net: LookupHost and Resolve{TCP,UDP,IP}Addr should use zone from getaddrinfo

The unix and windows getaddrinfo calls return a zone with IPv6
addresses. IPv6 link-local addresses returned are only valid on the
given zone. When the zone is dropped, connections to the address
will fail. This patch replaces IP with IPAddr in several internal
resolver functions, and plumbs through the zone.

Change-Id: Ifea891654f586f15b76988464f82e04a42ccff6d
Reviewed-on: https://go-review.googlesource.com/5851Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>

src/net/cgo_stub.go

@@ -16,7 +16,7 @@ func cgoLookupPort(network, service string) (port int, err error, completed bool
 	return 0, nil, false
 }
 
-func cgoLookupIP(name string) (addrs []IP, err error, completed bool) {
+func cgoLookupIP(name string) (addrs []IPAddr, err error, completed bool) {
 	return nil, nil, false
 }
 

src/net/cgo_unix.go

@@ -81,7 +81,7 @@ func cgoLookupPort(net, service string) (port int, err error, completed bool) {
 	return 0, &AddrError{"unknown port", net + "/" + service}, true
 }
 
-func cgoLookupIPCNAME(name string) (addrs []IP, cname string, err error, completed bool) {
+func cgoLookupIPCNAME(name string) (addrs []IPAddr, cname string, err error, completed bool) {
 	acquireThread()
 	defer releaseThread()
 
@@ -135,16 +135,18 @@ func cgoLookupIPCNAME(name string) (addrs []IP, cname string, err error, complet
 			continue
 		case C.AF_INET:
 			sa := (*syscall.RawSockaddrInet4)(unsafe.Pointer(r.ai_addr))
-			addrs = append(addrs, copyIP(sa.Addr[:]))
+			addr := IPAddr{IP: copyIP(sa.Addr[:])}
+			addrs = append(addrs, addr)
 		case C.AF_INET6:
 			sa := (*syscall.RawSockaddrInet6)(unsafe.Pointer(r.ai_addr))
-			addrs = append(addrs, copyIP(sa.Addr[:]))
+			addr := IPAddr{IP: copyIP(sa.Addr[:]), Zone: zoneToString(int(sa.Scope_id))}
+			addrs = append(addrs, addr)
 		}
 	}
 	return addrs, cname, nil, true
 }
 
-func cgoLookupIP(name string) (addrs []IP, err error, completed bool) {
+func cgoLookupIP(name string) (addrs []IPAddr, err error, completed bool) {
 	addrs, _, err, completed = cgoLookupIPCNAME(name)
 	return
 }

src/net/dnsclient_unix.go

@@ -361,13 +361,15 @@ func goLookupHost(name string) (addrs []string, err error) {
 // Normally we let cgo use the C library resolver instead of
 // depending on our lookup code, so that Go and C get the same
 // answers.
-func goLookupIP(name string) (addrs []IP, err error) {
+func goLookupIP(name string) (addrs []IPAddr, err error) {
 	// Use entries from /etc/hosts if possible.
 	haddrs := lookupStaticHost(name)
 	if len(haddrs) > 0 {
 		for _, haddr := range haddrs {
+			haddr, zone := splitHostZone(haddr)
 			if ip := ParseIP(haddr); ip != nil {
-				addrs = append(addrs, ip)
+				addr := IPAddr{IP: ip, Zone: zone}
+				addrs = append(addrs, addr)
 			}
 		}
 		if len(addrs) > 0 {
@@ -396,9 +398,15 @@ func goLookupIP(name string) (addrs []IP, err error) {
 		}
 		switch racer.qtype {
 		case dnsTypeA:
-			addrs = append(addrs, convertRR_A(racer.rrs)...)
+			for _, ip := range convertRR_A(racer.rrs) {
+				addr := IPAddr{IP: ip}
+				addrs = append(addrs, addr)
+			}
 		case dnsTypeAAAA:
-			addrs = append(addrs, convertRR_AAAA(racer.rrs)...)
+			for _, ip := range convertRR_AAAA(racer.rrs) {
+				addr := IPAddr{IP: ip}
+				addrs = append(addrs, addr)
+			}
 		}
 	}
 	if len(addrs) == 0 && lastErr != nil {

