core: don't manage externally created software devices until IFF_UP (rh #1030947) (bgo #725647)

Externally created software devices would be managed/assumed immediately
upon creation, which includes setting them IFF_UP and possibly turning
on NM-managed IPv6LL.

With this commit, expected behavior for external software devices is:

1) created: unmanaged state, no further action
2) IP address added but !IFF_UP: connection assumed, but device is not set IFF_UP
3) slave attached but !IFF_UP: connection assumed, but master is not set IFF_UP
3) set IFF_UP: connection assumed (if any), if not -> DISCONNECTED

This branch ensures that external software devices are not set IFF_UP
by NetworkManager when they are discovered.  It additionally ensures that
they are not set IFF_UP during connection assumption.  They may be set
IFF_UP later through specific user action.

https://bugzilla.gnome.org/show_bug.cgi?id=725647
https://bugzilla.redhat.com/show_bug.cgi?id=1030947
(cherry picked from commit f6a9898f626b8b366b686e4c43d134366d9c6129)

3 files changed, 87 insertions, 15 deletions

diff --git a/src/devices/nm-device.c b/src/devices/nm-device.c
index c04a973877..6805175d47 100644
--- a/src/devices/nm-device.c
+++ b/src/devices/nm-device.c
@@ -1153,6 +1153,14 @@ update_for_ip_ifname_change (NMDevice *self)
 	}
 }
 
+static gboolean
+is_software_external (NMDevice *self)
+{
+	return   nm_device_is_software (self)
+	      && !nm_device_get_is_nm_owned (self)
+	      && NM_DEVICE_GET_PRIVATE (self)->ifindex > 0;
+}
+
 static void
 device_set_master (NMDevice *self, int ifindex)
 {
@@ -1228,10 +1236,35 @@ device_link_changed (NMDevice *self, NMPlatformLink *info)
 	if (klass->link_changed)
 		klass->link_changed (self, info);
 
-
 	/* Update DHCP, etc, if needed */
 	if (ip_ifname_changed)
 		update_for_ip_ifname_change (self);
+
+	/* Manage externally-created software interfaces only when they are IFF_UP */
+	if (is_software_external (self) && (nm_device_get_state (self) <= NM_DEVICE_STATE_DISCONNECTED)) {
+		gboolean external_down = nm_device_get_unmanaged_flag (self, NM_UNMANAGED_EXTERNAL_DOWN);
+
+		if (external_down && info->up) {
+			/* Resetting the EXTERNAL_DOWN flag may change the device's state
+			 * to UNAVAILABLE.  To ensure that the state change doesn't touch
+			 * the device before assumption occurs, pass
+			 * NM_DEVICE_STATE_REASON_CONNECTION_ASSUMED as the reason.
+			 */
+			nm_device_set_unmanaged (self,
+			                         NM_UNMANAGED_EXTERNAL_DOWN,
+			                         FALSE,
+			                         NM_DEVICE_STATE_REASON_CONNECTION_ASSUMED);
+			nm_device_queue_recheck_assume (self);
+		} else if (!external_down && !info->up) {
+			/* If the device is already disconnected and is set !IFF_UP,
+			 * unmanage it.
+			 */
+			nm_device_set_unmanaged (self,
+			                         NM_UNMANAGED_EXTERNAL_DOWN,
+			                         TRUE,
+			                         NM_DEVICE_STATE_REASON_UNKNOWN);
+		}
+	}
 }
 
 static void
@@ -6607,7 +6640,7 @@ nm_device_get_managed (NMDevice *self)
 gboolean
 nm_device_get_unmanaged_flag (NMDevice *self, NMUnmanagedFlags flag)
 {
-	return NM_DEVICE_GET_PRIVATE (self)->unmanaged_flags & flag;
+	return NM_FLAGS_ANY (NM_DEVICE_GET_PRIVATE (self)->unmanaged_flags, flag);
 }
 
 /**
@@ -6699,6 +6732,28 @@ nm_device_set_initial_unmanaged_flag (NMDevice *self,
 		priv->unmanaged_flags &= ~flag;
 }
 
+/**
+ * nm_device_update_initial_unmanaged_flags():
+ * @self: the #NMDevice
+ *
+ * Called before device export to allow the device to set any additional
+ * unmanaged flags.
+ */
+void
+nm_device_update_initial_unmanaged_flags (NMDevice *self)
+{
+	NMDevicePrivate *priv;
+
+	g_return_if_fail (NM_IS_DEVICE (self));
+
+	priv = NM_DEVICE_GET_PRIVATE (self);
+	g_return_if_fail (priv->path == NULL);
+
+	/* Do not manage externally created software devices until they are IFF_UP */
+	if (is_software_external (self) && !nm_platform_link_is_up (priv->ifindex))
+		nm_device_set_initial_unmanaged_flag (self, NM_UNMANAGED_EXTERNAL_DOWN, TRUE);
+}
+
 void
 nm_device_set_dhcp_timeout (NMDevice *self, guint32 timeout)
 {
@@ -7353,6 +7408,17 @@ notify_ip_properties (NMDevice *self)
 }
 
