Add wireframe for TunnelParametersGenerator

1 files changed, 22 insertions, 2 deletions

diff --git a/talpid-core/src/tunnel_state_machine/mod.rs b/talpid-core/src/tunnel_state_machine/mod.rs
index 91ca9aa7ad..00286427d2 100644
--- a/talpid-core/src/tunnel_state_machine/mod.rs
+++ b/talpid-core/src/tunnel_state_machine/mod.rs
@@ -44,6 +44,7 @@ error_chain! {
 /// Spawn the tunnel state machine thread, returning a channel for sending tunnel commands.
 pub fn spawn<P, T>(
     allow_lan: bool,
+    tunnel_parameters_generator: impl TunnelParametersGenerator,
     log_dir: Option<PathBuf>,
     resource_dir: PathBuf,
     cache_dir: P,
@@ -59,6 +60,7 @@ where
     thread::spawn(move || {
         match create_event_loop(
             allow_lan,
+            tunnel_parameters_generator,
             log_dir,
             resource_dir,
             cache_dir,
@@ -92,6 +94,7 @@ where
 
 fn create_event_loop<T>(
     allow_lan: bool,
+    tunnel_parameters_generator: impl TunnelParametersGenerator,
     log_dir: Option<PathBuf>,
     resource_dir: PathBuf,
     cache_dir: impl AsRef<Path>,
@@ -102,8 +105,14 @@ where
     T: From<TunnelStateTransition> + Send + 'static,
 {
     let reactor = Core::new().chain_err(|| ErrorKind::ReactorError)?;
-    let state_machine =
-        TunnelStateMachine::new(allow_lan, log_dir, resource_dir, cache_dir, commands)?;
+    let state_machine = TunnelStateMachine::new(
+        allow_lan,
+        tunnel_parameters_generator,
+        log_dir,
+        resource_dir,
+        cache_dir,
+        commands,
+    )?;
 
     let future = state_machine.for_each(move |state_change_event| {
         state_change_listener
@@ -152,6 +161,7 @@ struct TunnelStateMachine {
 impl TunnelStateMachine {
     fn new(
         allow_lan: bool,
+        tunnel_parameters_generator: impl TunnelParametersGenerator,
         log_dir: Option<PathBuf>,
         resource_dir: PathBuf,
         cache_dir: impl AsRef<Path>,
@@ -162,6 +172,7 @@ impl TunnelStateMachine {
         let mut shared_values = SharedTunnelStateValues {
             security,
             allow_lan,
+            tunnel_parameters_generator: Box::new(tunnel_parameters_generator),
             log_dir,
             resource_dir,
         };
@@ -225,12 +236,21 @@ impl<T: TunnelState> From<EventConsequence<T>> for TunnelStateMachineAction {
     }
 }
 
+/// Trait for any type that can provide a stream of `TunnelParameters` to the `TunnelStateMachine`.
+pub trait TunnelParametersGenerator: Send + 'static {
+    /// Given the number of consecutive failed retry attempts, it should yield a `TunnelParameters`
+    /// to establish a tunnel with.
+    /// If this returns `None` then the state machine goes into the `Blocked` state.
+    fn generate(&mut self, retry_attempt: u32) -> Option<TunnelParameters>;
+}
 
 /// Values that are common to all tunnel states.
 struct SharedTunnelStateValues {
     security: NetworkSecurity,
     /// Should LAN access be allowed outside the tunnel.
     allow_lan: bool,
+    /// The generator of new `TunnelParameter`s
+    tunnel_parameters_generator: Box<dyn TunnelParametersGenerator>,
     /// Directory to store tunnel log file.
     log_dir: Option<PathBuf>,
     /// Resource directory path.