fix: Remove MAC address matching from SysUtil.link_info_find()

The link_info_find() function previously allowed searching for links by
MAC address, but this introduced ambiguity and could cause false alarms
in certain cases (e.g. retrieving the link info by MAC might return the
link info that only matches the current MAC instead of the permanent
MAC). To ensure reliable behavior, this function should accept and match
the link info only by interface name.

To address the issues, the following changes were made:
- Removed MAC address matching logic to eliminate ambiguity.
- Simplified the function to only check ifname, making it more
  predictable.
- Updated all callers to adapt to this change, ensuring correctness.
- When a profile is tied to an interface via mac only, the validation of
  the existence of interface will now be delegated to NetworkManager
instead.

Resolves: https://issues.redhat.com/browse/RHEL-84197

Signed-off-by: Wen Liang <liangwen12year@gmail.com>

library/network_connections.py

@@ -222,31 +222,15 @@ class SysUtil:
         return linkinfos
 
     @classmethod
-    def link_info_find(cls, refresh=False, mac=None, ifname=None):
-        if mac is not None:
-            mac = Util.mac_norm(mac)
-        for linkinfo in cls.link_infos(refresh).values():
-            perm_address = linkinfo.get("perm-address", None)
-            current_address = linkinfo.get("address", None)
+    def link_info_find(cls, ifname):
+        result = None
 
-            # Match by perm-address (prioritized)
-            if mac is not None and perm_address not in [None, "00:00:00:00:00:00"]:
-                if mac == perm_address:
-                    return linkinfo
+        for linkinfo in cls.link_infos().values():
+            if ifname == linkinfo["ifname"]:
+                result = linkinfo
+                break
 
-            # Fallback to match by address
-            if mac is not None and (perm_address in [None, "00:00:00:00:00:00"]):
-                if mac == current_address:
-                    matched_by_address = linkinfo  # Save for potential fallback
-
-            if ifname is not None and ifname == linkinfo.get("ifname", None):
-                return linkinfo
-
-        # Return fallback match by address if no perm-address match found
-        if "matched_by_address" in locals():
-            return matched_by_address
-
-        return None
+        return result
 
 
 ###############################################################################
@@ -2155,18 +2139,8 @@ class Cmd(object):
                 # permanent MAC address.
                 li_mac = None
                 li_ifname = None
-                if connection["mac"]:
-                    li_mac = SysUtil.link_info_find(mac=connection["mac"])
-                    if not li_mac:
-                        self.log_fatal(
-                            idx,
-                            "profile specifies mac '%s' but no such interface exists"
-                            % (connection["mac"]),
-                        )
                 if connection["interface_name"]:
-                    li_ifname = SysUtil.link_info_find(
-                        ifname=connection["interface_name"]
-                    )
+                    li_ifname = SysUtil.link_info_find(connection["interface_name"])
                     if not li_ifname:
                         if connection["type"] == "ethernet":
                             self.log_fatal(

tests/ensure_provider_tests.py

@@ -79,6 +79,7 @@ ibution_major_version | int < 9",
     "playbooks/tests_infiniband.yml": {},
     "playbooks/tests_ipv6_disabled.yml": {},
     "playbooks/tests_ipv6_dns_search.yml": {},
+    "playbooks/tests_mac_address_match.yml": {},
     "playbooks/tests_provider.yml": {
         MINIMUM_VERSION: "'1.20.0'",
         "comment": "# NetworKmanager 1.20.0 added support for forgetting profiles",

tests/playbooks/tests_mac_address_match.yml

@@ -0,0 +1,75 @@
+# SPDX-License-Identifier: BSD-3-Clause
+---
+- name: Play for testing MAC address match on device
+  hosts: all
+  vars:
+    # This test requires an Ethernet interface whose permanent
+    # MAC address matches its current MAC address. Ensure that the
+    # specified interface meets this condition.
+    #
+    # Two VLAN profiles are defined to test deterministic behavior when fetching
+    # link information from sysfs. The issue being tested arises when `os.listdir(path)`
+    # returns interfaces in an arbitrary order, potentially listing a VLAN device
+    # before its parent interface. This can cause intermittent "no such interface
+    # exists" errors when applying configurations repeatedly.
+    #
+    # - `vlan_profile1` (e.g., `eth1.3732`) is named with the VLAN ID appended
+    #   after the parent interface, following the standard `<parent>.<vlan_id>` format.
+    # - `vlan_profile2` (e.g., `120-vlan`) has a fixed name, designed to test a scenario
+    #   where lexicographic sorting causes the VLAN to appear before its parent interface.
+    interface: "{{ lookup('env', 'MAC_ADDR_MATCH_INTERFACE') | default('eth1', true) }}"
+    profile: "{{ interface }}"
+    vlan_profile1: "{{ interface }}.3732"
+    vlan_profile2: "120-vlan"
+    lsr_fail_debug:
+      - __network_connections_result
+  tags:
+    - "tests::match"
+  tasks:
+    - name: Show playbook name
+      debug:
+        msg: "this is: playbooks/tests_mac_address_match.yml"
+      tags:
+        - always
+
+    - name: Install ethtool (test dependency)
+      package:
+        name: ethtool
+        state: present
+        use: "{{ (__network_is_ostree | d(false)) |
+          ternary('ansible.posix.rhel_rpm_ostree', omit) }}"
+
+    - name: Retrieve MAC address using ethtool
+      command: ethtool -P {{ interface }}
+      register: mac_address_result
+      changed_when: false
+      failed_when: mac_address_result.rc != 0
+
+    - name: Set the MAC address variable
+      set_fact:
+        mac: "{{ mac_address_result.stdout_lines[-1].split(' ')[-1] }}"
+
+    - name: Display the retrieved MAC address
+      debug:
+        msg: "Retrieved MAC address for {{ interface }}: {{ mac }}"
+
+    - name: Test the MAC address match
+      tags:
+        - tests::match:match
+      block:
+        - name: Include the task 'run_test.yml'
+          include_tasks: tasks/run_test.yml
+          vars:
+            lsr_description: Test MAC address match on device
+            lsr_setup:
+              - tasks/find+remove_profile.yml
+              - tasks/assert_profile_absent.yml
+            lsr_test:
+              - tasks/create_mac_address_match.yml
+              - tasks/create_mac_address_match.yml
+            lsr_assert:
+              - tasks/assert_profile_present.yml
+              - tasks/assert_network_connections_succeeded.yml
+            lsr_cleanup:
+              - tasks/cleanup_vlan_and_parent_profile+device.yml
+              - tasks/check_network_dns.yml

