From 69df418c0a918163d84cddaa0cf45e6c302c8103 Mon Sep 17 00:00:00 2001
From: Jan Vaclav <jvaclav@redhat.com>
Date: Wed, 29 Jul 2026 11:07:22 +0200
Subject: [PATCH] iface: include existing interfaces in name search

InterfaceNameSearch filtered kernel_nics to only up interfaces, which
excluded existing interfaces that were not UP in the merged state,
which broke copy-mac-from when referencing an interface that exists in
current state but is being added as a bond/bridge port in the same
transaction. The port's merged state isn't Up, so it gets filtered out
of kernel_nics.

Include all existing interfaces in kernel_nics, and only filter desired
interfaces to those that will be up.

Fixes: aaf11db38e97 ("iface: support matching against alt-name in copy-mac-from")
Signed-off-by: Jan Vaclav <jvaclav@redhat.com>
Assisted-by: Claude Sonnet 4.5
---
 rust/src/lib/ifaces/inter_ifaces.rs |  3 +-
 rust/src/lib/unit_tests/alt_name.rs | 82 +++++++++++++++++++++++++++++
 2 files changed, 84 insertions(+), 1 deletion(-)

diff --git a/rust/src/lib/ifaces/inter_ifaces.rs b/rust/src/lib/ifaces/inter_ifaces.rs
index 09c5a10f82..76b83a273b 100644
--- a/rust/src/lib/ifaces/inter_ifaces.rs
+++ b/rust/src/lib/ifaces/inter_ifaces.rs
@@ -1248,7 +1248,7 @@ impl InterfaceNameSearch {
     {
         let mut kernel_nics: HashSet<String> = HashSet::new();
 
-        for iface in merged_ifaces.clone().filter(|i| i.merged.is_up()) {
+        for iface in merged_ifaces.clone() {
             if let Some(cur_iface) = iface.current.as_ref() {
                 // Existing kernel interface
                 kernel_nics.insert(cur_iface.name().to_string());
@@ -1256,6 +1256,7 @@ impl InterfaceNameSearch {
                 // Creating new kernel interface
                 if des_iface.base_iface().identifier.as_ref()
                     != Some(&InterfaceIdentifier::MacAddress)
+                    && des_iface.is_up()
                 {
                     kernel_nics.insert(des_iface.name().to_string());
                 }
diff --git a/rust/src/lib/unit_tests/alt_name.rs b/rust/src/lib/unit_tests/alt_name.rs
index 4fa417df7c..8ff35f7d96 100644
--- a/rust/src/lib/unit_tests/alt_name.rs
+++ b/rust/src/lib/unit_tests/alt_name.rs
@@ -420,3 +420,85 @@ fn test_do_not_resolve_mac_identifer_iface_to_alt_name() {
     assert!(merged_iface.for_verify.is_none());
     assert!(merged_iface.desired.is_none());
 }
+
+#[test]
+fn test_copy_mac_from_existing_down_port() {
+    let desired: NetworkState = serde_yaml::from_str(
+        r"---
+        interfaces:
+          - name: bond99
+            type: bond
+            state: up
+            copy-mac-from: eth1
+            link-aggregation:
+              mode: balance-rr
+              port:
+                - eth1
+                - eth2",
+    )
+    .unwrap();
+    let current: NetworkState = serde_yaml::from_str(
+        r"---
+        interfaces:
+          - name: eth1
+            type: ethernet
+            state: down
+            mac-address: AA:BB:CC:DD:EE:FF
+          - name: eth2
+            type: ethernet
+            state: up
+            mac-address: 11:22:33:44:55:66",
+    )
+    .unwrap();
+
+    let merged_state =
+        MergedNetworkState::new(desired, current, Default::default(), false)
+            .unwrap();
+
+    let bond_iface =
+        merged_state.interfaces.kernel_ifaces.get("bond99").unwrap();
+    let bond_mac = bond_iface
+        .for_apply
+        .as_ref()
+        .and_then(|i| i.base_iface().mac_address.as_ref());
+
+    assert_eq!(bond_mac, Some(&"AA:BB:CC:DD:EE:FF".to_string()));
+}
+
+#[test]
+fn test_copy_mac_from_new_down_interface_fails() {
+    let desired: NetworkState = serde_yaml::from_str(
+        r"---
+        interfaces:
+          - name: eth1
+            type: ethernet
+            state: down
+            mac-address: AA:BB:CC:DD:EE:FF
+          - name: bond99
+            type: bond
+            state: up
+            copy-mac-from: eth1
+            link-aggregation:
+              mode: balance-rr
+              port:
+                - eth2",
+    )
+    .unwrap();
+    let current: NetworkState = serde_yaml::from_str(
+        r"---
+        interfaces:
+          - name: eth2
+            type: ethernet
+            state: up
+            mac-address: 11:22:33:44:55:66",
+    )
+    .unwrap();
+
+    let result =
+        MergedNetworkState::new(desired, current, Default::default(), false);
+
+    let e = result.unwrap_err();
+    assert_eq!(e.kind(), ErrorKind::InvalidArgument);
+    assert!(e.msg().contains("eth1"));
+    assert!(e.msg().contains("copy-mac-from"));
+}