Fix midplane network in bookworm with kernel 6.1

Signed-off-by: Ze Gan <ganze718@gmail.com>

files/build_templates/sonic_debian_extension.j2

@@ -633,16 +633,20 @@ sudo LANG=C chroot $FILESYSTEM_ROOT systemctl enable config-chassisdb.service
 # Copy midplane network service file for smart switch
 sudo cp $IMAGE_CONFIGS/midplane-network/bridge-midplane.netdev $FILESYSTEM_ROOT_USR_LIB_SYSTEMD_NETWORK/bridge-midplane.netdev
 sudo cp $IMAGE_CONFIGS/midplane-network/bridge-midplane.network $FILESYSTEM_ROOT_USR_LIB_SYSTEMD_NETWORK/bridge-midplane.network
+sudo cp $IMAGE_CONFIGS/midplane-network/dummy-midplane.netdev $FILESYSTEM_ROOT_USR_LIB_SYSTEMD_NETWORK/dummy-midplane.netdev
+sudo cp $IMAGE_CONFIGS/midplane-network/dummy-midplane.network $FILESYSTEM_ROOT_USR_LIB_SYSTEMD_NETWORK/dummy-midplane.network
 sudo cp $IMAGE_CONFIGS/midplane-network/midplane-network-npu.network $FILESYSTEM_ROOT_USR_LIB_SYSTEMD_NETWORK/midplane-network-npu.network
 sudo cp $IMAGE_CONFIGS/midplane-network/midplane-network-dpu.network $FILESYSTEM_ROOT_USR_LIB_SYSTEMD_NETWORK/midplane-network-dpu.network
 sudo cp $IMAGE_CONFIGS/midplane-network/midplane-network-npu.service $FILESYSTEM_ROOT_USR_LIB_SYSTEMD_SYSTEM/midplane-network-npu.service
 sudo cp $IMAGE_CONFIGS/midplane-network/midplane-network-dpu.service $FILESYSTEM_ROOT_USR_LIB_SYSTEMD_SYSTEM/midplane-network-dpu.service
 
 # Disable smart switch unit by default, these units will be controlled by systemd-sonic-generator
-sudo ln -s /dev/null /etc/systemd/network/bridge-midplane.netdev
+sudo ln -s /dev/null $FILESYSTEM_ROOT/etc/systemd/network/bridge-midplane.netdev
-sudo ln -s /dev/null /etc/systemd/network/bridge-midplane.network
+sudo ln -s /dev/null $FILESYSTEM_ROOT/etc/systemd/network/bridge-midplane.network
-sudo ln -s /dev/null /etc/systemd/network/midplane-network-npu.network
+sudo ln -s /dev/null $FILESYSTEM_ROOT/etc/systemd/network/dummy-midplane.netdev
-sudo ln -s /dev/null /etc/systemd/network/midplane-network-dpu.network
+sudo ln -s /dev/null $FILESYSTEM_ROOT/etc/systemd/network/dummy-midplane.network
+sudo ln -s /dev/null $FILESYSTEM_ROOT/etc/systemd/network/midplane-network-npu.network
+sudo ln -s /dev/null $FILESYSTEM_ROOT/etc/systemd/network/midplane-network-dpu.network
 echo "midplane-network-npu.service" | sudo tee -a $GENERATED_SERVICE_FILE
 sudo LANG=C chroot $FILESYSTEM_ROOT systemctl disable midplane-network-npu.service
 echo "midplane-network-dpu.service" | sudo tee -a $GENERATED_SERVICE_FILE
@@ -652,6 +656,7 @@ sudo LANG=C chroot $FILESYSTEM_ROOT systemctl disable midplane-network-dpu.servi
 sudo sed -i 's/#ManageForeignRoutingPolicyRules=yes/ManageForeignRoutingPolicyRules=no/g' $FILESYSTEM_ROOT/etc/systemd/networkd.conf
 
 sudo LANG=C chroot $FILESYSTEM_ROOT systemctl enable systemd-networkd
+sudo LANG=C chroot $FILESYSTEM_ROOT systemctl disable systemd-networkd-wait-online.service
 
