core: let kernel add IPv6LL address when method=ignore (rh #1132938)

The IPv6LL address handling in userspace patches failed to handle the
case where the IPv6 method was 'ignore'.  Previously the kernel would
usually add the IPv6LL address itself, but if NM has turned off kernel
IPv6LL then obviously this wouldn't happen.  So when the method is
'ignore', turn off userspace IPv6LL handling and bounce disable_ipv6
to make the kernel add the IPv6LL address if it wants to.

1 files changed, 15 insertions, 1 deletions

diff --git a/src/devices/nm-device.c b/src/devices/nm-device.c
index 1c01c8dc26..10dd77dbd7 100644
--- a/src/devices/nm-device.c
+++ b/src/devices/nm-device.c
@@ -3988,11 +3988,25 @@ act_stage3_ip6_config_start (NMDevice *self,
 	priv->dhcp6_mode = NM_RDISC_DHCP_LEVEL_NONE;
 
 	if (strcmp (method, NM_SETTING_IP6_CONFIG_METHOD_IGNORE) == 0) {
-		if (!priv->master)
+		if (!priv->master) {
+			/* When activating an IPv6 'ignore' connection we need to revert back
+			 * to kernel IPv6LL, but the kernel won't actually assign an address
+			 * to the interface until disable_ipv6 is bounced.
+			 */
+			set_nm_ipv6ll (self, FALSE);
+			nm_device_ipv6_sysctl_set (self, "disable_ipv6", "1");
 			restore_ip6_properties (self);
+		}
 		return NM_ACT_STAGE_RETURN_STOP;
 	}
 
+	/* Any method past this point requires an IPv6LL address. Use NM-controlled
+	 * IPv6LL if this is not an assumed connection, since assumed connections
+	 * will already have IPv6 set up.
+	 */
+	if (!nm_device_uses_generated_assumed_connection (self))
+		set_nm_ipv6ll (self, TRUE);
+
 	/* Re-enable IPv6 on the interface */
 	set_disable_ipv6 (self, "0");