From 126bf5a231c95eee4d2a2379d369dd4c779298fd Mon Sep 17 00:00:00 2001
From: Andrew Sy Kim <kiman@vmware.com>
Date: Wed, 27 Nov 2019 13:51:37 -0500
Subject: [PATCH] ipvs proxier: use util proxy methods for getting local
 addresses

Signed-off-by: Andrew Sy Kim <kiman@vmware.com>
---
 pkg/proxy/ipvs/proxier.go | 40 ++++++++-------------------------------
 1 file changed, 8 insertions(+), 32 deletions(-)

diff --git a/pkg/proxy/ipvs/proxier.go b/pkg/proxy/ipvs/proxier.go
index 83c9a01b3b1..f16f031390a 100644
--- a/pkg/proxy/ipvs/proxier.go
+++ b/pkg/proxy/ipvs/proxier.go
@@ -990,33 +990,6 @@ func (proxier *Proxier) OnNodeSynced() {
 // EntryInvalidErr indicates if an ipset entry is invalid or not
 const EntryInvalidErr = "error adding entry %s to ipset %s"
 
-func getLocalAddrs() ([]net.IP, error) {
-	var localAddrs []net.IP
-
-	addrs, err := net.InterfaceAddrs()
-	if err != nil {
-		return nil, err
-	}
-
-	for _, addr := range addrs {
-		ip, _, err := net.ParseCIDR(addr.String())
-		if err != nil {
-			return nil, err
-		}
-		localAddrs = append(localAddrs, ip)
-	}
-	return localAddrs, nil
-}
-
-func ipExists(ip net.IP, addrs []net.IP) bool {
-	for _, addr := range addrs {
-		if ip.Equal(addr) {
-			return true
-		}
-	}
-	return false
-}
-
 // This is where all of the ipvs calls happen.
 // assumes proxier.mu is held
 func (proxier *Proxier) syncProxyRules() {
@@ -1036,9 +1009,11 @@ func (proxier *Proxier) syncProxyRules() {
 		klog.V(4).Infof("syncProxyRules took %v", time.Since(start))
 	}()
 
-	localAddrs, err := getLocalAddrs()
+	localAddrs, err := utilproxy.GetLocalAddrs()
 	if err != nil {
-		klog.Errorf("Failed to get local addresses during proxy sync: %v", err)
+		klog.Errorf("Failed to get local addresses during proxy sync: %v, assuming external IPs are not local", err)
+	} else if len(localAddrs) == 0 {
+		klog.Warning("No local addresses found, assuming all external IPs are not local")
 	}
 
 	// We assume that if this was called, we really want to sync them,
@@ -1222,9 +1197,10 @@ func (proxier *Proxier) syncProxyRules() {
 
 		// Capture externalIPs.
 		for _, externalIP := range svcInfo.ExternalIPStrings() {
-			if len(localAddrs) == 0 {
-				klog.Errorf("couldn't find any local IPs, assuming %s is not local", externalIP)
-			} else if (svcInfo.Protocol() != v1.ProtocolSCTP) && ipExists(net.ParseIP(externalIP), localAddrs) {
+			// If the "external" IP happens to be an IP that is local to this
+			// machine, hold the local port open so no other process can open it
+			// (because the socket might open but it would never work).
+			if len(localAddrs) > 0 && (svcInfo.Protocol() != v1.ProtocolSCTP) && utilproxy.ContainsIP(localAddrs, net.ParseIP(externalIP)) {
 				// We do not start listening on SCTP ports, according to our agreement in the SCTP support KEP
 				lp := utilproxy.LocalPort{
 					Description: "externalIP for " + svcNameString,