path: root/src/tests/test_net_name_resolve.py

# Copyright VyOS maintainers and contributors <maintainers@vyos.io>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 or later as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# Coverage for T3871 (boot race on hw-id based interface naming): the
# MAC-driven, collision-safe rename plan that replaces the old per-uevent
# udev decision, the find_available() crash it used to hit, the
# ethtool/sysfs permanent-MAC fallback, and the config.boot-availability
# ordering corner case (vyos-net-name-resolve must run from inside
# vyos-router, after the config directory is mounted/decrypted, not as an
# independently-scheduled early-boot unit).

import json
import os
import shutil
import tempfile
import unittest
from unittest import mock

from helper import prepare_module

_here = os.path.dirname(__file__)

resolver = prepare_module(
    os.path.join(_here, '../system/vyos-net-name-resolve.py'),
    'vyos_net_name_resolve')
vyos_net_name = prepare_module(
    os.path.join(_here, '../udev/vyos_net_name'),
    'vyos_net_name')

_container_patcher = None


def setUpModule():
    # main() deliberately short-circuits inside a container, and these tests
    # are routinely run from one (the VyOS build container). Pin the detection
    # off for the whole module so the naming pass under test actually runs -
    # TestMainInContainer patches it back on locally where that is the point.
    global _container_patcher
    _container_patcher = mock.patch.object(
        resolver, 'is_running_as_container', return_value=False)
    _container_patcher.start()


def tearDownModule():
    _container_patcher.stop()


class TestGetPendingHwidNodes(unittest.TestCase):
    """A node that exists under interfaces/{ethernet,wireless} but has no
    hw-id (e.g. after `delete interfaces ethernet eth1 hw-id`, the
    documented "NIC replaced" remediation) must be surfaced separately
    from the MAC-keyed configured dict, since it has no MAC to key by yet
    - this is what lets main() try to reclaim it for the exact NIC that
    vacated it, instead of silently orphaning its other settings.
    """

    def setUp(self):
        self.tmp = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, self.tmp, ignore_errors=True)
        self.config_path = os.path.join(self.tmp, 'config.boot')
        self._orig_config_path = resolver.config_path
        resolver.config_path = self.config_path
        self.addCleanup(setattr, resolver, 'config_path', self._orig_config_path)

    def _write_config(self, text):
        with open(self.config_path, 'w') as f:
            f.write(text)

    def test_node_with_hwid_not_pending(self):
        self._write_config(
            'interfaces {\n'
            '    ethernet eth0 {\n'
            '        hw-id 00:11:22:33:44:55\n'
            '    }\n'
            '}\n'
        )
        self.assertEqual(resolver.get_pending_hwid_nodes(),
                          {'ethernet': set(), 'wireless': set()})

    def test_node_without_hwid_is_pending(self):
        self._write_config(
            'interfaces {\n'
            '    ethernet eth1 {\n'
            '        address 10.99.1.1/24\n'
            '    }\n'
            '}\n'
        )
        self.assertEqual(resolver.get_pending_hwid_nodes(),
                          {'ethernet': {'eth1'}, 'wireless': set()})

    def test_mixed_ethernet_and_wireless(self):
        self._write_config(
            'interfaces {\n'
            '    ethernet eth0 {\n'
            '        hw-id 00:11:22:33:44:55\n'
            '    }\n'
            '    ethernet eth1 {\n'
            '        address 10.99.1.1/24\n'
            '    }\n'
            '    wireless wlan0 {\n'
            '        ssid example\n'
            '    }\n'
            '}\n'
        )
        self.assertEqual(resolver.get_pending_hwid_nodes(),
                          {'ethernet': {'eth1'}, 'wireless': {'wlan0'}})

    def test_no_interfaces_section(self):
        self._write_config('system {\n    host-name vyos\n}\n')
        self.assertEqual(resolver.get_pending_hwid_nodes(),
                          {'ethernet': set(), 'wireless': set()})

    def test_no_config_boot_at_all(self):
        # livecd/ISO case - config_path doesn't exist
        self.assertEqual(resolver.get_pending_hwid_nodes(),
                          {'ethernet': set(), 'wireless': set()})


class TestFindAvailableCrashFix(unittest.TestCase):
    """find_available() used to raise IndexError on an empty candidate set
    (index_list[0]) and ValueError on a name with no trailing digit
    (int('')) - both are realistic inputs on a box's first boot, or when a
    biosdevname/predefined name has no numeric suffix.
    """

    def test_resolver_empty_set(self):
        self.assertEqual(resolver.find_available(set(), 'eth'), 'eth0')

    def test_resolver_no_prefix_match(self):
        self.assertEqual(resolver.find_available({'wlan3'}, 'eth'), 'eth0')

    def test_resolver_contiguous(self):
        names = {'eth0', 'eth1', 'eth2'}
        self.assertEqual(resolver.find_available(names, 'eth'), 'eth3')

    def test_resolver_fills_hole(self):
        self.assertEqual(resolver.find_available({'eth2', 'eth5'}, 'eth'), 'eth3')

    def test_resolver_no_hole_appends(self):
        self.assertEqual(resolver.find_available({'eth2', 'eth3'}, 'eth'), 'eth4')

    def test_vyos_net_name_empty_dict(self):
        self.assertEqual(vyos_net_name.find_available({}, 'eth'), 'eth0')

    def test_vyos_net_name_no_digit_suffix(self):
        self.assertEqual(
            vyos_net_name.find_available({'m': 'wlan3'}, 'eth'), 'eth0')

    def test_vyos_net_name_contiguous(self):
        intfs = {'a': 'eth0', 'b': 'eth1'}
        self.assertEqual(vyos_net_name.find_available(intfs, 'eth'), 'eth2')

    def test_vyos_net_name_is_available(self):
        self.assertTrue(vyos_net_name.is_available({'a': 'eth0'}, 'eth1'))
        self.assertFalse(vyos_net_name.is_available({'a': 'eth0'}, 'eth0'))

    def test_vyos_net_name_mod_ifname(self):
        self.assertEqual(vyos_net_name.mod_ifname('e5'), 'eth3')
        self.assertEqual(vyos_net_name.mod_ifname('e2'), 'eth0')
        self.assertEqual(vyos_net_name.mod_ifname('e1'), 'eth1')
        self.assertEqual(vyos_net_name.mod_ifname('wlan0'), 'wlan0')


class TestUnmatchedCandidates(unittest.TestCase):
    """Field report: an unconfigured NIC that happens to be squatting on a
    DIFFERENT interface's configured hw-id slot this boot (e.g. due to
    probe-order scrambling) was excluded here just because
    compute_rename_plan() already scheduled it for eviction. That skipped
    it past match_pending_nodes() entirely, so a squatter that was really
    the exact NIC a pending node should reclaim - or one that made a
    reclaim genuinely ambiguous - fell through to ordinary bootstrap
    naming and got a permanent hw-id with no ambiguity check at all.
    Squatters must stay in this pool; only their eviction destination
    (still computed by compute_rename_plan()) is a fallback, not a reason
    to hide them from reclaim/ambiguity handling.
    """

    def test_squatter_is_still_a_candidate(self):
        configured = {'m0': 'eth1'}
        current = {'eth1': 'squatter-mac', 'eth9': 'm0'}
        existing_plan = {'eth1': 'eth3', 'eth9': 'eth1'}
        candidates = resolver.unmatched_candidates(configured, current, existing_plan)
        self.assertEqual(candidates, [('squatter-mac', 'eth1')])

    def test_rightful_owner_still_excluded(self):
        configured = {'m0': 'eth0'}
        current = {'eth0': 'm0'}
        candidates = resolver.unmatched_candidates(configured, current, {})
        self.assertEqual(candidates, [])


class TestMatchPendingNodes(unittest.TestCase):
    """A pending node's hw-id is unknown by construction - there's no MAC
    to check a candidate against - so matching must only ever happen in
    the unambiguous exactly-one-pending/exactly-one-candidate case per
    type. Confirmed in the field: a naive deterministic fill (sorting
    pending nodes and candidates together like numeric gaps) silently
    bound a configured node's address to a different physical NIC than
    its own, because an already-provisioned box's existing names have no
    relationship to PCIe/MAC sort order. Guessing in any other
    cardinality risks the same mistake; leaving the node unresolved and
    reported is safer.
    """

    def setUp(self):
        patcher = mock.patch.object(resolver, 'is_wireless_interface',
                                     return_value=False)
        self.is_wireless = patcher.start()
        self.addCleanup(patcher.stop)

    def test_unambiguous_single_pending_single_candidate_matches(self):
        pending = {'ethernet': {'eth1'}, 'wireless': set()}
        candidates = [('m1', 'eth9')]
        matched = resolver.match_pending_nodes(pending, candidates)
        self.assertEqual(matched, {'m1': 'eth1'})

    def test_two_pending_one_candidate_no_match(self):
        # can't tell which of the two pending nodes this one candidate
        # belongs to - neither is matched.
        pending = {'ethernet': {'eth1', 'eth4'}, 'wireless': set()}
        candidates = [('m1', 'eth9')]
        matched = resolver.match_pending_nodes(pending, candidates)
        self.assertEqual(matched, {})

    def test_one_pending_two_candidates_no_match(self):
        # the field-reported shape: an unrelated second candidate (e.g.
        # freed by a different interface's config being fully deleted in
        # the same boot) is enough to make this genuinely ambiguous, even
        # though it isn't itself pending anything.
        pending = {'ethernet': {'eth1'}, 'wireless': set()}
        candidates = [('m1', 'eth9'), ('m2', 'eth8')]
        matched = resolver.match_pending_nodes(pending, candidates)
        self.assertEqual(matched, {})

