From 0b57d7f1aa54211d1d2459da6aad34df0f16194a Mon Sep 17 00:00:00 2001
From: Lan Tian <xuyh0120@outlook.com>
Date: Tue, 7 Jan 2025 01:41:04 -0800
Subject: [PATCH] hosts(lt-rpi4): setup lora multiplexer

---
 flake.lock                     |  6 ++--
 hosts/lt-rpi4/lora/default.nix | 60 +++++++++++++++++++++++++---------
 2 files changed, 47 insertions(+), 19 deletions(-)

diff --git a/flake.lock b/flake.lock
index ccaa96d3..f9465662 100644
--- a/flake.lock
+++ b/flake.lock
@@ -943,11 +943,11 @@
         "treefmt-nix": "treefmt-nix_3"
       },
       "locked": {
-        "lastModified": 1735987314,
-        "narHash": "sha256-zjOdlIxIMNmtQOk6pXqZfj33SbJQj4eh5byQQRBT5rE=",
+        "lastModified": 1736240807,
+        "narHash": "sha256-BT517AKtTJX6VVun6sS7hdWAUAnYfONYkW/6Y7YjZLo=",
         "owner": "xddxdd",
         "repo": "nur-packages",
-        "rev": "2005fcccf32b7b702db941744aac39075fc8e6b6",
+        "rev": "31d037a5792423669a9345f7e3c32c850f81a878",
         "type": "github"
       },
       "original": {
diff --git a/hosts/lt-rpi4/lora/default.nix b/hosts/lt-rpi4/lora/default.nix
index e6db7541..33c35d92 100644
--- a/hosts/lt-rpi4/lora/default.nix
+++ b/hosts/lt-rpi4/lora/default.nix
@@ -6,6 +6,15 @@
   ...
 }:
 let
+  gwmp-mux = pkgs.nur-xddxdd.gwmp-mux.overrideAttrs (old: {
+    postPatch =
+      (old.postPatch or "")
+      + ''
+        substituteInPlace src/gwmp_mux.rs \
+          --replace-fail "[0, 0, 0, 0]" "[127, 0, 0, 1]"
+      '';
+  });
+
   sx1302Hal = pkgs.nur-xddxdd.sx1302-hal.overrideAttrs (old: {
     postPatch =
       (old.postPatch or "")
@@ -14,24 +23,24 @@ let
       '';
   });
 
+  sx1302ServerConfig = {
+    "gateway_ID" = {
+      _secret = config.age.secrets.lora-euid.path;
+    };
+    "server_address" = "127.0.0.1";
+    "serv_port_up" = 1681;
+    "serv_port_down" = 1681;
+  };
+
   sx1302HalConfig = {
-    "gateway_conf" = {
-      "gateway_ID" = {
-        _secret = config.age.secrets.lora-euid.path;
-      };
-      "server_address" = "nam1.cloud.thethings.network";
-      "serv_port_up" = 1700;
-      "serv_port_down" = 1700;
+    "gateway_conf" = sx1302ServerConfig // {
       "servers" = [
-        {
-          "gateway_ID" = {
-            _secret = config.age.secrets.lora-euid.path;
-          };
-          "server_address" = "nam1.cloud.thethings.network";
-          "serv_port_up" = 1700;
-          "serv_port_down" = 1700;
-          "serv_enabled" = true;
-        }
+        (
+          sx1302ServerConfig
+          // {
+            "serv_enabled" = true;
+          }
+        )
       ];
 
       "gps_i2c_path" = "/dev/i2c-1";
@@ -54,6 +63,25 @@ in
 {
   age.secrets.lora-euid.file = inputs.secrets + "/lora-euid.age";
 
+  systemd.services.lora-gwmp-mux = {
+    description = "LoRa GWMP Mux";
+    wantedBy = [ "multi-user.target" ];
+
+    script = ''
+      TTN_IP=$(${pkgs.dnsutils}/bin/dig +short nam1.cloud.thethings.network | head -n1)
+
+      sleep infinity | ${gwmp-mux}/bin/gwmp-mux \
+        --host 1681 \
+        --client $TTN_IP:1700
+    '';
+
+    serviceConfig = {
+      Type = "simple";
+      Restart = "always";
+      RestartSec = "3";
+    };
+  };
+
   systemd.services.lora-sx1302-hal = {
     description = "LoRa SX1302 HAL";
     wantedBy = [ "multi-user.target" ];