("127.0.0.1", 80)
      .await
      .unwrap()
      .collect::<Vec<_>>();
    assert_eq!(actual, expected);
  }

  #[tokio::test]
  async fn resolve_addr2() {
    let expected = vec![SocketAddr::V4(SocketAddrV4::new(
      Ipv4Addr::new(0, 0, 0, 0),
      80,
    ))];
    let actual = resolve_addr("", 80).await.unwrap().collect::<Vec<_>>();
    assert_eq!(actual, expected);
  }

  #[tokio::test]
  async fn resolve_addr3() {
    let expected = vec![SocketAddr::V4(SocketAddrV4::new(
      Ipv4Addr::new(192, 0, 2, 1),
      25,
    ))];
    let actual = resolve_addr("192.0.2.1", 25)
      .await
      .unwrap()
      .collect::<Vec<_>>();
    assert_eq!(actual, expected);
  }

  #[tokio::test]
  async fn resolve_addr_ipv6() {
    let expected = vec![SocketAddr::V6(SocketAddrV6::new(
      Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0, 1),
      8080,
      0,
      0,
    ))];
    let actual = resolve_addr("[2001:db8::1]", 8080)
      .await
      .unwrap()
      .collect::<Vec<_>>();
    assert_eq!(actual, expected);
  }

  #[tokio::test]
  async fn resolve_addr_err() {
    assert!(resolve_addr("INVALID ADDR", 1234).await.is_err());
  }

  #[test]
  fn resolve_addr_sync1() {
    let expected = vec![SocketAddr::V4(SocketAddrV4::new(
      Ipv4Addr::new(127, 0, 0, 1),
      80,
    ))];
    let actual = resolve_addr_sync("127.0.0.1", 80)
      .unwrap()
      .collect::<Vec<_>>();
    assert_eq!(actual, expected);
  }

  #[test]
  fn resolve_addr_sync2() {
    let expected = vec![SocketAddr::V4(SocketAddrV4::new(
      Ipv4Addr::new(0, 0, 0, 0),
      80,
    ))];
    let actual = resolve_addr_sync("", 80).unwrap().collect::<Vec<_>>();
    assert_eq!(actual, expected);
  }

  #[test]
  fn resolve_addr_sync3() {
    let expected = vec![SocketAddr::V4(SocketAddrV4::new(
      Ipv4Addr::new(192, 0, 2, 1),
      25,
    ))];
    let actual = resolve_addr_sync("192.0.2.1", 25)
      .unwrap()
      .collect::<Vec<_>>();
    assert_eq!(actual, expected);
  }

  #[test]
  fn resolve_addr_sync_ipv6() {
    let expected = vec![SocketAddr::V6(SocketAddrV6::new(
      Ipv6Addr::new(0x2001, 0xdb8, 0, 0, 0, 0, 0, 1),
      8080,
      0,
      0,
    ))];
    let actual = resolve_addr_sync("[2001:db8::1]", 8080)
      .unwrap()
      .collect::<Vec<_>>();
    assert_eq!(actual, expected);
  }

  #[test]
  fn resolve_addr_sync_err() {
    assert!(resolve_addr_sync("INVALID ADDR", 1234).is_err());
  }
}