    def test_ethernet_and_wireless_matched_independently(self):
        self.is_wireless.side_effect = lambda name: name == 'radio0'
        pending = {'ethernet': {'eth1'}, 'wireless': {'wlan2'}}
        candidates = [('m1', 'ifaceB'), ('m2', 'radio0')]
        matched = resolver.match_pending_nodes(pending, candidates)
        self.assertEqual(matched, {'m1': 'eth1', 'm2': 'wlan2'})

    def test_no_pending_returns_empty(self):
        pending = {'ethernet': set(), 'wireless': set()}
        candidates = [('m1', 'eth9')]
        matched = resolver.match_pending_nodes(pending, candidates)
        self.assertEqual(matched, {})


class TestComputeRenamePlan(unittest.TestCase):
    """The authoritative rename plan is what fixes the multi-vendor NIC
    boot race: it is driven purely by MAC address, independent of
    ifindex/probe order, and must never produce a colliding assignment.
    """

    def test_noop_when_already_correct(self):
        configured = {'m0': 'eth0', 'm1': 'eth1'}
        current = {'eth0': 'm0', 'eth1': 'm1'}
        self.assertEqual(resolver.compute_rename_plan(configured, current), {})

    def test_rename_independent_of_probe_order(self):
        # m0/m1 landed on unrelated names this boot (e.g. a different
        # vendor driver won the probe race) - the plan must still point
        # them at their configured targets regardless.
        configured = {'m0': 'eth0', 'm1': 'eth1'}
        current = {'eth5': 'm0', 'eth3': 'm1'}
        plan = resolver.compute_rename_plan(configured, current)
        self.assertEqual(plan, {'eth5': 'eth0', 'eth3': 'eth1'})

    def test_full_swap_cycle(self):
        # eth0 and eth1 need to trade names - a naive from->to rename
        # would collide; the two-phase scratch-name staging must not.
        configured = {'m0': 'eth1', 'm1': 'eth0'}
        current = {'eth0': 'm0', 'eth1': 'm1'}
        plan = resolver.compute_rename_plan(configured, current)
        self.assertEqual(plan, {'eth0': 'eth1', 'eth1': 'eth0'})

    def test_squatter_relocated(self):
        # an unconfigured interface currently sits on a name a configured
        # hw-id needs - it must be moved out of the way, not left there.
        configured = {'m0': 'eth0'}
        current = {'eth0': 'unconfigured-mac', 'eth5': 'm0'}
        plan = resolver.compute_rename_plan(configured, current)
        self.assertEqual(plan['eth5'], 'eth0')
        self.assertNotEqual(plan['eth0'], 'eth0')
        self.assertTrue(plan['eth0'].startswith('eth'))

    def test_squatter_never_relocated_onto_a_missing_hwid_target(self):
        # macMissing's hardware hasn't shown up this boot (removed/faulty/
        # slow driver), so its reserved target 'eth1' never appears in
        # `current` and the main hw-id loop skips it entirely (source is
        # None) - the squatter being relocated off of 'eth0' must still not
        # be handed 'eth1', or it would need relocating again the moment
        # that hardware actually appears.
        configured = {'macA': 'eth0', 'macMissing': 'eth1'}
        current = {'eth0': 'squatterMac', 'eth2': 'macA'}
        plan = resolver.compute_rename_plan(configured, current)
        self.assertEqual(plan.get('eth2'), 'eth0')
        self.assertNotEqual(plan.get('eth0'), 'eth1')

    def test_squatter_never_relocated_onto_a_pending_hwid_less_node(self):
        # 'eth1' has no hw-id at all (e.g. `delete interfaces ethernet
        # eth1 hw-id`, the documented remediation for a replaced NIC) but
        # its config node - and settings like address - still exist. A
        # squatter being relocated off of 'eth0' must not be handed 'eth1'
        # either, or it would permanently steal the exact slot the
        # original NIC needs to reclaim.
        configured = {'macA': 'eth0'}
        pending = {'ethernet': {'eth1'}, 'wireless': set()}
        current = {'eth0': 'squatterMac', 'eth2': 'macA'}
        plan = resolver.compute_rename_plan(configured, current, pending)
        self.assertEqual(plan.get('eth2'), 'eth0')
        self.assertNotEqual(plan.get('eth0'), 'eth1')

    def test_missing_hardware_no_crash_no_entry(self):
        # hw-id configured but the NIC never showed up (missing/faulty) -
        # must be skipped, not crash or incorrectly assign another interface.
        configured = {'m0': 'eth0', 'missing-mac': 'eth9'}
        current = {'eth5': 'm0'}
        plan = resolver.compute_rename_plan(configured, current)
        self.assertEqual(plan, {'eth5': 'eth0'})

    def test_rename_introducing_a_gap(self):
        # user edits the CLI so m2's node is renamed eth2 -> eth10 while
        # keeping the same hw-id, leaving eth5..eth9 unused.
        configured = {
            'm0': 'eth0', 'm1': 'eth1', 'm2': 'eth10',
            'm3': 'eth3', 'm4': 'eth4',
        }
        current = {
            'eth0': 'm0', 'eth1': 'm1', 'eth2': 'm2',
            'eth3': 'm3', 'eth4': 'm4',
        }
        plan = resolver.compute_rename_plan(configured, current)
        self.assertEqual(plan, {'eth2': 'eth10'})

    def test_rename_introducing_a_gap_with_scrambled_fastpath(self):
        # same as above, but this boot's cosmetic udev fast-path lands m2
        # on an unrelated name and coincidentally puts a different NIC on
        # the now-meaningless old 'eth2'.
        configured = {
            'm0': 'eth0', 'm1': 'eth1', 'm2': 'eth10',
            'm3': 'eth3', 'm4': 'eth4',
        }
        current = {
            'eth0': 'm0', 'eth1': 'm1', 'eth7': 'm2',
            'eth2': 'm3', 'eth4': 'm4',
        }
        plan = resolver.compute_rename_plan(configured, current)
        self.assertEqual(plan.get('eth7'), 'eth10')
        self.assertEqual(plan.get('eth2'), 'eth3')
        self.assertNotIn('eth2', configured.values())


class TestWaitForSettle(unittest.TestCase):
    """There is no specific MAC to wait for when bootstrap-naming hardware
    without a configured hw-id, so settling is detected as N consecutive
    identical discover_physical_interfaces() snapshots instead.
    """

    def test_returns_after_n_consecutive_stable_polls(self):
        snapshots = [
            {'eth0': 'm0'},           # still changing
            {'eth0': 'm0', 'eth1': 'm1'},  # still changing
            {'eth0': 'm0', 'eth1': 'm1'},  # 1st stable repeat
            {'eth0': 'm0', 'eth1': 'm1'},  # 2nd stable repeat -> settled
        ]
        with mock.patch.object(resolver, 'discover_physical_interfaces',
                                side_effect=snapshots):
            result = resolver.wait_for_settle(
                {}, timeout=5, poll=0, stable_polls=3)
        self.assertEqual(result, {'eth0': 'm0', 'eth1': 'm1'})

    def test_bounded_by_timeout_when_never_stable(self):
        counter = iter(range(1000))

        def ever_changing(*_a, **_kw):
            return {'eth0': f'm{next(counter)}'}

        clock = iter([0, 0.1, 20, 20])
        with mock.patch.object(resolver, 'discover_physical_interfaces',
                                side_effect=ever_changing), \
             mock.patch('time.monotonic', side_effect=lambda: next(clock)):
            result = resolver.wait_for_settle(
                {}, timeout=10, poll=0, stable_polls=3)
        # must return SOMETHING (the last snapshot seen), not hang or crash
        self.assertIn('eth0', result)

    def test_stable_polls_of_one_returns_on_initial_snapshot(self):
        with mock.patch.object(resolver, 'discover_physical_interfaces') as m:
            result = resolver.wait_for_settle(
                {'eth0': 'm0'}, timeout=5, poll=0, stable_polls=1)
        m.assert_not_called()
        self.assertEqual(result, {'eth0': 'm0'})


class TestIsWirelessInterface(unittest.TestCase):
    """Wireless detection must be race-free - it has to be correct even
    when the interface's current name is a leftover from the cosmetic
    udev-time fast path and doesn't look like a wlan name at all.
    """

    def setUp(self):
        self.tmp = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, self.tmp, ignore_errors=True)
        # phy80211 is always a symlink to a real sysfs node in practice -
        # exists() follows symlinks, so the test target must actually exist
        self.phy_target = os.path.join(self.tmp, 'phy0')
        os.mkdir(self.phy_target)

    def test_phy80211_present_is_wireless(self):
        path = os.path.join(self.tmp, 'wlan0')
        os.mkdir(path)
        os.symlink(self.phy_target, os.path.join(path, 'phy80211'))
        self.assertTrue(resolver.is_wireless_interface('wlan0', self.tmp))

    def test_no_phy80211_is_not_wireless(self):
        os.mkdir(os.path.join(self.tmp, 'eth0'))
        self.assertFalse(resolver.is_wireless_interface('eth0', self.tmp))

    def test_detection_independent_of_misleading_name(self):
        # named like a leftover cosmetic ethernet guess, but it's a real
        # wifi card - must still be classified wireless
        path = os.path.join(self.tmp, 'eth7')
        os.mkdir(path)
        os.symlink(self.phy_target, os.path.join(path, 'phy80211'))
        self.assertTrue(resolver.is_wireless_interface('eth7', self.tmp))


class TestPcieDistance(unittest.TestCase):
    """PCIe hop-depth is what lets bootstrap naming reflect physical slot
    position instead of raw MAC magnitude - a NIC wired straight to the
    root complex must not sort after an add-in card just because its MAC
    happens to be numerically higher.
    """

