Improve handling of permissions around clock control.

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [unreleased]
 
+### Added
+- Server can now be run without permission to change the system clock so long
+  as no time sources are configured.
+
 ### Changed
 - The sources section can be left out of the configuration now.
 - When no sources are configured, the daemon will merely state it won't change 

ntp-proto/src/algorithm/kalman/mod.rs

@@ -311,19 +311,13 @@ impl<C: NtpClock, PeerID: Hash + Eq + Copy + Debug> TimeSyncController<C, PeerID
         synchronization_config: SynchronizationConfig,
         peer_defaults_config: SourceDefaultsConfig,
         algo_config: Self::AlgorithmConfig,
-    ) -> Self {
+    ) -> Result<Self, C::Error> {
         // Setup clock
-        clock
-            .disable_ntp_algorithm()
-            .expect("Unable to change system time");
-        clock
-            .status_update(NtpLeapIndicator::Unknown)
-            .expect("Unable to update clock");
-        clock
-            .set_frequency(0.0)
-            .expect("Unable to set system clock frequency");
-
-        KalmanClockController {
+        clock.disable_ntp_algorithm()?;
+        clock.status_update(NtpLeapIndicator::Unknown)?;
+        clock.set_frequency(0.0)?;
+
+        Ok(KalmanClockController {
             peers: HashMap::new(),
             clock,
             synchronization_config,
@@ -333,7 +327,7 @@ impl<C: NtpClock, PeerID: Hash + Eq + Copy + Debug> TimeSyncController<C, PeerID
             desired_freq: 0.0,
             timedata: TimeSnapshot::default(),
             in_startup: true,
-        }
+        })
     }
 
     fn update_config(
@@ -466,7 +460,8 @@ mod tests {
             synchronization_config,
             peer_defaults_config,
             algo_config,
-        );
+        )
+        .unwrap();
         let mut cur_instant = NtpInstant::now();
 
         // ignore startup steer of frequency.
@@ -531,7 +526,8 @@ mod tests {
             synchronization_config,
             peer_defaults_config,
             algo_config,
-        );
+        )
+        .unwrap();
 
         algo.in_startup = false;
         algo.steer_offset(1000.0, 0.0);
@@ -560,7 +556,8 @@ mod tests {
             synchronization_config,
             peer_defaults_config,
             algo_config,
-        );
+        )
+        .unwrap();
 
         algo.in_startup = false;
         algo.steer_offset(1000.0, 0.0);
@@ -584,7 +581,8 @@ mod tests {
             synchronization_config,
             peer_defaults_config,
             algo_config,
-        );
+        )
+        .unwrap();
         let mut cur_instant = NtpInstant::now();
 
         // ignore startup steer of frequency.
@@ -640,7 +638,8 @@ mod tests {
             synchronization_config,
             peer_defaults_config,
             algo_config,
-        );
+        )
+        .unwrap();
         let mut cur_instant = NtpInstant::now();
 
         // ignore startup steer of frequency.

ntp-proto/src/algorithm/mod.rs

@@ -45,7 +45,7 @@ impl<PeerID: Eq + Copy + Debug> Default for StateUpdate<PeerID> {
     }
 }
 
-pub trait TimeSyncController<C: NtpClock, PeerID: Hash + Eq + Copy + Debug> {
+pub trait TimeSyncController<C: NtpClock, PeerID: Hash + Eq + Copy + Debug>: Sized {
     type AlgorithmConfig: Debug + Copy + DeserializeOwned;
 
     /// Create a new clock controller controling the given clock
@@ -54,7 +54,7 @@ pub trait TimeSyncController<C: NtpClock, PeerID: Hash + Eq + Copy + Debug> {
         synchronization_config: SynchronizationConfig,
         peer_defaults_config: SourceDefaultsConfig,
         algorithm_config: Self::AlgorithmConfig,
-    ) -> Self;
+    ) -> Result<Self, C::Error>;
     /// Update used system config
     fn update_config(
         &mut self,

ntp-proto/src/clock.rs

@@ -7,7 +7,7 @@ use crate::{
 /// This needs to be a trait as a single system can have multiple clocks
 /// which need different implementation for steering and/or now.
 pub trait NtpClock: Clone + Send + 'static {
-    type Error: std::error::Error;
+    type Error: std::error::Error + Send + Sync;
 
     // Get current time
     fn now(&self) -> Result<NtpTimestamp, Self::Error>;

ntpd/bin/ntp-daemon.rs

@@ -1,6 +1,9 @@
 #![forbid(unsafe_code)]
 
+use std::process;
+
 #[tokio::main]
-async fn main() -> Result<(), Box<dyn std::error::Error>> {
-    ntpd::daemon_main().await
+async fn main() {
+    let result = ntpd::daemon_main().await;
+    process::exit(if result.is_ok() { 0 } else { 1 });
 }