src/net/ipsock.go

@@ -64,7 +64,7 @@ var errNoSuitableAddress = errors.New("no suitable address found")
 // implement the netaddr interface. Known filters are nil, ipv4only
 // and ipv6only. It returns any address when filter is nil. The result
 // contains at least one address when error is nil.
-func firstFavoriteAddr(filter func(IP) IP, ips []IP, inetaddr func(IP) netaddr) (netaddr, error) {
+func firstFavoriteAddr(filter func(IPAddr) bool, ips []IPAddr, inetaddr func(IPAddr) netaddr) (netaddr, error) {
 	if filter != nil {
 		return firstSupportedAddr(filter, ips, inetaddr)
 	}
@@ -79,14 +79,14 @@ func firstFavoriteAddr(filter func(IP) IP, ips []IP, inetaddr func(IP) netaddr)
 		// possible. This is especially relevant if localhost
 		// resolves to [ipv6-localhost, ipv4-localhost]. Too
 		// much code assumes localhost == ipv4-localhost.
-		if ip4 := ipv4only(ip); ip4 != nil && !ipv4 {
-			list = append(list, inetaddr(ip4))
+		if ipv4only(ip) && !ipv4 {
+			list = append(list, inetaddr(ip))
 			ipv4 = true
 			if ipv6 {
 				swap = true
 			}
-		} else if ip6 := ipv6only(ip); ip6 != nil && !ipv6 {
-			list = append(list, inetaddr(ip6))
+		} else if ipv6only(ip) && !ipv6 {
+			list = append(list, inetaddr(ip))
 			ipv6 = true
 		}
 		if ipv4 && ipv6 {
@@ -106,33 +106,25 @@ func firstFavoriteAddr(filter func(IP) IP, ips []IP, inetaddr func(IP) netaddr)
 	}
 }
 
-func firstSupportedAddr(filter func(IP) IP, ips []IP, inetaddr func(IP) netaddr) (netaddr, error) {
+func firstSupportedAddr(filter func(IPAddr) bool, ips []IPAddr, inetaddr func(IPAddr) netaddr) (netaddr, error) {
 	for _, ip := range ips {
-		if ip := filter(ip); ip != nil {
+		if filter(ip) {
 			return inetaddr(ip), nil
 		}
 	}
 	return nil, errNoSuitableAddress
 }
 
-// ipv4only returns IPv4 addresses that we can use with the kernel's
-// IPv4 addressing modes. If ip is an IPv4 address, ipv4only returns ip.
-// Otherwise it returns nil.
-func ipv4only(ip IP) IP {
-	if supportsIPv4 && ip.To4() != nil {
-		return ip
-	}
-	return nil
+// ipv4only reports whether the kernel supports IPv4 addressing mode
+// and addr is an IPv4 address.
+func ipv4only(addr IPAddr) bool {
+	return supportsIPv4 && addr.IP.To4() != nil
 }
 
-// ipv6only returns IPv6 addresses that we can use with the kernel's
-// IPv6 addressing modes.  It returns IPv4-mapped IPv6 addresses as
-// nils and returns other IPv6 address types as IPv6 addresses.
-func ipv6only(ip IP) IP {
-	if supportsIPv6 && len(ip) == IPv6len && ip.To4() == nil {
-		return ip
-	}
-	return nil
+// ipv6only reports whether the kernel supports IPv6 addressing mode
+// and addr is an IPv6 address except IPv4-mapped IPv6 address.
+func ipv6only(addr IPAddr) bool {
+	return supportsIPv6 && len(addr.IP) == IPv6len && addr.IP.To4() == nil
 }
 
