From 46d76b80c6b1b3b1c549b770b1a5ba791b49da8a Mon Sep 17 00:00:00 2001
From: Mathias Hall-Andersen <mathias@hall-andersen.dk>
Date: Sat, 31 Aug 2019 20:25:16 +0200
Subject: Reduce number of type parameters in router

Merge multiple related type parameters into trait,
allowing for easier refactoring and better maintainability.
---
 src/handshake/noise.rs |  2 --
 src/main.rs            | 40 ++++++++++++++++++++++++++++++++-
 src/router/device.rs   | 60 +++++++++++++++++++++++++++-----------------------
 src/router/messages.rs |  4 ++--
 src/router/mod.rs      |  2 +-
 src/router/peer.rs     | 48 ++++++++++++++++++++--------------------
 src/router/types.rs    | 23 +++++++++++++++++++
 src/router/workers.rs  | 30 +++++++++++++------------
 8 files changed, 137 insertions(+), 72 deletions(-)

diff --git a/src/handshake/noise.rs b/src/handshake/noise.rs
index 1e7c50d..9fc0eb4 100644
--- a/src/handshake/noise.rs
+++ b/src/handshake/noise.rs
@@ -1,5 +1,3 @@
-#![allow(dead_code)]
-
 // DH
 use x25519_dalek::PublicKey;
 use x25519_dalek::StaticSecret;
diff --git a/src/main.rs b/src/main.rs
index 600e144..cfe93eb 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -13,7 +13,44 @@ use std::net::SocketAddr;
 use std::sync::Arc;
 use std::time::Duration;
 
-use types::{Bind, KeyPair};
+use types::{Bind, KeyPair, Tun};
+
+#[derive(Debug)]
+enum TunError {}
+
+impl Error for TunError {
+    fn description(&self) -> &str {
+        "Generic Tun Error"
+    }
+
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        None
+    }
+}
+
+impl fmt::Display for TunError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "Not Possible")
+    }
+}
+
+struct TunTest {}
+
+impl Tun for TunTest {
+    type Error = TunError;
+
+    fn mtu(&self) -> usize {
+        1500
+    }
+
+    fn read(&self, buf: &mut [u8], offset: usize) -> Result<usize, Self::Error> {
+        Ok(0)
+    }
+
+    fn write(&self, src: &[u8]) -> Result<(), Self::Error> {
+        Ok(())
+    }
+}
 
 struct Test {}
 
@@ -73,6 +110,7 @@ fn main() {
     {
         let router = router::Device::new(
             4,
+            TunTest {},
             |t: &PeerTimer, data: bool, sent: bool| t.a.reset(Duration::from_millis(1000)),
             |t: &PeerTimer, data: bool, sent: bool| t.b.reset(Duration::from_millis(1000)),
             |t: &PeerTimer| println!("new key requested"),
diff --git a/src/router/device.rs b/src/router/device.rs
index a7f0590..84f25c6 100644
--- a/src/router/device.rs
+++ b/src/router/device.rs
@@ -5,7 +5,7 @@ use std::sync::{Arc, Weak};
 use std::thread;
 use std::time::Instant;
 
-use crossbeam_deque::{Injector, Steal, Stealer, Worker};
+use crossbeam_deque::{Injector, Worker};
 use spin;
 use treebitmap::IpLookupTable;
 
@@ -15,24 +15,25 @@ use super::anti_replay::AntiReplay;
 use super::peer;
 use super::peer::{Peer, PeerInner};
 
-use super::types::{Callback, KeyCallback, Opaque};
+use super::types::{Callback, Callbacks, CallbacksPhantom, KeyCallback, Opaque};
 use super::workers::{worker_parallel, JobParallel};
 
-pub struct DeviceInner<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>> {
+pub struct DeviceInner<C: Callbacks, T: Tun> {
+    // IO & timer generics
+    pub tun: T,
+    pub call_recv: C::CallbackRecv,
+    pub call_send: C::CallbackSend,
+    pub call_need_key: C::CallbackKey,
+
     // threading and workers
     pub running: AtomicBool,             // workers running?
     pub parked: AtomicBool,              // any workers parked?
     pub injector: Injector<JobParallel>, // parallel enc/dec task injector
 
