1 files changed, 86 insertions, 5 deletions

diff --git a/libgo/go/net/lookup_test.go b/libgo/go/net/lookup_test.go
index 2bc5592..68bffca 100644
--- a/libgo/go/net/lookup_test.go
+++ b/libgo/go/net/lookup_test.go
@@ -74,7 +74,7 @@ func TestLookupGoogleSRV(t *testing.T) {
 	t.Parallel()
 	mustHaveExternalNetwork(t)
 
-	if runtime.GOOS == "darwin" && (runtime.GOARCH == "arm" || runtime.GOARCH == "arm64") {
+	if iOS() {
 		t.Skip("no resolv.conf on iOS")
 	}
 
@@ -123,7 +123,7 @@ func TestLookupGmailMX(t *testing.T) {
 	t.Parallel()
 	mustHaveExternalNetwork(t)
 
-	if runtime.GOOS == "darwin" && (runtime.GOARCH == "arm" || runtime.GOARCH == "arm64") {
+	if iOS() {
 		t.Skip("no resolv.conf on iOS")
 	}
 
@@ -169,7 +169,7 @@ func TestLookupGmailNS(t *testing.T) {
 	t.Parallel()
 	mustHaveExternalNetwork(t)
 
-	if runtime.GOOS == "darwin" && (runtime.GOARCH == "arm" || runtime.GOARCH == "arm64") {
+	if iOS() {
 		t.Skip("no resolv.conf on iOS")
 	}
 
@@ -218,7 +218,7 @@ func TestLookupGmailTXT(t *testing.T) {
 	t.Parallel()
 	mustHaveExternalNetwork(t)
 
-	if runtime.GOOS == "darwin" && (runtime.GOARCH == "arm" || runtime.GOARCH == "arm64") {
+	if iOS() {
 		t.Skip("no resolv.conf on iOS")
 	}
 
@@ -637,7 +637,7 @@ func TestLookupDotsWithRemoteSource(t *testing.T) {
 		t.Skip("IPv4 is required")
 	}
 
-	if runtime.GOOS == "darwin" && (runtime.GOARCH == "arm" || runtime.GOARCH == "arm64") {
+	if iOS() {
 		t.Skip("no resolv.conf on iOS")
 	}
 
@@ -913,6 +913,7 @@ func TestNilResolverLookup(t *testing.T) {
 	r.LookupCNAME(ctx, "google.com")
 	r.LookupHost(ctx, "google.com")
 	r.LookupIPAddr(ctx, "google.com")
+	r.LookupIP(ctx, "ip", "google.com")
 	r.LookupMX(ctx, "gmail.com")
 	r.LookupNS(ctx, "google.com")
 	r.LookupPort(ctx, "tcp", "smtp")
@@ -1185,3 +1186,83 @@ func TestLookupNullByte(t *testing.T) {
 	testenv.SkipFlakyNet(t)
 	LookupHost("foo\x00bar") // check that it doesn't panic; it used to on Windows
 }
+
+func TestResolverLookupIP(t *testing.T) {
+	testenv.MustHaveExternalNetwork(t)
+
+	v4Ok := supportsIPv4() && *testIPv4
+	v6Ok := supportsIPv6() && *testIPv6
+
+	defer dnsWaitGroup.Wait()
+
+	for _, impl := range []struct {
+		name string
+		fn   func() func()
+	}{
+		{"go", forceGoDNS},
+		{"cgo", forceCgoDNS},
+	} {
+		t.Run("implementation: "+impl.name, func(t *testing.T) {
+			fixup := impl.fn()
+			if fixup == nil {
+				t.Skip("not supported")
+			}
+			defer fixup()
+
+			for _, network := range []string{"ip", "ip4", "ip6"} {
+				t.Run("network: "+network, func(t *testing.T) {
+					switch {
+					case network == "ip4" && !v4Ok:
+						t.Skip("IPv4 is not supported")
+					case network == "ip6" && !v6Ok:
+						t.Skip("IPv6 is not supported")
+					}
+
+					// google.com has both A and AAAA records.
+					const host = "google.com"
+					ips, err := DefaultResolver.LookupIP(context.Background(), network, host)
+					if err != nil {
+						testenv.SkipFlakyNet(t)
+						t.Fatalf("DefaultResolver.LookupIP(%q, %q): failed with unexpected error: %v", network, host, err)
+					}
+
+					var v4Addrs []IP
+					var v6Addrs []IP
+					for _, ip := range ips {
+						switch {
+						case ip.To4() != nil:
+							// We need to skip the test below because To16 will
+							// convent an IPv4 address to an IPv4-mapped IPv6
+							// address.
+							v4Addrs = append(v4Addrs, ip)
+						case ip.To16() != nil:
+							v6Addrs = append(v6Addrs, ip)
+						default:
+							t.Fatalf("IP=%q is neither IPv4 nor IPv6", ip)
+						}
+					}
+
+					// Check that we got the expected addresses.
+					if network == "ip4" || network == "ip" && v4Ok {
+						if len(v4Addrs) == 0 {
+							t.Errorf("DefaultResolver.LookupIP(%q, %q): no IPv4 addresses", network, host)
+						}
+					}
+					if network == "ip6" || network == "ip" && v6Ok {
+						if len(v6Addrs) == 0 {
+							t.Errorf("DefaultResolver.LookupIP(%q, %q): no IPv6 addresses", network, host)
+						}
+					}
+
+					// Check that we didn't get any unexpected addresses.
+					if network == "ip6" && len(v4Addrs) > 0 {
+						t.Errorf("DefaultResolver.LookupIP(%q, %q): unexpected IPv4 addresses: %v", network, host, v4Addrs)
+					}
+					if network == "ip4" && len(v6Addrs) > 0 {
+						t.Errorf("DefaultResolver.LookupIP(%q, %q): unexpected IPv6 addresses: %v", network, host, v6Addrs)
+					}
+				})
+			}
+		})
+	}
+}