test config macthing

backend/src/utilities/bridge_link_state_manager.py

@@ -204,6 +204,7 @@ class BridgeLinkStateWatcher:
         now = time.time()
 
         with self._lock:
+            previous_states = dict(self._member_states)
             self._last_event_ts = now
             self._last_error = None
             self._member_states = states
@@ -247,7 +248,7 @@ class BridgeLinkStateWatcher:
         )
 
         if failing_members:
-            config_source = self._find_config_sync_source(states, preferred_ifname=source_ifname)
+            config_source = self._find_config_sync_source(states, previous_states, preferred_ifname=source_ifname)
             if config_source is not None and self._has_config_mismatch(config_source, states):
                 with self._lock:
                     self._failing_since = {}
@@ -290,8 +291,9 @@ class BridgeLinkStateWatcher:
             self._failing_since = {}
             self._all_clear_since = None
 
-        if source_ifname in states and self._is_source_eligible(source_ifname, states):
-            self._sync_member_configuration(source_ifname, states)
+        config_source = self._find_config_sync_source(states, previous_states, preferred_ifname=source_ifname)
+        if config_source is not None and self._has_config_mismatch(config_source, states):
+            self._sync_member_configuration(config_source, states)
             return
 
         self._set_last_action(f"no_restore_needed ({reason})")
@@ -323,20 +325,84 @@ class BridgeLinkStateWatcher:
     def _find_config_sync_source(
         self,
         states: dict[str, MemberLinkState],
+        previous_states: dict[str, MemberLinkState],
         preferred_ifname: Optional[str] = None,
     ) -> Optional[str]:
         """Pick a healthy member whose configuration should be mirrored to siblings."""
+        changed_candidates = [
+            ifname
+            for ifname in sorted(states)
+            if self._config_changed(ifname, states, previous_states)
+        ]
+        if preferred_ifname in changed_candidates:
+            changed_candidates.remove(preferred_ifname)
+            changed_candidates.insert(0, preferred_ifname)
+
+        if changed_candidates:
+            for ifname in changed_candidates:
+                if self._is_changed_source_eligible(ifname, states):
+                    return ifname
+            self._set_last_action(
+                f"waiting for changed configuration on {changed_candidates} to settle before syncing"
+            )
+            return None
+
         candidates: list[str] = []
         if preferred_ifname:
             candidates.append(preferred_ifname)
         candidates.extend(ifname for ifname in sorted(states) if ifname != preferred_ifname)
 
+        seen: set[str] = set()
         for ifname in candidates:
+            if ifname in seen:
+                continue
+            seen.add(ifname)
             if self._is_source_eligible(ifname, states):
                 return ifname
 
         return None
 
+    def _is_changed_source_eligible(self, ifname: str, states: dict[str, MemberLinkState]) -> bool:
+        """Allow a changed member to drive sync even while the link is transiently renegotiating."""
+        with self._lock:
+            ignored = self._managed_event_deadlines.get(ifname, 0.0) > time.time()
+            suppressed = ifname in self._suppressed_members
+        if ignored or suppressed:
+            return False
+
+        state = states.get(ifname)
+        if state is None:
+            return False
+        if state.link_ready:
+            return True
+        return self._state_has_usable_config(state)
+
+    def _config_changed(
+        self,
+        ifname: str,
+        states: dict[str, MemberLinkState],
+        previous_states: dict[str, MemberLinkState],
+    ) -> bool:
+        """Return whether this member's MTU or link profile changed since the last snapshot."""
+        current = states.get(ifname)
+        previous = previous_states.get(ifname)
+        if current is None or previous is None:
+            return False
+
+        return current.mtu != previous.mtu or current.ethernet_profile != previous.ethernet_profile
+
+    def _state_has_usable_config(self, state: MemberLinkState) -> bool:
+        """Return whether this snapshot contains configuration that can be mirrored."""
+        if state.mtu is not None:
+            return True
+
+        profile = state.ethernet_profile
+        if profile is None:
+            return False
+        if profile.autoneg is True:
+            return True
+        return profile.autoneg is False and profile.speed_mbps is not None and profile.duplex is not None
+
     def _has_config_mismatch(self, source_ifname: str, states: dict[str, MemberLinkState]) -> bool:
         """Return whether any sibling differs from the chosen source configuration."""
         source = states.get(source_ifname)
@@ -348,7 +414,7 @@ class BridgeLinkStateWatcher:
                 continue
             if source.mtu is not None and target.mtu is not None and source.mtu != target.mtu:
                 return True
-            if source.ethernet_profile is not None and target.ethernet_profile is not None and source.ethernet_profile != target.ethernet_profile:
+            if source.ethernet_profile is not None and source.ethernet_profile != target.ethernet_profile:
                 return True
 
         return False