Add Daemon and main event handling

2 files changed, 292 insertions, 18 deletions

diff --git a/mullvad_daemon/Cargo.toml b/mullvad_daemon/Cargo.toml
index d98c32b0b1..ce2ffafa98 100644
--- a/mullvad_daemon/Cargo.toml
+++ b/mullvad_daemon/Cargo.toml
@@ -15,9 +15,10 @@ jsonrpc-macros = { git = "https://github.com/faern/jsonrpc", branch = "ws-close-
 jsonrpc-pubsub = { git = "https://github.com/faern/jsonrpc", branch = "ws-close-handle" }
 jsonrpc-ws-server = { git = "https://github.com/faern/jsonrpc", branch = "ws-close-handle" }
 uuid = { version = "0.5", features = ["v4"] }
+lazy_static = "0.2"
 
-[dependencies.talpid_ipc]
-path = "../talpid_ipc"
+talpid_core = { path = "../talpid_core" }
+talpid_ipc = { path = "../talpid_ipc" }
 
 [dev-dependencies]
 assert_matches = "1.0"
diff --git a/mullvad_daemon/src/main.rs b/mullvad_daemon/src/main.rs
index 95033b1564..8ab172b464 100644
--- a/mullvad_daemon/src/main.rs
+++ b/mullvad_daemon/src/main.rs
@@ -8,37 +8,310 @@ extern crate serde;
 #[macro_use]
 extern crate serde_derive;
 
-extern crate talpid_ipc;
-
 extern crate jsonrpc_core;
 extern crate jsonrpc_pubsub;
 #[macro_use]
 extern crate jsonrpc_macros;
 extern crate jsonrpc_ws_server;
+extern crate uuid;
+#[macro_use]
+extern crate lazy_static;
+
+extern crate talpid_core;
+extern crate talpid_ipc;
+
+mod management_interface;
+mod states;
+
+use management_interface::{ManagementInterfaceServer, TunnelCommand};
+use states::{SecurityState, TargetState};
+
+use std::sync::{Arc, Mutex, mpsc};
+use std::thread;
+
+use talpid_core::net::RemoteAddr;
+use talpid_core::tunnel::{self, TunnelEvent, TunnelMonitor};
+
+error_chain!{
+    errors {
+        /// The client is in the wrong state for the requested operation. Optimally the code should
+        /// be written in such a way so such states can't exist.
+        InvalidState {
+            description("Client is in an invalid state for the requested operation")
+        }
+        TunnelError(msg: &'static str) {
+            description("Error in the tunnel monitor")
+            display("Tunnel monitor error: {}", msg)
+        }
+        ManagementInterfaceError(msg: &'static str) {
+            description("Error in the management interface")
+            display("Management interface error: {}", msg)
+        }
+    }
+}
+
+lazy_static! {
+    // Temporary store of hardcoded remotes.
+    static ref REMOTES: [RemoteAddr; 3] = [
+        RemoteAddr::new("se5.mullvad.net", 1300),
+        RemoteAddr::new("se6.mullvad.net", 1300),
+        RemoteAddr::new("se7.mullvad.net", 1300),
+    ];
+}
+
+pub enum DaemonEvent {
+    TunnelEvent(TunnelEvent),
+    TunnelExit(tunnel::Result<()>),
+    ManagementInterfaceEvent(TunnelCommand),
+    ManagementInterfaceExit(talpid_ipc::Result<()>),
+}
+
+impl From<TunnelEvent> for DaemonEvent {
+    fn from(tunnel_event: TunnelEvent) -> Self {
+        DaemonEvent::TunnelEvent(tunnel_event)
+    }
+}
+
+impl From<TunnelCommand> for DaemonEvent {
+    fn from(tunnel_command: TunnelCommand) -> Self {
+        DaemonEvent::ManagementInterfaceEvent(tunnel_command)
+    }
+}
+
+/// Represents the internal state of the actual tunnel.
+#[derive(Debug, Eq, PartialEq)]
+pub enum TunnelState {
+    /// No tunnel is running.
+    NotRunning,
+    /// The tunnel has been started, but it is not established/functional.
+    Down,
+    /// The tunnel is up and working.
+    Up,
+}
+
+impl TunnelState {
+    pub fn as_security_state(&self) -> SecurityState {
+        match *self {
+            TunnelState::Up => SecurityState::Secured,
+            _ => SecurityState::Unsecured,
+        }
+    }
+}
+
 
