Feat: add optional byte_counters configuration section

Adds a [byte_counters] section that is absent by default, so existing configuration files keep working unchanged. The section will gate cumulative per-circuit and per-node byte counter collection in lqosd.

src/lqos.example

@@ -70,6 +70,10 @@ netflow_enabled = false
 # netflow_version = 9
 do_not_track_subnets = [ "192.168.66.0/24" ]
 
+[byte_counters]
+# Optional cumulative byte counters for nodes and circuits, exposed by lqos_api.
+enabled = false
+
 [integration_common]
 circuit_name_as_address = false
 queue_refresh_interval_mins = 30

src/rust/lqos_config/src/etc/v15/byte_counters.rs

@@ -0,0 +1,38 @@
+//! Configuration for optional cumulative byte counters.
+//!
+//! When enabled, `lqosd` accumulates per-circuit byte totals from the
+//! one-second throughput tracker and exposes cumulative per-circuit and
+//! per-node counters on the local bus.
+
+use allocative::Allocative;
+use serde::{Deserialize, Serialize};
+
+/// Configuration for optional cumulative byte counters.
+#[derive(Clone, Default, Serialize, Deserialize, Debug, PartialEq, Allocative)]
+pub struct ByteCountersConfig {
+    /// Enables cumulative per-circuit and per-node byte counters.
+    ///
+    /// Defaults to `false` when the `[byte_counters]` section is absent so
+    /// existing configuration files keep their current behavior.
+    #[serde(default)]
+    pub enabled: bool,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ByteCountersConfig;
+
+    #[test]
+    fn absent_section_defaults_to_disabled() {
+        let config: ByteCountersConfig =
+            toml::from_str("").expect("empty byte_counters section should parse");
+        assert!(!config.enabled);
+    }
+
+    #[test]
+    fn section_parses_enabled_flag() {
+        let config: ByteCountersConfig =
+            toml::from_str("enabled = true").expect("enabled flag should parse");
+        assert!(config.enabled);
+    }
+}

src/rust/lqos_config/src/etc/v15/example.toml

@@ -102,6 +102,10 @@ collation_period_seconds = 10
 license_key = "(data)"
 uisp_reporting_interval_seconds = 300
 
+[byte_counters]
+# Optional cumulative byte counters for nodes and circuits, exposed by lqos_api.
+enabled = false
+
 [local_api]
 bearer_token = ""
 

src/rust/lqos_config/src/etc/v15/mod.rs

@@ -5,6 +5,7 @@ pub use top_config::Config;
 pub use top_config::RttThresholds;
 pub use top_config::{SslConfig, normalize_external_hostname};
 mod bridge;
+mod byte_counters;
 mod dynamic_circuits;
 mod flows;
 pub mod influxdb;

src/rust/lqos_config/src/etc/v15/top_config.rs

@@ -277,6 +277,13 @@ pub struct Config {
     /// Enable per-ASN TemporalHeatmap collection.
     #[serde(default = "default_true")]
     pub enable_asn_heatmaps: bool,
+
+    /// Optional cumulative byte counters for nodes and circuits.
+    ///
+    /// The section is optional so older configuration files keep working
+    /// unchanged; counters are disabled when it is absent.
+    #[serde(default)]
+    pub byte_counters: super::byte_counters::ByteCountersConfig,
 }
 
 impl Config {
@@ -482,6 +489,7 @@ impl Default for Config {
             enable_circuit_heatmaps: true,
             enable_site_heatmaps: true,
             enable_asn_heatmaps: true,
+            byte_counters: super::byte_counters::ByteCountersConfig::default(),
         }
     }
 }