Implement stats message.

This message is used to indicate that a Relay Gateway is still alive and
to collect the path between Relay Gateway and Border Gateway (in case
there are multiple Relay Gateways in-between).

Cargo.toml

@@ -16,14 +16,15 @@
     "usage",
     "derive",
   ] }
-  chirpstack_api = { version = "4.8", default-features = false }
+  chirpstack_api = { version = "4.9.0-test.1", default-features = false }
   lrwn_filters = { version = "4.7", features = ["serde"] }
   log = "0.4"
   simple_logger = "5.0"
   syslog = "6.1"
   toml = "0.8"
   handlebars = "5.1"
   anyhow = "1.0"
+  humantime-serde = "1.1"
   serde = { version = "1.0", features = ["derive"] }
   tokio = { version = "1.37", features = [
     "macros",

src/cache.rs

@@ -1,3 +1,4 @@
+use std::time::UNIX_EPOCH;
 use std::{collections::VecDeque, usize};
 
 use crate::packets;
@@ -37,6 +38,7 @@ impl<T> Cache<T> {
 pub struct PayloadCache {
     p_type: packets::PayloadType,
     uplink_id: u16,
+    timestamp: u32,
     relay_id: [u8; 4],
 }
 
@@ -49,11 +51,23 @@ impl From<&packets::MeshPacket> for PayloadCache {
                 p_type,
                 uplink_id: v.metadata.uplink_id,
                 relay_id: v.relay_id,
+                timestamp: 0,
             },
             packets::Payload::Downlink(v) => PayloadCache {
                 p_type,
                 uplink_id: v.metadata.uplink_id,
                 relay_id: v.relay_id,
+                timestamp: 0,
+            },
+            packets::Payload::Stats(v) => PayloadCache {
+                p_type,
+                uplink_id: 0,
+                relay_id: v.relay_id,
+                timestamp: v
+                    .timestamp
+                    .duration_since(UNIX_EPOCH)
+                    .unwrap_or_default()
+                    .as_secs() as u32,
             },
         }
     }

src/cmd/configfile.rs

@@ -38,6 +38,12 @@ pub fn run() {
   # uplinks and forward these to the proxy API, rather than relaying these.
   border_gateway={{ mesh.border_gateway }}
 
+  # Stats interval (Relay Gateway only).
+  #
+  # This defines the interval in which a Relay Gateway (border_gateway=false)
+  # will emit stats messages.
+  stats_interval="{{ mesh.stats_interval }}"
+
   # Max hop count.
   #
   # This defines the maximum number of hops a relayed payload will pass.

src/cmd/root.rs

@@ -4,11 +4,12 @@ use signal_hook::consts::signal::*;
 use signal_hook_tokio::Signals;
 
 use crate::config::Configuration;
-use crate::{backend, proxy};
+use crate::{backend, proxy, stats};
 
 pub async fn run(conf: &Configuration) -> Result<()> {
     proxy::setup(conf).await?;
     backend::setup(conf).await?;
+    stats::setup(conf).await?;
 
     let mut signals = Signals::new([SIGINT, SIGTERM])?;
     let handle = signals.handle();

src/config.rs

@@ -1,5 +1,6 @@
 use std::fs;
 use std::sync::{Arc, Mutex};
+use std::time::Duration;
 
 use anyhow::Result;
 use once_cell::sync::OnceCell;
@@ -51,6 +52,8 @@ impl Default for Logging {
 #[serde(default)]
 pub struct Mesh {
     pub signing_key: Aes128Key,
+    #[serde(with = "humantime_serde")]
+    pub stats_interval: Duration,
     pub frequencies: Vec<u32>,
     pub data_rate: DataRate,
     pub tx_power: i32,
@@ -65,6 +68,7 @@ impl Default for Mesh {
     fn default() -> Self {
         Mesh {
             signing_key: Aes128Key::null(),
+            stats_interval: Duration::from_secs(300),
             frequencies: vec![868100000, 868300000, 868500000],
             data_rate: DataRate {
                 modulation: Modulation::LORA,