 // SplitHostPort splits a network address of the form "host:port",
@@ -236,9 +228,9 @@ func JoinHostPort(host, port string) string {
 // address when error is nil.
 func resolveInternetAddr(net, addr string, deadline time.Time) (netaddr, error) {
 	var (
-		err              error
-		host, port, zone string
-		portnum          int
+		err        error
+		host, port string
+		portnum    int
 	)
 	switch net {
 	case "tcp", "tcp4", "tcp6", "udp", "udp4", "udp6":
@@ -257,40 +249,40 @@ func resolveInternetAddr(net, addr string, deadline time.Time) (netaddr, error)
 	default:
 		return nil, UnknownNetworkError(net)
 	}
-	inetaddr := func(ip IP) netaddr {
+	inetaddr := func(ip IPAddr) netaddr {
 		switch net {
 		case "tcp", "tcp4", "tcp6":
-			return &TCPAddr{IP: ip, Port: portnum, Zone: zone}
+			return &TCPAddr{IP: ip.IP, Port: portnum, Zone: ip.Zone}
 		case "udp", "udp4", "udp6":
-			return &UDPAddr{IP: ip, Port: portnum, Zone: zone}
+			return &UDPAddr{IP: ip.IP, Port: portnum, Zone: ip.Zone}
 		case "ip", "ip4", "ip6":
-			return &IPAddr{IP: ip, Zone: zone}
+			return &IPAddr{IP: ip.IP, Zone: ip.Zone}
 		default:
 			panic("unexpected network: " + net)
 		}
 	}
 	if host == "" {
-		return inetaddr(nil), nil
+		return inetaddr(IPAddr{}), nil
 	}
 	// Try as a literal IP address.
 	var ip IP
 	if ip = parseIPv4(host); ip != nil {
-		return inetaddr(ip), nil
+		return inetaddr(IPAddr{IP: ip}), nil
 	}
+	var zone string
 	if ip, zone = parseIPv6(host, true); ip != nil {
-		return inetaddr(ip), nil
+		return inetaddr(IPAddr{IP: ip, Zone: zone}), nil
 	}
 	// Try as a DNS name.
-	host, zone = splitHostZone(host)
 	ips, err := lookupIPDeadline(host, deadline)
 	if err != nil {
 		return nil, err
 	}
-	var filter func(IP) IP
+	var filter func(IPAddr) bool
 	if net != "" && net[len(net)-1] == '4' {
 		filter = ipv4only
 	}
-	if net != "" && net[len(net)-1] == '6' || zone != "" {
+	if net != "" && net[len(net)-1] == '6' {
 		filter = ipv6only
 	}
 	return firstFavoriteAddr(filter, ips, inetaddr)

src/net/ipsock_test.go

@@ -9,20 +9,20 @@ import (
 	"testing"
 )
 
-var testInetaddr = func(ip IP) netaddr { return &TCPAddr{IP: ip, Port: 5682} }
+var testInetaddr = func(ip IPAddr) netaddr { return &TCPAddr{IP: ip.IP, Port: 5682, Zone: ip.Zone} }
 