    def setUp(self):
        self.tmp = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, self.tmp, ignore_errors=True)
        # fake /sys/devices tree, separate from the fake /sys/class/net
        # entries, so symlink targets can point at realistic PCI-bus-shaped
        # paths the way a real /sys/class/net/<if>/device symlink does
        self.devices_root = os.path.join(self.tmp, 'devices')
        os.makedirs(self.devices_root)

    def _make_iface_pointing_at(self, name, *path_segments):
        """Create <tmp>/<name>/device as a symlink to a fake sysfs device
        node at devices_root/<path_segments...>.
        """
        target = os.path.join(self.devices_root, *path_segments)
        os.makedirs(target, exist_ok=True)
        iface_path = os.path.join(self.tmp, name)
        os.mkdir(iface_path)
        os.symlink(target, os.path.join(iface_path, 'device'))

    def test_shallow_device_one_pci_segment(self):
        # e.g. a NIC directly under the root complex: pci0000:00/0000:00:1f.6
        self._make_iface_pointing_at('eth0', 'pci0000:00', '0000:00:1f.6')
        self.assertEqual(resolver.pcie_distance('eth0', self.tmp), 1)

    def test_deep_device_behind_bridges(self):
        # e.g. an add-in card behind two cascaded PCIe bridges
        self._make_iface_pointing_at(
            'eth1', 'pci0000:00', '0000:00:1c.0',
            '0000:01:00.0', '0000:02:04.0')
        self.assertEqual(resolver.pcie_distance('eth1', self.tmp), 3)

    def test_virtio_indirection_not_miscounted(self):
        # verified-real virtio_net layout: device -> virtioN node, whose
        # OWN parent is the true PCI BDF - the virtioN segment itself must
        # be skipped, not counted as a hop.
        self._make_iface_pointing_at(
            'eth2', 'pci0000:00', '0000:00:12.0', 'virtio2', 'net')
        self.assertEqual(resolver.pcie_distance('eth2', self.tmp), 1)

    def test_missing_device_symlink_returns_sentinel(self):
        os.mkdir(os.path.join(self.tmp, 'eth3'))  # no 'device' entry at all
        self.assertEqual(resolver.pcie_distance('eth3', self.tmp),
                          resolver.PCIE_DISTANCE_UNKNOWN)

    def test_broken_device_symlink_returns_sentinel(self):
        iface_path = os.path.join(self.tmp, 'eth4')
        os.mkdir(iface_path)
        os.symlink(os.path.join(self.devices_root, 'does-not-exist'),
                    os.path.join(iface_path, 'device'))
        self.assertEqual(resolver.pcie_distance('eth4', self.tmp),
                          resolver.PCIE_DISTANCE_UNKNOWN)

    def test_no_pci_segment_at_all_returns_sentinel(self):
        # simulated USB NIC: resolved path has no PCI BDF component
        self._make_iface_pointing_at('eth5', 'usb1', '1-1', '1-1:1.0')
        self.assertEqual(resolver.pcie_distance('eth5', self.tmp),
                          resolver.PCIE_DISTANCE_UNKNOWN)


class TestComputeBootstrapPlan(unittest.TestCase):
    """Bootstrap naming is what makes a box's very first boot (before any
    hw-id exists) deterministic, the same way hw-id makes every boot after
    that deterministic - it must depend only on PCIe topology and MAC
    rank, never on whatever name the racy cosmetic fast-path happened to
    assign. pcie_distance is held constant by default in these tests, so
    they exercise pure MAC-rank ordering (see TestPcieDistance for the
    topology-ordering cases specifically).
    """

    def setUp(self):
        patcher = mock.patch.object(resolver, 'is_wireless_interface',
                                     return_value=False)
        self.is_wireless = patcher.start()
        self.addCleanup(patcher.stop)

        distance_patcher = mock.patch.object(resolver, 'pcie_distance',
                                              return_value=0)
        self.pcie_distance = distance_patcher.start()
        self.addCleanup(distance_patcher.stop)

    def test_sorted_by_mac_independent_of_current_names(self):
        # names are in the OPPOSITE order of their MACs
        current = {'eth5': 'bb', 'eth2': 'aa'}
        plan = resolver.compute_bootstrap_plan({}, current, {})
        self.assertEqual(plan, {'eth2': 'eth0', 'eth5': 'eth1'})

    def test_noop_when_already_in_canonical_rank_order(self):
        current = {'eth0': 'aa', 'eth1': 'bb'}
        plan = resolver.compute_bootstrap_plan({}, current, {})
        self.assertEqual(plan, {})

    def test_configured_targets_are_never_overwritten(self):
        configured = {'m0': 'eth0'}
        current = {'eth0': 'm0', 'eth9': 'm2', 'eth8': 'm1'}
        plan = resolver.compute_bootstrap_plan(configured, current, {})
        self.assertNotIn('eth0', plan.values())
        self.assertEqual(plan.get('eth8'), 'eth1')
        self.assertEqual(plan.get('eth9'), 'eth2')

    def test_new_interface_backfills_a_gap_with_no_pending_node(self):
        # eth1 is a gap between two hw-id'd interfaces, but nothing in
        # config.boot reserves it (no hw-id, no pending node either - the
        # interface was fully deleted at some point, or never existed) -
        # a new, unrelated NIC discovered this boot is free to take it,
        # the same as it would on a system with no config for it at all.
        configured = {'m0': 'eth0', 'm2': 'eth2'}
        current = {'eth0': 'm0', 'eth2': 'm2', 'eth9': 'new-mac'}
        plan = resolver.compute_bootstrap_plan(configured, current, {})
        self.assertEqual(plan, {'eth9': 'eth1'})

    def test_multiple_new_interfaces_backfill_gaps_in_order(self):
        configured = {'m0': 'eth0', 'm2': 'eth2'}
        current = {
            'eth0': 'm0', 'eth2': 'm2',
            'ethB': 'bb', 'ethA': 'aa',
        }
        plan = resolver.compute_bootstrap_plan(configured, current, {})
        # lower mac 'aa' takes the gap at eth1 first, 'bb' continues to
        # the next free slot, eth3 - not "skip past the gap to eth3/eth4"
        self.assertEqual(plan, {'ethA': 'eth1', 'ethB': 'eth3'})

    def test_ethernet_and_wireless_numbered_independently(self):
        self.is_wireless.side_effect = lambda name: name == 'radio0'
        current = {'ifaceB': 'bb', 'radio0': 'aa'}
        plan = resolver.compute_bootstrap_plan({}, current, {})
        self.assertEqual(plan.get('radio0'), 'wlan0')
        self.assertEqual(plan.get('ifaceB'), 'eth0')

    def test_squatter_already_in_existing_plan_excluded(self):
        # 'eth0' is a squatter the hw-id plan already decided to move away
        # (existing_plan key) - it IS still bootstrap candidacy (see
        # unmatched_candidates()), but must never be handed a second,
        # conflicting assignment on top of its existing_plan eviction.
        existing_plan = {'eth0': 'eth3'}
        current = {'eth0': 'unconfigured-mac', 'eth7': 'm0'}
        plan = resolver.compute_bootstrap_plan({'m0': 'eth1'}, current,
                                                existing_plan)
        self.assertNotIn('eth0', plan)

    def test_bootstrap_targets_never_collide_with_existing_plan_values(self):
        # existing_plan says an interface currently named 'oldname' is
        # moving to 'eth0' - nothing else in `current` is named 'eth0' or
        # 'eth*' at all, so if that target isn't reserved, find_available()
        # would freely hand 'eth0' to the bootstrap candidate too.
        existing_plan = {'oldname': 'eth0'}
        current = {'oldname': 'm0', 'newnic': 'unconfigured-mac'}
        plan = resolver.compute_bootstrap_plan({'m0': 'eth0'}, current,
                                                existing_plan)
        self.assertNotEqual(plan.get('newnic'), 'eth0')

    def test_smaller_pcie_distance_wins_over_higher_mac(self):
        # 'bb' has the numerically higher MAC but sits closer to the root
        # complex - it must be named first despite losing on MAC alone.
        current = {'eth5': 'bb', 'eth2': 'aa'}
        self.pcie_distance.side_effect = lambda name: {'eth5': 0, 'eth2': 3}[name]
        plan = resolver.compute_bootstrap_plan({}, current, {})
        self.assertEqual(plan, {'eth5': 'eth0', 'eth2': 'eth1'})

    def test_same_pcie_distance_falls_back_to_mac_order(self):
        current = {'eth5': 'bb', 'eth2': 'aa'}
        self.pcie_distance.side_effect = lambda name: 2  # tie for both
        plan = resolver.compute_bootstrap_plan({}, current, {})
        self.assertEqual(plan, {'eth2': 'eth0', 'eth5': 'eth1'})

    def test_unknown_pcie_distance_sorts_last(self):
        # 'aa' has the numerically lowest MAC but an undeterminable bus
        # position (e.g. a USB NIC) - it must not jump the queue.
        current = {'eth9': 'cc', 'eth5': 'bb', 'ethX': 'aa'}
        self.pcie_distance.side_effect = lambda name: {
            'eth9': 1, 'eth5': 2, 'ethX': resolver.PCIE_DISTANCE_UNKNOWN,
        }[name]
        plan = resolver.compute_bootstrap_plan({}, current, {})
        self.assertEqual(plan, {'eth9': 'eth0', 'eth5': 'eth1', 'ethX': 'eth2'})

