feat(runtime): add op_network_interfaces

Add an op to list the network interfaces on the system.

Prep work for denoland#8137 and `os.networkInterfaces()` Node compat in std.

Refs denoland/deno_std#1436.

runtime/Cargo.toml

@@ -70,6 +70,7 @@ http = "0.2.4"
 hyper = { version = "0.14.12", features = ["server", "stream", "http1", "http2", "runtime"] }
 libc = "0.2.106"
 log = "0.4.14"
+netif = "0.1.0"
 notify = "=5.0.0-pre.12"
 once_cell = "=1.9.0"
 regex = "1.5.4"

runtime/ops/os.rs

@@ -25,6 +25,7 @@ pub fn init(maybe_exit_code: Option<Arc<AtomicI32>>) -> Extension {
       ("op_delete_env", op_sync(op_delete_env)),
       ("op_hostname", op_sync(op_hostname)),
       ("op_loadavg", op_sync(op_loadavg)),
+      ("op_network_interfaces", op_sync(op_network_interfaces)),
       ("op_os_release", op_sync(op_os_release)),
       ("op_set_exit_code", op_sync(op_set_exit_code)),
       ("op_system_memory_info", op_sync(op_system_memory_info)),
@@ -149,6 +150,60 @@ fn op_os_release(
   Ok(release)
 }
 
+fn op_network_interfaces(
+  state: &mut OpState,
+  _: (),
+  _: (),
+) -> Result<Vec<NetworkInterface>, AnyError> {
+  super::check_unstable(state, "Deno.networkInterfaces");
+  state.borrow_mut::<Permissions>().env.check_all()?;
+  Ok(netif::up()?.map(NetworkInterface::from).collect())
+}
+
+#[derive(serde::Serialize)]
+struct NetworkInterface {
+  family: &'static str,
+  name: String,
+  address: String,
+  netmask: String,
+  scopeid: Option<u32>,
+  cidr: String,
+  mac: String,
+}
+
+impl From<netif::Interface> for NetworkInterface {
+  fn from(ifa: netif::Interface) -> Self {
+    let family = match ifa.address() {
+      std::net::IpAddr::V4(_) => "IPv4",
+      std::net::IpAddr::V6(_) => "IPv6",
+    };
+
+    let (address, range) = ifa.cidr();
+    let cidr = format!("{:?}/{}", address, range);
+
+    let name = ifa.name().to_owned();
+    let address = format!("{:?}", ifa.address());
+    let netmask = format!("{:?}", ifa.netmask());
+    let scopeid = ifa.scope_id();
+
+    let [b0, b1, b2, b3, b4, b5] = ifa.mac();
+    let mac = format!(
+      "{:02x}:{:02x}:{:02x}:{:02x}:{:02x}:{:02x}",
+      b0, b1, b2, b3, b4, b5
+    );
+
+    Self {
+      family,
+      name,
+      address,
+      netmask,
+      scopeid,
+      cidr,
+      mac,
+    }
+  }
+}
+
 // Copied from sys-info/lib.rs (then tweaked)
 #[derive(Serialize)]
 #[serde(rename_all = "camelCase")]