Moved IO traits into platform module

11 files changed, 518 insertions, 53 deletions

diff --git a/src/platform/bind.rs b/src/platform/bind.rs
new file mode 100644
index 0000000..f22a5d7
--- /dev/null
+++ b/src/platform/bind.rs
@@ -0,0 +1,43 @@
+use super::Endpoint;
+use std::error::Error;
+
+pub trait Reader<E: Endpoint>: Send + Sync {
+    type Error: Error;
+
+    fn read(&self, buf: &mut [u8]) -> Result<(usize, E), Self::Error>;
+}
+
+pub trait Writer<E: Endpoint>: Send + Sync + Clone + 'static {
+    type Error: Error;
+
+    fn write(&self, buf: &[u8], dst: &E) -> Result<(), Self::Error>;
+}
+
+pub trait Bind: Send + Sync + 'static {
+    type Error: Error;
+    type Endpoint: Endpoint;
+
+    /* Until Rust gets type equality constraints these have to be generic */
+    type Writer: Writer<Self::Endpoint>;
+    type Reader: Reader<Self::Endpoint>;
+}
+
+/// On platforms where fwmark can be set and the
+/// implementation can bind to a new port during later configuration (UAPI support),
+/// this type provides the ability to set the fwmark and close the socket (by dropping the instance)
+pub trait Owner: Send {
+    type Error: Error;
+
+    fn set_fwmark(&self, value: Option<u32>) -> Option<Self::Error>;
+}
+
+/// On some platforms the application can itself bind to a socket.
+/// This enables configuration using the UAPI interface.
+pub trait Platform: Bind {
+    type Owner: Owner;
+
+    /// Bind to a new port, returning the reader/writer and
+    /// an associated instance of the owner type, which closes the UDP socket upon "drop"
+    /// and enables configuration of the fwmark value.
+    fn bind(port: u16) -> Result<(Vec<Self::Reader>, Self::Writer, Self::Owner), Self::Error>;
+}
diff --git a/src/platform/dummy.rs b/src/platform/dummy.rs
deleted file mode 100644
index 208febe..0000000
--- a/src/platform/dummy.rs
+++ /dev/null
@@ -1,22 +0,0 @@
-#[cfg(test)]
-use super::super::wireguard::dummy;
-use super::BindOwner;
-use super::PlatformBind;
-
-pub struct VoidOwner {}
-
-impl BindOwner for VoidOwner {
-    type Error = dummy::BindError;
-
-    fn set_fwmark(&self, value: Option<u32>) -> Option<Self::Error> {
-        None
-    }
-}
-
-impl PlatformBind for dummy::PairBind {
-    type Owner = VoidOwner;
-
-    fn bind(_port: u16) -> Result<(Vec<Self::Reader>, Self::Writer, Self::Owner), Self::Error> {
-        Err(dummy::BindError::Disconnected)
-    }
-}
diff --git a/src/platform/dummy/bind.rs b/src/platform/dummy/bind.rs
new file mode 100644
index 0000000..14143ae
--- /dev/null
+++ b/src/platform/dummy/bind.rs
@@ -0,0 +1,211 @@
+use std::error::Error;
+use std::fmt;
+use std::marker;
+use std::net::SocketAddr;
+use std::sync::mpsc::{sync_channel, Receiver, SyncSender};
+use std::sync::Arc;
+use std::sync::Mutex;
+
+use super::super::bind::*;
+use super::super::Endpoint;
+
+pub struct VoidOwner {}
+
+#[derive(Debug)]
+pub enum BindError {
+    Disconnected,
+}
+
+impl Error for BindError {
+    fn description(&self) -> &str {
+        "Generic Bind Error"
+    }
+
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        None
+    }
+}
+
+impl fmt::Display for BindError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            BindError::Disconnected => write!(f, "PairBind disconnected"),
+        }
+    }
+}
+
+/* TUN implementation */
+
+#[derive(Debug)]
+pub enum TunError {
+    Disconnected,
+}
+
+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")
+    }
+}
+
+/* Endpoint implementation */
+
+#[derive(Clone, Copy)]
+pub struct UnitEndpoint {}
+
+impl Endpoint for UnitEndpoint {
+    fn from_address(_: SocketAddr) -> UnitEndpoint {
+        UnitEndpoint {}
+    }
+
+    fn into_address(&self) -> SocketAddr {
+        "127.0.0.1:8080".parse().unwrap()
+    }
+
+    fn clear_src(&mut self) {}
+}
+
+impl UnitEndpoint {
+    pub fn new() -> UnitEndpoint {
+        UnitEndpoint {}
+    }
+}
+
+#[derive(Clone, Copy)]
+pub struct VoidBind {}
+
+impl Reader<UnitEndpoint> for VoidBind {
+    type Error = BindError;
+
+    fn read(&self, _buf: &mut [u8]) -> Result<(usize, UnitEndpoint), Self::Error> {