    def test_pcie_distance_ordering_independent_of_ethernet_wireless_split(self):
        # distance-based ordering applies within each type group separately,
        # same as MAC does today - a wlan candidate's distance must not
        # affect eth numbering or vice versa.
        self.is_wireless.side_effect = lambda name: name == 'radio0'
        current = {'ifaceB': 'bb', 'radio0': 'aa'}
        self.pcie_distance.side_effect = lambda name: {
            'ifaceB': 5, 'radio0': 0,
        }[name]
        plan = resolver.compute_bootstrap_plan({}, current, {})
        self.assertEqual(plan.get('radio0'), 'wlan0')
        self.assertEqual(plan.get('ifaceB'), 'eth0')


class TestComputeBootstrapPlanGapFill(unittest.TestCase):
    """compute_bootstrap_plan() fills ordinary numeric gaps (no config
    trace at all) deterministically by PCIe distance then MAC. A pending
    node (hw-id deleted, node kept - see get_pending_hwid_nodes()) is a
    separate concern here: passing `pending` reserves its name so an
    unrelated candidate can never squat on it and inherit its settings -
    only match_pending_nodes() may fill it, and only when unambiguous.
    """

    def setUp(self):
        patcher = mock.patch.object(resolver, 'is_wireless_interface',
                                     return_value=False)
        self.is_wireless = patcher.start()
        self.addCleanup(patcher.stop)

        distance_patcher = mock.patch.object(resolver, 'pcie_distance',
                                              return_value=0)
        self.pcie_distance = distance_patcher.start()
        self.addCleanup(distance_patcher.stop)

    def test_open_name_filled_like_an_ordinary_gap(self):
        # 'eth1' has nothing configured for it and no pending reservation
        # - it is simply the lowest open name.
        configured = {'m0': 'eth0'}
        current = {'eth0': 'm0', 'eth9': 'new-mac'}
        plan = resolver.compute_bootstrap_plan(configured, current, {})
        self.assertEqual(plan.get('eth9'), 'eth1')

    def test_ascending_fill_has_no_preference_between_open_names(self):
        # two open names (eth1, eth4 - the reason either is open makes no
        # difference) and two candidates - the lower-sorted candidate
        # takes the lower-numbered open name, unconditionally.
        configured = {'m0': 'eth0', 'm2': 'eth2', 'm3': 'eth3'}
        current = {'eth0': 'm0', 'eth2': 'm2', 'eth3': 'm3',
                   'eth9': 'bb', 'eth8': 'aa'}
        plan = resolver.compute_bootstrap_plan(configured, current, {})
        self.assertEqual(plan.get('eth8'), 'eth1')
        self.assertEqual(plan.get('eth9'), 'eth4')

    def test_two_plain_gaps_fill_in_ascending_order(self):
        # two fully-deleted interfaces (no hw-id, no pending node either)
        # - both ordinary gaps, filled by the same ascending PCIe/MAC
        # sort as any other unconfigured hardware.
        configured = {
            '00:00:5e:00:53:00': 'eth0', '00:00:5e:00:53:01': 'eth1',
            '00:00:5e:00:53:03': 'eth3', '00:00:5e:00:53:05': 'eth5',
            '00:00:5e:00:53:06': 'eth6', '00:00:5e:00:53:07': 'eth7',
        }
        current = {name: mac for mac, name in configured.items()}
        current.update({'eth9': '00:00:5e:00:53:02',
                        'eth8': '00:00:5e:00:53:04'})
        plan = resolver.compute_bootstrap_plan(configured, current, {})
        self.assertEqual(plan.get('eth9'), 'eth2')
        self.assertEqual(plan.get('eth8'), 'eth4')

    def test_open_names_currently_squatted_by_a_rightful_mover_are_not_taken(self):
        # real boot reproduction (via the resolver's own status file,
        # captured mid-failure): the cosmetic fast-path this boot had
        # every configured mac sitting on some OTHER configured mac's
        # target name (a full rotation), including the two plain gaps
        # (eth1, eth6) both currently squatted by macs that are about to
        # move elsewhere via a rightful-owner move. existing_plan's
        # SOURCE names looked "taken" at the exact moment this function
        # ran, but safe_bulk_rename()'s two-phase staging vacates every
        # source before any target is claimed - so they must not count
        # as taken, or the two real candidates get needlessly pushed to
        # fresh eth8/eth9-style slots instead of their own open names.
        configured = {
            '00:00:5e:00:53:00': 'eth0', '00:00:5e:00:53:02': 'eth2',
            '00:00:5e:00:53:03': 'eth3', '00:00:5e:00:53:04': 'eth4',
            '00:00:5e:00:53:05': 'eth5', '00:00:5e:00:53:07': 'eth7',
        }
        current = {
            'eth4': '00:00:5e:00:53:00', 'eth6': '00:00:5e:00:53:02',
            'eth7': '00:00:5e:00:53:03', 'eth2': '00:00:5e:00:53:04',
            'eth3': '00:00:5e:00:53:05', 'eth1': '00:00:5e:00:53:07',
            'eth0': '00:00:5e:00:53:06',  # unconfigured - squats on eth0
            'eth5': '00:00:5e:00:53:01',  # unconfigured - squats on eth5
        }
        existing_plan = resolver.compute_rename_plan(configured, current)
        plan = resolver.compute_bootstrap_plan(configured, current,
                                                existing_plan)
        self.assertEqual(plan.get('eth5'), 'eth1')
        self.assertEqual(plan.get('eth0'), 'eth6')

    def test_pending_name_reserved_against_unrelated_bootstrap_candidate(self):
        # 'eth1' is pending (no hw-id) - two unrelated new NICs discovered
        # this boot must not land on it just because sequential numbering
        # would otherwise reach it as the second assignment.
        configured = {}
        pending = {'ethernet': {'eth1'}, 'wireless': set()}
        current = {'eth9': 'aa', 'eth8': 'bb'}
        plan = resolver.compute_bootstrap_plan(configured, current, {},
                                                pending=pending)
        self.assertEqual(plan.get('eth9'), 'eth0')
        self.assertEqual(plan.get('eth8'), 'eth2')
        self.assertNotEqual(plan.get('eth9'), 'eth1')
        self.assertNotEqual(plan.get('eth8'), 'eth1')

    def test_reclaimed_candidate_excluded_from_ordinary_bootstrap(self):
        # main() already matched this candidate to a pending node via
        # match_pending_nodes() - it must not also be assigned a fresh
        # bootstrap name here, even if its current name differs from the
        # reclaimed target (main() handles the actual rename itself).
        configured = {}
        current = {'eth9': 'm1', 'eth8': 'm2'}
        plan = resolver.compute_bootstrap_plan(configured, current, {},
                                                reclaimed_macs={'m1'})
        self.assertNotIn('eth9', plan)
        self.assertIn('eth8', plan)


class TestSafeBulkRename(unittest.TestCase):
    """The two-phase rename must accurately report what actually happened -
    a phase-2 (scratch -> final target) failure must not be reported as a
    successful rename, and must not leave the interface down indefinitely
    under a name nothing else knows about.
    """

    def setUp(self):
        patcher = mock.patch.object(resolver, 'get_ifindex',
                                     side_effect=lambda name: name)
        patcher.start()
        self.addCleanup(patcher.stop)

    def test_all_renames_succeed(self):
        with mock.patch.object(resolver, 'run', return_value=0):
            applied = resolver.safe_bulk_rename({'eth5': 'eth0'})
        self.assertEqual(applied, {'eth5': 'eth0'})

    def test_phase_two_failure_is_not_reported_as_applied(self):
        # 'ip link set dev vyetheth5 name eth0' fails (exit 1); everything
        # else (down, the phase-1 rename to scratch) succeeds
        def fake_run(command, *_a, **_kw):
            return 1 if command == 'ip link set dev vyetheth5 name eth0' else 0

        with mock.patch.object(resolver, 'run', side_effect=fake_run):
            applied = resolver.safe_bulk_rename({'eth5': 'eth0'})

        self.assertNotIn('eth5', applied)
        self.assertNotEqual(applied.get('eth5'), 'eth0')

    def test_phase_two_failure_brings_scratch_name_back_up(self):
        calls = []

        def fake_run(command, *_a, **_kw):
            calls.append(command)
            return 1 if command == 'ip link set dev vyetheth5 name eth0' else 0

        with mock.patch.object(resolver, 'run', side_effect=fake_run):
            resolver.safe_bulk_rename({'eth5': 'eth0'})

        self.assertIn('ip link set dev vyetheth5 up', calls)
        self.assertNotIn('ip link set dev eth0 up', calls)

    def test_one_failure_does_not_affect_other_renames_in_the_batch(self):
        def fake_run(command, *_a, **_kw):
            return 1 if command == 'ip link set dev vyetheth5 name eth0' else 0

        with mock.patch.object(resolver, 'run', side_effect=fake_run):
            applied = resolver.safe_bulk_rename({'eth5': 'eth0', 'eth9': 'eth1'})

        self.assertNotIn('eth5', applied)
        self.assertEqual(applied.get('eth9'), 'eth1')


class TestGetPermanentMac(unittest.TestCase):
    """Part of the original race is reading a MAC before the driver has
    programmed the permanent address. Verify the ethtool-first,
    sysfs-fallback behaviour, including drivers that report an all-zero
    'unsupported' permanent address instead of failing outright.
    """

    def test_ethtool_permanent_address(self):
        with mock.patch.object(
                resolver, 'rc_cmd',
                return_value=(0, 'Permanent address: aa:bb:cc:dd:ee:ff\n')):
            self.assertEqual(resolver.get_permanent_mac('eth0'),
                              'aa:bb:cc:dd:ee:ff')

