device: merge branch 'bg/mtu-rh1586191'

https://bugzilla.redhat.com/show_bug.cgi?id=1586191

(cherry picked from commit cbfe9a6e1621775609c63675beae051cc018dfed)

11 files changed, 129 insertions, 141 deletions

diff --git a/src/devices/nm-device-ethernet.c b/src/devices/nm-device-ethernet.c
index 87d16dbe37..a9a9f968e6 100644
--- a/src/devices/nm-device-ethernet.c
+++ b/src/devices/nm-device-ethernet.c
@@ -1317,13 +1317,13 @@ act_stage3_ip4_config_start (NMDevice *device,
 }
 
 static guint32
-get_configured_mtu (NMDevice *device, gboolean *out_is_user_config)
+get_configured_mtu (NMDevice *device, NMDeviceMtuSource *out_source)
 {
 	/* MTU only set for plain ethernet */
 	if (NM_DEVICE_ETHERNET_GET_PRIVATE ((NMDeviceEthernet *) device)->ppp_manager)
 		return 0;
 
-	return nm_device_get_configured_mtu_for_wired (device, out_is_user_config);
+	return nm_device_get_configured_mtu_for_wired (device, out_source);
 }
 
 static void
diff --git a/src/devices/nm-device-infiniband.c b/src/devices/nm-device-infiniband.c
index 781bbd6921..99bcef0045 100644
--- a/src/devices/nm-device-infiniband.c
+++ b/src/devices/nm-device-infiniband.c
@@ -115,29 +115,11 @@ act_stage1_prepare (NMDevice *device, NMDeviceStateReason *out_failure_reason)
 }
 
 static guint32
-get_configured_mtu (NMDevice *device, gboolean *out_is_user_config)
+get_configured_mtu (NMDevice *device, NMDeviceMtuSource *out_source)
 {
-	NMSettingInfiniband *setting;
-	gint64 mtu_default;
-	guint32 mtu;
-
-	nm_assert (NM_IS_DEVICE (device));
-	nm_assert (out_is_user_config);
-
-	setting = NM_SETTING_INFINIBAND (nm_device_get_applied_setting (device, NM_TYPE_SETTING_INFINIBAND));
-	if (!setting)
-		g_return_val_if_reached (0);
-
-	mtu = nm_setting_infiniband_get_mtu (setting);
-	if (mtu == 0) {
-		mtu_default = nm_device_get_configured_mtu_from_connection_default (device, "infiniband.mtu");
-		if (mtu_default >= 0) {
-			*out_is_user_config = TRUE;
-			return (guint32) mtu_default;
-		}
-	}
-	*out_is_user_config = (mtu != 0);
-	return mtu;
+	return nm_device_get_configured_mtu_from_connection (device,
+	                                                     NM_TYPE_SETTING_INFINIBAND,
+	                                                     out_source);
 }
 
 static gboolean
diff --git a/src/devices/nm-device-ip-tunnel.c b/src/devices/nm-device-ip-tunnel.c
index 59ca9ed557..2e266bb90a 100644
--- a/src/devices/nm-device-ip-tunnel.c
+++ b/src/devices/nm-device-ip-tunnel.c
@@ -741,33 +741,15 @@ create_and_realize (NMDevice *device,
 }
 
 static guint32
-get_configured_mtu (NMDevice *self, gboolean *out_is_user_config)
+get_configured_mtu (NMDevice *device, NMDeviceMtuSource *out_source)
 {
-	NMSettingIPTunnel *setting;
-	gint64 mtu_default;
-	guint32 mtu;
-
-	nm_assert (NM_IS_DEVICE (self));
-	nm_assert (out_is_user_config);
-
-	setting = NM_SETTING_IP_TUNNEL (nm_device_get_applied_setting (self, NM_TYPE_SETTING_IP_TUNNEL));
-	if (!setting)
-		g_return_val_if_reached (0);
-
-	mtu = nm_setting_ip_tunnel_get_mtu (setting);
-	if (mtu == 0) {
-		mtu_default = nm_device_get_configured_mtu_from_connection_default (self, "ip-tunnel.mtu");
-		if (mtu_default >= 0) {
-			*out_is_user_config = TRUE;
-			return (guint32) mtu_default;
-		}
-	}
-	*out_is_user_config = (mtu != 0);
-	return mtu;
+	return nm_device_get_configured_mtu_from_connection (device,
+	                                                     NM_TYPE_SETTING_IP_TUNNEL,
+	                                                     out_source);
 }
 