+        Ok((0, UnitEndpoint {}))
+    }
+}
+
+impl Writer<UnitEndpoint> for VoidBind {
+    type Error = BindError;
+
+    fn write(&self, _buf: &[u8], _dst: &UnitEndpoint) -> Result<(), Self::Error> {
+        Ok(())
+    }
+}
+
+impl Bind for VoidBind {
+    type Error = BindError;
+    type Endpoint = UnitEndpoint;
+
+    type Reader = VoidBind;
+    type Writer = VoidBind;
+}
+
+impl VoidBind {
+    pub fn new() -> VoidBind {
+        VoidBind {}
+    }
+}
+
+/* Pair Bind */
+
+#[derive(Clone)]
+pub struct PairReader<E> {
+    recv: Arc<Mutex<Receiver<Vec<u8>>>>,
+    _marker: marker::PhantomData<E>,
+}
+
+impl Reader<UnitEndpoint> for PairReader<UnitEndpoint> {
+    type Error = BindError;
+    fn read(&self, buf: &mut [u8]) -> Result<(usize, UnitEndpoint), Self::Error> {
+        let vec = self
+            .recv
+            .lock()
+            .unwrap()
+            .recv()
+            .map_err(|_| BindError::Disconnected)?;
+        let len = vec.len();
+        buf[..len].copy_from_slice(&vec[..]);
+        Ok((vec.len(), UnitEndpoint {}))
+    }
+}
+
+impl Writer<UnitEndpoint> for PairWriter<UnitEndpoint> {
+    type Error = BindError;
+    fn write(&self, buf: &[u8], _dst: &UnitEndpoint) -> Result<(), Self::Error> {
+        let owned = buf.to_owned();
+        match self.send.lock().unwrap().send(owned) {
+            Err(_) => Err(BindError::Disconnected),
+            Ok(_) => Ok(()),
+        }
+    }
+}
+
+#[derive(Clone)]
+pub struct PairWriter<E> {
+    send: Arc<Mutex<SyncSender<Vec<u8>>>>,
+    _marker: marker::PhantomData<E>,
+}
+
+#[derive(Clone)]
+pub struct PairBind {}
+
+impl PairBind {
+    pub fn pair<E>() -> (
+        (PairReader<E>, PairWriter<E>),
+        (PairReader<E>, PairWriter<E>),
+    ) {
+        let (tx1, rx1) = sync_channel(128);
+        let (tx2, rx2) = sync_channel(128);
+        (
+            (
+                PairReader {
+                    recv: Arc::new(Mutex::new(rx1)),
+                    _marker: marker::PhantomData,
+                },
+                PairWriter {
+                    send: Arc::new(Mutex::new(tx2)),
+                    _marker: marker::PhantomData,
+                },
+            ),
+            (
+                PairReader {
+                    recv: Arc::new(Mutex::new(rx2)),
+                    _marker: marker::PhantomData,
+                },
+                PairWriter {
+                    send: Arc::new(Mutex::new(tx1)),
+                    _marker: marker::PhantomData,
+                },
+            ),
+        )
+    }
+}
+
+impl Bind for PairBind {
+    type Error = BindError;
+    type Endpoint = UnitEndpoint;
+    type Reader = PairReader<Self::Endpoint>;
+    type Writer = PairWriter<Self::Endpoint>;
+}
+
+impl Owner for VoidOwner {
+    type Error = BindError;
+
+    fn set_fwmark(&self, _value: Option<u32>) -> Option<Self::Error> {
+        None
+    }
+}
+
+impl Platform for PairBind {
+    type Owner = VoidOwner;
+    fn bind(_port: u16) -> Result<(Vec<Self::Reader>, Self::Writer, Self::Owner), Self::Error> {
+        Err(BindError::Disconnected)
+    }
+}
diff --git a/src/platform/dummy/endpoint.rs b/src/platform/dummy/endpoint.rs
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/src/platform/dummy/endpoint.rs
@@ -0,0 +1 @@
+
diff --git a/src/platform/dummy/mod.rs b/src/platform/dummy/mod.rs
new file mode 100644
index 0000000..884bd7e
--- /dev/null
+++ b/src/platform/dummy/mod.rs
@@ -0,0 +1,13 @@
+mod bind;
+mod endpoint;
+mod tun;
+
+/* A pure dummy platform available during "test-time"
+ *
+ * The use of the dummy platform is to enable unit testing of full WireGuard,
+ * the configuration interface and the UAPI parser.
+ */
+
+pub use bind::*;
+pub use endpoint::*;
+pub use tun::*;
diff --git a/src/platform/dummy/tun.rs b/src/platform/dummy/tun.rs
new file mode 100644
index 0000000..9fe9480
--- /dev/null
+++ b/src/platform/dummy/tun.rs
@@ -0,0 +1,172 @@
+use std::error::Error;