-    // unboxed callbacks (used for timers and handshake requests)
-    pub event_send: S,     // called when authenticated message send
-    pub event_recv: R,     // called when authenticated message received
-    pub event_need_key: K, // called when new key material is required
-
     // routing
-    pub recv: spin::RwLock<HashMap<u32, DecryptionState<T, S, R, K>>>, // receiver id -> decryption state
-    pub ipv4: spin::RwLock<IpLookupTable<Ipv4Addr, Weak<PeerInner<T, S, R, K>>>>, // ipv4 cryptkey routing
-    pub ipv6: spin::RwLock<IpLookupTable<Ipv6Addr, Weak<PeerInner<T, S, R, K>>>>, // ipv6 cryptkey routing
+    pub recv: spin::RwLock<HashMap<u32, DecryptionState<C, T>>>, // receiver id -> decryption state
+    pub ipv4: spin::RwLock<IpLookupTable<Ipv4Addr, Weak<PeerInner<C, T>>>>, // ipv4 cryptkey routing
+    pub ipv6: spin::RwLock<IpLookupTable<Ipv6Addr, Weak<PeerInner<C, T>>>>, // ipv6 cryptkey routing
 }
 
 pub struct EncryptionState {
@@ -43,21 +44,18 @@ pub struct EncryptionState {
                        // (birth + reject-after-time - keepalive-timeout - rekey-timeout)
 }
 
-pub struct DecryptionState<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>> {
+pub struct DecryptionState<C: Callbacks, T: Tun> {
     pub key: [u8; 32],
     pub keypair: Weak<KeyPair>,
     pub confirmed: AtomicBool,
     pub protector: spin::Mutex<AntiReplay>,
-    pub peer: Weak<PeerInner<T, S, R, K>>,
+    pub peer: Weak<PeerInner<C, T>>,
     pub death: Instant, // time when the key can no longer be used for decryption
 }
 
-pub struct Device<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>>(
-    Arc<DeviceInner<T, S, R, K>>,
-    Vec<thread::JoinHandle<()>>,
-);
+pub struct Device<C: Callbacks, T: Tun>(Arc<DeviceInner<C, T>>, Vec<thread::JoinHandle<()>>);
 
-impl<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>> Drop for Device<T, S, R, K> {
+impl<C: Callbacks, T: Tun> Drop for Device<C, T> {
     fn drop(&mut self) {
         // mark device as stopped
         let device = &self.0;
@@ -75,18 +73,22 @@ impl<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>> Drop for Devi
     }
 }
 
-impl<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>> Device<T, S, R, K> {
+impl<O: Opaque, R: Callback<O>, S: Callback<O>, K: KeyCallback<O>, T: Tun>
+    Device<CallbacksPhantom<O, R, S, K>, T>
+{
     pub fn new(
         num_workers: usize,
-        event_recv: R,
-        event_send: S,
-        event_need_key: K,
-    ) -> Device<T, S, R, K> {
+        tun: T,
+        call_recv: R,
+        call_send: S,
+        call_need_key: K,
+    ) -> Device<CallbacksPhantom<O, R, S, K>, T> {
         // allocate shared device state
         let inner = Arc::new(DeviceInner {
-            event_recv,
-            event_send,
-            event_need_key,
+            tun,
+            call_recv,
+            call_send,
+            call_need_key,
             parked: AtomicBool::new(false),
             running: AtomicBool::new(true),
             injector: Injector::new(),
@@ -95,7 +97,7 @@ impl<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>> Device<T, S,
             ipv6: spin::RwLock::new(IpLookupTable::new()),
         });
 
-        // alloacate work pool resources
+        // allocate work pool resources
         let mut workers = Vec::with_capacity(num_workers);
         let mut stealers = Vec::with_capacity(num_workers);
         for _ in 0..num_workers {
@@ -118,13 +120,15 @@ impl<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>> Device<T, S,
         // return exported device handle
         Device(inner, threads)
     }
+}
 
