support BGP ASNs in local topologies

tools/topology/config.py

@@ -95,6 +95,7 @@ def generate_all(self):
         Generate all needed files.
         """
         self._ensure_uniq_ases()
+        self._canonicalize_isd_asns()
         topo_dicts, self.all_networks = self._generate_topology()
         self.networks = remove_v4_nets(self.all_networks)
         self._generate_with_topo(topo_dicts)
@@ -110,6 +111,12 @@ def _ensure_uniq_ases(self):
                 sys.exit(1)
             seen.add(ia.as_str())
 
+    def _canonicalize_isd_asns(self):
+        canonicalized = {}
+        for asStr, value in self.topo_config["ASes"].items():
+            canonicalized[str(ISD_AS(asStr))] = value
+        self.topo_config["ASes"] = canonicalized
+
     def _generate_with_topo(self, topo_dicts):
         self._generate_go(topo_dicts)
         if self.args.docker:

tools/topology/scion_addr.py

@@ -55,18 +55,17 @@ def __hash__(self):
         return hash(str(self))
 
 
-# Regex matching ISD-AS (hex form), with either : or _ as hex-part separator
+# Regex matching ISD-AS (hex or decimal form), with either : or _ as hex-part separator
 _RE_ISD_AS = re.compile(
-    r"^([1-9][0-9]{0,4})-([0-9a-fA-F]{1,4})[:_]([0-9a-fA-F]{1,4})[:_]([0-9a-fA-F]{1,4})$"
+    r"^([1-9][0-9]{0,4})-([0-9a-fA-F]{1,4})[:_]([0-9a-fA-F]{1,4})[:_]([0-9a-fA-F]{1,4})" +
+    r"|([1-9][0-9]{0,4})-([1-9][0-9]{1,9})$"
 )
 
 
 def _clean_isd_as(isd_as_str):
     """
     Parse an ISD-AS-identifier and return the "canonical" string representation.
 
-    Note that the short form for decimal BGP AS numbers is not supported here.
-
     :param str as_id_str: AS-identifier to parse
     :returns: AS-identifier as integer
     :raises:
@@ -75,10 +74,20 @@ def _clean_isd_as(isd_as_str):
     m = _RE_ISD_AS.match(isd_as_str)
     if not m:
         raise ValueError('Invalid ISD-AS', isd_as_str)
-    isd = int(m.group(1), 10)
+    if m.group(1) is not None:
+        isd = int(m.group(1), 10)
+        hig = int(m.group(2), 16)
+        mid = int(m.group(3), 16)
+        low = int(m.group(4), 16)
+        asn = (hig << 32) | (mid << 16) | low
+    else:
+        isd = int(m.group(5), 10)
+        asn = int(m.group(6), 10)
+        if asn >= 2**32:
+            ValueError('Invalid ISD-AS, ASN out of range', isd_as_str)
     if isd >= 2**16:
         raise ValueError('Invalid ISD-AS, ISD out of range', isd_as_str)
-    hig = int(m.group(2), 16)
-    mid = int(m.group(3), 16)
-    low = int(m.group(4), 16)
-    return "%i-%x:%x:%x" % (isd, hig, mid, low)
+    if asn < 2**32:
+        return "%i-%d" % (isd, asn)
+    else:
+        return "%i-%x:%x:%x" % (isd, hig, mid, low)