bgp: enable to use system IP addr implicitly for binding

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, 41 insertions, 22 deletions

diff --git a/ryu/services/protocols/bgp/base.py b/ryu/services/protocols/bgp/base.py
index 24bb289f..77c8ef0b 100644
--- a/ryu/services/protocols/bgp/base.py
+++ b/ryu/services/protocols/bgp/base.py
@@ -351,7 +351,7 @@ class Activity(object):
                 # If connection is established, we call connection handler
                 # in a new thread.
                 self._spawn(conn_name, conn_handler, sock)
-
+        return sock
 
 #
 # Sink
diff --git a/ryu/services/protocols/bgp/peer.py b/ryu/services/protocols/bgp/peer.py
index 224dd8d3..7a11af14 100644
--- a/ryu/services/protocols/bgp/peer.py
+++ b/ryu/services/protocols/bgp/peer.py
@@ -278,6 +278,10 @@ class Peer(Source, Sink, NeighborConfListener, Activity):
         self._signal_bus = signal_bus
         self._peer_manager = peer_manager
 
+        # Host Bind IP
+        self._host_bind_ip = None
+        self._host_bind_port = None
+
         # TODO(PH): revisit maintaining state/stats information.
         # Peer state.
         self.state = PeerState(self, self._signal_bus)
@@ -331,6 +335,14 @@ class Peer(Source, Sink, NeighborConfListener, Activity):
         return self._neigh_conf.ip_address
 
     @property
+    def host_bind_ip(self):
+        return self._host_bind_ip
+
+    @property
+    def host_bind_port(self):
+        return self._host_bind_port
+
+    @property
     def enabled(self):
         return self._neigh_conf.enabled
 
@@ -573,7 +585,7 @@ class Peer(Source, Sink, NeighborConfListener, Activity):
         point/local ip address.
         """
         # By default we use BGPS's interface IP with this peer as next_hop.
-        next_hop = self._neigh_conf.host_bind_ip
+        next_hop = self.host_bind_ip
         if route_family == RF_IPv6_VPN:
             # Next hop ipv4_mapped ipv6
             def _ipv4_mapped_ipv6(ipv4):
@@ -617,7 +629,7 @@ class Peer(Source, Sink, NeighborConfListener, Activity):
             # 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.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:
@@ -790,19 +802,25 @@ class Peer(Source, Sink, NeighborConfListener, Activity):
                 self.state.bgp_state = const.BGP_FSM_CONNECT
                 # If we have specific host interface to bind to, we will do so
                 # else we will bind to system default.
-                # Use current values.
-                bind_addr = (self._neigh_conf.host_bind_ip,
-                             self._neigh_conf.host_bind_port)
+                if self._neigh_conf.host_bind_ip and \
+                        self._neigh_conf.host_bind_port:
+                    bind_addr = (self._neigh_conf.host_bind_ip,
+                                 self._neigh_conf.host_bind_port)
+                else:
+                    bind_addr = None
                 peer_address = (self._neigh_conf.ip_address,
                                 const.STD_BGP_SERVER_PORT_NUM)
 
                 LOG.debug('%s trying to connect to %s' % (self, peer_address))
                 tcp_conn_timeout = self._common_conf.tcp_conn_timeout
                 try:
-                    self._connect_tcp(peer_address,
-                                      client_factory,
-                                      time_out=tcp_conn_timeout,
-                                      bind_address=bind_addr)
+                    sock = self._connect_tcp(peer_address,
+                                             client_factory,
+                                             time_out=tcp_conn_timeout,
+                                             bind_address=bind_addr)
+                    bind_ip, bind_port = sock.getpeername()
+                    self._host_bind_ip = bind_ip
+                    self._host_bind_port = bind_port
                 except socket.error:
                     self.state.bgp_state = const.BGP_FSM_ACTIVE
                     LOG.debug('Socket could not be created in time (%s secs),'
@@ -1035,11 +1053,11 @@ class Peer(Source, Sink, NeighborConfListener, Activity):
             # Validate Next hop.
             # TODO(PH): Currently ignore other cases.
             if (not mp_reach_attr.next_hop or
-                    (mp_reach_attr.next_hop == self._neigh_conf.host_bind_ip)):
+                    (mp_reach_attr.next_hop == self.host_bind_ip)):
                 LOG.error('Nexthop of received UPDATE msg. (%s) same as local'
                           ' interface address %s.' %
                           (mp_reach_attr.next_hop,
-                           self._neigh_conf.host_bind_ip))
+                           self.host_bind_ip))
                 return False
 