 static NMDeviceCapabilities
-get_generic_capabilities (NMDevice *dev)
+get_generic_capabilities (NMDevice *device)
 {
 	return NM_DEVICE_CAP_IS_SOFTWARE;
 }
diff --git a/src/devices/nm-device-private.h b/src/devices/nm-device-private.h
index c76debffb3..ba28e9e429 100644
--- a/src/devices/nm-device-private.h
+++ b/src/devices/nm-device-private.h
@@ -120,7 +120,11 @@ gboolean nm_device_ipv6_sysctl_set (NMDevice *self, const char *property, const
 gint64 nm_device_get_configured_mtu_from_connection_default (NMDevice *self,
                                                              const char *property_name);
 
-guint32 nm_device_get_configured_mtu_for_wired (NMDevice *self, gboolean *out_is_user_config);
+guint32 nm_device_get_configured_mtu_from_connection (NMDevice *device,
+                                                      GType setting_type,
+                                                      NMDeviceMtuSource *out_source);
+
+guint32 nm_device_get_configured_mtu_for_wired (NMDevice *self, NMDeviceMtuSource *out_source);
 
 void nm_device_commit_mtu (NMDevice *self);
 
diff --git a/src/devices/nm-device-vlan.c b/src/devices/nm-device-vlan.c
index a7f4c4bce4..b0e746a822 100644
--- a/src/devices/nm-device-vlan.c
+++ b/src/devices/nm-device-vlan.c
@@ -534,19 +534,21 @@ act_stage1_prepare (NMDevice *device, NMDeviceStateReason *out_failure_reason)
 }
 
 static guint32
-get_configured_mtu (NMDevice *self, gboolean *out_is_user_config)
+get_configured_mtu (NMDevice *self, NMDeviceMtuSource *out_source)
 {
 	guint32 mtu = 0;
 	int ifindex;
 
-	mtu = nm_device_get_configured_mtu_for_wired (self, out_is_user_config);
-	if (*out_is_user_config)
+	mtu = nm_device_get_configured_mtu_for_wired (self, out_source);
+	if (*out_source != NM_DEVICE_MTU_SOURCE_NONE)
 		return mtu;
 
 	/* Inherit the MTU from parent device, if any */
 	ifindex = nm_device_parent_get_ifindex (self);
-	if (ifindex > 0)
+	if (ifindex > 0) {
 		mtu = nm_platform_link_get_mtu (nm_device_get_platform (NM_DEVICE (self)), ifindex);
+		*out_source = NM_DEVICE_MTU_SOURCE_PARENT;
+	}
 
 	return mtu;
 }
diff --git a/src/devices/nm-device.c b/src/devices/nm-device.c
index 24d8b3d415..c680acc355 100644
--- a/src/devices/nm-device.c
+++ b/src/devices/nm-device.c
@@ -349,8 +349,9 @@ typedef struct _NMDevicePrivate {
 	gulong          config_changed_id;
 	guint32         mtu;
 	guint32         ip6_mtu;
-	guint32 mtu_initial;
-	guint32 ip6_mtu_initial;
+	guint32         mtu_initial;
+	guint32         ip6_mtu_initial;
+	NMDeviceMtuSource mtu_source;
 
 	guint32         v4_route_table;
 	guint32         v6_route_table;
@@ -366,8 +367,6 @@ typedef struct _NMDevicePrivate {
 	bool            carrier:1;
 	bool            ignore_carrier:1;
 
-	bool mtu_initialized:1;
-
 	bool            up:1;   /* IFF_UP */
 
 	bool            v4_commit_first_time:1;
@@ -735,6 +734,14 @@ NM_UTILS_LOOKUP_STR_DEFINE (nm_device_state_reason_to_str, NMDeviceStateReason,
 #define reason_to_string(reason) \
 	NM_UTILS_LOOKUP_STR (nm_device_state_reason_to_str, reason)
 
+NM_UTILS_LOOKUP_STR_DEFINE_STATIC (mtu_source_to_str, NMDeviceMtuSource,
+	NM_UTILS_LOOKUP_DEFAULT_NM_ASSERT ("unknown"),
+	NM_UTILS_LOOKUP_STR_ITEM (NM_DEVICE_MTU_SOURCE_NONE,       "none"),
+	NM_UTILS_LOOKUP_STR_ITEM (NM_DEVICE_MTU_SOURCE_PARENT,     "parent"),
+	NM_UTILS_LOOKUP_STR_ITEM (NM_DEVICE_MTU_SOURCE_IP_CONFIG,  "ip-config"),
+	NM_UTILS_LOOKUP_STR_ITEM (NM_DEVICE_MTU_SOURCE_CONNECTION, "connection"),
+);
+
 /*****************************************************************************/
 