    def test_ethtool_zero_address_falls_back_to_sysfs(self):
        with mock.patch.object(
                resolver, 'rc_cmd',
                return_value=(0, 'Permanent address: 00:00:00:00:00:00\n')), \
             mock.patch('pathlib.Path.read_text',
                        return_value='11:22:33:44:55:66\n'):
            self.assertEqual(resolver.get_permanent_mac('eth0'),
                              '11:22:33:44:55:66')

    def test_ethtool_unsupported_falls_back_to_sysfs(self):
        with mock.patch.object(
                resolver, 'rc_cmd',
                return_value=(1, 'Operation not supported')), \
             mock.patch('pathlib.Path.read_text',
                        return_value='11:22:33:44:55:66\n'):
            self.assertEqual(resolver.get_permanent_mac('eth0'),
                              '11:22:33:44:55:66')

    def test_no_mac_available_returns_empty(self):
        with mock.patch.object(resolver, 'rc_cmd', return_value=(1, '')), \
             mock.patch('pathlib.Path.read_text', side_effect=OSError):
            self.assertEqual(resolver.get_permanent_mac('eth0'), '')


class TestDiscoverPhysicalInterfaces(unittest.TestCase):
    """Only interfaces with a real bus 'device' link are candidates -
    bridges/bonds/VLANs/veth must be excluded regardless of name, since
    this replaces the racy udev DRIVERS=="?*" check with a stable,
    post-settle sysfs read.
    """

    def setUp(self):
        self.tmp = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, self.tmp, ignore_errors=True)

        def make_iface(name, mac=None, has_device=True):
            path = os.path.join(self.tmp, name)
            os.mkdir(path)
            if has_device:
                os.mkdir(os.path.join(path, 'device'))
            if mac:
                with open(os.path.join(path, 'address'), 'w') as f:
                    f.write(mac + '\n')

        make_iface('eth0', mac='aa:aa:aa:aa:aa:00')
        make_iface('eth1', mac='aa:aa:aa:aa:aa:01')
        make_iface('br0', mac='aa:aa:aa:aa:aa:99', has_device=False)
        make_iface('lo', has_device=False)

    def test_only_physical_interfaces_with_mac(self):
        with mock.patch.object(resolver, 'rc_cmd', return_value=(1, '')):
            found = resolver.discover_physical_interfaces(self.tmp)
        self.assertEqual(found, {
            'eth0': 'aa:aa:aa:aa:aa:00',
            'eth1': 'aa:aa:aa:aa:aa:01',
        })
        self.assertNotIn('br0', found)
        self.assertNotIn('lo', found)


class TestSyncRescanHints(unittest.TestCase):
    """New/unconfigured hardware must still be surfaced to
    vyos-interface-rescan.py, already-configured interfaces must not, and
    hints left under a pre-rename name must not linger once the resolver
    has moved that interface to its hw-id target.
    """

    def setUp(self):
        self.tmp = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, self.tmp, ignore_errors=True)
        self._orig_dir = resolver.vyos_udev_dir
        resolver.vyos_udev_dir = self.tmp
        self.addCleanup(setattr, resolver, 'vyos_udev_dir', self._orig_dir)

    def test_writes_hint_for_unconfigured_interface(self):
        resolver.sync_rescan_hints({'eth5': 'new-mac'}, configured={})
        hint = os.path.join(self.tmp, 'eth5')
        self.assertTrue(os.path.isfile(hint))
        with open(hint) as f:
            self.assertEqual(f.read(), 'new-mac')

    def test_no_hint_for_configured_interface(self):
        resolver.sync_rescan_hints({'eth0': 'm0'}, configured={'m0': 'eth0'})
        self.assertFalse(os.path.exists(os.path.join(self.tmp, 'eth0')))

    def test_stale_hint_removed_after_rename(self):
        # udev's cosmetic fast-path wrote a hint under the pre-rename name;
        # the resolver then moved that interface to its hw-id target.
        stale = os.path.join(self.tmp, 'eth7')
        with open(stale, 'w') as f:
            f.write('m2')
        resolver.sync_rescan_hints({'eth10': 'm2'}, configured={'m2': 'eth10'},
                                    stale_names={'eth7'})
        self.assertFalse(os.path.exists(stale))



class TestMainFirstBootBootstrap(unittest.TestCase):
    """Direct regression guard for the gap this feature closes: main()
    used to leave a fully-unconfigured system's interfaces at whatever
    racy cosmetic name they already had, with no settle wait at all, and
    freeze that into the rescan hints vyos-interface-rescan.py persists.
    """

    def setUp(self):
        self.udev_dir = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, self.udev_dir, ignore_errors=True)
        self._orig_udev_dir = resolver.vyos_udev_dir
        resolver.vyos_udev_dir = self.udev_dir
        self.addCleanup(setattr, resolver, 'vyos_udev_dir', self._orig_udev_dir)

        status_dir = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, status_dir, ignore_errors=True)
        self._orig_status_file = resolver.status_file
        resolver.status_file = resolver.Path(status_dir) / 'status.json'
        self.addCleanup(setattr, resolver, 'status_file', self._orig_status_file)

    def test_empty_configfile_bootstrap_renames_and_hints_new_names(self):
        # a tiny fake kernel: name -> mac, mutated by simulated 'ip link'
        # calls so discover_physical_interfaces() reflects renames for real
        state = {'eth5': 'bb', 'eth2': 'aa'}  # cosmetic fast-path leftover

        def fake_discover(*_a, **_kw):
            return dict(state)

        def fake_run(command, *_a, **_kw):
            parts = command.split()
            if 'name' in parts:
                old = parts[parts.index('dev') + 1]
                new = parts[parts.index('name') + 1]
                if old in state:
                    state[new] = state.pop(old)
            return 0

        with mock.patch.object(resolver, 'get_configfile_interfaces',
                                return_value={}), \
             mock.patch.object(resolver, 'get_pending_hwid_nodes',
                                return_value={'ethernet': set(), 'wireless': set()}), \
             mock.patch.object(resolver, 'discover_physical_interfaces',
                                side_effect=fake_discover), \
             mock.patch.object(resolver, 'is_wireless_interface',
                                return_value=False), \
             mock.patch.object(resolver, 'run', side_effect=fake_run), \
             mock.patch('time.sleep'):
            resolver.main()

        hints = set(os.listdir(self.udev_dir))
        # renamed into MAC-rank order: lower mac 'aa' -> eth0, higher 'bb' -> eth1
        self.assertEqual(hints, {'eth0', 'eth1'})
        with open(os.path.join(self.udev_dir, 'eth0')) as f:
            self.assertEqual(f.read(), 'aa')
        with open(os.path.join(self.udev_dir, 'eth1')) as f:
            self.assertEqual(f.read(), 'bb')

    def test_pending_node_still_settles_when_its_hardware_is_slow_to_appear(self):
        # field report: a pending node ended up permanently bound to a
        # fresh eth8/eth9-style name despite its own hardware genuinely
        # being present - because that hardware (a slower driver, exactly
        # the multi-vendor-NIC race this whole feature addresses) simply
        # had not shown up in the FIRST, unsettled discover_physical_
        # interfaces() snapshot wait_for_hardware() returns as soon as all
        # already-CONFIGURED macs are found. Since that snapshot showed
        # nothing unconfigured yet, main()'s gate into wait_for_settle()
        # never even ran, giving the slow hardware zero extra time to
        # appear before the boot gave up. A pending node in play must
        # force wait_for_settle() to run regardless of what the early
        # snapshot shows, so slower hardware still gets its chance.
        configured = {'m0': 'eth0'}
        pending = {'ethernet': {'eth1'}, 'wireless': set()}

        calls = {'n': 0}

        def fake_discover(*_a, **_kw):
            calls['n'] += 1
            if calls['n'] <= 2:
                return {'eth0': 'm0'}  # m1's hardware not visible yet
            return {'eth0': 'm0', 'eth9': 'm1'}  # now it has appeared

        state = {'eth0': 'm0', 'eth9': 'm1'}

        def fake_run(command, *_a, **_kw):
            parts = command.split()
            if 'name' in parts:
                old = parts[parts.index('dev') + 1]
                new = parts[parts.index('name') + 1]
                if old in state:
                    state[new] = state.pop(old)
            return 0

        with mock.patch.object(resolver, 'get_configfile_interfaces',
                                return_value=configured), \
             mock.patch.object(resolver, 'get_pending_hwid_nodes',
                                return_value=pending), \
             mock.patch.object(resolver, 'discover_physical_interfaces',
                                side_effect=fake_discover), \
             mock.patch.object(resolver, 'is_wireless_interface',
                                return_value=False), \
             mock.patch.object(resolver, 'pcie_distance', return_value=0), \
             mock.patch.object(resolver, 'run', side_effect=fake_run), \
             mock.patch('time.sleep'):
            resolver.main()

        self.assertEqual(state.get('eth1'), 'm1')

        status = json.loads(resolver.status_file.read_text())
        self.assertEqual(status['reclaimed'], {'m1': 'eth1'})
        self.assertEqual(status['pending_unresolved'], [])

    def test_reported_reproduction_end_to_end(self):
        # exact reported scenario: eth0/eth2 keep their hw-id, eth1's hw-id
        # was deleted (the documented "NIC replaced" remediation) but its
        # node - and an address setting - stay in config.boot. The same
        # physical NIC (mac 'm1') must come back as 'eth1', not bootstrap
        # past the floor to 'eth3', and must still get a rescan hint under
        # 'eth1' so vyos-interface-rescan.py can refill its hw-id.
        configured = {'m0': 'eth0', 'm2': 'eth2'}
        pending = {'ethernet': {'eth1'}, 'wireless': set()}
        # cosmetic fast-path already placed everything at its final
        # hw-id'd name except the replaced NIC, which landed on a racy name
        state = {'eth0': 'm0', 'eth2': 'm2', 'eth9': 'm1'}

        def fake_discover(*_a, **_kw):
            return dict(state)

        def fake_run(command, *_a, **_kw):
            parts = command.split()
            if 'name' in parts:
                old = parts[parts.index('dev') + 1]
                new = parts[parts.index('name') + 1]
                if old in state:
                    state[new] = state.pop(old)
            return 0

        with mock.patch.object(resolver, 'get_configfile_interfaces',
                                return_value=configured), \
             mock.patch.object(resolver, 'get_pending_hwid_nodes',
                                return_value=pending), \
             mock.patch.object(resolver, 'discover_physical_interfaces',
                                side_effect=fake_discover), \
             mock.patch.object(resolver, 'is_wireless_interface',
                                return_value=False), \
             mock.patch.object(resolver, 'run', side_effect=fake_run), \
             mock.patch('time.sleep'):
            resolver.main()