         return True
diff --git a/ryu/services/protocols/bgp/rtconf/neighbors.py b/ryu/services/protocols/bgp/rtconf/neighbors.py
index ab7fa482..8acd62ed 100644
--- a/ryu/services/protocols/bgp/rtconf/neighbors.py
+++ b/ryu/services/protocols/bgp/rtconf/neighbors.py
@@ -147,14 +147,14 @@ class NeighborConf(ConfWithId, ConfWithStats):
     UPDATE_MED_EVT = 'update_med_evt'
 
     VALID_EVT = frozenset([UPDATE_ENABLED_EVT, UPDATE_MED_EVT])
-    REQUIRED_SETTINGS = frozenset([REMOTE_AS, IP_ADDRESS, LOCAL_ADDRESS,
-                                   LOCAL_PORT])
+    REQUIRED_SETTINGS = frozenset([REMOTE_AS, IP_ADDRESS])
     OPTIONAL_SETTINGS = frozenset([CAP_REFRESH,
                                    CAP_ENHANCED_REFRESH, CAP_MBGP_VPNV4,
                                    CAP_MBGP_IPV4, CAP_MBGP_VPNV6,
                                    CAP_RTC, RTC_AS, HOLD_TIME,
                                    ENABLED, MULTI_EXIT_DISC, MAX_PREFIXES,
-                                   ADVERTISE_PEER_AS, SITE_OF_ORIGINS])
+                                   ADVERTISE_PEER_AS, SITE_OF_ORIGINS,
+                                   LOCAL_ADDRESS, LOCAL_PORT])
 
     def __init__(self, **kwargs):
         super(NeighborConf, self).__init__(**kwargs)
@@ -193,6 +193,14 @@ class NeighborConf(ConfWithId, ConfWithStats):
         if soos and validate_soo_list(soos):
             self._settings[SITE_OF_ORIGINS] = soos
 
+        # We do not have valid default LOCAL_ADDRESS and LOCAL_PORT value.
+        # If no LOCAL_ADDRESS/PORT is provided then we will bind to system
+        # default.
+        self._settings[LOCAL_ADDRESS] = compute_optional_conf(
+            LOCAL_ADDRESS, None, **kwargs)
+        self._settings[LOCAL_PORT] = compute_optional_conf(
+            LOCAL_PORT, None, **kwargs)
+
         # RTC configurations.
         self._settings[CAP_RTC] = \
             compute_optional_conf(CAP_RTC, DEFAULT_CAP_RTC, **kwargs)
@@ -417,13 +425,6 @@ class NeighborsConf(BaseConf):
             message = 'Neighbor with given ip address already exists'
             raise RuntimeConfigError(desc=message)
 
-        # Check if this neighbor's host address overlaps with other neighbors
-        for nconf in self._neighbors.itervalues():
-            if ((neigh_conf.host_bind_ip, neigh_conf.host_bind_port) ==
-                    (nconf.host_bind_ip, nconf.host_bind_port)):
-                raise RuntimeConfigError(desc='Given host_bind_ip and '
-                                         'host_bind_port already taken')
-
         # Add this neighbor to known configured neighbors and generate update
         # event
         self._neighbors[neigh_conf.ip_address] = neigh_conf