Implement CRC forwarding options.

By default, only uplinks with CRC OK are forwarded but these options
make it possible to also (or only) forward uplinks with invalid CRC or
CRC missing.

Author: brocaar

Cargo.lock

@@ -9,7 +9,7 @@ edition = "2018"
 publish = false
 
 [dependencies]
-chirpstack_api = { version = "4.1.1", default-features = false }
+chirpstack_api = { version = "4.2.0-test.1", default-features = false }
 serde_json = "1.0"
 zmq = "0.10"
 clap = { version = "4.1", default-features = false, features = ["std", "help", "usage", "derive"] }

Cargo.toml

@@ -52,6 +52,15 @@ Configuration example:
     # the server address is a hostname.
     keepalive_max_failures=12
 
+	# Forward CRC OK.
+	forward_crc_ok=true
+
+	# Forward CRC invalid.
+	forward_crc_invalid=false
+
+	# Forward CRC missing.
+	forward_crc_missing=false
+
 
 # Concentratord configuration.
 [concentratord]

README.md

@@ -14,11 +14,27 @@ pub struct UdpForwarder {
     pub servers: Vec<Server>,
 }
 
-#[derive(Deserialize, Default)]
+#[derive(Deserialize)]
 pub struct Server {
     pub server: String,
     pub keepalive_interval_secs: u64,
     pub keepalive_max_failures: u32,
+    pub forward_crc_ok: bool,
+    pub forward_crc_invalid: bool,
+    pub forward_crc_missing: bool,
+}
+
+impl Default for Server {
+    fn default() -> Self {
+        Server {
+            server: "127.0.0.1:1700".into(),
+            keepalive_interval_secs: 10,
+            keepalive_max_failures: 12,
+            forward_crc_ok: true,
+            forward_crc_invalid: false,
+            forward_crc_missing: false,
+        }
+    }
 }
 
 #[derive(Deserialize, Default)]

src/config.rs

@@ -4,6 +4,7 @@ use std::sync::{Arc, Mutex};
 use std::{thread, time};
 
 use anyhow::Result;
+use chirpstack_api::gw;
 use prost::Message;
 use rand::Rng;
 
@@ -17,6 +18,9 @@ use super::structs;
 struct State {
     server: String,
     keepalive_interval: time::Duration,
+    forward_crc_ok: bool,
+    forward_crc_invalid: bool,
+    forward_crc_missing: bool,
     keepalive_max_failures: u32,
     gateway_id: Vec<u8>,
     socket: UdpSocket,
@@ -121,6 +125,9 @@ pub fn start(conf: &Server, event_url: String, command_url: String, gateway_id:
                 0 => time::Duration::from_secs(5),
                 _ => time::Duration::from_secs(conf.keepalive_interval_secs),
             },
+            forward_crc_ok: conf.forward_crc_ok,
+            forward_crc_invalid: conf.forward_crc_invalid,
+            forward_crc_missing: conf.forward_crc_missing,
             keepalive_max_failures: conf.keepalive_max_failures,
             gateway_id: gateway_id.clone(),
             push_data_token: Mutex::new(0),
@@ -374,6 +381,15 @@ fn events_stats(state: &Arc<State>, stats: chirpstack_api::gw::GatewayStats) {
 }
 
 fn events_up(state: &Arc<State>, up: chirpstack_api::gw::UplinkFrame) {
+    if let Some(rx_info) = &up.rx_info {
+        if !((rx_info.crc_status() == gw::CrcStatus::CrcOk && state.forward_crc_ok)
+            || (rx_info.crc_status() == gw::CrcStatus::BadCrc && state.forward_crc_invalid)
+            || (rx_info.crc_status() == gw::CrcStatus::NoCrc && state.forward_crc_missing))
+        {
+            return;
+        }
+    }
+
     let rxpk = match structs::RxPk::from_proto(&up) {
         Ok(v) => v,
         Err(err) => {

src/forwarder.rs

@@ -13,7 +13,9 @@ use chirpstack_api::gw;
 const PROTOCOL_VERSION: u8 = 0x02;
 
 pub enum Crc {
-    OK,
+    Ok,
+    Invalid,
+    Missing,
 }
 
 impl Serialize for Crc {
@@ -22,7 +24,9 @@ impl Serialize for Crc {
         S: Serializer,
     {
         match self {
-            Crc::OK => serializer.serialize_i32(1),
+            Crc::Ok => serializer.serialize_i32(1),
+            Crc::Invalid => serializer.serialize_i32(-1),
+            Crc::Missing => serializer.serialize_i32(0),
         }
     }
 }
@@ -249,7 +253,11 @@ impl RxPk {
             freq: tx_info.frequency as f64 / 1000000.0,
             chan: rx_info.channel,
             rfch: rx_info.rf_chain,
-            stat: Crc::OK,
+            stat: match rx_info.crc_status() {
+                gw::CrcStatus::CrcOk => Crc::Ok,
+                gw::CrcStatus::BadCrc => Crc::Invalid,
+                gw::CrcStatus::NoCrc => Crc::Missing,
+            },
             modu: match &tx_info.modulation {
                 Some(v) => match &v.parameters {
                     Some(v) => match &v {
@@ -704,6 +712,7 @@ mod tests {
             rf_chain: 1,
             antenna: 3,
             context: vec![1, 2, 3, 4],
+            crc_status: gw::CrcStatus::CrcOk.into(),
             ..Default::default()
         };
 
@@ -763,6 +772,7 @@ mod tests {
             board: 3,
             antenna: 4,
             context: vec![1, 2, 3, 4],
+            crc_status: gw::CrcStatus::CrcOk.into(),
             ..Default::default()
         };