core: fix handling IPv6 device-route and use correct route metric

Before commit 6698bf58bb53fb07838c52ca67293dd5352ec31c, we would rely on
kernel to add the device-route for manual IPv6 routes. We broke that and now
kernel would still add the device-route, however nm_platform_ip_route_sync()
would delete it immediately after.
That is because previously nm_platform_ip_route_sync() would ignore routes
with rtm_protocol RTPRO_KERNEL. Now, it will sync and delete those too.

Fix that by adding the device-route like we do it for IPv4. This also
fixes an actual issue where the automatically added route always had
route-metric 256. Instead, we now use the metric from ipv6.route-metric
setting.

Fixes: 6698bf58bb53fb07838c52ca67293dd5352ec31c

1 files changed, 4 insertions, 0 deletions

diff --git a/src/nm-ip6-config.h b/src/nm-ip6-config.h
index 71ae1e469c..03dee47b27 100644
--- a/src/nm-ip6-config.h
+++ b/src/nm-ip6-config.h
@@ -107,6 +107,10 @@ struct _NMDedupMultiIndex *nm_ip6_config_get_multi_idx (const NMIP6Config *self)
 
 NMIP6Config *nm_ip6_config_capture (struct _NMDedupMultiIndex *multi_idx, NMPlatform *platform, int ifindex,
                                     gboolean capture_resolv_conf, NMSettingIP6ConfigPrivacy use_temporary);
+
+void nm_ip6_config_add_device_routes (NMIP6Config *self,
+                                      guint32 default_route_metric);
+
 gboolean nm_ip6_config_commit (const NMIP6Config *self,
                                NMPlatform *platform,
                                GPtrArray **out_temporary_not_available);