table: fix to compare new best path with old best path

The current code uses Path.Equal(), which just check out if pathes are
idential. However, it doesn't work for two cloned pathes of a path
(soft update in case).

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

1 files changed, 20 insertions, 1 deletions

diff --git a/table/destination.go b/table/destination.go
index 232ed032..e3e1b914 100644
--- a/table/destination.go
+++ b/table/destination.go
@@ -254,7 +254,26 @@ func (dest *Destination) Calculate(ids []string) (map[string]*Path, []*Path) {
 			return nil
 		}()
 		best := dest.GetBestPath(id)
-		if best != nil && best.Equal(old) {
+		equal := func(lhs, rhs *Path) bool {
+			// already know the NLRIs are same and
+			// timestamp must be ignored so check out only
+			// source.
+			if lhs.GetSource() != rhs.GetSource() {
+				return false
+			}
+
+			pattrs := func(arg []bgp.PathAttributeInterface) []byte {
+				ret := make([]byte, 0)
+				for _, a := range arg {
+					aa, _ := a.Serialize()
+					ret = append(ret, aa...)
+				}
+				return ret
+			}
+			return bytes.Equal(pattrs(lhs.GetPathAttrs()), pattrs(rhs.GetPathAttrs()))
+		}
+
+		if best != nil && old != nil && equal(best, old) {
 			// RFC4684 3.2. Intra-AS VPN Route Distribution
 			// When processing RT membership NLRIs received from internal iBGP
 			// peers, it is necessary to consider all available iBGP paths for a