packet lib: add mpls

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

ryu/lib/packet/ethernet.py

@@ -16,6 +16,7 @@
 import struct
 from . import packet_base
 from . import vlan
+from . import mpls
 from ryu.ofproto import ether
 
 
@@ -43,3 +44,4 @@ class ethernet(packet_base.PacketBase):
 # copy vlan _TYPES
 ethernet._TYPES = vlan.vlan._TYPES
 ethernet.register_packet_type(vlan.vlan, ether.ETH_TYPE_8021Q)
+ethernet.register_packet_type(mpls.mpls, ether.ETH_TYPE_MPLS)

ryu/lib/packet/mpls.py

@@ -0,0 +1,51 @@
+# Copyright (C) 2012 Nippon Telegraph and Telephone Corporation.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import struct
+import socket
+from . import packet_base
+from . import packet_utils
+from . import ipv4
+from ryu.ofproto import ether
+
+
+class mpls(packet_base.PacketBase):
+    _PACK_STR = '!I'
+    _MIN_LEN = struct.calcsize(_PACK_STR)
+
+    def __init__(self, label, exp, bsb, ttl):
+        super(mpls, self).__init__()
+        self.label = label
+        self.exp = exp
+        self.bsb = bsb
+        self.ttl = ttl
+        self.length = mpls._MIN_LEN
+
+    @classmethod
+    def parser(cls, buf):
+        (label,) = struct.unpack_from(cls._PACK_STR, buf)
+        ttl = label & 0xff
+        bsb = (label >> 8) & 1
+        exp = (label >> 9) & 7
+        label = label >> 12
+        msg = cls(label, exp, bsb, ttl)
+        if bsb:
+            return msg, ipv4.ipv4
+        else:
+            return msg, mpls
+
+    def serialize(self, payload, prev):
+        val = self.label << 12 | self.exp << 9 | self.bsb << 8 | self.ttl
+        return struct.pack(mpls._PACK_STR, val)