-pub mod ipc_api;
-pub mod mock_ipc;
+struct Daemon {
+    state: TunnelState,
+    last_broadcasted_state: SecurityState,
+    target_state: TargetState,
+    rx: mpsc::Receiver<DaemonEvent>,
+    tx: mpsc::Sender<DaemonEvent>,
+    tunnel_close_handle: Option<tunnel::CloseHandle>,
+    management_interface_subscribers: management_interface::EventBroadcaster,
+
+    // Just for testing. A cyclic iterator iterating over the hardcoded remotes,
+    // picking a new one for each retry.
+    remote_iter: std::iter::Cycle<std::iter::Cloned<std::slice::Iter<'static, RemoteAddr>>>,
+}
+
+impl Daemon {
+    pub fn new() -> Result<Self> {
+        let (tx, rx) = mpsc::channel();
+        let management_interface_subscribers = Self::start_management_interface(tx.clone())?;
+        Ok(
+            Daemon {
+                state: TunnelState::NotRunning,
+                last_broadcasted_state: SecurityState::Unsecured,
+                target_state: TargetState::Unsecured,
+                rx,
+                tx,
+                tunnel_close_handle: None,
+                remote_iter: REMOTES.iter().cloned().cycle(),
+                management_interface_subscribers,
+            },
+        )
+    }
+
+    // Starts the management interface and spawns a thread that will process it.
+    // Returns a handle that allows notifying all subscribers on events.
+    fn start_management_interface(event_tx: mpsc::Sender<DaemonEvent>)
+                                  -> Result<management_interface::EventBroadcaster> {
+        let server = Self::start_management_interface_server(event_tx.clone())?;
+        let event_broadcaster = server.event_broadcaster();
+        Self::spawn_management_interface_wait_thread(server, event_tx);
+        Ok(event_broadcaster)
+    }
+
+    fn start_management_interface_server(event_tx: mpsc::Sender<DaemonEvent>)
+                                         -> Result<ManagementInterfaceServer> {
+        let server =
+            ManagementInterfaceServer::start(event_tx.clone())
+                .chain_err(|| ErrorKind::ManagementInterfaceError("Failed to start server"),)?;
+        info!(
+            "Mullvad management interface listening on {}",
+            server.address()
+        );
+        Ok(server)
+    }
+
+    fn spawn_management_interface_wait_thread(server: ManagementInterfaceServer,
+                                              exit_tx: mpsc::Sender<DaemonEvent>) {
+        thread::spawn(
+            move || {
+                let result = server.wait();
+                debug!("Mullvad management interface shut down");
+                let _ = exit_tx.send(DaemonEvent::ManagementInterfaceExit(result));
+            },
+        );
+    }
+
+    /// Consume the `Daemon` and run the main event loop. Blocks until an error happens.
+    pub fn run(mut self) -> Result<()> {
+        while let Ok(event) = self.rx.recv() {
+            self.handle_event(event)?;
+        }
+        Ok(())
+    }
+
+    fn handle_event(&mut self, event: DaemonEvent) -> Result<()> {
+        use DaemonEvent::*;
+        match event {
+            TunnelEvent(event) => Ok(self.handle_tunnel_event(event)),
+            TunnelExit(result) => self.handle_tunnel_exit(result),
+            ManagementInterfaceEvent(event) => self.handle_management_interface_event(event),
+            ManagementInterfaceExit(result) => self.handle_management_interface_exit(result),
+        }
+    }
+
+    fn handle_tunnel_event(&mut self, tunnel_event: TunnelEvent) {
+        info!("Tunnel event: {:?}", tunnel_event);
+        let new_state = match tunnel_event {
+            TunnelEvent::Up => TunnelState::Up,
+            TunnelEvent::Down => TunnelState::Down,
+        };
+        self.set_state(new_state);
+    }
+
+    fn handle_tunnel_exit(&mut self, result: tunnel::Result<()>) -> Result<()> {
+        self.tunnel_close_handle = None;
+        if let Err(e) = result {
+            error!("Tunnel exited in an unexpected way:");
+            for e in e.iter() {
+                error!("Caused by {}", e);
+            }
+        }
+        self.set_state(TunnelState::NotRunning);
+        if self.target_state == TargetState::Secured {
+            self.start_tunnel()?;
+        }
+        Ok(())
+    }
+
+    fn handle_management_interface_event(&mut self, event: TunnelCommand) -> Result<()> {
+        match event {
+            TunnelCommand::SetTargetState(state) => self.set_target_state(state)?,