+use std::fmt;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use std::sync::mpsc::{sync_channel, Receiver, SyncSender};
+use std::sync::Arc;
+use std::sync::Mutex;
+
+use super::super::tun::*;
+
+/* This submodule provides pure/dummy implementations of the IO interfaces
+ * for use in unit tests thoughout the project.
+ */
+
+/* Error implementation */
+
+#[derive(Debug)]
+pub enum BindError {
+    Disconnected,
+}
+
+impl Error for BindError {
+    fn description(&self) -> &str {
+        "Generic Bind Error"
+    }
+
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        None
+    }
+}
+
+impl fmt::Display for BindError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            BindError::Disconnected => write!(f, "PairBind disconnected"),
+        }
+    }
+}
+
+#[derive(Debug)]
+pub enum TunError {
+    Disconnected,
+}
+
+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")
+    }
+}
+
+pub struct TunTest {}
+
+pub struct TunFakeIO {
+    store: bool,
+    tx: SyncSender<Vec<u8>>,
+    rx: Receiver<Vec<u8>>,
+}
+
+pub struct TunReader {
+    rx: Receiver<Vec<u8>>,
+}
+
+pub struct TunWriter {
+    store: bool,
+    tx: Mutex<SyncSender<Vec<u8>>>,
+}
+
+#[derive(Clone)]
+pub struct TunMTU {
+    mtu: Arc<AtomicUsize>,
+}
+
+impl Reader for TunReader {
+    type Error = TunError;
+
+    fn read(&self, buf: &mut [u8], offset: usize) -> Result<usize, Self::Error> {
+        match self.rx.recv() {
+            Ok(m) => {
+                buf[offset..].copy_from_slice(&m[..]);
+                Ok(m.len())
+            }
+            Err(_) => Err(TunError::Disconnected),
+        }
+    }
+}
+
+impl Writer for TunWriter {
+    type Error = TunError;
+
+    fn write(&self, src: &[u8]) -> Result<(), Self::Error> {
+        if self.store {
+            let m = src.to_owned();
+            match self.tx.lock().unwrap().send(m) {
+                Ok(_) => Ok(()),
+                Err(_) => Err(TunError::Disconnected),
+            }
+        } else {
+            Ok(())
+        }
+    }
+}
+
+impl MTU for TunMTU {
+    fn mtu(&self) -> usize {
+        self.mtu.load(Ordering::Acquire)
+    }
+}
+
+impl Tun for TunTest {
+    type Writer = TunWriter;
+    type Reader = TunReader;
+    type MTU = TunMTU;
+    type Error = TunError;
+}
+
+impl TunFakeIO {
+    pub fn write(&self, msg: Vec<u8>) {
+        if self.store {
+            self.tx.send(msg).unwrap();
+        }
+    }
+
+    pub fn read(&self) -> Vec<u8> {
+        self.rx.recv().unwrap()
+    }
+}
+
+impl TunTest {
+    pub fn create(mtu: usize, store: bool) -> (TunFakeIO, TunReader, TunWriter, TunMTU) {
+        let (tx1, rx1) = if store {
+            sync_channel(32)
+        } else {
+            sync_channel(1)
+        };
+        let (tx2, rx2) = if store {
+            sync_channel(32)
+        } else {
+            sync_channel(1)
+        };
+
+        let fake = TunFakeIO {
+            tx: tx1,
+            rx: rx2,
+            store,
+        };
+        let reader = TunReader { rx: rx1 };
+        let writer = TunWriter {
+            tx: Mutex::new(tx2),
+            store,
+        };
+        let mtu = TunMTU {
+            mtu: Arc::new(AtomicUsize::new(mtu)),
+        };
+
+        (fake, reader, writer, mtu)
+    }
+}
+
+impl Platform for TunTest {
+    fn create(_name: &str) -> Result<(Vec<Self::Reader>, Self::Writer, Self::MTU), Self::Error> {
+        Err(TunError::Disconnected)
+    }
+}
diff --git a/src/platform/endpoint.rs b/src/platform/endpoint.rs
new file mode 100644
index 0000000..4702aab
--- /dev/null
+++ b/src/platform/endpoint.rs
@@ -0,0 +1,7 @@
+use std::net::SocketAddr;
+
+pub trait Endpoint: Send + 'static {
+    fn from_address(addr: SocketAddr) -> Self;
+    fn into_address(&self) -> SocketAddr;
+    fn clear_src(&mut self);
+}
diff --git a/src/platform/linux/tun.rs b/src/platform/linux/tun.rs
index 5b7b105..090569a 100644
--- a/src/platform/linux/tun.rs
+++ b/src/platform/linux/tun.rs
@@ -1,6 +1,4 @@
-use super::super::super::wireguard::tun::*;
-use super::super::PlatformTun;
-use super::super::Tun;
+use super::super::tun::*;
 
