1 files changed, 156 insertions, 0 deletions
diff --git a/ext/net/resolve_addr.rs b/ext/net/resolve_addr.rs
new file mode 100644
index 000000000..ebf1374d1
--- /dev/null
+++ b/ext/net/resolve_addr.rs
@@ -0,0 +1,156 @@
+// Copyright 2018-2021 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());
+  }
+}