 var firstFavoriteAddrTests = []struct {
-	filter   func(IP) IP
-	ips      []IP
-	inetaddr func(IP) netaddr
+	filter   func(IPAddr) bool
+	ips      []IPAddr
+	inetaddr func(IPAddr) netaddr
 	addr     netaddr
 	err      error
 }{
 	{
 		nil,
-		[]IP{
-			IPv4(127, 0, 0, 1),
-			IPv6loopback,
+		[]IPAddr{
+			IPAddr{IP: IPv4(127, 0, 0, 1)},
+			IPAddr{IP: IPv6loopback},
 		},
 		testInetaddr,
 		addrList{
@@ -33,9 +33,9 @@ var firstFavoriteAddrTests = []struct {
 	},
 	{
 		nil,
-		[]IP{
-			IPv6loopback,
-			IPv4(127, 0, 0, 1),
+		[]IPAddr{
+			IPAddr{IP: IPv6loopback},
+			IPAddr{IP: IPv4(127, 0, 0, 1)},
 		},
 		testInetaddr,
 		addrList{
@@ -46,9 +46,9 @@ var firstFavoriteAddrTests = []struct {
 	},
 	{
 		nil,
-		[]IP{
-			IPv4(127, 0, 0, 1),
-			IPv4(192, 168, 0, 1),
+		[]IPAddr{
+			IPAddr{IP: IPv4(127, 0, 0, 1)},
+			IPAddr{IP: IPv4(192, 168, 0, 1)},
 		},
 		testInetaddr,
 		&TCPAddr{IP: IPv4(127, 0, 0, 1), Port: 5682},
@@ -56,9 +56,9 @@ var firstFavoriteAddrTests = []struct {
 	},
 	{
 		nil,
-		[]IP{
-			IPv6loopback,
-			ParseIP("fe80::1"),
+		[]IPAddr{
+			IPAddr{IP: IPv6loopback},
+			IPAddr{IP: ParseIP("fe80::1"), Zone: "eth0"},
 		},
 		testInetaddr,
 		&TCPAddr{IP: IPv6loopback, Port: 5682},
@@ -66,11 +66,11 @@ var firstFavoriteAddrTests = []struct {
 	},
 	{
 		nil,
-		[]IP{
-			IPv4(127, 0, 0, 1),
-			IPv4(192, 168, 0, 1),
-			IPv6loopback,
-			ParseIP("fe80::1"),
+		[]IPAddr{
+			IPAddr{IP: IPv4(127, 0, 0, 1)},
+			IPAddr{IP: IPv4(192, 168, 0, 1)},
+			IPAddr{IP: IPv6loopback},
+			IPAddr{IP: ParseIP("fe80::1"), Zone: "eth0"},
 		},
 		testInetaddr,
 		addrList{
@@ -81,11 +81,11 @@ var firstFavoriteAddrTests = []struct {
 	},
 	{
 		nil,
-		[]IP{
-			IPv6loopback,
-			ParseIP("fe80::1"),
-			IPv4(127, 0, 0, 1),
-			IPv4(192, 168, 0, 1),
+		[]IPAddr{
+			IPAddr{IP: IPv6loopback},
+			IPAddr{IP: ParseIP("fe80::1"), Zone: "eth0"},
+			IPAddr{IP: IPv4(127, 0, 0, 1)},
+			IPAddr{IP: IPv4(192, 168, 0, 1)},
 		},
 		testInetaddr,
 		addrList{
@@ -96,11 +96,11 @@ var firstFavoriteAddrTests = []struct {
 	},
 	{
 		nil,
-		[]IP{
-			IPv4(127, 0, 0, 1),
-			IPv6loopback,
-			IPv4(192, 168, 0, 1),
-			ParseIP("fe80::1"),
+		[]IPAddr{
+			IPAddr{IP: IPv4(127, 0, 0, 1)},
+			IPAddr{IP: IPv6loopback},
+			IPAddr{IP: IPv4(192, 168, 0, 1)},
+			IPAddr{IP: ParseIP("fe80::1"), Zone: "eth0"},
 		},
 		testInetaddr,
 		addrList{
@@ -111,11 +111,11 @@ var firstFavoriteAddrTests = []struct {
 	},
 	{
 		nil,
-		[]IP{
-			IPv6loopback,
-			IPv4(127, 0, 0, 1),
-			ParseIP("fe80::1"),
-			IPv4(192, 168, 0, 1),
+		[]IPAddr{
+			IPAddr{IP: IPv6loopback},
+			IPAddr{IP: IPv4(127, 0, 0, 1)},
+			IPAddr{IP: ParseIP("fe80::1"), Zone: "eth0"},
+			IPAddr{IP: IPv4(192, 168, 0, 1)},
 		},
 		testInetaddr,
 		addrList{
@@ -127,9 +127,9 @@ var firstFavoriteAddrTests = []struct {
 
 	{
 		ipv4only,
-		[]IP{
-			IPv4(127, 0, 0, 1),
-			IPv6loopback,
+		[]IPAddr{
+			IPAddr{IP: IPv4(127, 0, 0, 1)},
+			IPAddr{IP: IPv6loopback},
 		},
 		testInetaddr,
 		&TCPAddr{IP: IPv4(127, 0, 0, 1), Port: 5682},
@@ -137,9 +137,9 @@ var firstFavoriteAddrTests = []struct {
 	},
 	{
 		ipv4only,
-		[]IP{
-			IPv6loopback,
-			IPv4(127, 0, 0, 1),
+		[]IPAddr{
+			IPAddr{IP: IPv6loopback},
+			IPAddr{IP: IPv4(127, 0, 0, 1)},
 		},
 		testInetaddr,
 		&TCPAddr{IP: IPv4(127, 0, 0, 1), Port: 5682},
@@ -148,9 +148,9 @@ var firstFavoriteAddrTests = []struct {
 
 	{
 		ipv6only,
-		[]IP{
-			IPv4(127, 0, 0, 1),
-			IPv6loopback,
+		[]IPAddr{
+			IPAddr{IP: IPv4(127, 0, 0, 1)},
+			IPAddr{IP: IPv6loopback},
 		},
 		testInetaddr,
 		&TCPAddr{IP: IPv6loopback, Port: 5682},
@@ -158,9 +158,9 @@ var firstFavoriteAddrTests = []struct {
 	},
 	{
 		ipv6only,
-		[]IP{
-			IPv6loopback,
-			IPv4(127, 0, 0, 1),
+		[]IPAddr{
+			IPAddr{IP: IPv6loopback},
+			IPAddr{IP: IPv4(127, 0, 0, 1)},
 		},
 		testInetaddr,
 		&TCPAddr{IP: IPv6loopback, Port: 5682},
@@ -170,10 +170,10 @@ var firstFavoriteAddrTests = []struct {
 	{nil, nil, testInetaddr, nil, errNoSuitableAddress},
 