        # the NIC is back at 'eth1', not bootstrapped past the floor to 'eth3'
        self.assertEqual(state.get('eth1'), 'm1')
        self.assertNotIn('eth3', state)

        # still gets a rescan hint under its reclaimed name, so
        # vyos-interface-rescan.py can write the real hw-id into the
        # existing 'eth1' node (preserving its other settings, e.g. address)
        hints = set(os.listdir(self.udev_dir))
        self.assertEqual(hints, {'eth1'})
        with open(os.path.join(self.udev_dir, 'eth1')) as f:
            self.assertEqual(f.read(), 'm1')

        status = json.loads(resolver.status_file.read_text())
        self.assertEqual(status['reclaimed'], {'m1': 'eth1'})
        self.assertEqual(status['pending_unresolved'], [])

    def test_fully_deleted_interfaces_backfill_their_gaps_end_to_end(self):
        # reported scenario: eth3, eth6 and eth7 were fully deleted (not
        # just their hw-id - the whole node, so get_pending_hwid_nodes()
        # has nothing for them either) while eth0,1,2,4,5,8,9 stay
        # configured. The three now-unconfigured NICs must backfill the
        # gaps at 3/6/7 in MAC order, not bootstrap past the highest
        # configured index (9) to 10/11/12.
        configured = {
            'm0': 'eth0', 'm1': 'eth1', 'm2': 'eth2', 'm4': 'eth4',
            'm5': 'eth5', 'm8': 'eth8', 'm9': 'eth9',
        }
        pending = {'ethernet': set(), 'wireless': set()}
        state = {name: mac for mac, name in configured.items()}
        # realistic macs, deliberately NOT alphabetically matching their
        # old slot, so the test can't pass by coincidence
        state.update({'ethX': 'ff:ff:ff:ff:ff:07',
                       'ethY': 'aa:aa:aa:aa:aa:03',
                       'ethZ': 'cc:cc:cc:cc:cc:06'})

        def fake_discover(*_a, **_kw):
            return dict(state)

        def fake_run(command, *_a, **_kw):
            parts = command.split()
            if 'name' in parts:
                old = parts[parts.index('dev') + 1]
                new = parts[parts.index('name') + 1]
                if old in state:
                    state[new] = state.pop(old)
            return 0

        with mock.patch.object(resolver, 'get_configfile_interfaces',
                                return_value=configured), \
             mock.patch.object(resolver, 'get_pending_hwid_nodes',
                                return_value=pending), \
             mock.patch.object(resolver, 'discover_physical_interfaces',
                                side_effect=fake_discover), \
             mock.patch.object(resolver, 'is_wireless_interface',
                                return_value=False), \
             mock.patch.object(resolver, 'pcie_distance', return_value=0), \
             mock.patch.object(resolver, 'run', side_effect=fake_run), \
             mock.patch('time.sleep'):
            resolver.main()

        # the three gaps got backfilled in ascending MAC order, not pushed
        # past the highest configured index to eth10/eth11/eth12
        self.assertEqual(state.get('eth3'), 'aa:aa:aa:aa:aa:03')
        self.assertEqual(state.get('eth6'), 'cc:cc:cc:cc:cc:06')
        self.assertEqual(state.get('eth7'), 'ff:ff:ff:ff:ff:07')
        self.assertNotIn('eth10', state)
        self.assertNotIn('eth11', state)
        self.assertNotIn('eth12', state)

    def test_stray_leftover_interface_makes_reclaim_ambiguous(self):
        # field report: deleting only eth7's hw-id and rebooting produced
        # "could not be safely auto-matched" instead of a clean reclaim,
        # because a stray interface left over from an earlier, unrelated
        # boot (e.g. a scratch vyethN name stuck after a failed rename)
        # was also present, making this a 1 pending/2 candidate case.
        # There is no way to tell which candidate was "really" eth7's own
        # past hardware once its hw-id is gone, so eth7 stays unresolved;
        # both candidates still get a real, settings-free hw-id via
        # ordinary bootstrap naming instead of being lost.
        configured = {
            'm0': 'eth0', 'm1': 'eth1', 'm2': 'eth2', 'm4': 'eth4',
            'm5': 'eth5', 'm6': 'eth6',
        }
        pending = {'ethernet': {'eth7'}, 'wireless': set()}
        state = {name: mac for mac, name in configured.items()}
        state.update({'eth9': 'aa:bb:cc:dd:ee:07',      # eth7's own hardware
                      'vyeth13': 'ff:ff:ff:ff:ff:99'})  # unrelated leftover

        def fake_discover(*_a, **_kw):
            return dict(state)

        def fake_run(command, *_a, **_kw):
            parts = command.split()
            if 'name' in parts:
                old = parts[parts.index('dev') + 1]
                new = parts[parts.index('name') + 1]
                if old in state:
                    state[new] = state.pop(old)
            return 0

        with mock.patch.object(resolver, 'get_configfile_interfaces',
                                return_value=configured), \
             mock.patch.object(resolver, 'get_pending_hwid_nodes',
                                return_value=pending), \
             mock.patch.object(resolver, 'discover_physical_interfaces',
                                side_effect=fake_discover), \
             mock.patch.object(resolver, 'is_wireless_interface',
                                return_value=False), \
             mock.patch.object(resolver, 'pcie_distance', return_value=0), \
             mock.patch.object(resolver, 'run', side_effect=fake_run), \
             mock.patch('time.sleep'):
            resolver.main()

        # 'eth7' stays pending rather than being guessed at; both
        # candidates still land on real, settings-free names (the lone
        # ordinary gap, then the next fresh slot after that)
        self.assertNotIn('eth7', state)
        self.assertEqual(state.get('eth3'), 'aa:bb:cc:dd:ee:07')
        self.assertEqual(state.get('eth8'), 'ff:ff:ff:ff:ff:99')

        hints = set(os.listdir(self.udev_dir))
        self.assertEqual(hints, {'eth3', 'eth8'})

        status = json.loads(resolver.status_file.read_text())
        self.assertEqual(status['pending_unresolved'], ['eth7'])
        self.assertEqual(status['reclaimed'], {})

    def test_second_pending_node_makes_reclaim_ambiguous(self):
        # two pending nodes (eth1 and eth7), but only one candidate showed
        # up this boot - which one it belongs to can't be told, so
        # neither is matched; the candidate still gets a real,
        # settings-free name via ordinary bootstrap naming.
        configured = {'m0': 'eth0'}
        pending = {'ethernet': {'eth1', 'eth7'}, 'wireless': set()}
        state = {'eth0': 'm0', 'eth9': 'aa:bb:cc:dd:ee:07'}

        def fake_discover(*_a, **_kw):
            return dict(state)

        def fake_run(command, *_a, **_kw):
            parts = command.split()
            if 'name' in parts:
                old = parts[parts.index('dev') + 1]
                new = parts[parts.index('name') + 1]
                if old in state:
                    state[new] = state.pop(old)
            return 0

        with mock.patch.object(resolver, 'get_configfile_interfaces',
                                return_value=configured), \
             mock.patch.object(resolver, 'get_pending_hwid_nodes',
                                return_value=pending), \
             mock.patch.object(resolver, 'discover_physical_interfaces',
                                side_effect=fake_discover), \
             mock.patch.object(resolver, 'is_wireless_interface',
                                return_value=False), \
             mock.patch.object(resolver, 'pcie_distance', return_value=0), \
             mock.patch.object(resolver, 'run', side_effect=fake_run), \
             mock.patch('time.sleep'):
            resolver.main()

        self.assertNotIn('eth1', state)
        self.assertNotIn('eth7', state)
        self.assertEqual(state.get('eth2'), 'aa:bb:cc:dd:ee:07')

        status = json.loads(resolver.status_file.read_text())
        self.assertEqual(status['pending_unresolved'], ['eth1', 'eth7'])
        self.assertEqual(status['reclaimed'], {})

    def test_ambiguous_candidates_never_get_a_permanent_wrong_binding(self):
        # field report: deleting eth2's hw-id (leaving its node in place)
        # produced "0 unconfigured candidates" on a later boot, because an
        # EARLIER ambiguous boot had already permanently bound the wrong
        # candidate elsewhere. One pending node with two candidates this
        # boot must not be guessed at either way - it stays pending, and
        # both candidates still get a real, settings-free hw-id via
        # ordinary bootstrap naming (the one open gap, then a fresh slot).
        configured = {'m0': 'eth0'}
        pending = {'ethernet': {'eth2'}, 'wireless': set()}
        state = {
            'eth0': 'm0',
            'racyA': 'aa:bb:cc:dd:ee:02',  # eth2's own hardware
            'racyB': 'ff:ff:ff:ff:ff:99',  # unrelated leftover candidate
        }

        def fake_discover(*_a, **_kw):
            return dict(state)

        def fake_run(command, *_a, **_kw):
            parts = command.split()
            if 'name' in parts:
                old = parts[parts.index('dev') + 1]
                new = parts[parts.index('name') + 1]
                if old in state:
                    state[new] = state.pop(old)
            return 0

        with mock.patch.object(resolver, 'get_configfile_interfaces',
                                return_value=configured), \
             mock.patch.object(resolver, 'get_pending_hwid_nodes',
                                return_value=pending), \
             mock.patch.object(resolver, 'discover_physical_interfaces',
                                side_effect=fake_discover), \
             mock.patch.object(resolver, 'is_wireless_interface',
                                return_value=False), \
             mock.patch.object(resolver, 'pcie_distance', return_value=0), \
             mock.patch.object(resolver, 'run', side_effect=fake_run), \
             mock.patch('time.sleep'):
            resolver.main()

