Implemented cross-clock synchronization for hardware timestamping.

statime-linux/Cargo.toml

@@ -19,5 +19,5 @@ rand = { version = "0.8.5", default-features = false, features = ["std", "std_rn
 serde = { version = "1.0.188", features = ["derive"] }
 
 
-clock-steering = { git = "https://github.com/pendulum-project/clock-steering.git", rev = "3ab6721" }
+clock-steering = { git = "https://github.com/pendulum-project/clock-steering.git", rev = "46974d3" }
 timestamped-socket = { git =  "https://github.com/pendulum-project/timestamped-socket.git", rev = "021bebb", features = ["serde"] }

statime-linux/src/clock/mod.rs

@@ -7,7 +7,7 @@ use statime::{Clock, Duration, Time, TimePropertiesDS};
 
 #[derive(Debug, Clone)]
 pub struct LinuxClock {
-    clock: clock_steering::unix::UnixClock,
+    pub clock: clock_steering::unix::UnixClock,
 }
 
 impl LinuxClock {
@@ -20,16 +20,6 @@ impl LinuxClock {
 
         Ok(Self { clock })
     }
-
-    pub fn timespec(&self) -> std::io::Result<libc::timespec> {
-        use clock_steering::Clock;
-
-        let now = self.clock.now()?;
-        Ok(libc::timespec {
-            tv_sec: now.seconds,
-            tv_nsec: now.nanos as _,
-        })
-    }
 }
 
 impl clock_steering::Clock for LinuxClock {

statime-linux/src/config/mod.rs

@@ -13,7 +13,6 @@ pub struct Config {
     pub domain: u8,
     pub priority1: u8,
     pub priority2: u8,
-    pub hardware_clock: Option<String>,
     #[serde(rename = "port")]
     pub ports: Vec<PortConfig>,
 }
@@ -22,6 +21,8 @@ pub struct Config {
 pub struct PortConfig {
     pub interface: InterfaceName,
     #[serde(default)]
+    pub hardware_clock: Option<String>,
+    #[serde(default)]
     pub network_mode: NetworkMode,
     pub announce_interval: i8,
     pub sync_interval: i8,

