From fe5a91a500028b96cf9a65e0eabc8f31dad9391d Mon Sep 17 00:00:00 2001
From: Ben Noordhuis <info@bnoordhuis.nl>
Date: Thu, 2 Dec 2021 13:09:02 +0100
Subject: [PATCH] feat(ext/net): add op_network_interfaces

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

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

Refs denoland/deno_std#1436.
---
 Cargo.lock             |  9 +++++++
 ext/net/Cargo.toml     |  1 +
 ext/net/README.md      |  1 +
 ext/net/lib.rs         |  1 +
 ext/net/ops.rs         | 54 ++++++++++++++++++++++++++++++++++++++++++
 runtime/build.rs       |  6 +++++
 runtime/permissions.rs |  4 ++++
 7 files changed, 76 insertions(+)

diff --git a/Cargo.lock b/Cargo.lock
index 92b491b5e1f5ac..e1b40426ada255 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -885,6 +885,7 @@ dependencies = [
  "deno_core",
  "deno_tls",
  "log",
+ "netif",
  "serde",
  "tokio",
  "trust-dns-proto",
@@ -2268,6 +2269,14 @@ dependencies = [
  "thiserror",
 ]
 
+[[package]]
+name = "netif"
+version = "0.1.0"
+source = "git+https://github.com/bnoordhuis/netif#ff2b73735a9ad16288a5ad3013a69b8367ace41d"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "new_debug_unreachable"
 version = "1.0.4"
diff --git a/ext/net/Cargo.toml b/ext/net/Cargo.toml
index 912dac88436de3..13ee6d6cb62977 100644
--- a/ext/net/Cargo.toml
+++ b/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"
diff --git a/ext/net/README.md b/ext/net/README.md
index 1928fc375b1632..998c572f392f60 100644
--- a/ext/net/README.md
+++ b/ext/net/README.md
@@ -20,3 +20,4 @@ Following ops are provided:
 - "op_tls_listen"
 - "op_tls_accept"
 - "op_tls_handshake"
+- "op_network_interfaces"
diff --git a/ext/net/lib.rs b/ext/net/lib.rs
index bbbfb3331a8661..82f20d952b7975 100644
--- a/ext/net/lib.rs
+++ b/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`;
diff --git a/ext/net/ops.rs b/ext/net/ops.rs
index 739807123e6492..04cadcdd2e4566 100644
--- a/ext/net/ops.rs
+++ b/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::*;
diff --git a/runtime/build.rs b/runtime/build.rs
index 14e2e0362c6543..008268359a82ff 100644
--- a/runtime/build.rs
+++ b/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>) {
diff --git a/runtime/permissions.rs b/runtime/permissions.rs
index 9a85e5e5833235..aa6cf4ffda33db 100644
--- a/runtime/permissions.rs
+++ b/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 {