+            TunnelCommand::GetState(tx) => {
+                if let Err(_) = tx.send(self.last_broadcasted_state) {
+                    warn!("Unable to send current state to management interface client",);
+                }
+            }
+        }
+        Ok(())
+    }
+
+    fn handle_management_interface_exit(&self, result: talpid_ipc::Result<()>) -> Result<()> {
+        let error = ErrorKind::ManagementInterfaceError("Server exited unexpectedly");
+        match result {
+            Ok(()) => Err(error.into()),
+            e => e.chain_err(|| error),
+        }
+    }
+
+    /// Set the target state of the client. If it changed trigger the operations needed to progress
+    /// towards that state.
+    fn set_target_state(&mut self, new_state: TargetState) -> Result<()> {
+        if new_state != self.target_state {
+            self.target_state = new_state;
+            match self.target_state {
+                TargetState::Secured => {
+                    if self.state == TunnelState::NotRunning {
+                        debug!("Triggering tunnel start from management interface event");
+                        self.start_tunnel()?;
+                    }
+                }
+                TargetState::Unsecured => {
+                    if let Some(ref close_handle) = self.tunnel_close_handle {
+                        debug!("Triggering tunnel stop from management interface event");
+                        close_handle
+                            .close()
+                            .chain_err(|| ErrorKind::TunnelError("Unable to kill tunnel"))?;
+                    }
+                }
+            }
+        }
+        Ok(())
+    }
+
+    /// Update the state of the client. If it changed, notify the subscribers.
+    fn set_state(&mut self, new_state: TunnelState) {
+        if new_state != self.state {
+            self.state = new_state;
+            let new_security_state = self.state.as_security_state();
+            if self.last_broadcasted_state != new_security_state {
+                self.last_broadcasted_state = new_security_state;
+                self.management_interface_subscribers.notify_new_state(new_security_state);
+            }
+        }
+    }
+
+    fn start_tunnel(&mut self) -> Result<()> {
+        ensure!(
+            self.state == TunnelState::NotRunning,
+            ErrorKind::InvalidState
+        );
+        let remote = self.remote_iter.next().unwrap();
+        let tunnel_monitor = self.spawn_tunnel_monitor(remote)?;
+        self.tunnel_close_handle = Some(tunnel_monitor.close_handle());
+        self.spawn_tunnel_monitor_wait_thread(tunnel_monitor);
+
+        self.set_state(TunnelState::Down);
+        Ok(())
+    }
+
+    fn spawn_tunnel_monitor(&self, remote: RemoteAddr) -> Result<TunnelMonitor> {
+        // Must wrap the channel in a Mutex because TunnelMonitor forces the closure to be Sync
+        let event_tx = Arc::new(Mutex::new(self.tx.clone()));
+        let on_tunnel_event = move |event| {
+            let _ = event_tx.lock().unwrap().send(DaemonEvent::TunnelEvent(event));
+        };
+        TunnelMonitor::new(remote, on_tunnel_event)
+            .chain_err(|| ErrorKind::TunnelError("Unable to start tunnel monitor"))
+    }
+
+    fn spawn_tunnel_monitor_wait_thread(&self, tunnel_monitor: TunnelMonitor) {
+        let error_tx = self.tx.clone();
+        thread::spawn(
+            move || {
+                let result = tunnel_monitor.wait();
+                let _ = error_tx.send(DaemonEvent::TunnelExit(result));
+                trace!("Tunnel monitor thread exit");
+            },
+        );
+    }
+}
 
-error_chain!{}
 
 quick_main!(run);
 
 fn run() -> Result<()> {
     init_logger()?;
 
-    let server = start_ipc()?;
-    info!("Mullvad daemon listening on {}", server.address());
-    main_loop(server)
+    let daemon = Daemon::new().chain_err(|| "Unable to initialize daemon")?;
+    daemon.run()?;
+
+    debug!("Mullvad daemon is quitting");
+    Ok(())
 }
 
 fn init_logger() -> Result<()> {
     env_logger::init().chain_err(|| "Failed to bootstrap logging system")
 }
-
-fn start_ipc() -> Result<mock_ipc::IpcServer> {
-    mock_ipc::IpcServer::start().chain_err(|| "Failed to start IPC server")
-}
-
-fn main_loop(server: mock_ipc::IpcServer) -> Result<()> {
-    server.wait().chain_err(|| "Error while waiting for server to process")
-}