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bgp: send BGP UPDATE msg in BGP4 format when nlri is ipv4

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Signed-off-by: ISHIDA Wataru <ishida.wataru@lab.ntt.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
This commit is contained in:
ISHIDA Wataru 2014-03-30 08:45:03 +00:00 committed by FUJITA Tomonori
parent 706cd11ce3
commit 06c84f4b05
2 changed files with 167 additions and 4 deletions
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7
ryu/services/protocols/bgp/model.py
View File

@ -44,11 +44,11 @@ class OutgoingRoute(object):
"""Holds state about a route that is queued for being sent to a given sink.
"""
__slots__ = ('_path', '_for_route_refresh',
__slots__ = ('_path', '_for_route_refresh', 'bgp4_format',
'sink', 'next_outgoing_route', 'prev_outgoing_route',
'next_sink_out_route', 'prev_sink_out_route')
def __init__(self, path, for_route_refresh=False):
def __init__(self, path, for_route_refresh=False, bgp4_format=False):
assert(path)
self.sink = None
@ -59,6 +59,9 @@ class OutgoingRoute(object):
# No sent-route is queued for the destination for this update.
self._for_route_refresh = for_route_refresh
# Construct UPDATE msg using bgp4 format
self.bgp4_format = bgp4_format
# Automatically generated, for list off of Destination.
#
# self.next_outgoing_route

