policy: send a withdrawal if export policy blocks an existing route

This patch fixes a bug of export policy and implicit withdrawal.

When a path is filtered by export policy, we need to check whether the
old path (implicit withdrawn path) was sent before the new path.
If it has been sent, we need to send a withdrawal message.

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

1 files changed, 61 insertions, 1 deletions

diff --git a/server/server_test.go b/server/server_test.go
index 8f5fcc4d..3aaa7374 100644
--- a/server/server_test.go
+++ b/server/server_test.go
@@ -187,11 +187,13 @@ func TestNumGoroutineWithAddDeleteNeighbor(t *testing.T) {
 func newPeerandInfo(myAs, as uint32, address string, rib *table.TableManager) (*Peer, *table.PeerInfo) {
 	nConf := &config.Neighbor{Config: config.NeighborConfig{PeerAs: as, NeighborAddress: address}}
 	config.SetDefaultNeighborConfigValues(nConf, myAs)
+	policy := table.NewRoutingPolicy()
+	policy.Reset(&config.RoutingPolicy{}, nil)
 	p := NewPeer(
 		&config.Global{Config: config.GlobalConfig{As: myAs}},
 		nConf,
 		rib,
-		&table.RoutingPolicy{})
+		policy)
 	for _, f := range rib.GetRFlist() {
 		p.fsm.rfMap[f] = true
 	}
@@ -283,3 +285,61 @@ func TestFilterpathWithiBGP(t *testing.T) {
 	assert.Nil(t, path)
 
 }
+
+func TestFilterpathWithRejectPolicy(t *testing.T) {
+	rib1 := table.NewTableManager([]bgp.RouteFamily{bgp.RF_IPv4_UC})
+	_, pi1 := newPeerandInfo(1, 2, "192.168.0.1", rib1)
+	rib2 := table.NewTableManager([]bgp.RouteFamily{bgp.RF_IPv4_UC})
+	p2, _ := newPeerandInfo(1, 3, "192.168.0.2", rib2)
+
+	comSet1 := config.CommunitySet{
+		CommunitySetName: "comset1",
+		CommunityList:    []string{"100:100"},
+	}
+	s, _ := table.NewCommunitySet(comSet1)
+	p2.policy.AddDefinedSet(s)
+
+	statement := config.Statement{
+		Name: "stmt1",
+		Conditions: config.Conditions{
+			BgpConditions: config.BgpConditions{
+				MatchCommunitySet: config.MatchCommunitySet{
+					CommunitySet: "comset1",
+				},
+			},
+		},
+		Actions: config.Actions{
+			RouteDisposition: config.ROUTE_DISPOSITION_REJECT_ROUTE,
+		},
+	}
+	policy := config.PolicyDefinition{
+		Name:       "policy1",
+		Statements: []config.Statement{statement},
+	}
+	p, _ := table.NewPolicy(policy)
+	p2.policy.AddPolicy(p, false)
+	policies := []*config.PolicyDefinition{
+		&config.PolicyDefinition{
+			Name: "policy1",
+		},
+	}
+	p2.policy.AddPolicyAssignment(p2.TableID(), table.POLICY_DIRECTION_EXPORT, policies, table.ROUTE_TYPE_ACCEPT)
+
+	for _, addCommunity := range []bool{false, true, false, true} {
+		nlri := bgp.NewIPAddrPrefix(24, "10.10.10.0")
+		pa1 := []bgp.PathAttributeInterface{bgp.NewPathAttributeAsPath([]bgp.AsPathParamInterface{bgp.NewAs4PathParam(2, []uint32{1})}), bgp.NewPathAttributeLocalPref(200)}
+		if addCommunity {
+			pa1 = append(pa1, bgp.NewPathAttributeCommunities([]uint32{100<<16 | 100}))
+		}
+		path1 := table.NewPath(pi1, nlri, false, pa1, time.Now(), false)
+		new, old := process(rib2, []*table.Path{path1})
+		assert.Equal(t, new, path1)
+		path2 := p2.filterpath(new, old)
+		if addCommunity {
+			assert.True(t, path2.IsWithdraw)
+		} else {
+			assert.False(t, path2.IsWithdraw)
+		}
+	}
+
+}