BGPSpeaker: Enable to get path from EventPrefix

To get more detail information about BGP route by using
best_path_change_handler, this patch adds path member into
EventPrefix and implements property to get existing attributes.

Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>

1 files changed, 47 insertions, 27 deletions

diff --git a/ryu/services/protocols/bgp/bgpspeaker.py b/ryu/services/protocols/bgp/bgpspeaker.py
index 62ba1462..3fd4bfff 100644
--- a/ryu/services/protocols/bgp/bgpspeaker.py
+++ b/ryu/services/protocols/bgp/bgpspeaker.py
@@ -78,6 +78,7 @@ from ryu.services.protocols.bgp.info_base.ipv4 import Ipv4Path
 from ryu.services.protocols.bgp.info_base.ipv6 import Ipv6Path
 from ryu.services.protocols.bgp.info_base.vpnv4 import Vpnv4Path
 from ryu.services.protocols.bgp.info_base.vpnv6 import Vpnv6Path
+from ryu.services.protocols.bgp.info_base.evpn import EvpnPath
 
 
 NEIGHBOR_CONF_MED = MULTI_EXIT_DISC  # for backward compatibility
@@ -95,23 +96,56 @@ class EventPrefix(object):
     Attribute        Description
     ================ ======================================================
     remote_as        The AS number of a peer that caused this change
-    route_dist       None in the case of ipv4 or ipv6 family
+    route_dist       None in the case of IPv4 or IPv6 family
     prefix           A prefix was changed
     nexthop          The nexthop of the changed prefix
-    label            mpls label for vpnv4 prefix
+    label            MPLS label for VPNv4, VPNv6 or EVPN prefix
+    path             An instance of ``info_base.base.Path`` subclass
     is_withdraw      True if this prefix has gone otherwise False
     ================ ======================================================
     """
 
-    def __init__(self, remote_as, route_dist, prefix, nexthop, label,
-                 is_withdraw):
-        self.remote_as = remote_as
-        self.route_dist = route_dist
-        self.prefix = prefix
-        self.nexthop = nexthop
-        self.label = label
+    def __init__(self, path, is_withdraw):
+        self.path = path
         self.is_withdraw = is_withdraw
 
+    @property
+    def remote_as(self):
+        return self.path.source.remote_as
+
+    @property
+    def route_dist(self):
+        if (isinstance(self.path, Vpnv4Path)
+                or isinstance(self.path, Vpnv6Path)
+                or isinstance(self.path, EvpnPath)):
+            return self.path.nlri.route_dist
+        else:
+            return None
+
+    @property
+    def prefix(self):
+        if isinstance(self.path, Ipv4Path) or isinstance(self.path, Ipv6Path):
+            return self.path.nlri.addr + '/' + str(self.path.nlri.length)
+        elif (isinstance(self.path, Vpnv4Path)
+              or isinstance(self.path, Vpnv6Path)
+              or isinstance(self.path, EvpnPath)):
+            return self.path.nlri.prefix
+        else:
+            return None
+
+    @property
+    def nexthop(self):
+        return self.path.nexthop
+
+    @property
+    def label(self):
+        if (isinstance(self.path, Vpnv4Path)
+                or isinstance(self.path, Vpnv6Path)
+                or isinstance(self.path, EvpnPath)):
+            return getattr(self.path.nlri, 'label_list', None)
+        else:
+            return None
+
 
 class BGPSpeaker(object):
     def __init__(self, as_number, router_id,
@@ -189,26 +223,12 @@ class BGPSpeaker(object):
             self._peer_up_handler(remote_ip, remote_as)
 
     def _notify_best_path_changed(self, path, is_withdraw):
-        if path.source:
-            nexthop = path.nexthop
-            is_withdraw = is_withdraw
-            remote_as = path.source.remote_as
-        else:
-            return
-
-        if isinstance(path, Ipv4Path) or isinstance(path, Ipv6Path):
-            prefix = path.nlri.addr + '/' + str(path.nlri.length)
-            route_dist = None
-            label = None
-        elif isinstance(path, Vpnv4Path) or isinstance(path, Vpnv6Path):
-            prefix = path.nlri.prefix
-            route_dist = path.nlri.route_dist
-            label = path.nlri.label_list
-        else:
+        if (not path.source
+                or not isinstance(path, (Ipv4Path, Ipv6Path,
+                                         Vpnv4Path, Vpnv6Path, EvpnPath))):
             return
 
-        ev = EventPrefix(remote_as, route_dist, prefix, nexthop, label,
-                         is_withdraw)
+        ev = EventPrefix(path, is_withdraw)
 
         if self._best_path_change_handler:
             self._best_path_change_handler(ev)