From 92b454f1cc1faaa5a8406773f95d124aca34ad63 Mon Sep 17 00:00:00 2001
From: Nils Schneider <nils.schneider@gmail.com>
Date: Mon, 20 Aug 2012 23:00:39 +0200
Subject: [PATCH] much better mac matching

---
 nodedb.py | 38 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 37 insertions(+), 1 deletion(-)

diff --git a/nodedb.py b/nodedb.py
index f60cf12..a5ba8d5 100644
--- a/nodedb.py
+++ b/nodedb.py
@@ -27,7 +27,7 @@ class NodeDB:
 
     for node in self._nodes:
       for mac_b in node.macs:
-        if is_similar(mac_a, mac_b):
+        if is_derived_mac(mac_a, mac_b):
           return node
 
     raise KeyError
@@ -313,3 +313,39 @@ def is_similar(a, b):
   # These addresses look pretty similar!
   return delta < 8
 
+def is_derived_mac(a, b):
+  if a == b:
+    return True
+
+  try:
+    mac_a = list(int(i, 16) for i in a.split(":"))
+    mac_b = list(int(i, 16) for i in b.split(":"))
+  except ValueError:
+    return False
+
+  x = mac_a
+  x[5] += 1
+  if mac_b == x:
+    return True
+
+  x[0] |= 2
+  if mac_b == x:
+    return True
+
+  x[3] += 1
+  if mac_b == x:
+    return True
+
+  x = mac_a
+  x[0] |= 2
+  x[5] += 2
+  if mac_b == x:
+    return True
+
+  x = mac_a
+  x[0] |= 2
+  x[3] += 1
+  if mac_b == x:
+    return True
+
+  return False