 # Copy backend-acl script and service file
 sudo cp $IMAGE_CONFIGS/backend_acl/backend-acl.service $FILESYSTEM_ROOT_USR_LIB_SYSTEMD_SYSTEM/backend-acl.service

files/image_config/midplane-network/bridge-midplane.network

@@ -1,7 +1,8 @@
-# Midplane network for NPU
+# Network configuration for bridge midplane
 
 [Match]
 Name=bridge-midplane
 
 [Network]
 Address=169.254.200.254/24
+LinkLocalAddressing=no

files/image_config/midplane-network/dummy-midplane.netdev

@@ -0,0 +1,5 @@
+# Dummy interface for midplane network
+
+[NetDev]
+Name=dummy-midplane
+Kind=dummy

files/image_config/midplane-network/dummy-midplane.network

@@ -0,0 +1,8 @@
+# The systemd-networkd requires that the bridge interface(bridge-midplane) has at least one member interface, otherwise the IP address will not be configured.
+# This dummy interface will be added into the bridge-midplane as a member to guarantee the IP address configuration correctly.
+
+[Match]
+Name=dummy-midplane
+
+[Network]
+Bridge=bridge-midplane

src/systemd-sonic-generator/ssg-test.cc

@@ -391,9 +391,9 @@ class SsgMainTest : public SsgFunctionTest {
             }
             else if (cfg.is_smart_switch_npu) {
                 ASSERT_EQ(cfg.is_smart_switch_dpu, false);
-                nlohmann::json::array_t dpus;
+                nlohmann::json dpus;
                 for (int i = 0; i < cfg.num_dpus; i++) {
-                    dpus.push_back(nlohmann::json::object());
+                    dpus["dpu" + std::to_string(i)] = nlohmann::json::object();
                 }
                 platform_config["DPUS"] = dpus;
             }
@@ -496,6 +496,8 @@ const std::vector<std::string>
 SsgMainTest::npu_network_service_list = {
     "bridge-midplane.netdev",
     "bridge-midplane.network",
+    "dummy-midplane.netdev",
+    "dummy-midplane.network",
     "midplane-network-npu.network",
 };
 

src/systemd-sonic-generator/systemd-sonic-generator.c

@@ -860,10 +860,7 @@ static bool is_smart_switch_npu() {
     if (platform_info == NULL) {
         return false;
     }
-    if (!json_object_object_get_ex(platform_info, "DPUS", &dpus)) {
+    return json_object_object_get_ex(platform_info, "DPUS", &dpus);
-        return false;
-    }
-    return true;
 }
 
 
@@ -878,11 +875,7 @@ static bool is_smart_switch_dpu() {
     if (platform_info == NULL) {
         return false;
     }
-    if (!json_object_object_get_ex(platform_info, "DPU", &dpu)) {
+    return json_object_object_get_ex(platform_info, "DPU", &dpu);
-        return false;
-    }
-    
-    return true;
 }
 
 
@@ -904,7 +897,10 @@ static int get_num_of_dpu() {
     if (!json_object_object_get_ex(platform_info, "DPUS", &dpus)) {
         return 0;
     }
-    size_t num_dpu = json_object_array_length(dpus);
+    size_t num_dpu = 0;
+    json_object_object_foreach(dpus, key, val) {
+        num_dpu++;
+    }
     return num_dpu;
 }
 
@@ -1076,6 +1072,8 @@ static int install_network_service_for_smart_switch() {
         static const char* npu_network_units[] = {
             "bridge-midplane.netdev",
             "bridge-midplane.network",
+            "dummy-midplane.netdev",
+            "dummy-midplane.network",
             "midplane-network-npu.network",
             NULL
         };

src/systemd-sonic-generator/tests/testfiles/dummy-midplane.netdev

@@ -0,0 +1 @@
+../../../../files/image_config/midplane-network/dummy-midplane.netdev

src/systemd-sonic-generator/tests/testfiles/dummy-midplane.network

@@ -0,0 +1 @@
+../../../../files/image_config/midplane-network/dummy-midplane.network