Enable wireguard-rs to build on stable.

WireGuard Rust targets the latest nightly compiler,
primarily for security and speed reasons.

The recommended way to build WireGuard Rust is still with latest nightly.

src/main.rs

@@ -1,5 +1,4 @@
-#![feature(test)]
-#![feature(weak_into_raw)]
+#![cfg_attr(feature = "unstable", feature(test))]
 
 extern crate alloc;
 

src/wireguard/handshake/noise.rs

@@ -1,7 +1,7 @@
 use std::time::Instant;
 
 // DH
-use x25519_dalek::{PublicKey, StaticSecret, SharedSecret};
+use x25519_dalek::{PublicKey, SharedSecret, StaticSecret};
 
 // HASH & MAC
 use blake2::Blake2s;
@@ -215,7 +215,7 @@ mod tests {
 }
 
 // Computes an X25519 shared secret.
-// 
+//
 // This function wraps dalek to add a zero-check.
 // This is not recommended by the Noise specification,
 // but implemented in the kernel with which we strive for absolute equivalent behavior.
@@ -290,7 +290,6 @@ pub(super) fn create_initiation<R: RngCore + CryptoRng, O>(
 
         // (C, k) := Kdf2(C, DH(S_priv, S_pub))
 
-
         let (ck, key) = KDF2!(&ck, &peer.ss);
 
         // msg.timestamp := Aead(k, 0, Timestamp(), H)
@@ -360,7 +359,7 @@ pub(super) fn consume_initiation<'a, O>(
         let peer = device.lookup_pk(&PublicKey::from(pk))?;
 
         // check for zero shared-secret (see "shared_secret" note).
-        
+
         if peer.ss.ct_eq(&[0u8; 32]).into() {
             return Err(HandshakeError::InvalidSharedSecret);
         }

src/wireguard/router/tests/bench.rs

@@ -1,13 +1,21 @@
+#[cfg(feature = "unstable")]
 extern crate test;
 
 use super::*;
 
-use std::net::IpAddr;
 use std::sync::atomic::AtomicUsize;
 use std::sync::atomic::Ordering;
 use std::sync::Arc;
 
+// only used in benchmark
+#[cfg(feature = "unstable")]
+use std::net::IpAddr;
+
+// only used in benchmark
+#[cfg(feature = "unstable")]
 use num_cpus;
+
+#[cfg(feature = "unstable")]
 use test::Bencher;
 
 //
@@ -78,6 +86,7 @@ fn profiler_start(name: &str) {
     }
 }
 
+#[cfg(feature = "unstable")]
 #[bench]
 fn bench_router_outbound(b: &mut Bencher) {
     // 10 GB transmission per iteration

src/wireguard/router/tests/tests.rs

@@ -11,6 +11,7 @@ use rand::Rng;
 
 use super::*;
 
+#[cfg(feature = "unstable")]
 extern crate test;
 
 const SIZE_MSG: usize = 1024;