 NMSettings *
@@ -4001,7 +4008,7 @@ realize_start_setup (NMDevice *self,
 	/* Balanced by a thaw in nm_device_realize_finish() */
 	g_object_freeze_notify (G_OBJECT (self));
 
-	priv->mtu_initialized = FALSE;
+	priv->mtu_source = NM_DEVICE_MTU_SOURCE_NONE;
 	priv->mtu_initial = 0;
 	priv->ip6_mtu_initial = 0;
 	priv->ip6_mtu = 0;
@@ -8371,40 +8378,68 @@ nm_device_get_configured_mtu_from_connection_default (NMDevice *self,
 }
 
 guint32
-nm_device_get_configured_mtu_for_wired (NMDevice *self, gboolean *out_is_user_config)
+nm_device_get_configured_mtu_from_connection (NMDevice *self,
+                                              GType setting_type,
+                                              NMDeviceMtuSource *out_source)
 {
+	const char *global_property_name;
 	NMConnection *connection;
-	NMSettingWired *setting;
+	NMSetting *setting;
 	gint64 mtu_default;
-	guint32 mtu;
+	guint32 mtu = 0;
 
 	nm_assert (NM_IS_DEVICE (self));
-	nm_assert (out_is_user_config);
+	nm_assert (out_source);
 
 	connection = nm_device_get_applied_connection (self);
 	if (!connection)
 		g_return_val_if_reached (0);
 
-	setting = nm_connection_get_setting_wired (connection);
+	setting = nm_connection_get_setting (connection, setting_type);
+
+	if (setting_type == NM_TYPE_SETTING_WIRED) {
+		if (setting)
+			mtu = nm_setting_wired_get_mtu (NM_SETTING_WIRED (setting));
+		global_property_name = "ethernet.mtu";
+	} else if (setting_type == NM_TYPE_SETTING_WIRELESS) {
+		if (setting)
+			mtu = nm_setting_wireless_get_mtu (NM_SETTING_WIRELESS (setting));
+		global_property_name = "wifi.mtu";
+	} else if (setting_type == NM_TYPE_SETTING_INFINIBAND) {
+		if (setting)
+			mtu = nm_setting_infiniband_get_mtu (NM_SETTING_INFINIBAND (setting));
+		global_property_name = "infiniband.mtu";
+	} else if (setting_type == NM_TYPE_SETTING_IP_TUNNEL) {
+		if (setting)
+			mtu = nm_setting_ip_tunnel_get_mtu (NM_SETTING_IP_TUNNEL (setting));
+		global_property_name = "ip-tunnel.mtu";
+	} else
+		g_return_val_if_reached (0);
+
 
-	if (setting) {
-		mtu = nm_setting_wired_get_mtu (setting);
-		if (mtu) {
-			*out_is_user_config = TRUE;
-			return mtu;
-		}
+	if (mtu) {
+		*out_source = NM_DEVICE_MTU_SOURCE_CONNECTION;
+		return mtu;
 	}
 
-	mtu_default = nm_device_get_configured_mtu_from_connection_default (self, "ethernet.mtu");
+	mtu_default = nm_device_get_configured_mtu_from_connection_default (self, global_property_name);
 	if (mtu_default >= 0) {
-		*out_is_user_config = TRUE;
+		*out_source = NM_DEVICE_MTU_SOURCE_CONNECTION;
 		return (guint32) mtu_default;
 	}
 
-	*out_is_user_config = FALSE;
+	*out_source = NM_DEVICE_MTU_SOURCE_NONE;
 	return 0;
 }
 
