bgp: fix handling unknown and unsupported transitive path

 attributes

we must forward optional transitive path attributes.

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

3 files changed, 31 insertions, 20 deletions

diff --git a/ryu/lib/packet/bgp.py b/ryu/lib/packet/bgp.py
index f5575c46..66dbc3c7 100644
--- a/ryu/lib/packet/bgp.py
+++ b/ryu/lib/packet/bgp.py
@@ -1558,6 +1558,7 @@ class BGPPathAttributeAsPath(_BGPPathAttributeAsPathCommon):
 @_PathAttribute.register_type(BGP_ATTR_TYPE_AS4_PATH)
 class BGPPathAttributeAs4Path(_BGPPathAttributeAsPathCommon):
     _AS_PACK_STR = '!I'
+    _ATTR_FLAGS = BGP_ATTR_FLAG_TRANSITIVE | BGP_ATTR_FLAG_OPTIONAL
 
     @classmethod
     def _is_valid_16bit_as_path(cls, buf):
diff --git a/ryu/services/protocols/bgp/peer.py b/ryu/services/protocols/bgp/peer.py
index fc8ee558..f95836ce 100644
--- a/ryu/services/protocols/bgp/peer.py
+++ b/ryu/services/protocols/bgp/peer.py
@@ -847,7 +847,7 @@ class Peer(Source, Sink, NeighborConfListener, Activity):
             extcomm_attr = None
             community_attr = None
             localpref_attr = None
-            unkown_opttrans_attrs = None
+            unknown_opttrans_attrs = None
             nlri_list = [path.nlri]
 
             # By default we use BGPS's interface IP with this peer as next_hop.
@@ -995,7 +995,7 @@ class Peer(Source, Sink, NeighborConfListener, Activity):
 
             # UNKOWN Attributes.
             # Get optional transitive path attributes
-            unkown_opttrans_attrs = bgp_utils.get_unknow_opttrans_attr(path)
+            unknown_opttrans_attrs = bgp_utils.get_unknown_opttrans_attr(path)
 
             # Ordering path attributes according to type as RFC says. We set
             # MPReachNLRI first as advised by experts as a new trend in BGP
@@ -1015,8 +1015,8 @@ class Peer(Source, Sink, NeighborConfListener, Activity):
                 new_pathattr.append(community_attr)
             if extcomm_attr:
                 new_pathattr.append(extcomm_attr)
-            if unkown_opttrans_attrs:
-                new_pathattr.extend(unkown_opttrans_attrs.values())
+            if unknown_opttrans_attrs:
+                new_pathattr.extend(unknown_opttrans_attrs.values())
 
         if isinstance(path, Ipv4Path):
             update = BGPUpdate(path_attributes=new_pathattr,
diff --git a/ryu/services/protocols/bgp/utils/bgp.py b/ryu/services/protocols/bgp/utils/bgp.py
index 28e010a2..43793570 100644
--- a/ryu/services/protocols/bgp/utils/bgp.py
+++ b/ryu/services/protocols/bgp/utils/bgp.py
@@ -19,17 +19,23 @@
 import logging
 import socket
 
-from ryu.lib.packet.bgp import BGPUpdate
-from ryu.lib.packet.bgp import RF_IPv4_UC
-from ryu.lib.packet.bgp import RF_IPv6_UC
-from ryu.lib.packet.bgp import RF_IPv4_VPN
-from ryu.lib.packet.bgp import RF_IPv6_VPN
-from ryu.lib.packet.bgp import RF_RTC_UC
-from ryu.lib.packet.bgp import RouteTargetMembershipNLRI
-from ryu.lib.packet.bgp import BGP_ATTR_TYPE_MULTI_EXIT_DISC
-from ryu.lib.packet.bgp import BGPPathAttributeMultiExitDisc
-from ryu.lib.packet.bgp import BGPPathAttributeMpUnreachNLRI
-from ryu.lib.packet.bgp import BGPPathAttributeUnknown
+from ryu.lib.packet.bgp import (
+    BGPUpdate,
+    RF_IPv4_UC,
+    RF_IPv6_UC,
+    RF_IPv4_VPN,
+    RF_IPv6_VPN,
+    RF_RTC_UC,
+    RouteTargetMembershipNLRI,
+    BGP_ATTR_TYPE_MULTI_EXIT_DISC,
+    BGPPathAttributeMultiExitDisc,
+    BGPPathAttributeMpUnreachNLRI,
+    BGPPathAttributeAs4Path,
+    BGPPathAttributeAs4Aggregator,
+    BGPPathAttributeUnknown,
+    BGP_ATTR_FLAG_OPTIONAL,
+    BGP_ATTR_FLAG_TRANSITIVE,
+)
 from ryu.services.protocols.bgp.info_base.rtc import RtcPath
 from ryu.services.protocols.bgp.info_base.ipv4 import Ipv4Path
 from ryu.services.protocols.bgp.info_base.ipv6 import Ipv6Path
@@ -102,9 +108,9 @@ def from_inet_ptoi(bgp_id):
     return four_byte_id
 
 
-def get_unknow_opttrans_attr(path):
-    """Utility method that gives a `dict` of unknown optional transitive
-    path attributes of `path`.
+def get_unknown_opttrans_attr(path):
+    """Utility method that gives a `dict` of unknown and unsupported optional
+    transitive path attributes of `path`.
 
     Returns dict: <key> - attribute type code, <value> - unknown path-attr.
     """
@@ -112,8 +118,12 @@ def get_unknow_opttrans_attr(path):
     unknown_opt_tran_attrs = {}
     for _, attr in path_attrs.items():
         if (isinstance(attr, BGPPathAttributeUnknown) and
-                attr.is_optional_transitive()):
-            unknown_opt_tran_attrs[attr.type_code] = attr
+                attr.flags & (BGP_ATTR_FLAG_OPTIONAL |
+                              BGP_ATTR_FLAG_TRANSITIVE)) or \
+                isinstance(attr, BGPPathAttributeAs4Path) or \
+                isinstance(attr, BGPPathAttributeAs4Aggregator):
+            unknown_opt_tran_attrs[attr.type] = attr
+
     return unknown_opt_tran_attrs