tests/tasks/assert_network_connections_succeeded.yml

@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: BSD-3-Clause
+---
+- name: Assert that configuring network connections is succeeded
+  assert:
+    that:
+      - __network_connections_result.failed == false
+    msg: Configuring network connections is failed with the error
+      "{{ __network_connections_result.stderr }}"

tests/tasks/cleanup_vlan_and_parent_profile+device.yml

@@ -0,0 +1,26 @@
+# SPDX-License-Identifier: BSD-3-Clause
+---
+- name: Clean up the test devices and the connection profiles
+  tags:
+    - "tests::cleanup"
+  block:
+    - name: Import network role
+      import_role:
+        name: linux-system-roles.network
+      vars:
+        network_connections:
+          - name: "{{ profile }}"
+            persistent_state: absent
+            state: down
+          - name: "{{ vlan_profile1 }}"
+            persistent_state: absent
+            state: down
+          - name: "{{ vlan_profile2 }}"
+            persistent_state: absent
+            state: down
+      failed_when: false
+    - name: Delete the device '{{ interface }}'
+      command: ip link del {{ interface }}
+      failed_when: false
+      changed_when: false
+...

tests/tasks/create_mac_address_match.yml

@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: BSD-3-Clause
+---
+- name: Include network role
+  include_role:
+    name: linux-system-roles.network
+  vars:
+    network_connections:
+      - name: "{{ interface }}"
+        state: up
+        persistent_state: present
+        autoconnect: true
+        type: ethernet
+        interface_name: "{{ interface }}"
+        mac: "{{ mac }}"
+        ip:
+          dhcp4: false
+          auto6: false
+
+      - name: "{{ vlan_profile1 }}"
+        state: up
+        persistent_state: present
+        type: vlan
+        parent: "{{ interface }}"
+        vlan:
+          id: 3732
+        autoconnect: true
+        ip:
+          auto_gateway: false
+          gateway4: 10.10.0.1
+          address: 10.10.0.6/24
+          dhcp4: false
+          auto6: false
+
+      - name: "{{ vlan_profile2 }}"
+        state: up
+        persistent_state: present
+        type: vlan
+        parent: "{{ interface }}"
+        vlan:
+          id: 120
+        autoconnect: true
+        ip:
+          auto_gateway: false
+          gateway4: 10.10.120.1
+          address: 10.10.120.120/24
+          dhcp4: false
+          auto6: false
+- name: Show result
+  debug:
+    var: __network_connections_result
+...

tests/tasks/find+remove_profile.yml

@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: BSD-3-Clause
+---
+- name: Get connection profile for '{{ interface }}'
+  command: "nmcli -g GENERAL.CONNECTION device show {{ interface }}"
+  register: connection_name
+  changed_when: false
+
+- name: Bring down and delete the connection profile for '{{ interface }}'
+  include_role:
+    name: linux-system-roles.network
+  vars:
+    network_connections:
+      - name: "{{ connection_name.stdout }}"
+        persistent_state: absent
+        state: down

tests/tests_mac_address_match_nm.yml

@@ -0,0 +1,23 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# This file was generated by ensure_provider_tests.py
+---
+# set network provider and gather facts
+# yamllint disable rule:line-length
+- name: Run playbook 'playbooks/tests_mac_address_match.yml' with nm as provider
+  hosts: all
+  tasks:
+    - name: Include the task 'el_repo_setup.yml'
+      include_tasks: tasks/el_repo_setup.yml
+    - name: Set network provider to 'nm'
+      set_fact:
+        network_provider: nm
+      tags:
+        - always
+
+
+# The test requires or should run with NetworkManager, therefore it cannot run
+# on RHEL/CentOS 6
+- name: Import the playbook 'playbooks/tests_mac_address_match.yml'
+  import_playbook: playbooks/tests_mac_address_match.yml
+  when:
+    - ansible_distribution_major_version != '6'