Begin drafting cross-platform interface

8 files changed, 77 insertions, 42 deletions

diff --git a/Cargo.lock b/Cargo.lock
index d25d5fe..9aad567 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1026,6 +1026,7 @@ dependencies = [
  "arraydeque 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "blake2 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "byteorder 1.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "crossbeam-deque 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "digest 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures 0.1.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "generic-array 0.12.3 (registry+https://github.com/rust-lang/crates.io-index)",
diff --git a/Cargo.toml b/Cargo.toml
index 5b81617..82d31ec 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -21,6 +21,7 @@ tokio = "0.1.22"
 futures = "0.1.28"
 arraydeque = "^0.4"
 treebitmap = "^0.4"
+crossbeam-deque = "0.7"
 
 [dependencies.x25519-dalek]
 version = "^0.5"
diff --git a/src/main.rs b/src/main.rs
index 90ba496..22e1585 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,6 +1,7 @@
 #![feature(test)]
 
 mod handshake;
+mod platform;
 mod router;
 mod types;
 
@@ -13,7 +14,7 @@ fn main() {
     // choose optimal crypto implementations for platform
     sodiumoxide::init().unwrap();
 
-    let mut rdev = router::Device::new();
+    let mut rdev = router::Device::new(8);
 
     let pref = rdev.add();
 }
diff --git a/src/platform/mod.rs b/src/platform/mod.rs
new file mode 100644
index 0000000..46f712a
--- /dev/null
+++ b/src/platform/mod.rs
@@ -0,0 +1,2 @@
+mod tun;
+mod udp;
diff --git a/src/platform/tun.rs b/src/platform/tun.rs
new file mode 100644
index 0000000..45fd591
--- /dev/null
+++ b/src/platform/tun.rs
@@ -0,0 +1,10 @@
+use std::sync::atomic::AtomicUsize;
+use std::sync::Arc;
+
+pub trait Tun: Send + Sync {
+    type Error;
+
+    fn new(mtu: Arc<AtomicUsize>) -> Self;
+    fn read(&self, dst: &mut [u8]) -> Result<usize, Self::Error>;
+    fn write(&self, src: &[u8]) -> Result<(), Self::Error>;
+}
diff --git a/src/platform/udp.rs b/src/platform/udp.rs
new file mode 100644
index 0000000..f21a3d3
--- /dev/null
+++ b/src/platform/udp.rs
@@ -0,0 +1,11 @@
+/* Often times an a file descriptor in an atomic might suffice.
+ */
+pub trait Bind<Endpoint>: Send + Sync {
+    type Error;
+
+    fn new() -> Self;
+    fn set_port(&self, port: u16) -> Result<(), Self::Error>;
+    fn get_port(&self) -> u16;
+    fn recv(&self, dst: &mut [u8]) -> Endpoint;
+    fn send(&self, src: &[u8], dst: &Endpoint);
+}
diff --git a/src/router/device.rs b/src/router/device.rs
index 3b29312..5dfd22c 100644
--- a/src/router/device.rs
+++ b/src/router/device.rs
@@ -1,11 +1,11 @@
-use arraydeque::{ArrayDeque, Saturating, Wrapping};
+use arraydeque::{ArrayDeque, Wrapping};
 use treebitmap::IpLookupTable;
 
+use crossbeam_deque::{Injector, Steal};
 use std::collections::HashMap;
-use std::error::Error;
+use std::mem;
 use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr};
-use std::ptr;
-use std::sync::atomic::{AtomicBool, AtomicPtr, AtomicU64, Ordering};
+use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
 use std::sync::mpsc::{sync_channel, Receiver, SyncSender};
 use std::sync::{Arc, Mutex, Weak};
 use std::thread;
@@ -21,12 +21,29 @@ use std::u64;
 const REJECT_AFTER_MESSAGES: u64 = u64::MAX - (1 << 4);
 const MAX_STAGED_PACKETS: usize = 128;
 
-pub struct Device {
+struct DeviceInner {
+    stopped: AtomicBool,
+    injector: Injector<()>, // parallel enc/dec task injector
+    threads: Vec<thread::JoinHandle<()>>,
     recv: spin::RwLock<HashMap<u32, DecryptionState>>,
     ipv4: IpLookupTable<Ipv4Addr, Weak<PeerInner>>,
     ipv6: IpLookupTable<Ipv6Addr, Weak<PeerInner>>,
 }
 
+struct PeerInner {
+    stopped: AtomicBool,
+    thread_outbound: spin::Mutex<thread::JoinHandle<()>>,
+    thread_inbound: spin::Mutex<thread::JoinHandle<()>>,
+    inorder_outbound: SyncSender<()>,
+    inorder_inbound: SyncSender<()>,
+    staged_packets: Mutex<ArrayDeque<[Vec<u8>; MAX_STAGED_PACKETS], Wrapping>>, // packets awaiting handshake
+    rx_bytes: AtomicU64,                                                        // received bytes
+    tx_bytes: AtomicU64,                                                        // transmitted bytes
+    keys: spin::Mutex<KeyWheel>,                                                // key-wheel
+    ekey: spin::Mutex<EncryptionState>,                                         // encryption state
+    endpoint: spin::Mutex<Option<Arc<SocketAddr>>>,
+}
+
 struct EncryptionState {
     key: [u8; 32], // encryption key
     id: u32,       // sender id
@@ -48,33 +65,34 @@ struct KeyWheel {
     previous: Option<KeyPair>, // old key state (used for decryption)
 }
 