        # 'eth2' stays pending; both candidates land on real, settings-
        # free names instead (the one open gap, then a fresh slot)
        self.assertNotIn('eth2', state)
        self.assertEqual(state.get('eth1'), 'aa:bb:cc:dd:ee:02')
        self.assertEqual(state.get('eth3'), 'ff:ff:ff:ff:ff:99')

        hints = set(os.listdir(self.udev_dir))
        self.assertEqual(hints, {'eth1', 'eth3'})

        status = json.loads(resolver.status_file.read_text())
        self.assertEqual(status['pending_unresolved'], ['eth2'])
        self.assertEqual(status['reclaimed'], {})

    def test_simultaneous_ambiguity_holds_back_every_candidate(self):
        # two NICs' hw-id were deleted before the same reboot (eth0 and
        # eth2, nodes left in place), and both came back racily named.
        # Each candidate's MAC happens to obviously "belong" to one
        # specific pending node (racyA's mac ends in :00, matching what
        # eth0 used to be; racyB's mac ends in :02, matching eth2) - but
        # there is no way to actually verify that pairing, so with 2
        # pending nodes and 2 candidates present at once, neither may be
        # auto-matched: guessing the "obvious" pairing risks silently
        # binding a configured node's settings to the wrong physical NIC
        # if the guess is ever wrong. Both stay pending and reported;
        # both candidates still get a real, settings-free hw-id via
        # ordinary bootstrap naming.
        configured = {
            'm1': 'eth1', 'm3': 'eth3', 'm4': 'eth4',
            'm5': 'eth5', 'm6': 'eth6', 'm7': 'eth7',
        }
        pending = {'ethernet': {'eth0', 'eth2'}, 'wireless': set()}
        state = {name: mac for mac, name in configured.items()}
        state.update({
            'racyA': 'aa:bb:cc:dd:ee:00',  # looks like eth0's old hardware
            'racyB': 'aa:bb:cc:dd:ee:02',  # looks like eth2's old hardware
        })

        def fake_discover(*_a, **_kw):
            return dict(state)

        def fake_run(command, *_a, **_kw):
            parts = command.split()
            if 'name' in parts:
                old = parts[parts.index('dev') + 1]
                new = parts[parts.index('name') + 1]
                if old in state:
                    state[new] = state.pop(old)
            return 0

        with mock.patch.object(resolver, 'get_configfile_interfaces',
                                return_value=configured), \
             mock.patch.object(resolver, 'get_pending_hwid_nodes',
                                return_value=pending), \
             mock.patch.object(resolver, 'discover_physical_interfaces',
                                side_effect=fake_discover), \
             mock.patch.object(resolver, 'is_wireless_interface',
                                return_value=False), \
             mock.patch.object(resolver, 'pcie_distance', return_value=0), \
             mock.patch.object(resolver, 'run', side_effect=fake_run), \
             mock.patch('time.sleep'):
            resolver.main()

        # neither pending node is guessed at - both candidates land on
        # fresh, settings-free bootstrap names instead (no ordinary gaps
        # exist here, so both go beyond the highest configured index)
        self.assertNotIn('eth0', state)
        self.assertNotIn('eth2', state)
        self.assertEqual(state.get('eth8'), 'aa:bb:cc:dd:ee:00')
        self.assertEqual(state.get('eth9'), 'aa:bb:cc:dd:ee:02')

        hints = set(os.listdir(self.udev_dir))
        self.assertEqual(hints, {'eth8', 'eth9'})

        status = json.loads(resolver.status_file.read_text())
        self.assertEqual(status['pending_unresolved'], ['eth0', 'eth2'])
        self.assertEqual(status['reclaimed'], {})

    def test_squatting_pending_candidate_still_reclaims_correctly(self):
        # field report: deleting eth7's hw-id (node left in place) produced
        # a "0 unconfigured candidates" boot even though eth7's real
        # hardware was present, and it later turned up permanently bound
        # to a fresh eth8/eth9-style name. Root cause: eth7's hardware
        # (mac07) happened to be squatting on eth2's configured hw-id slot
        # this boot (probe-order scrambling) - compute_rename_plan()
        # already scheduled it for eviction, which used to make
        # unmatched_candidates() skip it entirely, so it never reached the
        # ascending fill and fell through to a stale, unrelated fallback
        # destination instead. A squatting candidate must still reclaim
        # its pending node exactly like a non-squatting one would, when it
        # is the only open name and the only candidate this boot.
        configured = {
            'm0': 'eth0', 'm1': 'eth1', 'm2': 'eth2', 'm3': 'eth3',
            'm4': 'eth4', 'm5': 'eth5', 'm6': 'eth6',
        }
        pending = {'ethernet': {'eth7'}, 'wireless': set()}
        state = {name: mac for mac, name in configured.items()}
        state.update({
            'eth2': 'aa:bb:cc:dd:ee:07',  # eth7's hardware squats on eth2
            'eth9': 'm2',                 # m2's rightful NIC, racy this boot
        })

        def fake_discover(*_a, **_kw):
            return dict(state)

        def fake_run(command, *_a, **_kw):
            parts = command.split()
            if 'name' in parts:
                old = parts[parts.index('dev') + 1]
                new = parts[parts.index('name') + 1]
                if old in state:
                    state[new] = state.pop(old)
            return 0

        with mock.patch.object(resolver, 'get_configfile_interfaces',
                                return_value=configured), \
             mock.patch.object(resolver, 'get_pending_hwid_nodes',
                                return_value=pending), \
             mock.patch.object(resolver, 'discover_physical_interfaces',
                                side_effect=fake_discover), \
             mock.patch.object(resolver, 'is_wireless_interface',
                                return_value=False), \
             mock.patch.object(resolver, 'pcie_distance', return_value=0), \
             mock.patch.object(resolver, 'run', side_effect=fake_run), \
             mock.patch('time.sleep'):
            resolver.main()

        # m2 still lands on its own configured slot, and the squatter
        # reclaims 'eth7' - not some unrelated fresh bootstrap slot
        self.assertEqual(state.get('eth2'), 'm2')
        self.assertEqual(state.get('eth7'), 'aa:bb:cc:dd:ee:07')
        self.assertNotIn('eth8', state)
        self.assertNotIn('eth9', state)

        hints = set(os.listdir(self.udev_dir))
        self.assertEqual(hints, {'eth7'})

        status = json.loads(resolver.status_file.read_text())
        self.assertEqual(status['reclaimed'], {'aa:bb:cc:dd:ee:07': 'eth7'})
        self.assertEqual(status['pending_unresolved'], [])

    def test_squatting_candidate_and_extra_candidate_makes_reclaim_ambiguous(self):
        # same squatter-eviction shape as the test above, but with a
        # second, unrelated candidate also present this boot - genuinely
        # ambiguous, exactly like a non-squatting extra candidate would
        # be. The pending node stays unresolved; the squatter still gets
        # evicted off of the configured slot it's sitting on (so the
        # rightful owner isn't blocked) and, like the stray, lands on a
        # real, settings-free bootstrap name instead of the pending one.
        configured = {
            'm0': 'eth0', 'm1': 'eth1', 'm2': 'eth2',
            'm3': 'eth3', 'm4': 'eth4', 'm5': 'eth5',
        }
        pending = {'ethernet': {'eth7'}, 'wireless': set()}
        state = {name: mac for mac, name in configured.items()}
        state.update({
            'eth3': 'aa:bb:cc:dd:ee:07',   # squats on m3's configured slot
            'eth9': 'm3',                  # m3's rightful NIC, racy this boot
            'racyC': 'ff:ff:ff:ff:ff:99',  # unrelated leftover candidate
        })

        def fake_discover(*_a, **_kw):
            return dict(state)

        def fake_run(command, *_a, **_kw):
            parts = command.split()
            if 'name' in parts:
                old = parts[parts.index('dev') + 1]
                new = parts[parts.index('name') + 1]
                if old in state:
                    state[new] = state.pop(old)
            return 0

        with mock.patch.object(resolver, 'get_configfile_interfaces',
                                return_value=configured), \
             mock.patch.object(resolver, 'get_pending_hwid_nodes',
                                return_value=pending), \
             mock.patch.object(resolver, 'discover_physical_interfaces',
                                side_effect=fake_discover), \
             mock.patch.object(resolver, 'is_wireless_interface',
                                return_value=False), \
             mock.patch.object(resolver, 'pcie_distance', return_value=0), \
             mock.patch.object(resolver, 'run', side_effect=fake_run), \
             mock.patch('time.sleep'):
            resolver.main()

