From f7549c8fe94d98b9c7d839fd8754c8b50ae122e9 Mon Sep 17 00:00:00 2001
From: Sergei Poljanski <me@asxp.io>
Date: Tue, 23 Dec 2025 11:49:25 +0200
Subject: [PATCH] modem fix

---
 modules/networking.nix | 81 +++++++++++++++++++++++++++++++++++++++---
 1 file changed, 76 insertions(+), 5 deletions(-)

diff --git a/modules/networking.nix b/modules/networking.nix
index 96db55a..da4be62 100644
--- a/modules/networking.nix
+++ b/modules/networking.nix
@@ -12,7 +12,7 @@
   # Enable networking
   networking.networkmanager.enable = true;
 
-  # Fibocom EM120R-GL WWAN Modem Support
+  # Quectel EM120R-GL WWAN Modem Support
   # FCC unlock for Quectel EM120R-GL
   networking.modemmanager.fccUnlockScripts = [
     {
@@ -21,14 +21,85 @@
     }
   ];
 
+  # Kernel modules for WWAN/MBIM modems
+  boot.kernelModules = [ "cdc_mbim" "qmi_wwan" "cdc_wdm" "mhi" ];
+
   # udev rules for WWAN devices
   services.udev.extraRules = ''
-    KERNEL=="wwan*mbim*", MODE="0660", GROUP="dialout"
-    KERNEL=="wwan*qcdm*", MODE="0660", GROUP="dialout"
-    KERNEL=="wwan*at*", MODE="0660", GROUP="dialout"
-    KERNEL=="cdc-wdm*", MODE="0660", GROUP="dialout"
+    KERNEL=="wwan*mbim*", MODE="0660", GROUP="networkmanager"
+    KERNEL=="wwan*qcdm*", MODE="0660", GROUP="networkmanager"
+    KERNEL=="wwan*at*", MODE="0660", GROUP="networkmanager"
+    KERNEL=="cdc-wdm*", MODE="0660", GROUP="networkmanager"
+    KERNEL=="wwan*", MODE="0660", GROUP="networkmanager"
   '';
 
+  # Ensure ModemManager starts before NetworkManager
+  systemd.services.ModemManager = {
+    wantedBy = [ "multi-user.target" ];
+    before = [ "NetworkManager.service" ];
+  };
+
+  # Auto-connect WWAN modem on boot (workaround for NM/MBIM-PCIe issue)
+  systemd.services.wwan-autoconnect = {
+    description = "Auto-connect WWAN modem";
+    after = [ "ModemManager.service" ];
+    wants = [ "ModemManager.service" ];
+    wantedBy = [ "multi-user.target" ];
+    serviceConfig = {
+      Type = "oneshot";
+      RemainAfterExit = true;
+      ExecStartPre = "${pkgs.coreutils}/bin/sleep 5";
+      ExecStart = pkgs.writeShellScript "wwan-connect" ''
+        # Wait for modem to be available and get modem index
+        MODEM=""
+        for i in $(${pkgs.coreutils}/bin/seq 1 30); do
+          MODEM=$(${pkgs.modemmanager}/bin/mmcli -L 2>/dev/null | ${pkgs.gnugrep}/bin/grep -oE 'Modem/[0-9]+' | ${pkgs.coreutils}/bin/head -1 | ${pkgs.coreutils}/bin/cut -d/ -f2)
+          [ -n "$MODEM" ] && break
+          ${pkgs.coreutils}/bin/sleep 1
+        done
+
+        if [ -z "$MODEM" ]; then
+          echo "No modem found"
+          exit 1
+        fi
+
+        # Enable modem
+        ${pkgs.modemmanager}/bin/mmcli -m $MODEM -e || true
+        ${pkgs.coreutils}/bin/sleep 2
+
+        # Connect with APN
+        ${pkgs.modemmanager}/bin/mmcli -m $MODEM --simple-connect="apn=internet" || exit 0
+        ${pkgs.coreutils}/bin/sleep 2
+
+        # Get bearer info and configure interface
+        BEARER=$(${pkgs.modemmanager}/bin/mmcli -m $MODEM 2>/dev/null | ${pkgs.gnugrep}/bin/grep "Bearer" | ${pkgs.gnugrep}/bin/grep -oE '/[0-9]+' | ${pkgs.coreutils}/bin/tail -1 | ${pkgs.coreutils}/bin/tr -d '/')
+        if [ -n "$BEARER" ]; then
+          IP=$(${pkgs.modemmanager}/bin/mmcli -b $BEARER 2>/dev/null | ${pkgs.gnugrep}/bin/grep "address:" | ${pkgs.gawk}/bin/awk '{print $NF}')
+          GW=$(${pkgs.modemmanager}/bin/mmcli -b $BEARER 2>/dev/null | ${pkgs.gnugrep}/bin/grep "gateway:" | ${pkgs.gawk}/bin/awk '{print $NF}')
+          PREFIX=$(${pkgs.modemmanager}/bin/mmcli -b $BEARER 2>/dev/null | ${pkgs.gnugrep}/bin/grep "prefix:" | ${pkgs.gawk}/bin/awk '{print $NF}')
+          [ -z "$PREFIX" ] && PREFIX=30
+          if [ -n "$IP" ] && [ -n "$GW" ]; then
+            ${pkgs.iproute2}/bin/ip link set wwan0 up
+            ${pkgs.iproute2}/bin/ip addr add $IP/$PREFIX dev wwan0 2>/dev/null || true
+            # Add source-based routing for wwan0
+            ${pkgs.iproute2}/bin/ip route add default via $GW dev wwan0 table 100 2>/dev/null || true
+            ${pkgs.iproute2}/bin/ip rule add from $IP table 100 priority 100 2>/dev/null || true
+            # Also add regular default route with low priority
+            ${pkgs.iproute2}/bin/ip route add default via $GW dev wwan0 metric 700 2>/dev/null || true
+          fi
+        fi
+      '';
+      ExecStop = pkgs.writeShellScript "wwan-disconnect" ''
+        MODEM=$(${pkgs.modemmanager}/bin/mmcli -L 2>/dev/null | ${pkgs.gnugrep}/bin/grep -oE 'Modem/[0-9]+' | ${pkgs.coreutils}/bin/head -1 | ${pkgs.coreutils}/bin/cut -d/ -f2)
+        [ -n "$MODEM" ] && ${pkgs.modemmanager}/bin/mmcli -m $MODEM --simple-disconnect 2>/dev/null || true
+        ${pkgs.iproute2}/bin/ip link set wwan0 down 2>/dev/null || true
+      '';
+    };
+  };
+
+  # IVPN service
+  services.ivpn.enable = false;
+
   # Open ports in the firewall.
   # networking.firewall.allowedTCPPorts = [ ... ];
   # networking.firewall.allowedUDPPorts = [ ... ];