-struct PeerInner {
-    inorder_outbound: SyncSender<()>,
-    inorder_inbound: SyncSender<()>,
-    staged_packets: Mutex<ArrayDeque<[Vec<u8>; MAX_STAGED_PACKETS], Wrapping>>, // packets awaiting handshake
-    rx_bytes: AtomicU64,                                                        // received bytes
-    tx_bytes: AtomicU64,                                                        // transmitted bytes
-    keys: spin::Mutex<KeyWheel>,                                                // key-wheel
-    ekey: spin::Mutex<EncryptionState>,                                         // encryption state
-    endpoint: spin::Mutex<Option<Arc<SocketAddr>>>,
-}
-
 pub struct Peer(Arc<PeerInner>);
+pub struct Device(DeviceInner);
 
 impl Drop for Peer {
     fn drop(&mut self) {
-        // stop threads and remove peer from device
+        // mark peer as stopped
+        let inner = &self.0;
+        inner.stopped.store(true, Ordering::SeqCst);
+
+        // unpark threads to stop
+        inner.thread_inbound.lock().thread().unpark();
+        inner.thread_outbound.lock().thread().unpark();
     }
 }
 
 impl Drop for Device {
     fn drop(&mut self) {
-        // stop threads
+        // mark device as stopped
+        let inner = &self.0;
+        inner.stopped.store(true, Ordering::SeqCst);
+
+        // eat all parallel jobs
+        while inner.injector.steal() != Steal::Empty {}
     }
 }
 
 impl Peer {
-    fn set_endpoint(&self, endpoint: SocketAddr) {
+    pub fn set_endpoint(&self, endpoint: SocketAddr) {
         *self.0.endpoint.lock() = Some(Arc::new(endpoint))
     }
 
@@ -87,7 +105,7 @@ impl Peer {
         };
     }
 
-    pub fn keypair_add(&self, new: KeyPair) -> Option<u32> {
+    fn keypair_add(&self, new: KeyPair) -> Option<u32> {
         let mut keys = self.0.keys.lock();
         let release = keys.previous.map(|k| k.recv.id);
 
@@ -124,30 +142,21 @@ impl Peer {
 }
 
 impl Device {
-    pub fn new() -> Device {
-        Device {
+    pub fn new(workers: usize) -> Device {
+        Device(DeviceInner {
+            threads: vec![],
+            stopped: AtomicBool::new(false),
+            injector: Injector::new(),
             recv: spin::RwLock::new(HashMap::new()),
             ipv4: IpLookupTable::new(),
             ipv6: IpLookupTable::new(),
-        }
-    }
-
-    pub fn release(&self, id: u32) {
-        debug_assert!(
-            if let Some(_) = self.recv.read().get(&id) {
-                true
-            } else {
-                false
-            },
-            true
-        );
-        self.recv.write().remove(&id);
+        })
     }
 
     pub fn add_subnet(&mut self, ip: IpAddr, masklen: u32, peer: Peer) {
         match ip {
-            IpAddr::V4(v4) => self.ipv4.insert(v4, masklen, Arc::downgrade(&peer.0)),
-            IpAddr::V6(v6) => self.ipv6.insert(v6, masklen, Arc::downgrade(&peer.0)),
+            IpAddr::V4(v4) => self.0.ipv4.insert(v4, masklen, Arc::downgrade(&peer.0)),
+            IpAddr::V6(v6) => self.0.ipv6.insert(v6, masklen, Arc::downgrade(&peer.0)),
         };
     }
 
@@ -155,7 +164,7 @@ impl Device {
         let mut subnets = Vec::new();
 
         // extract ipv4 entries
-        for subnet in self.ipv4.iter() {
+        for subnet in self.0.ipv4.iter() {
             let (ip, masklen, p) = subnet;
             if let Some(p) = p.upgrade() {
                 if Arc::ptr_eq(&p, &peer.0) {
@@ -165,7 +174,7 @@ impl Device {
         }
 
         // extract ipv6 entries
-        for subnet in self.ipv6.iter() {
+        for subnet in self.0.ipv6.iter() {
             let (ip, masklen, p) = subnet;
             if let Some(p) = p.upgrade() {
                 if Arc::ptr_eq(&p, &peer.0) {
@@ -182,7 +191,7 @@ impl Device {
         let release = peer.keypair_add(new);
 
         // update incoming packet id map
-        let mut recv = self.recv.write();
+        let mut recv = self.0.recv.write();
 
         // release id of previous keypair
         if let Some(id) = release {
diff --git a/src/router/mod.rs b/src/router/mod.rs
index b53b10c..7055875 100644
--- a/src/router/mod.rs
+++ b/src/router/mod.rs
@@ -4,4 +4,4 @@ mod device;
 // mod inbound;
 // mod outbound;
 
-pub use device::Device;
\ No newline at end of file
+pub use device::{Device, Peer};
\ No newline at end of file