 static void
+ip6_managed_setup (NMDevice *self)
+{
+	set_nm_ipv6ll (self, TRUE);
+	set_disable_ipv6 (self, "1");
+	nm_device_ipv6_sysctl_set (self, "accept_ra_defrtr", "0");
+	nm_device_ipv6_sysctl_set (self, "accept_ra_pinfo", "0");
+	nm_device_ipv6_sysctl_set (self, "accept_ra_rtr_pref", "0");
+	nm_device_ipv6_sysctl_set (self, "use_tempaddr", "0");
+}
+
+static void
 _set_state_full (NMDevice *self,
                  NMDeviceState state,
                  NMDeviceStateReason reason,
@@ -7428,14 +7494,8 @@ _set_state_full (NMDevice *self,
 	case NM_DEVICE_STATE_UNAVAILABLE:
 		if (old_state == NM_DEVICE_STATE_UNMANAGED) {
 			save_ip6_properties (self);
-			if (reason != NM_DEVICE_STATE_REASON_CONNECTION_ASSUMED) {
-				set_nm_ipv6ll (self, TRUE);
-				set_disable_ipv6 (self, "1");
-				nm_device_ipv6_sysctl_set (self, "accept_ra_defrtr", "0");
-				nm_device_ipv6_sysctl_set (self, "accept_ra_pinfo", "0");
-				nm_device_ipv6_sysctl_set (self, "accept_ra_rtr_pref", "0");
-				nm_device_ipv6_sysctl_set (self, "use_tempaddr", "0");
-			}
+			if (reason != NM_DEVICE_STATE_REASON_CONNECTION_ASSUMED)
+				ip6_managed_setup (self);
 		}
 
 		if (old_state == NM_DEVICE_STATE_UNMANAGED || priv->firmware_missing) {
@@ -7462,6 +7522,13 @@ _set_state_full (NMDevice *self,
 			set_nm_ipv6ll (self, TRUE);
 
 			nm_device_cleanup (self, reason);
+		} else if (old_state < NM_DEVICE_STATE_DISCONNECTED) {
+			if (reason != NM_DEVICE_STATE_REASON_CONNECTION_ASSUMED) {
+				/* Ensure IPv6 is set up as it may not have been done when
+				 * entering the UNAVAILABLE state depending on the reason.
+				 */
+				ip6_managed_setup (self);
+			}
 		}
 		break;
 	case NM_DEVICE_STATE_NEED_AUTH:
diff --git a/src/devices/nm-device.h b/src/devices/nm-device.h
index 38eddaa8df..794693f28b 100644
--- a/src/devices/nm-device.h
+++ b/src/devices/nm-device.h
@@ -304,13 +304,15 @@ RfKillType nm_device_get_rfkill_type (NMDevice *device);
  *   because NM is sleeping or not managed for some other reason)
  * @NM_UNMANAGED_USER: %TRUE when unmanaged by user decision (via unmanaged-specs)
  * @NM_UNMANAGED_PARENT: %TRUE when unmanaged due to parent device being unmanaged
+ * @NM_UNMANAGED_EXTERNAL_DOWN: %TRUE when unmanaged because !IFF_UP and not created by NM
  */
 typedef enum {
-	NM_UNMANAGED_NONE     = 0x00,
-	NM_UNMANAGED_DEFAULT  = 0x01,
-	NM_UNMANAGED_INTERNAL = 0x02,
-	NM_UNMANAGED_USER     = 0x04,
-	NM_UNMANAGED_PARENT   = 0x08,
+	NM_UNMANAGED_NONE          = 0x00,
+	NM_UNMANAGED_DEFAULT       = 0x01,
+	NM_UNMANAGED_INTERNAL      = 0x02,
+	NM_UNMANAGED_USER          = 0x04,
+	NM_UNMANAGED_PARENT        = 0x08,
+	NM_UNMANAGED_EXTERNAL_DOWN = 0x10,
 
 	/* Boundary value */
 	__NM_UNMANAGED_LAST,
@@ -327,6 +329,7 @@ void nm_device_set_unmanaged_quitting (NMDevice *device);
 void nm_device_set_initial_unmanaged_flag (NMDevice *device,
                                            NMUnmanagedFlags flag,
                                            gboolean unmanaged);
+void nm_device_update_initial_unmanaged_flags (NMDevice *device);
 
 gboolean nm_device_get_is_nm_owned (NMDevice *device);
 void     nm_device_set_nm_owned    (NMDevice *device);
diff --git a/src/nm-manager.c b/src/nm-manager.c
index bed07e4162..4c5fff5d76 100644
--- a/src/nm-manager.c
+++ b/src/nm-manager.c
@@ -1820,6 +1820,8 @@ add_device (NMManager *self, NMDevice *device, gboolean try_assume)
 	sleeping = manager_sleeping (self);
 	nm_device_set_initial_unmanaged_flag (device, NM_UNMANAGED_INTERNAL, sleeping);
 
+	nm_device_update_initial_unmanaged_flags (device);
+
 	nm_device_dbus_export (device);
 	nm_device_finish_init (device);