Make IO traits suitable for Tun events (up/down)

1 files changed, 47 insertions, 0 deletions

diff --git a/src/platform/udp.rs b/src/platform/udp.rs
new file mode 100644
index 0000000..3671229
--- /dev/null
+++ b/src/platform/udp.rs
@@ -0,0 +1,47 @@
+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 UDP: 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 get_port(&self) -> u16;
+
+    fn get_fwmark(&self) -> Option<u32>;
+
+    fn set_fwmark(&mut self, value: Option<u32>) -> Result<(), Self::Error>;
+}
+
+/// On some platforms the application can itself bind to a socket.
+/// This enables configuration using the UAPI interface.
+pub trait PlatformUDP: UDP {
+    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>;
+}