+guint32
+nm_device_get_configured_mtu_for_wired (NMDevice *self, NMDeviceMtuSource *out_source)
+{
+	return nm_device_get_configured_mtu_from_connection (self,
+	                                                     NM_TYPE_SETTING_WIRED,
+	                                                     out_source);
+}
+
 /*****************************************************************************/
 
 static void
@@ -8431,6 +8466,7 @@ static void
 _commit_mtu (NMDevice *self, const NMIP4Config *config)
 {
 	NMDevicePrivate *priv = NM_DEVICE_GET_PRIVATE (self);
+	NMDeviceMtuSource source = NM_DEVICE_MTU_SOURCE_NONE;
 	guint32 ip6_mtu, ip6_mtu_orig;
 	guint32 mtu_desired, mtu_desired_orig;
 	guint32 mtu_plat;
@@ -8440,6 +8476,7 @@ _commit_mtu (NMDevice *self, const NMIP4Config *config)
 	} ip6_mtu_sysctl = { 0, };
 	int ifindex;
 	char sbuf[64], sbuf1[64], sbuf2[64];
+	gboolean success = TRUE;
 
 	ifindex = nm_device_get_ip_ifindex (self);
 	if (ifindex <= 0)
@@ -8453,7 +8490,6 @@ _commit_mtu (NMDevice *self, const NMIP4Config *config)
 	}
 
 	{
-		gboolean mtu_is_user_config = FALSE;
 		guint32 mtu = 0;
 
 		/* preferably, get the MTU from explict user-configuration.
@@ -8461,23 +8497,30 @@ _commit_mtu (NMDevice *self, const NMIP4Config *config)
 		 * MTUs from DHCP/PPP) or maybe fallback to a device-specific MTU. */
 
 		if (NM_DEVICE_GET_CLASS (self)->get_configured_mtu)
-			mtu = NM_DEVICE_GET_CLASS (self)->get_configured_mtu (self, &mtu_is_user_config);
+			mtu = NM_DEVICE_GET_CLASS (self)->get_configured_mtu (self, &source);
+
+		if (   config
+		    && source < NM_DEVICE_MTU_SOURCE_IP_CONFIG
+		    && nm_ip4_config_get_mtu (config)) {
+			mtu = nm_ip4_config_get_mtu (config);
+			source = NM_DEVICE_MTU_SOURCE_IP_CONFIG;
+		}
 
-		if (mtu_is_user_config)
+		if (mtu != 0) {
+			_LOGT (LOGD_DEVICE,
+			       "mtu: value %u from source '%s' (%u), current source '%s' (%u)",
+			       (guint) mtu,
+			       mtu_source_to_str (source), (guint) source,
+			       mtu_source_to_str (priv->mtu_source), (guint) priv->mtu_source);
+		}
+
+		if (   mtu != 0
+		    && (   source > priv->mtu_source
+		        || (priv->mtu_source == NM_DEVICE_MTU_SOURCE_PARENT && source == priv->mtu_source)))
 			mtu_desired = mtu;
 		else {
-			if (config)
-				mtu_desired = nm_ip4_config_get_mtu (config);
-			else
-				mtu_desired = 0;
-			if (!mtu_desired && !priv->mtu_initialized) {
-				/* there is no MTU specified, and this is the first commit of the MTU.
-				 * Reset a per-device MTU default, as returned from get_configured_mtu().
-				 *
-				 * The device might choose not to return a default MTU via get_configured_mtu()
-				 * to suppress this behavior. */
-				mtu_desired = mtu;
-			}
+			mtu_desired = 0;
+			source = NM_DEVICE_MTU_SOURCE_NONE;
 		}
 	}
 
@@ -8499,7 +8542,7 @@ _commit_mtu (NMDevice *self, const NMIP4Config *config)
 	}
 
 	ip6_mtu = priv->ip6_mtu;
-	if (!ip6_mtu && !priv->mtu_initialized) {
+	if (!ip6_mtu && priv->mtu_source == NM_DEVICE_MTU_SOURCE_NONE) {
 		/* initially, if the IPv6 MTU is not specified, grow it as large as the
 		 * link MTU @mtu_desired. Only exception is, if @mtu_desired is so small
 		 * to disable IPv6. */
@@ -8507,8 +8550,6 @@ _commit_mtu (NMDevice *self, const NMIP4Config *config)
 			ip6_mtu = mtu_desired;
 	}
 
-	priv->mtu_initialized = TRUE;
-
 	if (!ip6_mtu && !mtu_desired)
 		return;
 
