Separate `rpc_info` module in two

Rename `rpc_info` into `rpc_address_file` and move RPC client code used
for checking for other instances to a separate `rpc_uniqueness_check`
module.

3 files changed, 48 insertions, 40 deletions

diff --git a/mullvad-daemon/src/main.rs b/mullvad-daemon/src/main.rs
index f07138b8ff..2f3c25598b 100644
--- a/mullvad-daemon/src/main.rs
+++ b/mullvad-daemon/src/main.rs
@@ -47,7 +47,8 @@ mod geoip;
 mod logging;
 mod management_interface;
 mod relays;
-mod rpc_info;
+mod rpc_uniqueness_check;
+mod rpc_address_file;
 mod settings;
 mod shutdown;
 
@@ -288,7 +289,7 @@ impl Daemon {
         require_auth: bool,
     ) -> Result<ManagementInterfaceServer> {
         ensure!(
-            !rpc_info::is_another_instance_running(),
+            !rpc_uniqueness_check::is_another_instance_running(),
             ErrorKind::DaemonIsAlreadyRunning
         );
 
@@ -307,7 +308,7 @@ impl Daemon {
         );
 
         let written_shared_secret = shared_secret.unwrap_or(String::from(""));
-        rpc_info::write(server.address(), &written_shared_secret).chain_err(|| {
+        rpc_address_file::write(server.address(), &written_shared_secret).chain_err(|| {
             ErrorKind::ManagementInterfaceError("Failed to write RPC connection info to file")
         })?;
         Ok(server)
@@ -778,7 +779,9 @@ impl DaemonShutdownHandle {
 
 impl Drop for Daemon {
     fn drop(self: &mut Daemon) {
-        if let Err(e) = rpc_info::remove().chain_err(|| "Unable to clean up rpc address file") {
+        if let Err(e) =
+            rpc_address_file::remove().chain_err(|| "Unable to clean up rpc address file")
+        {
             error!("{}", e.display_chain());
         }
     }
diff --git a/mullvad-daemon/src/rpc_info.rs b/mullvad-daemon/src/rpc_address_file.rs
index 43a573d8bb..788ddd6df7 100644
--- a/mullvad-daemon/src/rpc_info.rs
+++ b/mullvad-daemon/src/rpc_address_file.rs
@@ -1,10 +1,6 @@
 use std::fs::{self, File, OpenOptions};
 use std::io::{self, BufRead, BufReader, Write};
 use std::path::{Path, PathBuf};
-use std::result;
-
-use mullvad_types::states::DaemonState;
-use talpid_ipc::WsIpcClient;
 
 error_chain! {
     errors {
@@ -32,17 +28,13 @@ lazy_static! {
 }
 
 
-/// Checks if there is another instance of the daemon running.
-///
-/// Tries to connect to another daemon and perform a simple RPC call. If it fails, assumes the
-/// other daemon has stopped.
-pub fn is_another_instance_running() -> bool {
-    if let Err(message) = call_other_daemon() {
-        info!("{}; assuming it has stopped", message);
-        false
-    } else {
-        true
-    }
+/// Reads the address of the RPC connection from the RPC info file.
+pub fn read() -> io::Result<String> {
+    let file = File::open(RPC_ADDRESS_FILE_PATH.as_path())?;
+    let mut reader = BufReader::new(file);
+    let mut address = String::new();
+    reader.read_line(&mut address)?;
+    Ok(address)
 }
 
 /// Writes down the RPC connection info to some API to a file.
@@ -75,27 +67,6 @@ pub fn remove() -> Result<()> {
     }
 }
 
-fn call_other_daemon() -> result::Result<(), String> {
-    let method = "get_state";
-    let args: [u8; 0] = [];
-    let address = read_rpc_file().map_err(|_| "Failed to read RPC address file of other daemon")?;
-    // TODO: Authenticate with server
-    let mut rpc_client =
-        WsIpcClient::new(address).map_err(|_| "Failed to connect to other daemon")?;
-    let _: DaemonState = rpc_client
-        .call(method, &args)
-        .map_err(|_| "Failed to execute RPC call to other daemon")?;
-    Ok(())
-}
-
-fn read_rpc_file() -> io::Result<String> {
-    let file = File::open(RPC_ADDRESS_FILE_PATH.as_path())?;
-    let mut reader = BufReader::new(file);
-    let mut address = String::new();
-    reader.read_line(&mut address)?;
-    Ok(address)
-}
-
 fn open_file(path: &Path) -> io::Result<File> {
     let file = OpenOptions::new()
         .write(true)
diff --git a/mullvad-daemon/src/rpc_uniqueness_check.rs b/mullvad-daemon/src/rpc_uniqueness_check.rs
new file mode 100644
index 0000000000..f06daa8ba3
--- /dev/null
+++ b/mullvad-daemon/src/rpc_uniqueness_check.rs
@@ -0,0 +1,34 @@
+use std::result;
+
+use mullvad_types::states::DaemonState;
+use talpid_ipc::WsIpcClient;
+
+use rpc_address_file;
+
+
+/// Checks if there is another instance of the daemon running.
+///
+/// Tries to connect to another daemon and perform a simple RPC call. If it fails, assumes the
+/// other daemon has stopped.
+pub fn is_another_instance_running() -> bool {
+    if let Err(message) = call_other_daemon() {
+        info!("{}; assuming it has stopped", message);
+        false
+    } else {
+        true
+    }
+}
+
+fn call_other_daemon() -> result::Result<(), String> {
+    let method = "get_state";
+    let args: [u8; 0] = [];
+    let address =
+        rpc_address_file::read().map_err(|_| "Failed to read RPC address file of other daemon")?;
+    // TODO: Authenticate with server
+    let mut rpc_client =
+        WsIpcClient::new(address).map_err(|_| "Failed to connect to other daemon")?;
+    let _: DaemonState = rpc_client
+        .call(method, &args)
+        .map_err(|_| "Failed to execute RPC call to other daemon")?;
+    Ok(())
+}