statime-linux/src/main.rs

@@ -1,4 +1,5 @@
 use std::{
+    collections::HashMap,
     future::Future,
     path::PathBuf,
     pin::{pin, Pin},
@@ -9,8 +10,9 @@ use clap::Parser;
 use fern::colors::Color;
 use rand::{rngs::StdRng, SeedableRng};
 use statime::{
-    BasicFilter, ClockIdentity, InBmca, InstanceConfig, Port, PortAction, PortActionIterator,
-    PtpInstance, SdoId, Time, TimePropertiesDS, TimeSource, TimestampContext, MAX_DATA_LEN,
+    BasicFilter, ClockIdentity, Filter, InBmca, InstanceConfig, Measurement, Port, PortAction,
+    PortActionIterator, PtpInstance, SdoId, Time, TimePropertiesDS, TimeSource, TimestampContext,
+    MAX_DATA_LEN,
 };
 use statime_linux::{
     clock::LinuxClock,
@@ -23,7 +25,7 @@ use statime_linux::{
 use timestamped_socket::{
     interface::InterfaceIterator,
     networkaddress::NetworkAddress,
-    socket::{Open, Socket},
+    socket::{InterfaceTimestampMode, Open, Socket},
 };
 use tokio::{
     sync::mpsc::{Receiver, Sender},
@@ -152,6 +154,102 @@ impl Future for Timer {
     }
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Default)]
+enum ClockSyncMode {
+    #[default]
+    FromSystem,
+    ToSystem,
+}
+
+fn start_clock_task(clock: LinuxClock) -> tokio::sync::watch::Sender<ClockSyncMode> {
+    let (mode_sender, mode_receiver) = tokio::sync::watch::channel(ClockSyncMode::FromSystem);
+
+    tokio::spawn(clock_task(clock, mode_receiver));
+
+    mode_sender
+}
+
+fn clock_timestamp_to_time(t: clock_steering::Timestamp) -> statime::Time {
+    Time::from_nanos((t.seconds as u64) * 1_000_000_000 + (t.nanos as u64))
+}
+
+async fn clock_task(
+    clock: LinuxClock,
+    mut mode_receiver: tokio::sync::watch::Receiver<ClockSyncMode>,
+) {
+    let mut measurement_timer = pin!(Timer::new());
+    let mut update_timer = pin!(Timer::new());
+
+    measurement_timer.as_mut().reset(std::time::Duration::ZERO);
+
+    let mut filter = BasicFilter::new(0.25);
+
+    let mut current_mode = *mode_receiver.borrow_and_update();
+    let mut filter_clock = match current_mode {
+        ClockSyncMode::FromSystem => clock.clone(),
+        ClockSyncMode::ToSystem => LinuxClock::CLOCK_REALTIME,
+    };
+    loop {
+        tokio::select! {
+            () = &mut measurement_timer => {
+                let (t1, t2, t3) = clock.clock.system_offset().expect("Unable to determine offset from system clock");
+                let t1 = clock_timestamp_to_time(t1);
+                let t2 = clock_timestamp_to_time(t2);
+                let t3 = clock_timestamp_to_time(t3);
+
+                log::debug!("Interclock measurement: {} {} {}", t1, t2, t3);
+
+                let delay = (t3-t1)/2;
+                let offset_a = t2 - t1;
+                let offset_b = t3 - t2;
+
+                let m = match current_mode {
+                    ClockSyncMode::FromSystem => Measurement {
+                        event_time: t2,
+                        offset: Some(offset_a - delay),
+                        delay: Some(delay),
+                        raw_sync_offset: Some(offset_a),
+                        raw_delay_offset: Some(-offset_b),
+                    },
+                    ClockSyncMode::ToSystem => Measurement {
+                        event_time: t1+delay,
+                        offset: Some(offset_b - delay),
+                        delay: Some(delay),
+                        raw_sync_offset: Some(offset_b),
+                        raw_delay_offset: Some(-offset_a),
+                    },
+                };
+
+                let update = filter.measurement(m, &mut filter_clock);
+                if let Some(timeout) = update.next_update {
+                    update_timer.as_mut().reset(timeout);
+                }
+
+                measurement_timer.as_mut().reset(std::time::Duration::from_millis(250));
+            }
+            () = &mut update_timer => {
+                let update = filter.update(&mut filter_clock);
+                if let Some(timeout) = update.next_update {
+                    update_timer.as_mut().reset(timeout);
+                }
+            }
+            _ = mode_receiver.changed() => {
+                let new_mode = *mode_receiver.borrow_and_update();
+                if new_mode != current_mode {
+                    let mut new_filter = BasicFilter::new(0.25);
+                    std::mem::swap(&mut filter, &mut new_filter);
+                    new_filter.demobilize(&mut filter_clock);
+                    match new_mode {
+                        ClockSyncMode::FromSystem => filter_clock = clock.clone(),
+                        ClockSyncMode::ToSystem => filter_clock = LinuxClock::CLOCK_REALTIME,
+                    }
+                    current_mode = new_mode;
+                }
+            }
+        }
+    }
+}
+
 #[tokio::main]
 async fn main() {
     actual_main().await;
@@ -170,12 +268,6 @@ async fn actual_main() {
     let log_level = log::LevelFilter::from_str(&config.loglevel).unwrap();
     setup_logger(log_level).expect("could not setup logging");
 
-    let local_clock = if let Some(hardware_clock) = config.hardware_clock {
-        LinuxClock::open(hardware_clock).expect("could not open hardware clock")
-    } else {
-        LinuxClock::CLOCK_REALTIME
-    };
-
     let clock_identity = ClockIdentity(get_clock_id().expect("could not get clock identity"));
 
     let instance_config = InstanceConfig {
@@ -202,11 +294,37 @@ async fn actual_main() {
     let mut main_task_senders = Vec::with_capacity(config.ports.len());
     let mut main_task_receivers = Vec::with_capacity(config.ports.len());
 
+    let mut internal_sync_senders = vec![];
+
+    let mut clock_name_map = HashMap::new();
+    let mut clock_port_map = Vec::with_capacity(config.ports.len());
+
     for port_config in config.ports {
         let interface = port_config.interface;
         let network_mode = port_config.network_mode;
+        let (port_clock, timestamping) = match &port_config.hardware_clock {
+            Some(path) => {
+                let clock = LinuxClock::open(path).expect("Unable to open clock");
+                if let Some(id) = clock_name_map.get(path) {
+                    clock_port_map.push(Some(*id));
+                } else {
+                    let id = internal_sync_senders.len();
+                    clock_port_map.push(Some(id));
+                    clock_name_map.insert(path.clone(), id);
+                    internal_sync_senders.push(start_clock_task(clock.clone()));
+                }
+                (clock, InterfaceTimestampMode::HardwarePTPAll)
+            }
+            None => {
+                clock_port_map.push(None);
+                (
+                    LinuxClock::CLOCK_REALTIME,
+                    InterfaceTimestampMode::SoftwareAll,
+                )
+            }
+        };
         let rng = StdRng::from_entropy();
-        let port = instance.add_port(port_config.into(), 0.25, local_clock.clone(), rng);
+        let port = instance.add_port(port_config.into(), 0.25, port_clock, rng);
 
