From 3b086f4179335b4f2a2fd4c664877f96acfd1a1a Mon Sep 17 00:00:00 2001
From: Antonin Bas <abas@vmware.com>
Date: Thu, 25 Feb 2021 11:06:45 -0800
Subject: [PATCH] Address review comments

---
 pkg/agent/util/net_linux.go   | 41 ++++++++++++++------------
 pkg/agent/util/net_windows.go | 54 +++++++++++++++++++----------------
 2 files changed, 51 insertions(+), 44 deletions(-)

diff --git a/pkg/agent/util/net_linux.go b/pkg/agent/util/net_linux.go
index 9c7714ef894..f26e711f351 100644
--- a/pkg/agent/util/net_linux.go
+++ b/pkg/agent/util/net_linux.go
@@ -130,6 +130,28 @@ func SetLinkUp(name string) (net.HardwareAddr, int, error) {
 	return mac, index, nil
 }
 
+func addrSliceDifference(s1, s2 []netlink.Addr) []*netlink.Addr {
+	var diff []*netlink.Addr
+
+	for i, e1 := range s1 {
+		found := false
+		for _, e2 := range s2 {
+			if e1.Equal(e2) {
+				found = true
+				break
+			}
+		}
+		if !found {
+			diff = append(diff, &s1[i])
+		}
+	}
+
+	return diff
+}
+
+// ConfigureLinkAddresses adds the provided addresses to the interface identified by index idx, if
+// they are missing from the interface. Any other existing address already configured for the
+// interface will be removed, unless it is a link-local address.
 func ConfigureLinkAddresses(idx int, ipNets []*net.IPNet) error {
 	// No need to check the error here, since the link is found in previous steps.
 	link, _ := netlink.LinkByIndex(idx)
@@ -151,25 +173,6 @@ func ConfigureLinkAddresses(idx int, ipNets []*net.IPNet) error {
 		}
 	}
 
-	addrSliceDifference := func(s1, s2 []netlink.Addr) []*netlink.Addr {
-		var diff []*netlink.Addr
-
-		for i, e1 := range s1 {
-			found := false
-			for _, e2 := range s2 {
-				if e1.Equal(e2) {
-					found = true
-					break
-				}
-			}
-			if !found {
-				diff = append(diff, &s1[i])
-			}
-		}
-
-		return diff
-	}
-
 	addrsToAdd := addrSliceDifference(newAddrs, addrs)
 	addrsToRemove := addrSliceDifference(addrs, newAddrs)
 
diff --git a/pkg/agent/util/net_windows.go b/pkg/agent/util/net_windows.go
index 1b117f32fb8..c01cc1d9140 100644
--- a/pkg/agent/util/net_windows.go
+++ b/pkg/agent/util/net_windows.go
@@ -281,6 +281,35 @@ func SetLinkUp(name string) (net.HardwareAddr, int, error) {
 	return mac, index, nil
 }
 
+func addrEqual(addr1, addr2 *net.IPNet) bool {
+	size1, _ := addr1.Mask.Size()
+	size2, _ := addr2.Mask.Size()
+	return addr1.IP.Equal(addr2.IP) && size1 == size2
+}
+
+func addrSliceDifference(s1, s2 []*net.IPNet) []*net.IPNet {
+	var diff []*net.IPNet
+
+	for _, e1 := range s1 {
+		found := false
+		for _, e2 := range s2 {
+			if addrEqual(e1, e2) {
+				found = true
+				break
+			}
+		}
+		if !found {
+			diff = append(diff, e1)
+		}
+	}
+
+	return diff
+}
+
+// ConfigureLinkAddresses adds the provided addresses to the interface identified by index idx, if
+// they are missing from the interface. Any other existing address already configured for the
+// interface will be removed, unless it is a link-local address. At the moment, this function only
+// supports IPv4 addresses and will ignore any address in ipNets that is not IPv4.
 func ConfigureLinkAddresses(idx int, ipNets []*net.IPNet) error {
 	iface, _ := net.InterfaceByIndex(idx)
 	ifaceName := iface.Name
@@ -297,31 +326,6 @@ func ConfigureLinkAddresses(idx int, ipNets []*net.IPNet) error {
 		}
 	}
 
-	addrEqual := func(addr1, addr2 *net.IPNet) bool {
-		size1, _ := addr1.Mask.Size()
-		size2, _ := addr2.Mask.Size()
-		return addr1.IP.Equal(addr2.IP) && size1 == size2
-	}
-
-	addrSliceDifference := func(s1, s2 []*net.IPNet) []*net.IPNet {
-		var diff []*net.IPNet
-
-		for _, e1 := range s1 {
-			found := false
-			for _, e2 := range s2 {
-				if addrEqual(e1, e2) {
-					found = true
-					break
-				}
-			}
-			if !found {
-				diff = append(diff, e1)
-			}
-		}
-
-		return diff
-	}
-
 	addrsToAdd := addrSliceDifference(ipNets, addrs)
 	addrsToRemove := addrSliceDifference(addrs, ipNets)