+impl<C: Callbacks, T: Tun> Device<C, T> {
     /// Adds a new peer to the device
     ///
     /// # Returns
     ///
     /// A atomic ref. counted peer (with liftime matching the device)
-    pub fn new_peer(&self, opaque: T) -> Peer<T, S, R, K> {
+    pub fn new_peer(&self, opaque: C::Opaque) -> Peer<C, T> {
         peer::new_peer(self.0.clone(), opaque)
     }
 
diff --git a/src/router/messages.rs b/src/router/messages.rs
index d09bbb3..bec24ac 100644
--- a/src/router/messages.rs
+++ b/src/router/messages.rs
@@ -7,5 +7,5 @@ use zerocopy::{AsBytes, ByteSlice, FromBytes, LayoutVerified};
 pub struct TransportHeader {
     pub f_type: U32<LittleEndian>,
     pub f_receiver: U32<LittleEndian>,
-    pub f_counter: U64<LittleEndian>
-}
\ No newline at end of file
+    pub f_counter: U64<LittleEndian>,
+}
diff --git a/src/router/mod.rs b/src/router/mod.rs
index 70ac868..c1ecf1c 100644
--- a/src/router/mod.rs
+++ b/src/router/mod.rs
@@ -1,9 +1,9 @@
 mod anti_replay;
 mod device;
+mod messages;
 mod peer;
 mod types;
 mod workers;
-mod messages;
 
 pub use device::Device;
 pub use peer::Peer;
diff --git a/src/router/peer.rs b/src/router/peer.rs
index 234c353..647d24f 100644
--- a/src/router/peer.rs
+++ b/src/router/peer.rs
@@ -12,7 +12,7 @@ use treebitmap::address::Address;
 use treebitmap::IpLookupTable;
 
 use super::super::constants::*;
-use super::super::types::KeyPair;
+use super::super::types::{KeyPair, Tun};
 
 use super::anti_replay::AntiReplay;
 use super::device::DecryptionState;
@@ -20,7 +20,7 @@ use super::device::DeviceInner;
 use super::device::EncryptionState;
 use super::workers::{worker_inbound, worker_outbound, JobInbound, JobOutbound};
 
-use super::types::{Callback, KeyCallback, Opaque};
+use super::types::Callbacks;
 
 const MAX_STAGED_PACKETS: usize = 128;
 
@@ -31,14 +31,14 @@ pub struct KeyWheel {
     retired: Option<u32>,           // retired id (previous id, after confirming key-pair)
 }
 
-pub struct PeerInner<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>> {
+pub struct PeerInner<C: Callbacks, T: Tun> {
     pub stopped: AtomicBool,
-    pub opaque: T,
-    pub device: Arc<DeviceInner<T, S, R, K>>,
+    pub opaque: C::Opaque,
+    pub device: Arc<DeviceInner<C, T>>,
     pub thread_outbound: spin::Mutex<Option<thread::JoinHandle<()>>>,
     pub thread_inbound: spin::Mutex<Option<thread::JoinHandle<()>>>,
     pub queue_outbound: SyncSender<JobOutbound>,
-    pub queue_inbound: SyncSender<JobInbound<T, S, R, K>>,
+    pub queue_inbound: SyncSender<JobInbound<C, T>>,
     pub staged_packets: spin::Mutex<ArrayDeque<[Vec<u8>; MAX_STAGED_PACKETS], Wrapping>>, // packets awaiting handshake
     pub rx_bytes: AtomicU64,                        // received bytes
     pub tx_bytes: AtomicU64,                        // transmitted bytes
@@ -47,15 +47,15 @@ pub struct PeerInner<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T
     pub endpoint: spin::Mutex<Option<Arc<SocketAddr>>>,
 }
 
-pub struct Peer<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>>(
-    Arc<PeerInner<T, S, R, K>>,
+pub struct Peer<C: Callbacks, T: Tun>(
+    Arc<PeerInner<C, T>>,
 );
 
-fn treebit_list<A, O, T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>>(
-    peer: &Arc<PeerInner<T, S, R, K>>,
-    table: &spin::RwLock<IpLookupTable<A, Weak<PeerInner<T, S, R, K>>>>,
-    callback: Box<dyn Fn(A, u32) -> O>,
-) -> Vec<O>
+fn treebit_list<A, E, C: Callbacks, T: Tun>(
+    peer: &Arc<PeerInner<C, T>>,
+    table: &spin::RwLock<IpLookupTable<A, Weak<PeerInner<C, T>>>>,
+    callback: Box<dyn Fn(A, u32) -> E>,
+) -> Vec<E>
 where
     A: Address,
 {
@@ -71,9 +71,9 @@ where
     res
 }
 