src/lib.rs

@@ -11,3 +11,4 @@ pub mod logging;
 pub mod mesh;
 pub mod packets;
 pub mod proxy;
+pub mod stats;

src/mesh.rs

@@ -54,9 +54,10 @@ pub async fn handle_mesh(border_gateway: bool, pl: gw::UplinkFrame) -> Result<()
     };
 
     match border_gateway {
-        // In this case we only care about proxy-ing relayed uplinks
+        // Proxy relayed uplink
         true => match packet.mhdr.payload_type {
             PayloadType::Uplink => proxy_uplink_mesh_packet(&pl, packet).await,
+            PayloadType::Stats => proxy_stats_mesh_packet(&pl, packet).await,
             _ => Ok(()),
         },
         false => relay_mesh_packet(&pl, packet).await,
@@ -151,11 +152,35 @@ async fn proxy_uplink_mesh_packet(pl: &gw::UplinkFrame, packet: MeshPacket) -> R
     proxy::send_uplink(&pl).await
 }
 
+async fn proxy_stats_mesh_packet(pl: &gw::UplinkFrame, packet: MeshPacket) -> Result<()> {
+    let mesh_pl = match &packet.payload {
+        Payload::Stats(v) => v,
+        _ => {
+            return Err(anyhow!("Expected Stats payload"));
+        }
+    };
+
+    info!(
+        "Unwrapping relay stats packet, uplink_id: {}, mesh_packet: {}",
+        pl.rx_info.as_ref().map(|v| v.uplink_id).unwrap_or_default(),
+        packet
+    );
+
+    let stats_pl = gw::MeshStats {
+        gateway_id: hex::encode(backend::get_gateway_id().await?),
+        relay_id: hex::encode(mesh_pl.relay_id),
+        relay_path: mesh_pl.relay_path.iter().map(hex::encode).collect(),
+        time: Some(mesh_pl.timestamp.into()),
+    };
+
+    proxy::send_mesh_stats(&stats_pl).await
+}
+
 async fn relay_mesh_packet(_: &gw::UplinkFrame, mut packet: MeshPacket) -> Result<()> {
     let conf = config::get();
     let relay_id = backend::get_relay_id().await?;
 
-    match &packet.payload {
+    match &mut packet.payload {
         packets::Payload::Uplink(pl) => {
             if pl.relay_id == relay_id {
                 trace!("Dropping packet as this relay was the sender");
@@ -203,13 +228,27 @@ async fn relay_mesh_packet(_: &gw::UplinkFrame, mut packet: MeshPacket) -> Resul
                 return helpers::tx_ack_to_err(&backend::send_downlink(&pl).await?);
             }
         }
+        packets::Payload::Stats(pl) => {
+            if pl.relay_id == relay_id {
+                trace!("Dropping packet as this relay was the sender");
+
+                // Drop the packet, as we are the sender.
+                return Ok(());
+            }
+
+            // Add our Relay ID to the path.
+            pl.relay_path.push(relay_id);
+        }
     }
 
     // In any other case, we increment the hop_count and re-transmit the mesh encapsulated
     // packet.
 
     // Increment hop count.
     packet.mhdr.hop_count += 1;
+
+    // We need to re-set the MIC as we have changed the payload by incrementing
+    // the hop count (and in casee of stats, we have modified the Relay path).
     packet.set_mic(conf.mesh.signing_key)?;
 
     if packet.mhdr.hop_count > conf.mesh.max_hop_count {
@@ -429,7 +468,7 @@ async fn relay_downlink_lora_packet(pl: &gw::DownlinkFrame) -> Result<gw::Downli
     })
 }
 
-fn get_mesh_frequency(conf: &Configuration) -> Result<u32> {
+pub fn get_mesh_frequency(conf: &Configuration) -> Result<u32> {
     if conf.mesh.frequencies.is_empty() {
         return Err(anyhow!("No mesh frequencies are configured"));
     }