init evpn class

Signed-off-by: Peng Xiao <xiaoquwl@gmail.com>

yabgp/common/safn.py

@@ -24,6 +24,7 @@
 SAFNUM_TUNNEL = 64  # draft-nalawade-kapoor-tunnel-safi-02.txt
 SAFNUM_VPLS = 65
 SAFNUM_MDT = 66  # rfc6037
+SAFNUM_EVPN = 70  # RFC 7432
 SAFNUM_BGPLS = 71
 SAFNUM_LAB_VPNUNICAST = 128  # Draft-rosen-rfc2547bis-03
 SAFNUM_LAB_VPNMULCAST = 129

yabgp/message/attribute/mpreachnlri.py

@@ -128,6 +128,13 @@ def parse(cls, value):
                 else:
                     return dict(afi_safi=(afi, safi), nexthop=nexthop, nlri=nlri)
 
+        # for l2vpn
+        elif afi == afn.AFNUM_L2VPN:
+            if safi == safn.SAFNUM_EVPN:
+                pass
+            else:
+                nlri = repr(nlri_bin)
+
         else:
             nlri = repr(nlri_bin)
 

yabgp/message/attribute/nlri/evpn.py

@@ -0,0 +1,38 @@
+# Copyright 2016 Cisco Systems, Inc.
+# All rights reserved.
+#
+#    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.
+
+from yabgp.message.attribute.nlri import NLRI
+from yabgp.message.attribute.nlri.mpls_vpn import MPLSVPN
+
+
+class EVPN(MPLSVPN, NLRI):
+    """
+      The format of the EVPN NLRI is as follows:
+    +-----------------------------------+
+    |    Route Type (1 octet)           |
+    +-----------------------------------+
+    |     Length (1 octet)              |
+    +-----------------------------------+
+    | Route Type specific (variable)    |
+    +-----------------------------------+
+    """
+
+    @classmethod
+    def parse(cls, nlri_data):
+        pass
+
+    @classmethod
+    def construct(cls, nlri_list):
+        pass