-fn treebit_remove<A: Address, T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>>(
-    peer: &Peer<T, S, R, K>,
-    table: &spin::RwLock<IpLookupTable<A, Weak<PeerInner<T, S, R, K>>>>,
+fn treebit_remove<A: Address, C: Callbacks, T: Tun>(
+    peer: &Peer<C, T>,
+    table: &spin::RwLock<IpLookupTable<A, Weak<PeerInner<C, T>>>>,
 ) {
     let mut m = table.write();
 
@@ -95,7 +95,7 @@ fn treebit_remove<A: Address, T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyC
     }
 }
 
-impl<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>> Drop for Peer<T, S, R, K> {
+impl<C: Callbacks, T: Tun> Drop for Peer<C, T> {
     fn drop(&mut self) {
         // mark peer as stopped
 
@@ -150,10 +150,10 @@ impl<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>> Drop for Peer
     }
 }
 
-pub fn new_peer<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>>(
-    device: Arc<DeviceInner<T, S, R, K>>,
-    opaque: T,
-) -> Peer<T, S, R, K> {
+pub fn new_peer<C: Callbacks, T: Tun>(
+    device: Arc<DeviceInner<C, T>>,
+    opaque: C::Opaque,
+) -> Peer<C, T> {
     // allocate in-order queues
     let (send_inbound, recv_inbound) = sync_channel(MAX_STAGED_PACKETS);
     let (send_outbound, recv_outbound) = sync_channel(MAX_STAGED_PACKETS);
@@ -204,7 +204,7 @@ pub fn new_peer<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>>(
     Peer(peer)
 }
 
-impl<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>> PeerInner<T, S, R, K> {
+impl<C: Callbacks, T: Tun> PeerInner<C, T> {
     pub fn confirm_key(&self, kp: Weak<KeyPair>) {
         // upgrade key-pair to strong reference
 
@@ -214,8 +214,8 @@ impl<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>> PeerInner<T,
     }
 }
 
-impl<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>> Peer<T, S, R, K> {
-    fn new(inner: PeerInner<T, S, R, K>) -> Peer<T, S, R, K> {
+impl<C: Callbacks, T: Tun> Peer<C, T> {
+    fn new(inner: PeerInner<C, T>) -> Peer<C, T> {
         Peer(Arc::new(inner))
     }
 
diff --git a/src/router/types.rs b/src/router/types.rs
index 3d486bc..f6a0311 100644
--- a/src/router/types.rs
+++ b/src/router/types.rs
@@ -1,3 +1,5 @@
+use std::marker::PhantomData;
+
 pub trait Opaque: Send + Sync + 'static {}
 
 impl<T> Opaque for T where T: Send + Sync + 'static {}
@@ -23,3 +25,24 @@ pub trait TunCallback<T>: Fn(&T, bool, bool) -> () + Sync + Send + 'static {}
 pub trait BindCallback<T>: Fn(&T, bool, bool) -> () + Sync + Send + 'static {}
 
 pub trait Endpoint: Send + Sync {}
+
+pub trait Callbacks: Send + Sync + 'static {
+    type Opaque: Opaque;
+    type CallbackRecv: Callback<Self::Opaque>;
+    type CallbackSend: Callback<Self::Opaque>;
+    type CallbackKey: KeyCallback<Self::Opaque>;
+}
+
+pub struct CallbacksPhantom<O: Opaque, R: Callback<O>, S: Callback<O>, K: KeyCallback<O>> {
+    _phantom_opaque: PhantomData<O>,
+    _phantom_recv: PhantomData<R>,
+    _phantom_send: PhantomData<S>,
+    _phantom_key: PhantomData<K>
+}
+
+impl <O: Opaque, R: Callback<O>, S: Callback<O>, K: KeyCallback<O>> Callbacks for CallbacksPhantom<O, R, S, K> {
+    type Opaque = O;
+    type CallbackRecv = R;
+    type CallbackSend = S;
+    type CallbackKey = K;
+}
\ No newline at end of file
diff --git a/src/router/workers.rs b/src/router/workers.rs
index 4861847..2b0b9ec 100644
--- a/src/router/workers.rs
+++ b/src/router/workers.rs
@@ -15,7 +15,9 @@ use super::device::DecryptionState;
 use super::device::DeviceInner;
 use super::messages::TransportHeader;
 use super::peer::PeerInner;
-use super::types::{Callback, KeyCallback, Opaque};
+use super::types::Callbacks;
+
+use super::super::types::Tun;
 