 use libc::*;
 
@@ -127,7 +125,7 @@ impl Tun for LinuxTun {
     type MTU = LinuxTunMTU;
 }
 
-impl PlatformTun for LinuxTun {
+impl Platform for LinuxTun {
     fn create(name: &str) -> Result<(Vec<Self::Reader>, Self::Writer, Self::MTU), Self::Error> {
         // construct request struct
         let mut req = Ifreq {
diff --git a/src/platform/linux/udp.rs b/src/platform/linux/udp.rs
index 0a1a186..52e4c45 100644
--- a/src/platform/linux/udp.rs
+++ b/src/platform/linux/udp.rs
@@ -1,6 +1,5 @@
-use super::super::Bind;
+use super::super::bind::*;
 use super::super::Endpoint;
-use super::super::PlatformBind;
 
 use std::net::SocketAddr;
 
diff --git a/src/platform/mod.rs b/src/platform/mod.rs
index a0bbc13..ecd559a 100644
--- a/src/platform/mod.rs
+++ b/src/platform/mod.rs
@@ -1,33 +1,15 @@
-use std::error::Error;
+mod endpoint;
 
-use super::wireguard::bind::Bind;
-use super::wireguard::tun::Tun;
-use super::wireguard::Endpoint;
+pub mod bind;
+pub mod tun;
 
-#[cfg(test)]
-mod dummy;
+pub use endpoint::Endpoint;
 
 #[cfg(target_os = "linux")]
 mod linux;
 
+#[cfg(test)]
+pub mod dummy;
+
 #[cfg(target_os = "linux")]
 pub use linux::LinuxTun as TunInstance;
-
-pub trait BindOwner: Send {
-    type Error: Error;
-
-    fn set_fwmark(&self, value: Option<u32>) -> Option<Self::Error>;
-}
-
-pub trait PlatformBind: Bind {
-    type Owner: BindOwner;
-
-    /// Bind to a new port, returning the reader/writer and
-    /// an associated instance of the owner type, which closes the UDP socket upon "drop"
-    /// and enables configuration of the fwmark value.
-    fn bind(port: u16) -> Result<(Vec<Self::Reader>, Self::Writer, Self::Owner), Self::Error>;
-}
-
-pub trait PlatformTun: Tun {
-    fn create(name: &str) -> Result<(Vec<Self::Reader>, Self::Writer, Self::MTU), Self::Error>;
-}
diff --git a/src/platform/tun.rs b/src/platform/tun.rs
new file mode 100644
index 0000000..f49d4af
--- /dev/null
+++ b/src/platform/tun.rs
@@ -0,0 +1,61 @@
+use std::error::Error;
+
+pub trait Writer: Send + Sync + 'static {
+    type Error: Error;
+
+    /// Receive a cryptkey routed IP packet
+    ///
+    /// # Arguments
+    ///
+    /// - src: Buffer containing the IP packet to be written
+    ///
+    /// # Returns
+    ///
+    /// Unit type or an error
+    fn write(&self, src: &[u8]) -> Result<(), Self::Error>;
+}
+
+pub trait Reader: Send + 'static {
+    type Error: Error;
+
+    /// Reads an IP packet into dst[offset:] from the tunnel device
+    ///
+    /// The reason for providing space for a prefix
+    /// is to efficiently accommodate platforms on which the packet is prefaced by a header.
+    /// This space is later used to construct the transport message inplace.
+    ///
+    /// # Arguments
+    ///
+    /// - buf: Destination buffer (enough space for MTU bytes + header)
+    /// - offset: Offset for the beginning of the IP packet
+    ///
+    /// # Returns
+    ///
+    /// The size of the IP packet (ignoring the header) or an std::error::Error instance:
+    fn read(&self, buf: &mut [u8], offset: usize) -> Result<usize, Self::Error>;
+}
+
+pub trait MTU: Send + Sync + Clone + 'static {
+    /// Returns the MTU of the device
+    ///
+    /// This function needs to be efficient (called for every read).
+    /// The goto implementation strategy is to .load an atomic variable,
+    /// then use e.g. netlink to update the variable in a separate thread.
+    ///
+    /// # Returns
+    ///
+    /// The MTU of the interface in bytes
+    fn mtu(&self) -> usize;
+}
+
+pub trait Tun: Send + Sync + 'static {
+    type Writer: Writer;
+    type Reader: Reader;
+    type MTU: MTU;
+    type Error: Error;
+}
+
+/// On some platforms the application can create the TUN device itself.
+pub trait Platform: Tun {
+    fn create(name: &str) -> Result<(Vec<Self::Reader>, Self::Writer, Self::MTU), Self::Error>;
+}