164
ryu/services/protocols/bgp/peer.py
View File

@ -553,6 +553,160 @@ class Peer(Source, Sink, NeighborConfListener, Activity):
return next_hop
def _construct_update(self, outgoing_route):
"""Construct update message with Outgoing-routes path attribute
appropriately cloned/copied/updated.
"""
is_bgp4_format = outgoing_route.bgp4_format
if is_bgp4_format:
update = self._construct_bgp4_update(outgoing_route)
else:
update = self._construct_mpbgp_update(outgoing_route)
return update
def _construct_bgp4_update(self, outgoing_route):
update = None
path = outgoing_route.path
# Get copy of path's path attributes.
pathattr_map = path.pathattr_map
new_pathattr_map = OrderedDict()
if path.is_withdraw:
update = messages.Update(withdraw_list=path.nlri)
return update
else:
# Supported and un-supported/unknown attributes.
origin_attr = None
nexthop_attr = None
aspath_attr = None
extcomm_attr = None
community_attr = None
localpref_attr = None
unkown_opttrans_attrs = None
nlri_list = [path.nlri]
# MP_REACH_NLRI Attribute.
# By default we use BGPS's interface IP with this peer as next_hop.
# TODO(PH): change to use protocol's local address.
# next_hop = self._neigh_conf.host_bind_ip
next_hop = self._session_next_hop(path.route_family)
# If this is a iBGP peer.
if not self.is_ebgp_peer() and path.source is not None:
# If the path came from a bgp peer and not from NC, according
# to RFC 4271 we should not modify next_hop.
next_hop = path.nexthop
nexthop_attr = pathattr.NextHop(next_hop)
assert nexthop_attr, 'Missing NEXTHOP mandatory attribute.'
# ORIGIN Attribute.
# According to RFC this attribute value SHOULD NOT be changed by
# any other speaker.
origin_attr = pathattr_map.get(pathattr.Origin.ATTR_NAME)
assert origin_attr, 'Missing ORIGIN mandatory attribute.'
# AS_PATH Attribute.
# Construct AS-path-attr using paths aspath attr. with local AS as
# first item.
path_aspath = pathattr_map.get(pathattr.AsPath.ATTR_NAME)
assert path_aspath, 'Missing AS_PATH mandatory attribute.'
# Deep copy aspath_attr value
path_seg_list = path_aspath.path_seg_list
# If this is a iBGP peer.
if not self.is_ebgp_peer():
# When a given BGP speaker advertises the route to an internal
# peer, the advertising speaker SHALL NOT modify the AS_PATH
# attribute associated with the route.
aspath_attr = pathattr.AsPath(path_seg_list)
else:
# When a given BGP speaker advertises the route to an external
# peer, the advertising speaker updates the AS_PATH attribute
# as follows:
# 1) if the first path segment of the AS_PATH is of type
# AS_SEQUENCE, the local system prepends its own AS num as
# the last element of the sequence (put it in the left-most
# position with respect to the position of octets in the
# protocol message). If the act of prepending will cause an
# overflow in the AS_PATH segment (i.e., more than 255
# ASes), it SHOULD prepend a new segment of type AS_SEQUENCE
# and prepend its own AS number to this new segment.
#
# 2) if the first path segment of the AS_PATH is of type AS_SET
# , the local system prepends a new path segment of type
# AS_SEQUENCE to the AS_PATH, including its own AS number in
# that segment.
#
# 3) if the AS_PATH is empty, the local system creates a path
# segment of type AS_SEQUENCE, places its own AS into that
# segment, and places that segment into the AS_PATH.
if (len(path_seg_list) > 0 and
isinstance(path_seg_list[0], list) and
len(path_seg_list[0]) < 255):
path_seg_list[0].insert(0, self._core_service.asn)
else:
path_seg_list.insert(0, [self._core_service.asn])
aspath_attr = pathattr.AsPath(path_seg_list)
# MULTI_EXIT_DISC Attribute.
# For eBGP session we can send multi-exit-disc if configured.
multi_exit_disc = None
if self.is_ebgp_peer():
multi_exit_disc = pathattr_map.get(pathattr.Med.ATTR_NAME)
if not multi_exit_disc and self._neigh_conf.multi_exit_disc:
multi_exit_disc = pathattr.Med(
self._neigh_conf.multi_exit_disc
)
# LOCAL_PREF Attribute.
if not self.is_ebgp_peer():
# For iBGP peers we are required to send local-pref attribute
# for connected or local prefixes. We send default local-pref.
localpref_attr = pathattr.LocalPref(100)
# COMMUNITY Attribute.
community_attr = pathattr_map.get(pathattr.Community.ATTR_NAME)
# EXTENDED COMMUNITY Attribute.
# Construct ExtCommunity path-attr based on given.
path_extcomm_attr = pathattr_map.get(
pathattr.ExtCommunity.ATTR_NAME
)
if path_extcomm_attr:
# SOO list can be configured per VRF and/or per Neighbor.
# NeighborConf has this setting we add this to existing list.
soo_list = path_extcomm_attr.soo_list
if self._neigh_conf.soo_list:
soo_list.extend(self._neigh_conf.soo_list)
extcomm_attr = pathattr.ExtCommunity(
path_extcomm_attr.rt_list,
soo_list
)
# UNKOWN Attributes.
# Get optional transitive path attributes
unkown_opttrans_attrs = bgp_utils.get_unknow_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
# implementation.
new_pathattr_map[pathattr.NextHop.ATTR_NAME] = nexthop_attr
new_pathattr_map[pathattr.Origin.ATTR_NAME] = origin_attr
new_pathattr_map[pathattr.AsPath.ATTR_NAME] = aspath_attr
if multi_exit_disc:
new_pathattr_map[pathattr.Med.ATTR_NAME] = multi_exit_disc
if localpref_attr:
new_pathattr_map[pathattr.LocalPref.ATTR_NAME] = localpref_attr
if community_attr:
new_pathattr_map[pathattr.Community.ATTR_NAME] = community_attr
if extcomm_attr:
new_pathattr_map[pathattr.ExtCommunity.ATTR_NAME] =\
extcomm_attr
if unkown_opttrans_attrs:
new_pathattr_map.update(unkown_opttrans_attrs)
update = messages.Update(pathattr_map=new_pathattr_map,
nlri_list=nlri_list)
return update
def _construct_mpbgp_update(self, outgoing_route):
"""Construct update message with Outgoing-routes path attribute
appropriately cloned/copied/updated.
"""
@ -1519,7 +1673,10 @@ class Peer(Source, Sink, NeighborConfListener, Activity):
if path.source is None:
# Construct OutgoingRoute specific for this peer and put it in
# its sink.
outgoing_route = OutgoingRoute(path)
bgp4_format = False
if self._neigh_conf.cap_mbgp_ipv4:
bgp4_format = True
outgoing_route = OutgoingRoute(path, bgp4_format=bgp4_format)
self.enque_outgoing_msg(outgoing_route)
# If path from a bgp-peer is new best path, we share it with
@ -1568,7 +1725,10 @@ class Peer(Source, Sink, NeighborConfListener, Activity):
# Construct OutgoingRoute specific for this peer and put it in
# its sink.
outgoing_route = OutgoingRoute(path)
bgp4_format = False
if self._neigh_conf.cap_mbgp_ipv4:
bgp4_format = True
outgoing_route = OutgoingRoute(path, bgp4_format=bgp4_format)
self.enque_outgoing_msg(outgoing_route)
LOG.debug('Enqueued outgoing route %s for peer %s' %
(outgoing_route.path.nlri, self))