Add proxy config generator to daemon

1 files changed, 54 insertions, 0 deletions

diff --git a/mullvad-daemon/src/api.rs b/mullvad-daemon/src/api.rs
new file mode 100644
index 0000000000..2ed689b418
--- /dev/null
+++ b/mullvad-daemon/src/api.rs
@@ -0,0 +1,54 @@
+use crate::DaemonEventSender;
+use futures::{channel::oneshot, stream, Stream, StreamExt};
+use mullvad_rpc::proxy::ApiConnectionMode;
+use talpid_core::mpsc::Sender;
+use talpid_types::ErrorExt;
+
+pub(crate) struct ApiConnectionModeRequest {
+    pub response_tx: oneshot::Sender<ApiConnectionMode>,
+    pub retry_attempt: u32,
+}
+
+/// Returns a stream that returns the next API bridge to try.
+/// `initial_config` refers to the first config returned by the stream. The daemon is not notified
+/// of this.
+pub(crate) fn create_api_config_provider(
+    daemon_sender: DaemonEventSender<ApiConnectionModeRequest>,
+    initial_config: ApiConnectionMode,
+) -> impl Stream<Item = ApiConnectionMode> + Unpin {
+    struct Context {
+        attempt: u32,
+        daemon_sender: DaemonEventSender<ApiConnectionModeRequest>,
+    }
+
+    let ctx = Context {
+        attempt: 1,
+        daemon_sender,
+    };
+
+    Box::pin(
+        stream::once(async move { initial_config }).chain(stream::unfold(
+            ctx,
+            |mut ctx| async move {
+                ctx.attempt = ctx.attempt.wrapping_add(1);
+                let (response_tx, response_rx) = oneshot::channel();
+
+                let _ = ctx.daemon_sender.send(ApiConnectionModeRequest {
+                    response_tx,
+                    retry_attempt: ctx.attempt,
+                });
+
+                let new_config = response_rx.await.unwrap_or_else(|error| {
+                    log::error!(
+                        "{}",
+                        error.display_chain_with_msg("Failed to receive API proxy config")
+                    );
+                    // Fall back on unbridged connection
+                    ApiConnectionMode::Direct
+                });
+
+                Some((new_config, ctx))
+            },
+        )),
+    )
+}