refactor: Make SysUtil.link_info_find() more pythonic

The existing implementation of `link_info_find()` had several issues
that made it error-prone and harder to maintain:

- The refresh parameter was unused, adding unnecessary complexity.
- MAC address matching logic was convoluted, with redundant variables
  and conditions.
- The use of locals() for fallback results was unclear and could lead to
  subtle bugs.
- The order of checks (MAC vs ifname) didn't prioritize the most
  reliable matching criteria.

To address these issues, the following changes were made:

- Removed the unused `refresh` argument to reduce complexity.
- Used `None` checks more idiomatically with `if mac` instead of `is not
  None`.
- Eliminated redundant variables and conditions to improve readability.
- Avoided using `locals()` by explicitly storing fallback results.
- Made `ifname` matching take priority before checking MAC addresses.
- Ensured that the function returns early when a definitive match is
  found.

Signed-off-by: Wen Liang <[email protected]>

Author: liangwen12year

library/network_connections.py

@@ -95,6 +95,7 @@
 
 DEFAULT_ACTIVATION_TIMEOUT = 90
 DEFAULT_TIMEOUT = 10
+NULL_MAC = "00:00:00:00:00:00"
 
 
 class CheckMode:
@@ -222,31 +223,28 @@ def link_infos(cls, refresh=False):
         return linkinfos
 
     @classmethod
-    def link_info_find(cls, refresh=False, mac=None, ifname=None):
-        if mac is not None:
+    def link_info_find(cls, mac=None, ifname=None):
+        if mac:
             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)
 
-            # 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
+        result = None
 
-            # 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
+        for linkinfo in cls.link_infos().values():
+            perm_address = linkinfo.get("perm-address", NULL_MAC)
+            current_address = linkinfo.get("address", NULL_MAC)
 
-            if ifname is not None and ifname == linkinfo.get("ifname", None):
-                return linkinfo
+            if ifname and ifname == linkinfo["ifname"]:
+                result = linkinfo
+                break
 
-        # Return fallback match by address if no perm-address match found
-        if "matched_by_address" in locals():
-            return matched_by_address
+            if mac:
+                if mac == perm_address:
+                    result = linkinfo
+                    break
+                elif mac == current_address:
+                    result = linkinfo
 
-        return None
+        return result
 
 
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