From 9b6a3b192ba0f22ce99aa5c48c6c7143d12dddba Mon Sep 17 00:00:00 2001
From: Nick Rosbrook <nick.rosbrook@canonical.com>
Date: Wed, 2 Nov 2022 05:36:14 -0400
Subject: [PATCH] sd-netlink: restore altname on error in rtnl_set_link_name

If a current alternative name is to be used to rename a network
interface, the alternative name must be removed first. If interface
renaming fails, restore the alternative name that was deleted if
necessary.

(cherry picked from commit 4d600667f8af2985850b03a46357e068d3fb8570)

Related: RHEL-5988
---
 src/libsystemd/sd-netlink/netlink-util.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/src/libsystemd/sd-netlink/netlink-util.c b/src/libsystemd/sd-netlink/netlink-util.c
index 6b4c25fe5a..cfcf2578d6 100644
--- a/src/libsystemd/sd-netlink/netlink-util.c
+++ b/src/libsystemd/sd-netlink/netlink-util.c
@@ -14,6 +14,7 @@
 int rtnl_set_link_name(sd_netlink **rtnl, int ifindex, const char *name) {
         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *message = NULL;
         _cleanup_strv_free_ char **alternative_names = NULL;
+        bool altname_deleted = false;
         int r;
 
         assert(rtnl);
@@ -33,21 +34,33 @@ int rtnl_set_link_name(sd_netlink **rtnl, int ifindex, const char *name) {
                 if (r < 0)
                         return log_debug_errno(r, "Failed to remove '%s' from alternative names on network interface %i: %m",
                                                name, ifindex);
+
+                altname_deleted = true;
         }
 
         r = sd_rtnl_message_new_link(*rtnl, &message, RTM_SETLINK, ifindex);
         if (r < 0)
-                return r;
+                goto fail;
 
         r = sd_netlink_message_append_string(message, IFLA_IFNAME, name);
         if (r < 0)
-                return r;
+                goto fail;
 
         r = sd_netlink_call(*rtnl, message, 0, NULL);
         if (r < 0)
-                return r;
+                goto fail;
 
         return 0;
+
+fail:
+        if (altname_deleted) {
+                int q = rtnl_set_link_alternative_names(rtnl, ifindex, STRV_MAKE(name));
+                if (q < 0)
+                        log_debug_errno(q, "Failed to restore '%s' as an alternative name on network interface %i, ignoring: %m",
+                                        name, ifindex);
+        }
+
+        return r;
 }
 
 int rtnl_set_link_properties(