 	{ipv4only, nil, testInetaddr, nil, errNoSuitableAddress},
-	{ipv4only, []IP{IPv6loopback}, testInetaddr, nil, errNoSuitableAddress},
+	{ipv4only, []IPAddr{IPAddr{IP: IPv6loopback}}, testInetaddr, nil, errNoSuitableAddress},
 
 	{ipv6only, nil, testInetaddr, nil, errNoSuitableAddress},
-	{ipv6only, []IP{IPv4(127, 0, 0, 1)}, testInetaddr, nil, errNoSuitableAddress},
+	{ipv6only, []IPAddr{IPAddr{IP: IPv4(127, 0, 0, 1)}}, testInetaddr, nil, errNoSuitableAddress},
 }
 
 func TestFirstFavoriteAddr(t *testing.T) {

src/net/lookup.go

@@ -27,8 +27,16 @@ func LookupHost(host string) (addrs []string, err error) {
 
 // LookupIP looks up host using the local resolver.
 // It returns an array of that host's IPv4 and IPv6 addresses.
-func LookupIP(host string) (addrs []IP, err error) {
-	return lookupIPMerge(host)
+func LookupIP(host string) (ips []IP, err error) {
+	addrs, err := lookupIPMerge(host)
+	if err != nil {
+		return
+	}
+	ips = make([]IP, len(addrs))
+	for i, addr := range addrs {
+		ips[i] = addr.IP
+	}
+	return
 }
 
 var lookupGroup singleflight
@@ -36,7 +44,7 @@ var lookupGroup singleflight
 // lookupIPMerge wraps lookupIP, but makes sure that for any given
 // host, only one lookup is in-flight at a time. The returned memory
 // is always owned by the caller.
-func lookupIPMerge(host string) (addrs []IP, err error) {
+func lookupIPMerge(host string) (addrs []IPAddr, err error) {
 	addrsi, err, shared := lookupGroup.Do(host, func() (interface{}, error) {
 		return lookupIP(host)
 	})
@@ -45,13 +53,13 @@ func lookupIPMerge(host string) (addrs []IP, err error) {
 
 // lookupIPReturn turns the return values from singleflight.Do into
 // the return values from LookupIP.
-func lookupIPReturn(addrsi interface{}, err error, shared bool) ([]IP, error) {
+func lookupIPReturn(addrsi interface{}, err error, shared bool) ([]IPAddr, error) {
 	if err != nil {
 		return nil, err
 	}
-	addrs := addrsi.([]IP)
+	addrs := addrsi.([]IPAddr)
 	if shared {
-		clone := make([]IP, len(addrs))
+		clone := make([]IPAddr, len(addrs))
 		copy(clone, addrs)
 		addrs = clone
 	}
@@ -59,7 +67,7 @@ func lookupIPReturn(addrsi interface{}, err error, shared bool) ([]IP, error) {
 }
 
 // lookupIPDeadline looks up a hostname with a deadline.
-func lookupIPDeadline(host string, deadline time.Time) (addrs []IP, err error) {
+func lookupIPDeadline(host string, deadline time.Time) (addrs []IPAddr, err error) {
 	if deadline.IsZero() {
 		return lookupIPMerge(host)
 	}

src/net/lookup_plan9.go

@@ -147,14 +147,16 @@ loop:
 	return
 }
 
-func lookupIP(host string) (ips []IP, err error) {
-	addrs, err := LookupHost(host)
+func lookupIP(host string) (addrs []IPAddr, err error) {
+	lits, err := LookupHost(host)
 	if err != nil {
 		return
 	}
-	for _, addr := range addrs {
-		if ip := ParseIP(addr); ip != nil {
-			ips = append(ips, ip)
+	for _, lit := range lits {
+		host, zone := splitHostZone(lit)
+		if ip := ParseIP(host); ip != nil {
+			addr := IPAddr{IP: ip, Zone: zone}
+			addrs = append(addrs, addr)
 		}
 	}
 	return

src/net/lookup_stub.go

@@ -16,7 +16,7 @@ func lookupHost(host string) (addrs []string, err error) {
 	return nil, syscall.ENOPROTOOPT
 }
 
