feat(ext/net): 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.

ext/net/Cargo.toml

@@ -17,6 +17,7 @@ path = "lib.rs"
 deno_core = { version = "0.109.0", path = "../../core" }
 deno_tls = { version = "0.14.0", path = "../tls" }
 log = "0.4.14"
+netif = { git = "https://github.com/bnoordhuis/netif" }
 serde = { version = "1.0.129", features = ["derive"] }
 tokio = { version = "1.10.1", features = ["full"] }
 trust-dns-proto = "0.20.3"

ext/net/README.md

@@ -20,3 +20,4 @@ Following ops are provided:
 - "op_tls_listen"
 - "op_tls_accept"
 - "op_tls_handshake"
+- "op_network_interfaces"

ext/net/lib.rs

@@ -24,6 +24,7 @@ pub trait NetPermissions {
   ) -> Result<(), AnyError>;
   fn check_read(&mut self, _p: &Path) -> Result<(), AnyError>;
   fn check_write(&mut self, _p: &Path) -> Result<(), AnyError>;
+  fn check_network_interfaces(&mut self) -> Result<(), AnyError>;
 }
 
 /// `UnstableChecker` is a struct so it can be placed inside `GothamState`;

ext/net/ops.rs

@@ -55,6 +55,7 @@ pub fn init<P: NetPermissions + 'static>() -> Vec<OpPair> {
     ("op_dgram_recv", op_async(op_dgram_recv)),
     ("op_dgram_send", op_async(op_dgram_send::<P>)),
     ("op_dns_resolve", op_async(op_dns_resolve::<P>)),
+    ("op_network_interfaces", op_sync(op_network_interfaces::<P>)),
   ]
 }
 
@@ -709,6 +710,59 @@ fn rdata_to_return_record(
   }
 }
 
+fn op_network_interfaces<NP>(
+  state: &mut OpState,
+  _: (),
+  _: (),
+) -> Result<Vec<NetworkInterface>, AnyError>
+where
+  NP: NetPermissions + 'static,
+{
+  state.borrow_mut::<NP>().check_network_interfaces()?;
+  Ok(netif::all()?.map(NetworkInterface::from).collect())
+}
+
+#[derive(serde::Serialize)]
+struct NetworkInterface {
+  family: &'static str,
+  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 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,
+      address,
+      netmask,
+      scopeid,
+      cidr,
+      mac,
+    }
+  }
+}
+
 #[cfg(test)]
 mod tests {
   use super::*;

runtime/build.rs

@@ -112,6 +112,12 @@ mod not_docs {
     ) -> Result<(), deno_core::error::AnyError> {
       unreachable!("snapshotting!")
     }
+
+    fn check_network_interfaces(
+      &mut self,
+    ) -> Result<(), deno_core::error::AnyError> {
+      unreachable!("snapshotting!")
+    }
   }
 
   fn create_runtime_snapshot(snapshot_path: &Path, files: Vec<PathBuf>) {

runtime/permissions.rs

@@ -1285,6 +1285,10 @@ impl deno_net::NetPermissions for Permissions {
   fn check_write(&mut self, path: &Path) -> Result<(), AnyError> {
     self.write.check(path)
   }
+
+  fn check_network_interfaces(&mut self) -> Result<(), AnyError> {
+    Ok(()) // TODO(bnoordhuis)
+  }
 }
 
 impl deno_fetch::FetchPermissions for Permissions {