 #[derive(PartialEq, Debug)]
 pub enum Operation {
@@ -39,7 +41,7 @@ pub struct JobInner {
 
 pub type JobBuffer = Arc<spin::Mutex<JobInner>>;
 pub type JobParallel = (Arc<thread::JoinHandle<()>>, JobBuffer);
-pub type JobInbound<T, S, R, K> = (Weak<DecryptionState<T, S, R, K>>, JobBuffer);
+pub type JobInbound<C, T> = (Weak<DecryptionState<C, T>>, JobBuffer);
 pub type JobOutbound = JobBuffer;
 
 /* Strategy for workers acquiring a new job:
@@ -87,10 +89,10 @@ fn wait_recv<T>(running: &AtomicBool, recv: &Receiver<T>) -> Result<T, TryRecvEr
     return Err(TryRecvError::Disconnected);
 }
 
-pub fn worker_inbound<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>>(
-    device: Arc<DeviceInner<T, S, R, K>>,   // related device
-    peer: Arc<PeerInner<T, S, R, K>>,       // related peer
-    recv: Receiver<JobInbound<T, S, R, K>>, // in order queue
+pub fn worker_inbound<C: Callbacks, T: Tun>(
+    device: Arc<DeviceInner<C, T>>,   // related device
+    peer: Arc<PeerInner<C, T>>,       // related peer
+    recv: Receiver<JobInbound<C, T>>, // in order queue
 ) {
     loop {
         match wait_recv(&peer.stopped, &recv) {
@@ -134,7 +136,7 @@ pub fn worker_inbound<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<
                                     packet.len() >= CHACHA20_POLY1305.nonce_len(),
                                     "this should be checked earlier in the pipeline"
                                 );
-                                (device.event_recv)(
+                                (device.call_recv)(
                                     &peer.opaque,
                                     packet.len() > CHACHA20_POLY1305.nonce_len(),
                                     true,
@@ -155,10 +157,10 @@ pub fn worker_inbound<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<
     }
 }
 
-pub fn worker_outbound<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>>(
-    device: Arc<DeviceInner<T, S, R, K>>, // related device
-    peer: Arc<PeerInner<T, S, R, K>>,     // related peer
-    recv: Receiver<JobOutbound>,          // in order queue
+pub fn worker_outbound<C: Callbacks, T: Tun>(
+    device: Arc<DeviceInner<C, T>>, // related device
+    peer: Arc<PeerInner<C, T>>,     // related peer
+    recv: Receiver<JobOutbound>,    // in order queue
 ) {
     loop {
         match wait_recv(&peer.stopped, &recv) {
@@ -180,7 +182,7 @@ pub fn worker_outbound<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback
                                 let xmit = false;
 
                                 // trigger callback
-                                (device.event_send)(
+                                (device.call_send)(
                                     &peer.opaque,
                                     buf.msg.len()
                                         > CHACHA20_POLY1305.nonce_len()
@@ -203,8 +205,8 @@ pub fn worker_outbound<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback
     }
 }
 
-pub fn worker_parallel<T: Opaque, S: Callback<T>, R: Callback<T>, K: KeyCallback<T>>(
-    device: Arc<DeviceInner<T, S, R, K>>,
+pub fn worker_parallel<C: Callbacks, T: Tun>(
+    device: Arc<DeviceInner<C, T>>,
     local: Worker<JobParallel>, // local job queue (local to thread)
     stealers: Vec<Stealer<JobParallel>>, // stealers (from other threads)
 ) {
-- 
cgit v1.2.3-59-g8ed1b