From 5e3bb5da982b53bd71f1486fcd96f7ff06707b6d Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Mon, 14 Jun 2021 07:13:58 +0900
Subject: [PATCH] network: do not drop foreign configs for loopback and
 critical interfaces on carrier lost

---
 src/network/networkd-link.c | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c
index bb5f60a8289..f8dee666a6d 100644
--- a/src/network/networkd-link.c
+++ b/src/network/networkd-link.c
@@ -1005,6 +1005,16 @@ static int link_drop_foreign_config(Link *link) {
         assert(link);
         assert(link->manager);
 
+        /* Drop foreign config, but ignore unmanaged, loopback, or critical interfaces. We do not want
+         * to remove loopback address or addresses used for root NFS. */
+
+        if (IN_SET(link->state, LINK_STATE_UNMANAGED, LINK_STATE_PENDING, LINK_STATE_INITIALIZED))
+                return 0;
+        if (FLAGS_SET(link->flags, IFF_LOOPBACK))
+                return 0;
+        if (link->network->keep_configuration == KEEP_CONFIGURATION_YES)
+                return 0;
+
         r = link_drop_foreign_routes(link);
 
         k = link_drop_foreign_nexthops(link);
@@ -1157,14 +1167,9 @@ static int link_configure(Link *link) {
         if (r < 0)
                 return r;
 
-        /* Drop foreign config, but ignore loopback or critical devices.
-         * We do not want to remove loopback address or addresses used for root NFS. */
-        if (!(link->flags & IFF_LOOPBACK) &&
-            link->network->keep_configuration != KEEP_CONFIGURATION_YES) {
-                r = link_drop_foreign_config(link);
-                if (r < 0)
-                        return r;
-        }
+        r = link_drop_foreign_config(link);
+        if (r < 0)
+                return r;
 
         r = link_request_static_configs(link);
         if (r < 0)
@@ -1622,14 +1627,7 @@ static int link_carrier_lost(Link *link) {
         if (r < 0)
                 return r;
 
-        if (!IN_SET(link->state, LINK_STATE_UNMANAGED, LINK_STATE_PENDING, LINK_STATE_INITIALIZED)) {
-                log_link_debug(link, "State is %s, dropping foreign config", link_state_to_string(link->state));
-                r = link_drop_foreign_config(link);
-                if (r < 0)
-                        return r;
-        }
-
-        return 0;
+        return link_drop_foreign_config(link);
 }
 
 static int link_admin_state_up(Link *link) {