Check for another daemon outside of `Daemon`

2 files changed, 6 insertions, 2 deletions

diff --git a/mullvad-daemon/src/lib.rs b/mullvad-daemon/src/lib.rs
index 5fc605d990..2eb97c16f5 100644
--- a/mullvad-daemon/src/lib.rs
+++ b/mullvad-daemon/src/lib.rs
@@ -9,7 +9,7 @@ mod geoip;
 pub mod logging;
 mod management_interface;
 mod relays;
-mod rpc_uniqueness_check;
+pub mod rpc_uniqueness_check;
 mod settings;
 pub mod version;
 mod version_check;
diff --git a/mullvad-daemon/src/main.rs b/mullvad-daemon/src/main.rs
index 9bbfdf4d27..2f567b27d1 100644
--- a/mullvad-daemon/src/main.rs
+++ b/mullvad-daemon/src/main.rs
@@ -1,7 +1,7 @@
 #![deny(rust_2018_idioms)]
 
 use log::{debug, error, info, warn};
-use mullvad_daemon::{logging, version, Daemon, DaemonCommandChannel};
+use mullvad_daemon::{logging, rpc_uniqueness_check, version, Daemon, DaemonCommandChannel};
 use std::{path::PathBuf, thread, time::Duration};
 use talpid_types::ErrorExt;
 
@@ -84,6 +84,10 @@ fn run_platform(_config: &cli::Config, log_dir: Option<PathBuf>) -> Result<(), S
 }
 
 fn run_standalone(log_dir: Option<PathBuf>) -> Result<(), String> {
+    if rpc_uniqueness_check::is_another_instance_running() {
+        return Err("Another instance of the daemon is already running".to_owned());
+    }
+
     if !running_as_admin() {
         warn!("Running daemon as a non-administrator user, clients might refuse to connect");
     }