Add LinkSetARPOff and LinkSetARPOn

Signed-off-by: Jay Dunkelberger <ldunkelberger@pivotal.io>

link_linux.go

@@ -58,6 +58,44 @@ func (h *Handle) ensureIndex(link *LinkAttrs) {
 	}
 }
 
+func (h *Handle) LinkSetARPOff(link Link) error {
+	base := link.Attrs()
+	h.ensureIndex(base)
+	req := h.newNetlinkRequest(syscall.RTM_SETLINK, syscall.NLM_F_ACK)
+
+	msg := nl.NewIfInfomsg(syscall.AF_UNSPEC)
+	msg.Change |= syscall.IFF_NOARP
+	msg.Flags |= syscall.IFF_NOARP
+	msg.Index = int32(base.Index)
+	req.AddData(msg)
+
+	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
+	return err
+}
+
+func LinkSetARPOff(link Link) error {
+	return pkgHandle.LinkSetARPOff(link)
+}
+
+func (h *Handle) LinkSetARPOn(link Link) error {
+	base := link.Attrs()
+	h.ensureIndex(base)
+	req := h.newNetlinkRequest(syscall.RTM_SETLINK, syscall.NLM_F_ACK)
+
+	msg := nl.NewIfInfomsg(syscall.AF_UNSPEC)
+	msg.Change |= syscall.IFF_NOARP
+	msg.Flags &= ^uint32(syscall.IFF_NOARP)
+	msg.Index = int32(base.Index)
+	req.AddData(msg)
+
+	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
+	return err
+}
+
+func LinkSetARPOn(link Link) error {
+	return pkgHandle.LinkSetARPOn(link)
+}
+
 func (h *Handle) SetPromiscOn(link Link) error {
 	base := link.Attrs()
 	h.ensureIndex(base)

link_test.go

@@ -812,6 +812,49 @@ func TestLinkSet(t *testing.T) {
 	}
 }
 
+func TestLinkSetARP(t *testing.T) {
+	tearDown := setUpNetlinkTest(t)
+	defer tearDown()
+
+	iface := &Veth{LinkAttrs: LinkAttrs{Name: "foo", TxQLen: testTxQLen, MTU: 1500}, PeerName: "banana"}
+	if err := LinkAdd(iface); err != nil {
+		t.Fatal(err)
+	}
+
+	link, err := LinkByName("foo")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = LinkSetARPOff(link)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	link, err = LinkByName("foo")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if link.Attrs().RawFlags&syscall.IFF_NOARP != uint32(syscall.IFF_NOARP) {
+		t.Fatalf("NOARP was not set!")
+	}
+
+	err = LinkSetARPOn(link)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	link, err = LinkByName("foo")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if link.Attrs().RawFlags&syscall.IFF_NOARP != 0 {
+		t.Fatalf("NOARP is still set!")
+	}
+}
+
 func expectLinkUpdate(ch <-chan LinkUpdate, ifaceName string, up bool) bool {
 	for {
 		timeout := time.After(time.Minute)

netlink_unspecified.go

@@ -64,6 +64,14 @@ func LinkSetXdpFd(link Link, fd int) error {
 	return ErrNotImplemented
 }
 
+func LinkSetARPOff(link Link) error {
+	return ErrNotImplemented
+}
+
+func LinkSetARPOn(link Link) error {
+	return ErrNotImplemented
+}
+
 func LinkByName(name string) (Link, error) {
 	return nil, ErrNotImplemented
 }