Add secondary_net_ids config option.

This can be useful when using multiple NetIDs (e.g. after a merge of two
networks, or when using multiple NetIDs). Previously, any other NetID
than the configured net_id would be considered roaming.

chirpstack/src/backend/roaming.rs

@@ -149,8 +149,8 @@ pub fn get_passive_roaming_kek_label(net_id: NetID) -> Result<String> {
 }
 
 pub fn is_enabled() -> bool {
-    let clients_r = CLIENTS.read().unwrap();
-    !clients_r.is_empty()
+    let conf = config::get();
+    conf.roaming.default.enabled || !conf.roaming.servers.is_empty()
 }
 
 pub fn is_roaming_dev_addr(dev_addr: DevAddr) -> bool {
@@ -164,7 +164,7 @@ pub fn is_roaming_dev_addr(dev_addr: DevAddr) -> bool {
         // Configured NetID.
         conf.network.net_id,
         // Test NetIDs. For roaming it is expected that non-testing NetIDs will be used. These are
-        // included as non-roaming NetIDs as one might start with a test-NetID and then aquires an
+        // included as non-roaming NetIDs as one might start with a test-NetID and then acquires an
         // official NetID to setup roaming. Not including these would mean that all devices must
         // re-join to obtain a new DevAddr.
         NetID::from_be_bytes([0, 0, 0]),
@@ -175,6 +175,12 @@ pub fn is_roaming_dev_addr(dev_addr: DevAddr) -> bool {
         }
     }
 
+    for net_id in &conf.network.secondary_net_ids {
+        if dev_addr.is_net_id(*net_id) {
+            return false;
+        }
+    }
+
     true
 }
 
@@ -320,3 +326,61 @@ pub fn reset() {
     let mut clients_w = CLIENTS.write().unwrap();
     *clients_w = HashMap::new();
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_is_roaming_dev_addr() {
+        struct Test {
+            dev_addr: DevAddr,
+            net_id: NetID,
+            secondary_net_ids: Vec<NetID>,
+            is_roaming: bool,
+        }
+
+        let tests = vec![
+            Test {
+                dev_addr: {
+                    let mut dev_addr = DevAddr::from_be_bytes([1, 2, 3, 4]);
+                    dev_addr.set_dev_addr_prefix(NetID::from_be_bytes([1, 2, 3]).dev_addr_prefix());
+                    dev_addr
+                },
+                net_id: NetID::from_be_bytes([1, 2, 3]),
+                secondary_net_ids: vec![],
+                is_roaming: false,
+            },
+            Test {
+                dev_addr: {
+                    let mut dev_addr = DevAddr::from_be_bytes([1, 2, 3, 4]);
+                    dev_addr.set_dev_addr_prefix(NetID::from_be_bytes([1, 2, 3]).dev_addr_prefix());
+                    dev_addr
+                },
+                net_id: NetID::from_be_bytes([3, 2, 1]),
+                secondary_net_ids: vec![],
+                is_roaming: true,
+            },
+            Test {
+                dev_addr: {
+                    let mut dev_addr = DevAddr::from_be_bytes([1, 2, 3, 4]);
+                    dev_addr.set_dev_addr_prefix(NetID::from_be_bytes([1, 2, 3]).dev_addr_prefix());
+                    dev_addr
+                },
+                net_id: NetID::from_be_bytes([3, 2, 1]),
+                secondary_net_ids: vec![NetID::from_be_bytes([1, 2, 3])],
+                is_roaming: false,
+            },
+        ];
+
+        for tst in &tests {
+            let mut conf = config::Configuration::default();
+            conf.network.net_id = tst.net_id;
+            conf.network.secondary_net_ids = tst.secondary_net_ids.clone();
+            conf.roaming.default.enabled = true;
+            config::set(conf);
+
+            assert_eq!(tst.is_roaming, is_roaming_dev_addr(tst.dev_addr));
+        }
+    }
+}

chirpstack/src/cmd/configfile.rs

@@ -142,13 +142,25 @@ pub fn run() {
   # Network identifier (NetID, 3 bytes) encoded as HEX (e.g. 010203).
   net_id="{{ network.net_id }}"
 
+  # Secondary NetIDs.
+  #
+  # Additional NetIDs. At this moment, the additional NetIDs are only used to
+  # validate if an uplink belongs to the ChirpStack instance or if it is a
+  # roaming device (if roaming is enabled).
+  # If you would like to assign DevAddrs from multiple NetIDs, you must specify
+  # these in the dev_addr_prefixes configuration.
+  secondary_net_ids=[
+    {{#each network.secondary_net_ids}}
+    "{{this}}",
+    {{/each}}
+  ]
+
   # DevAddr prefix(es).
   #
-  # This makes it possible to configure one or multiple sub-ranges within
-  # the configured NetID. If left blank, then the complete DevAddr space
-  # provided by the configured NetID will be used.
-  # If multiple prefixes are configured, a random prefix will be chosen when
-  # generating a DevAddr.
+  # This makes it possible to configure one or multiple DevAddr (sub)ranges
+  # If left blank, then the complete DevAddr space provided by the configured
+  # net_id value will be used. If multiple prefixes are configured, a random
+  # prefix will be chosen when generating a DevAddr.
   #
   # Example configuration:
   # dev_addr_prefixes=["0000ff00/24"]

chirpstack/src/config.rs

@@ -130,6 +130,7 @@ impl Default for Gateway {
 #[serde(default)]
 pub struct Network {
     pub net_id: NetID,
+    pub secondary_net_ids: Vec<NetID>,
     pub dev_addr_prefixes: Vec<DevAddrPrefix>,
     pub enabled_regions: Vec<String>,
     #[serde(with = "humantime_serde")]
@@ -147,6 +148,7 @@ impl Default for Network {
     fn default() -> Self {
         Network {
             net_id: NetID::from_be_bytes([0x00, 0x00, 0x00]),
+            secondary_net_ids: vec![],
             dev_addr_prefixes: vec![],
             enabled_regions: vec![],
             device_session_ttl: Duration::from_secs(60 * 60 * 24 * 31),