Add testmap

testmap.py

@@ -0,0 +1,49 @@
+import sys
+import ipaddress
+
+IPV4_PREFIX = bytes([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff])
+
+def interpret(asmap, num, bits):
+    pos = 0
+    while True:
+        assert(len(asmap) >= pos + 1)
+        opcode = int(asmap[pos])
+        pos += 1
+        if opcode < 2:
+            assert(len(asmap) >= pos + 3 + opcode)
+            return int.from_bytes(asmap[pos:pos+3+opcode], 'little')
+        elif opcode >= 240:
+            assert(len(asmap) >= pos + 2)
+            return int.from_bytes(asmap[pos:pos+2], 'big') + ((opcode - 240) << 16)
+        elif opcode < 128:
+            nbits = opcode.bit_length() - 1
+            assert(bits >= nbits)
+            if (opcode ^ (num >> (bits - nbits))) & ((1 << nbits) - 1):
+                return None
+            bits -= nbits
+        elif opcode >= 132:
+            assert(bits >= 1)
+            if (num >> (bits - 1)) & 1:
+                pos += opcode - 129
+            bits -= 1
+        else:
+            assert(bits >= 1)
+            offlen = opcode - 127
+            assert(len(asmap) >= pos + offlen)
+            offset = int.from_bytes(asmap[pos:pos+offlen], 'little')
+            pos += offlen
+            if (num >> (bits - 1)) & 1:
+                pos += offset
+            bits -= 1
+
+with open(sys.argv[1], "rb") as f:
+    asmap = f.read()
+addr = ipaddress.ip_address(sys.argv[2])
+if isinstance(addr, ipaddress.IPv4Address):
+    num = int.from_bytes(IPV4_PREFIX + addr.packed, 'big')
+elif isinstance(addr, ipaddress.IPv6Address):
+    num = int.from_bytes(addr.packed, 'big')
+
+ret = interpret(asmap, num, 128)
+if ret:
+    print("AS%i" % ret)