table: fix longer-prefixes lookup

probably regression due to the introduction of critbitgo.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>

2 files changed, 38 insertions, 1 deletions

diff --git a/internal/pkg/table/table.go b/internal/pkg/table/table.go
index 2e0dc94a..a9f1323e 100644
--- a/internal/pkg/table/table.go
+++ b/internal/pkg/table/table.go
@@ -209,6 +209,7 @@ func (t *Table) GetLongerPrefixDestinations(key string) ([]*Destination, error)
 	switch t.routeFamily {
 	case bgp.RF_IPv4_UC, bgp.RF_IPv6_UC, bgp.RF_IPv4_MPLS, bgp.RF_IPv6_MPLS:
 		_, prefix, err := net.ParseCIDR(key)
+		ones, bits := prefix.Mask.Size()
 		if err != nil {
 			return nil, err
 		}
@@ -216,7 +217,25 @@ func (t *Table) GetLongerPrefixDestinations(key string) ([]*Destination, error)
 		for _, dst := range t.GetDestinations() {
 			r.Add(nlriToIPNet(dst.nlri), dst)
 		}
-		r.WalkPrefix(prefix, func(_ *net.IPNet, v interface{}) bool {
+		p := &net.IPNet{
+			IP:   prefix.IP,
+			Mask: net.CIDRMask((ones>>3)<<3, bits),
+		}
+		mask := 0
+		div := 0
+		if ones%8 != 0 {
+			mask = 8 - ones&0x7
+			div = ones >> 3
+		}
+		r.WalkPrefix(p, func(n *net.IPNet, v interface{}) bool {
+			if mask != 0 && n.IP[div]>>mask != p.IP[div]>>mask {
+				return true
+			}
+			l, _ := n.Mask.Size()
+
+			if ones > l {
+				return true
+			}
 			results = append(results, v.(*Destination))
 			return true
 		})
diff --git a/internal/pkg/table/table_test.go b/internal/pkg/table/table_test.go
index e0f1f3cf..f72e62b9 100644
--- a/internal/pkg/table/table_test.go
+++ b/internal/pkg/table/table_test.go
@@ -24,6 +24,23 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+func TestLookupLonger(t *testing.T) {
+	tbl := NewTable(bgp.RF_IPv4_UC)
+
+	tbl.setDestination(NewDestination(bgp.NewIPAddrPrefix(23, "11.0.0.0"), 0))
+	tbl.setDestination(NewDestination(bgp.NewIPAddrPrefix(24, "11.0.0.0"), 0))
+	tbl.setDestination(NewDestination(bgp.NewIPAddrPrefix(32, "11.0.0.4"), 0))
+	tbl.setDestination(NewDestination(bgp.NewIPAddrPrefix(32, "11.0.0.129"), 0))
+	tbl.setDestination(NewDestination(bgp.NewIPAddrPrefix(28, "11.0.0.144"), 0))
+	tbl.setDestination(NewDestination(bgp.NewIPAddrPrefix(29, "11.0.0.144"), 0))
+	tbl.setDestination(NewDestination(bgp.NewIPAddrPrefix(32, "11.0.0.145"), 0))
+
+	r, _ := tbl.GetLongerPrefixDestinations("11.0.0.128/25")
+	assert.Equal(t, len(r), 4)
+	r, _ = tbl.GetLongerPrefixDestinations("11.0.0.0/24")
+	assert.Equal(t, len(r), 6)
+}
+
 func TestTableDeleteDest(t *testing.T) {
 	peerT := TableCreatePeer()
 	pathT := TableCreatePath(peerT)
@@ -146,6 +163,7 @@ func updateMsgT2() *bgp.BGPMessage {
 	nlri := []*bgp.IPAddrPrefix{bgp.NewIPAddrPrefix(24, "20.20.20.0")}
 	return bgp.NewBGPUpdateMessage(nil, pathAttributes, nlri)
 }
+
 func updateMsgT3() *bgp.BGPMessage {
 	origin := bgp.NewPathAttributeOrigin(0)
 	aspathParam := []bgp.AsPathParamInterface{bgp.NewAsPathParam(2, []uint16{65100})}