@@ -8560,6 +8601,7 @@ _commit_mtu (NMDevice *self, const NMIP4Config *config)
 		if (mtu_desired && mtu_desired != mtu_plat) {
 			if (nm_platform_link_set_mtu (nm_device_get_platform (self), ifindex, mtu_desired) == NM_PLATFORM_ERROR_CANT_SET_MTU) {
 				anticipated_failure = TRUE;
+				success = FALSE;
 				_LOGW (LOGD_DEVICE, "mtu: failure to set MTU. %s",
 				       NM_IS_DEVICE_VLAN (self)
 				         ? "Is the parent's MTU size large enough?"
@@ -8581,10 +8623,15 @@ _commit_mtu (NMDevice *self, const NMIP4Config *config)
 				        anticipated_failure && errsv == EINVAL
 				           ? ": Is the underlying MTU value successfully set?"
 				           : "");
+				success = FALSE;
 			}
 			priv->carrier_wait_until_ms = nm_utils_get_monotonic_timestamp_ms () + CARRIER_WAIT_TIME_AFTER_MTU_MS;
 		}
 	}
+
+	if (success && source != NM_DEVICE_MTU_SOURCE_NONE)
+		priv->mtu_source = source;
+
 #undef _IP6_MTU_SYS
 }
 
@@ -13623,7 +13670,7 @@ nm_device_cleanup (NMDevice *self, NMDeviceStateReason reason, CleanupType clean
 		NM_DEVICE_GET_CLASS (self)->deactivate_reset_hw_addr (self);
 	}
 
-	priv->mtu_initialized = FALSE;
+	priv->mtu_source = NM_DEVICE_MTU_SOURCE_NONE;
 	if (priv->mtu_initial || priv->ip6_mtu_initial) {
 		ifindex = nm_device_get_ip_ifindex (self);
 
diff --git a/src/devices/nm-device.h b/src/devices/nm-device.h
index 0d4d5cf8c4..010a0521c8 100644
--- a/src/devices/nm-device.h
+++ b/src/devices/nm-device.h
@@ -44,6 +44,13 @@ typedef enum {
 	NM_DEVICE_SYS_IFACE_STATE_REMOVED,
 } NMDeviceSysIfaceState;
 
+typedef enum {
+	NM_DEVICE_MTU_SOURCE_NONE,
+	NM_DEVICE_MTU_SOURCE_PARENT,
+	NM_DEVICE_MTU_SOURCE_IP_CONFIG,
+	NM_DEVICE_MTU_SOURCE_CONNECTION,
+} NMDeviceMtuSource;
+
 static inline NMDeviceStateReason
 nm_device_state_reason_check (NMDeviceStateReason reason)
 {
@@ -287,7 +294,7 @@ typedef struct _NMDeviceClass {
 	                                  NMConnection *connection,
 	                                  char **specific_object);
 
-	guint32     (*get_configured_mtu) (NMDevice *self, gboolean *out_is_user_config);
+	guint32     (*get_configured_mtu) (NMDevice *self, NMDeviceMtuSource *out_source);
 
 	/* Checks whether the connection is compatible with the device using
 	 * only the devices type and characteristics.  Does not use any live
diff --git a/src/devices/wifi/nm-device-iwd.c b/src/devices/wifi/nm-device-iwd.c
index 4acabdb178..7667816a70 100644
--- a/src/devices/wifi/nm-device-iwd.c
+++ b/src/devices/wifi/nm-device-iwd.c
@@ -1434,29 +1434,11 @@ out:
 }
 
 static guint32
-get_configured_mtu (NMDevice *device, gboolean *out_is_user_config)
+get_configured_mtu (NMDevice *device, NMDeviceMtuSource *out_source)
 {
-	NMSettingWireless *setting;
-	gint64 mtu_default;
-	guint32 mtu;
-
-	nm_assert (NM_IS_DEVICE (device));
-	nm_assert (out_is_user_config);
-
-	setting = NM_SETTING_WIRELESS (nm_device_get_applied_setting (device, NM_TYPE_SETTING_WIRELESS));
-	if (!setting)
-		g_return_val_if_reached (0);
-
-	mtu = nm_setting_wireless_get_mtu (setting);
-	if (mtu == 0) {
-		mtu_default = nm_device_get_configured_mtu_from_connection_default (device, "wifi.mtu");
-		if (mtu_default >= 0) {
-			*out_is_user_config = TRUE;
-			return (guint32) mtu_default;
-		}
-	}
-	*out_is_user_config = (mtu != 0);
-	return mtu;
+	return nm_device_get_configured_mtu_from_connection (device,
+	                                                     NM_TYPE_SETTING_WIRELESS,
+	                                                     out_source);
 }
 
