Configure Wolfram network with systemd-networkd and disable hardware offloading for RTL8125

Signed-off-by: Mel <mel@rnrd.eu>

2 files changed, 48 insertions, 14 deletions

diff --git a/machines/wolfram/devices.nix b/machines/wolfram/devices.nix
index bd3a07e..fa695c4 100644
--- a/machines/wolfram/devices.nix
+++ b/machines/wolfram/devices.nix
@@ -47,7 +47,45 @@
     enable = true;
     algorithm = "zstd";
     swapDevices = 1;
-    memoryPercent = 50; 
+    memoryPercent = 50;
+  };
+
+  networking = {
+    useDHCP = false;
+    dhcpcd.enable = false;
+  };
+  systemd.network = {
+    enable = true;
+    networks = {
+      # ethernet through the rtl8125 ethernet controller (supports 2.5g)
+      "10-ether" = {
+        name = "enp7s0";
+        DHCP = "yes";
+      };
+      # wifi connection via mediatek mt7921k (supports wifi 6e)
+      "10-wlan" = {
+        name = "wlp6s0";
+        DHCP = "yes";
+        networkConfig.IgnoreCarrierLoss = "3s";
+        # authentication handled via wpa_supplicant in modules/wireless.nix
+      };
+    };
+
+    # the rtl8125 notoriously has extreme issues with offloaded calculations
+    # sent from linux machines, and corrupts packets badly, crippling connectivity.
+    # we disable most forms of offloading to the chip here, instead handling them
+    # in our own kernel. this fixes most of the issues.
+    links."10-rtl8125-hardware-offloading" = {
+      matchConfig.Name = "enp7s0";
+      linkConfig = {
+        ReceiveChecksumOffload = false; # rx off
+        TransmitChecksumOffload = false; # tx off
+        TCPSegmentationOffload = false; # tso off
+        TCP6SegmentationOffload = false; # tso off (ipv6)
+        GenericSegmentationOffload = false; # gso off
+        GenericReceiveOffload = false; # gro off
+      };
+    };
   };
 
   # storage
diff --git a/modules/wireless.nix b/modules/wireless.nix
index 89d8b65..beb0955 100644
--- a/modules/wireless.nix
+++ b/modules/wireless.nix
@@ -5,21 +5,17 @@
     file = ../secrets/wireless-secrets.age;
   };
 
-  networking = {
-    useDHCP = true;
+  networking.wireless = {
+    enable = true;
 
-    wireless = {
-      enable = true;
+    # force wpa_supplicant to use all wlan interfaces
+    interfaces = lib.mkForce [ ];
 
-      # force wpa_supplicant to use all wlan interfaces
-      interfaces = lib.mkForce [ ];
-
-      secretsFile = config.age.secrets.wireless-secrets.path;
-      networks = {
-        # yea this is my home network :3
-        # (my boyfriends brother picked the name)
-        "Das asoziale Netzwerk".pskRaw = "ext:psk_home";
-      };
+    secretsFile = config.age.secrets.wireless-secrets.path;
+    networks = {
+      # yea this is my home network :3
+      # (my boyfriends brother picked the name)
+      "Das asoziale Netzwerk".pskRaw = "ext:psk_home";
     };
   };
 }