         let (main_task_sender, port_task_receiver) = tokio::sync::mpsc::channel(1);
         let (port_task_sender, main_task_receiver) = tokio::sync::mpsc::channel(1);
@@ -221,8 +339,8 @@ async fn actual_main() {
 
         match network_mode {
             statime_linux::config::NetworkMode::Ipv4 => {
-                let event_socket =
-                    open_ipv4_event_socket(interface).expect("Could not open event socket");
+                let event_socket = open_ipv4_event_socket(interface, timestamping)
+                    .expect("Could not open event socket");
                 let general_socket =
                     open_ipv4_general_socket(interface).expect("Could not open general socket");
 
@@ -235,8 +353,8 @@ async fn actual_main() {
                 ));
             }
             statime_linux::config::NetworkMode::Ipv6 => {
-                let event_socket =
-                    open_ipv6_event_socket(interface).expect("Could not open event socket");
+                let event_socket = open_ipv6_event_socket(interface, timestamping)
+                    .expect("Could not open event socket");
                 let general_socket =
                     open_ipv6_general_socket(interface).expect("Could not open general socket");
 
@@ -256,6 +374,8 @@ async fn actual_main() {
         bmca_notify_sender,
         main_task_receivers,
         main_task_senders,
+        internal_sync_senders,
+        clock_port_map,
     )
     .await
 }
@@ -265,6 +385,8 @@ async fn run(
     bmca_notify_sender: tokio::sync::watch::Sender<bool>,
     mut main_task_receivers: Vec<Receiver<Port<InBmca<'static>, StdRng, LinuxClock, BasicFilter>>>,
     main_task_senders: Vec<Sender<Port<InBmca<'static>, StdRng, LinuxClock, BasicFilter>>>,
+    internal_sync_senders: Vec<tokio::sync::watch::Sender<ClockSyncMode>>,
+    clock_port_map: Vec<Option<usize>>,
 ) -> ! {
     // run bmca over all of the ports at the same time. The ports don't perform
     // their normal actions at this time: bmca is stop-the-world!
@@ -300,6 +422,21 @@ async fn run(
 
         instance.bmca(&mut mut_bmca_ports);
 
+        let mut clock_states: Vec<_> = internal_sync_senders
+            .iter()
+            .map(|_| ClockSyncMode::FromSystem)
+            .collect();
+        for (idx, port) in mut_bmca_ports.iter().enumerate() {
+            if port.is_steering() {
+                if let Some(id) = clock_port_map[idx] {
+                    clock_states[id] = ClockSyncMode::ToSystem;
+                }
+            }
+        }
+        for (mode, sender) in clock_states.into_iter().zip(internal_sync_senders.iter()) {
+            sender.send(mode).expect("Clock mode change failed");
+        }
+
         drop(mut_bmca_ports);
 
         for (port, sender) in bmca_ports.into_iter().zip(main_task_senders.iter()) {

statime-linux/src/socket.rs

@@ -42,8 +42,9 @@ impl PtpTargetAddress for SocketAddrV6 {
 
 pub fn open_ipv4_event_socket(
     interface: InterfaceName,
+    timestamping: InterfaceTimestampMode,
 ) -> std::io::Result<Socket<SocketAddrV4, Open>> {
-    let socket = open_interface_udp4(interface, EVENT_PORT, InterfaceTimestampMode::SoftwareAll)?;
+    let socket = open_interface_udp4(interface, EVENT_PORT, timestamping)?;
     socket.join_multicast(SocketAddrV4::new(IPV4_PRIMARY_MULTICAST, 0))?;
     socket.join_multicast(SocketAddrV4::new(IPV4_PDELAY_MULTICAST, 0))?;
     Ok(socket)
@@ -60,8 +61,9 @@ pub fn open_ipv4_general_socket(
 
 pub fn open_ipv6_event_socket(
     interface: InterfaceName,
+    timestamping: InterfaceTimestampMode,
 ) -> std::io::Result<Socket<SocketAddrV6, Open>> {
-    let socket = open_interface_udp6(interface, EVENT_PORT, InterfaceTimestampMode::SoftwareAll)?;
+    let socket = open_interface_udp6(interface, EVENT_PORT, timestamping)?;
     socket.join_multicast(SocketAddrV6::new(IPV6_PRIMARY_MULTICAST, 0, 0, 0))?;
     socket.join_multicast(SocketAddrV6::new(IPV6_PDELAY_MULTICAST, 0, 0, 0))?;
     Ok(socket)