-func lookupIP(host string) (ips []IP, err error) {
+func lookupIP(host string) (addrs []IPAddr, err error) {
 	return nil, syscall.ENOPROTOOPT
 }
 

src/net/lookup_unix.go

@@ -60,7 +60,7 @@ func lookupHost(host string) (addrs []string, err error) {
 	return
 }
 
-func lookupIP(host string) (addrs []IP, err error) {
+func lookupIP(host string) (addrs []IPAddr, err error) {
 	addrs, err, ok := cgoLookupIP(host)
 	if !ok {
 		addrs, err = goLookupIP(host)

src/net/lookup_windows.go

@@ -62,7 +62,7 @@ func lookupHost(name string) (addrs []string, err error) {
 	return
 }
 
-func gethostbyname(name string) (addrs []IP, err error) {
+func gethostbyname(name string) (addrs []IPAddr, err error) {
 	// caller already acquired thread
 	h, err := syscall.GetHostByName(name)
 	if err != nil {
@@ -71,9 +71,9 @@ func gethostbyname(name string) (addrs []IP, err error) {
 	switch h.AddrType {
 	case syscall.AF_INET:
 		i := 0
-		addrs = make([]IP, 100) // plenty of room to grow
+		addrs = make([]IPAddr, 100) // plenty of room to grow
 		for p := (*[100](*[4]byte))(unsafe.Pointer(h.AddrList)); i < cap(addrs) && p[i] != nil; i++ {
-			addrs[i] = IPv4(p[i][0], p[i][1], p[i][2], p[i][3])
+			addrs[i] = IPAddr{IP: IPv4(p[i][0], p[i][1], p[i][2], p[i][3])}
 		}
 		addrs = addrs[0:i]
 	default: // TODO(vcc): Implement non IPv4 address lookups.
@@ -82,11 +82,11 @@ func gethostbyname(name string) (addrs []IP, err error) {
 	return addrs, nil
 }
 
-func oldLookupIP(name string) (addrs []IP, err error) {
+func oldLookupIP(name string) (addrs []IPAddr, err error) {
 	// GetHostByName return value is stored in thread local storage.
 	// Start new os thread before the call to prevent races.
 	type result struct {
-		addrs []IP
+		addrs []IPAddr
 		err   error
 	}
 	ch := make(chan result)
@@ -99,10 +99,10 @@ func oldLookupIP(name string) (addrs []IP, err error) {
 		ch <- result{addrs: addrs, err: err}
 	}()
 	r := <-ch
-	return r.addrs, r.err
+	return addrs, r.err
 }
 
-func newLookupIP(name string) (addrs []IP, err error) {
+func newLookupIP(name string) (addrs []IPAddr, err error) {
 	acquireThread()
 	defer releaseThread()
 	hints := syscall.AddrinfoW{
@@ -116,16 +116,17 @@ func newLookupIP(name string) (addrs []IP, err error) {
 		return nil, os.NewSyscallError("GetAddrInfoW", e)
 	}
 	defer syscall.FreeAddrInfoW(result)
-	addrs = make([]IP, 0, 5)
+	addrs = make([]IPAddr, 0, 5)
 	for ; result != nil; result = result.Next {
 		addr := unsafe.Pointer(result.Addr)
 		switch result.Family {
 		case syscall.AF_INET:
 			a := (*syscall.RawSockaddrInet4)(addr).Addr
-			addrs = append(addrs, IPv4(a[0], a[1], a[2], a[3]))
+			addrs = append(addrs, IPAddr{IP: IPv4(a[0], a[1], a[2], a[3])})
 		case syscall.AF_INET6:
 			a := (*syscall.RawSockaddrInet6)(addr).Addr
-			addrs = append(addrs, IP{a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], a[10], a[11], a[12], a[13], a[14], a[15]})
+			zone := zoneToString(int((*syscall.RawSockaddrInet6)(addr).Scope_id))
+			addrs = append(addrs, IPAddr{IP: IP{a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], a[10], a[11], a[12], a[13], a[14], a[15]}, Zone: zone})
 		default:
 			return nil, os.NewSyscallError("LookupIP", syscall.EWINDOWS)
 		}