DNS wars: a new hope

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "defguard_wireguard_rs"
-version = "0.11.2"
+version = "0.12.0"
 edition = "2024"
 rust-version = "1.91"
 description = "A unified multi-platform high-level API for managing WireGuard interfaces"
@@ -36,7 +36,10 @@ windows = { version = "0.62", features = [
     "Win32_NetworkManagement_IpHelper",
     "Win32_NetworkManagement_Ndis",
     "Win32_Networking_WinSock",
+    "Win32_Security",
     "Win32_System_Com",
+    "Win32_System_LibraryLoader",
+    "Win32_System_Registry",
 ] }
 wireguard-nt = "0.5"
 
@@ -48,9 +51,6 @@ netlink-packet-utils = "0.6"
 netlink-packet-wireguard = "0.5"
 netlink-sys = "0.9"
 
-[target.'cfg(any(target_os = "linux", target_os = "freebsd", target_os = "netbsd"))'.dependencies]
-regex = "1.12"
-
 [features]
 default = ["serde"]
 check_dependencies = []

examples/client.rs

@@ -5,6 +5,7 @@ use defguard_wireguard_rs::{
 };
 use x25519_dalek::{EphemeralSecret, PublicKey};
 
+#[cfg(not(target_os = "netbsd"))]
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     // Create new API object for interface
     let ifname: String = if cfg!(target_os = "linux") || cfg!(target_os = "freebsd") {
@@ -57,3 +58,8 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     Ok(())
 }
+
+#[cfg(target_os = "netbsd")]
+fn main() {
+    println!("This example is not for NetBSD");
+}

examples/server.rs

@@ -5,6 +5,7 @@ use defguard_wireguard_rs::{
 };
 use x25519_dalek::{EphemeralSecret, PublicKey};
 
+#[cfg(not(target_os = "netbsd"))]
 fn main() -> Result<(), Box<dyn std::error::Error>> {
     env_logger::init();
 
@@ -91,3 +92,8 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     Ok(())
 }
+
+#[cfg(target_os = "netbsd")]
+fn main() {
+    println!("This example is not for NetBSD");
+}

src/bsd/tests.rs

@@ -16,5 +16,8 @@ fn test_assign_address() {
 fn test_get_mtu() {
     let ifname = "lo0";
     let mtu = get_mtu(ifname).unwrap();
+    #[cfg(not(target_os = "netbsd"))]
     assert_eq!(mtu, 16384);
+    #[cfg(target_os = "netbsd")]
+    assert_eq!(mtu, 33624);
 }

src/dependencies.rs

@@ -1,18 +1,17 @@
 use std::env;
 
+#[cfg(any(target_os = "freebsd", target_os = "linux", target_os = "netbsd"))]
+use crate::dns::detect_dns_backend;
 use crate::{error::WireguardInterfaceError, utils::get_command_path};
 
 #[cfg(target_os = "linux")]
-const COMMANDS: [&str; 2] = ["resolvconf", "ip"];
-
-#[cfg(target_os = "windows")]
-const COMMANDS: [&str; 0] = [];
+const COMMANDS: [&str; 1] = ["ip"];
 
 #[cfg(target_os = "macos")]
 const COMMANDS: [&str; 1] = ["networksetup"];
 
-#[cfg(any(target_os = "freebsd", target_os = "netbsd"))]
-const COMMANDS: [&str; 1] = ["resolvconf"];
+#[cfg(any(target_os = "freebsd", target_os = "netbsd", target_os = "windows"))]
+const COMMANDS: [&str; 0] = [];
 
 pub(crate) fn check_external_dependencies() -> Result<(), WireguardInterfaceError> {
     debug!("Checking if all commands required by wireguard-rs are available");
@@ -25,10 +24,17 @@ pub(crate) fn check_external_dependencies() -> Result<(), WireguardInterfaceErro
         .iter()
         .find(|cmd| get_command_path(cmd).map_or(true, |path_opt| path_opt.is_none()));
 
-    missing_command.map_or_else(|| {
-            debug!("All commands required by wireguard-rs are available");
-            Ok(())
-    }, |cmd| Err(WireguardInterfaceError::MissingDependency(format!(
-        "Command `{cmd}` required by wireguard-rs couldn't be found. The following directories were checked: {paths:?}"
-    ))))
+    if let Some(cmd) = missing_command {
+        return Err(WireguardInterfaceError::MissingDependency(format!(
+            "Command `{cmd}` required by wireguard-rs couldn't be found. The following directories were checked: {paths:?}"
+        )));
+    }
+
+    // DNS can be configured through more than one backend, so check that at least one of them
+    // is available instead of requiring a specific command.
+    #[cfg(any(target_os = "freebsd", target_os = "linux", target_os = "netbsd"))]
+    detect_dns_backend()?;
+
+    debug!("All commands required by wireguard-rs are available");
+    Ok(())
 }