 static gboolean
diff --git a/src/devices/wifi/nm-device-wifi.c b/src/devices/wifi/nm-device-wifi.c
index 1a86e13bf6..6bd06524ad 100644
--- a/src/devices/wifi/nm-device-wifi.c
+++ b/src/devices/wifi/nm-device-wifi.c
@@ -2786,29 +2786,11 @@ act_stage3_ip6_config_start (NMDevice *device,
 }
 
 static guint32
-get_configured_mtu (NMDevice *device, gboolean *out_is_user_config)
+get_configured_mtu (NMDevice *device, NMDeviceMtuSource *out_source)
 {
-	NMSettingWireless *setting;
-	gint64 mtu_default;
-	guint32 mtu;
-
-	nm_assert (NM_IS_DEVICE (device));
-	nm_assert (out_is_user_config);
-
-	setting = NM_SETTING_WIRELESS (nm_device_get_applied_setting (device, NM_TYPE_SETTING_WIRELESS));
-	if (!setting)
-		g_return_val_if_reached (0);
-
-	mtu = nm_setting_wireless_get_mtu (setting);
-	if (mtu == 0) {
-		mtu_default = nm_device_get_configured_mtu_from_connection_default (device, "wifi.mtu");
-		if (mtu_default >= 0) {
-			*out_is_user_config = TRUE;
-			return (guint32) mtu_default;
-		}
-	}
-	*out_is_user_config = (mtu != 0);
-	return mtu;
+	return nm_device_get_configured_mtu_from_connection (device,
+	                                                     NM_TYPE_SETTING_WIRELESS,
+	                                                     out_source);
 }
 
 static gboolean
diff --git a/src/devices/wwan/nm-modem.c b/src/devices/wwan/nm-modem.c
index ff1579d102..617d5c4a54 100644
--- a/src/devices/wwan/nm-modem.c
+++ b/src/devices/wwan/nm-modem.c
@@ -859,7 +859,7 @@ nm_modem_stage3_ip6_config_start (NMModem *self,
 }
 
 guint32
-nm_modem_get_configured_mtu (NMDevice *self, gboolean *out_is_user_config)
+nm_modem_get_configured_mtu (NMDevice *self, NMDeviceMtuSource *out_source)
 {
 	NMConnection *connection;
 	NMSetting *setting;
@@ -868,7 +868,7 @@ nm_modem_get_configured_mtu (NMDevice *self, gboolean *out_is_user_config)
 	const char *property_name;
 
 	nm_assert (NM_IS_DEVICE (self));
-	nm_assert (out_is_user_config);
+	nm_assert (out_source);
 
 	connection = nm_device_get_applied_connection (self);
 	if (!connection)
@@ -881,19 +881,19 @@ nm_modem_get_configured_mtu (NMDevice *self, gboolean *out_is_user_config)
 	if (setting) {
 		g_object_get (setting, "mtu", &mtu, NULL);
 		if (mtu) {
-			*out_is_user_config = TRUE;
+			*out_source = NM_DEVICE_MTU_SOURCE_CONNECTION;
 			return mtu;
 		}
 
 		property_name = NM_IS_SETTING_GSM (setting) ? "gsm.mtu" : "cdma.mtu";
 		mtu_default = nm_device_get_configured_mtu_from_connection_default (self, property_name);
 		if (mtu_default >= 0) {
-			*out_is_user_config = TRUE;
+			*out_source = NM_DEVICE_MTU_SOURCE_CONNECTION;
 			return (guint32) mtu_default;
 		}
 	}
 
-	*out_is_user_config = FALSE;
+	*out_source = NM_DEVICE_MTU_SOURCE_NONE;
 	return 0;
 }
 
diff --git a/src/devices/wwan/nm-modem.h b/src/devices/wwan/nm-modem.h
index 6e78d2d5d7..cad9ece415 100644
--- a/src/devices/wwan/nm-modem.h
+++ b/src/devices/wwan/nm-modem.h
@@ -275,6 +275,6 @@ void nm_modem_emit_ip6_config_result (NMModem *self,
 
 const gchar *nm_modem_ip_type_to_string (NMModemIPType ip_type);
 
-guint32 nm_modem_get_configured_mtu (NMDevice *self, gboolean *out_is_user_config);
+guint32 nm_modem_get_configured_mtu (NMDevice *self, NMDeviceMtuSource *out_source);
 
 #endif /* __NETWORKMANAGER_MODEM_H__ */