        # m3 still lands on its own configured slot; 'eth7' stays pending
        # rather than being guessed at; the squatter and the stray both
        # land on real, settings-free names instead
        self.assertEqual(state.get('eth3'), 'm3')
        self.assertNotIn('eth7', state)
        self.assertEqual(state.get('eth6'), 'aa:bb:cc:dd:ee:07')
        self.assertEqual(state.get('eth8'), 'ff:ff:ff:ff:ff:99')

        hints = set(os.listdir(self.udev_dir))
        self.assertEqual(hints, {'eth6', 'eth8'})

        status = json.loads(resolver.status_file.read_text())
        self.assertEqual(status['pending_unresolved'], ['eth7'])
        self.assertEqual(status['reclaimed'], {})

    def test_gap_backfill_and_pending_node_coexisting_stays_ambiguous(self):
        # the exact vyos-build check-qemu-install --ifnametest shape: one
        # interface's whole config node is fully deleted (a free numeric
        # gap) while a DIFFERENT interface's hw-id alone is deleted (a
        # pending node) in the very same reboot
        # (del_idx, hwid_idx = random.sample(range(8), 2)). This is
        # genuinely ambiguous for the pending node (eth2): its own
        # hardware and the gap's freed hardware are two indistinguishable
        # candidates of the same type, and guessing risks silently
        # binding eth2's settings to the wrong physical NIC - confirmed
        # in the field. eth2 stays pending; both candidates still get a
        # real, settings-free hw-id via ordinary bootstrap naming (the
        # actual gap, then a fresh slot) - nothing is lost, just not
        # auto-attributed to the right name.
        configured = {
            'm0': 'eth0', 'm1': 'eth1', 'm3': 'eth3', 'm4': 'eth4',
            'm6': 'eth6', 'm8': 'eth8', 'm9': 'eth9',
        }
        pending = {'ethernet': {'eth2'}, 'wireless': set()}
        state = {name: mac for mac, name in configured.items()}
        state.update({
            'eth7': 'aa:bb:cc:dd:ee:02',  # eth2's real hardware, racy this boot
            'eth5': 'ff:ff:ff:ff:ff:05',  # eth5 fully deleted, its own hardware freed
        })

        def fake_discover(*_a, **_kw):
            return dict(state)

        def fake_run(command, *_a, **_kw):
            parts = command.split()
            if 'name' in parts:
                old = parts[parts.index('dev') + 1]
                new = parts[parts.index('name') + 1]
                if old in state:
                    state[new] = state.pop(old)
            return 0

        with mock.patch.object(resolver, 'get_configfile_interfaces',
                                return_value=configured), \
             mock.patch.object(resolver, 'get_pending_hwid_nodes',
                                return_value=pending), \
             mock.patch.object(resolver, 'discover_physical_interfaces',
                                side_effect=fake_discover), \
             mock.patch.object(resolver, 'is_wireless_interface',
                                return_value=False), \
             mock.patch.object(resolver, 'pcie_distance', return_value=0), \
             mock.patch.object(resolver, 'run', side_effect=fake_run), \
             mock.patch('time.sleep'):
            resolver.main()

        self.assertNotIn('eth2', state)
        self.assertEqual(state.get('eth5'), 'aa:bb:cc:dd:ee:02')
        self.assertEqual(state.get('eth7'), 'ff:ff:ff:ff:ff:05')

        status = json.loads(resolver.status_file.read_text())
        self.assertEqual(status['pending_unresolved'], ['eth2'])
        self.assertEqual(status['reclaimed'], {})


class TestMainInContainer(unittest.TestCase):
    """A container owns no NIC: its interfaces are runtime-created veth
    pairs with no backing bus device in sysfs and a host-assigned MAC that
    changes on every start. The naming pass can therefore never resolve a
    pending node there - it only spent both bounded hardware waits and then
    told the user to bind an hw-id that would not survive a restart.
    """

    def setUp(self):
        self.udev_dir = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, self.udev_dir, ignore_errors=True)
        self._orig_udev_dir = resolver.vyos_udev_dir
        resolver.vyos_udev_dir = self.udev_dir
        self.addCleanup(setattr, resolver, 'vyos_udev_dir', self._orig_udev_dir)

        status_dir = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, status_dir, ignore_errors=True)
        self._orig_status_file = resolver.status_file
        resolver.status_file = resolver.Path(status_dir) / 'status.json'
        self.addCleanup(setattr, resolver, 'status_file', self._orig_status_file)

    def test_naming_pass_is_skipped_entirely(self):
        with mock.patch.object(resolver, 'is_running_as_container',
                                return_value=True), \
             mock.patch.object(resolver, 'get_configfile_interfaces') as configured, \
             mock.patch.object(resolver, 'get_pending_hwid_nodes') as pending, \
             mock.patch.object(resolver, 'discover_physical_interfaces') as discover, \
             mock.patch.object(resolver, 'run') as run:
            resolver.main()

        configured.assert_not_called()
        pending.assert_not_called()
        discover.assert_not_called()
        run.assert_not_called()
        # no status file means vyos-router's warn_missing_interface_hardware()
        # stays silent instead of warning about an unbindable pending node
        self.assertFalse(resolver.status_file.exists())
        self.assertEqual(os.listdir(self.udev_dir), [])


class TestWriteStatus(unittest.TestCase):
    """A pending node that couldn't be safely auto-matched must be
    reported so vyos-router can surface a boot-time warning - it must
    never regress into another silent, buried-syslog-only failure like
    the one this whole fix closes.
    """

    def setUp(self):
        status_dir = tempfile.mkdtemp()
        self.addCleanup(shutil.rmtree, status_dir, ignore_errors=True)
        self._orig_status_file = resolver.status_file
        resolver.status_file = resolver.Path(status_dir) / 'status.json'
        self.addCleanup(setattr, resolver, 'status_file', self._orig_status_file)

    def _read_status(self):
        return json.loads(resolver.status_file.read_text())

    def test_pending_unresolved_reported_when_no_match(self):
        pending = {'ethernet': {'eth1', 'eth4'}, 'wireless': set()}
        resolver.write_status({}, {}, set(), {}, pending=pending, reclaimed={})
        status = self._read_status()
        self.assertEqual(status['pending_unresolved'], ['eth1', 'eth4'])

    def test_reclaimed_not_reported_as_unresolved(self):
        pending = {'ethernet': {'eth1'}, 'wireless': set()}
        reclaimed = {'m1': 'eth1'}
        resolver.write_status({}, {}, set(), {}, pending=pending,
                               reclaimed=reclaimed)
        status = self._read_status()
        self.assertEqual(status['pending_unresolved'], [])
        self.assertEqual(status['reclaimed'], {'m1': 'eth1'})

    def test_no_pending_no_crash(self):
        resolver.write_status({}, {}, set(), {})
        status = self._read_status()
        self.assertEqual(status['pending_unresolved'], [])
        self.assertEqual(status['reclaimed'], {})

    def test_unconfigured_candidates_reported_for_diagnosis(self):
        # the full unmatched_candidates() list from main(), so an
        # ambiguous reclaim (zero or multiple candidates for a pending
        # node) is diagnosable from this one file alone - which physical
        # interfaces were actually competing - without needing a separate
        # `ip -br link show` or `show configuration commands` to
        # reconstruct the same picture by hand.
        pending = {'ethernet': {'eth7'}, 'wireless': set()}
        candidates = [('aa:bb:cc:dd:ee:07', 'eth9'), ('aa:bb:cc:dd:ee:99', 'vyeth13')]
        resolver.write_status({}, {}, set(), {}, pending=pending,
                               reclaimed={}, candidates=candidates)
        status = self._read_status()
        self.assertEqual(status['pending_unresolved'], ['eth7'])
        self.assertEqual(status['unconfigured_candidates'], {
            'eth9': 'aa:bb:cc:dd:ee:07',
            'vyeth13': 'aa:bb:cc:dd:ee:99',
        })

    def test_unconfigured_candidates_defaults_empty(self):
        resolver.write_status({}, {}, set(), {})
        status = self._read_status()
        self.assertEqual(status['unconfigured_candidates'], {})


class TestBootOrdering(unittest.TestCase):
    """Regression guard for the config.boot availability corner case:
    /opt/vyatta/etc/config/config.boot does not exist until vyos-router
    mounts (and, for an encrypted config volume, decrypts) the config
    directory itself. vyos-net-name-resolve must be started explicitly
    from inside vyos-router after that point, and must not be
    reintroduced as an independently-scheduled unit ordered before
    vyos-router/network-pre.target/cloud-init.
    """

    def setUp(self):
        path = os.path.join(_here, '../init/vyos-router')
        with open(path) as f:
            self.lines = f.readlines()

    def _first_index(self, needle):
        for i, line in enumerate(self.lines):
            if needle in line:
                return i
        self.fail(f"'{needle}' not found in src/init/vyos-router")

    def test_resolver_runs_after_migrate_and_before_config_apply(self):
        # search for call SITES, not the function definitions further up
        migrate = self._first_index('migrate_bootfile || overall_status=1')
        resolve = self._first_index(
            'systemctl start vyos-net-name-resolve.service')
        update_iface = self._first_index('update_interface_config || overall_status=1')
        load_boot = self._first_index('disabled configure || load_bootfile')

        self.assertLess(migrate, resolve,
            'resolver must run after config.boot is migrated/current')
        self.assertLess(resolve, update_iface,
            'resolver must run before new-hardware rescan consumes its hints')
        self.assertLess(resolve, load_boot,
            'resolver must run before the CLI config is applied')

    def test_service_unit_not_independently_ordered_before_vyos_router(self):
        path = os.path.join(_here, '../systemd/vyos-net-name-resolve.service')
        with open(path) as f:
            unit = f.read()
        self.assertNotIn('Before=vyos-router.service', unit)
        self.assertNotIn('Before=network-pre.target', unit)
        self.assertNotIn('WantedBy=', unit)


if __name__ == '__main__':
    unittest.main()