winipcfg: SetInterfaceDnsSettings is now documented on MSDN

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

4 files changed, 36 insertions, 33 deletions

diff --git a/tunnel/winipcfg/luid.go b/tunnel/winipcfg/luid.go
index 02ba65b4..0aae7755 100644
--- a/tunnel/winipcfg/luid.go
+++ b/tunnel/winipcfg/luid.go
@@ -353,17 +353,17 @@ func (luid LUID) SetDNS(family AddressFamily, servers []net.IP, domains []string
 	if err != nil {
 		return err
 	}
-	var maybeV6 uint64
+	dnsInterfaceSettings := &DnsInterfaceSettings{
+		Version:    DnsInterfaceSettingsVersion1,
+		Flags:      DnsInterfaceSettingsFlagNameserver | DnsInterfaceSettingsFlagSearchList,
+		NameServer: servers16,
+		SearchList: domains16,
+	}
 	if family == windows.AF_INET6 {
-		maybeV6 = disFlagsIPv6
+		dnsInterfaceSettings.Flags |= DnsInterfaceSettingsFlagIPv6
 	}
 	// For >= Windows 10 1809
-	err = setInterfaceDnsSettings(*guid, &dnsInterfaceSettings{
-		Version:    disVersion1,
-		Flags:      disFlagsNameServer | disFlagsSearchList | maybeV6,
-		NameServer: servers16,
-		SearchList: domains16,
-	})
+	err = SetInterfaceDnsSettings(*guid, dnsInterfaceSettings)
 	if err == nil || !errors.Is(err, windows.ERROR_PROC_NOT_FOUND) {
 		return err
 	}
diff --git a/tunnel/winipcfg/types.go b/tunnel/winipcfg/types.go
index b06f05dd..4672fb84 100644
--- a/tunnel/winipcfg/types.go
+++ b/tunnel/winipcfg/types.go
@@ -964,11 +964,11 @@ func (tab *mibIPforwardTable2) free() {
 }
 
 //
-// Undocumented DNS API
+// DNS API
 //
 
 // dnsInterfaceSettings is mean to be used with setInterfaceDnsSettings
-type dnsInterfaceSettings struct {
+type DnsInterfaceSettings struct {
 	Version             uint32
 	_                   [4]byte
 	Flags               uint64
@@ -983,21 +983,24 @@ type dnsInterfaceSettings struct {
 }
 
 const (
-	disVersion1 = 1
-	disVersion2 = 2
-
-	disFlagsIPv6                = 0x1
-	disFlagsNameServer          = 0x2
-	disFlagsSearchList          = 0x4
-	disFlagsRegistrationEnabled = 0x8
-	disFlagsRegisterAdapterName = 0x10
-	disFlagsDomain              = 0x20
-	disFlagsHostname            = 0x40 // ??
-	disFlagsEnableLLMNR         = 0x80
-	disFlagsQueryAdapterName    = 0x100
-	disFlagsProfileNameServer   = 0x200
-	disFlagsVersion2            = 0x400 // ?? - v2 only
-	disFlagsMoreFlags           = 0x800 // ?? - v2 only
+	DnsInterfaceSettingsVersion1 = 1 // for DnsInterfaceSettings
+	DnsInterfaceSettingsVersion2 = 2 // for DnsInterfaceSettingsEx
+	DnsInterfaceSettingsVersion3 = 3 // for DnsInterfaceSettings3
+
+	DnsInterfaceSettingsFlagIPv6                        = 0x0001
+	DnsInterfaceSettingsFlagNameserver                  = 0x0002
+	DnsInterfaceSettingsFlagSearchList                  = 0x0004
+	DnsInterfaceSettingsFlagRegistrationEnabled         = 0x0008
+	DnsInterfaceSettingsFlagRegisterAdapterName         = 0x0010
+	DnsInterfaceSettingsFlagDomain                      = 0x0020
+	DnsInterfaceSettingsFlagHostname                    = 0x0040
+	DnsInterfaceSettingsFlagEenableLLMNR                = 0x0080
+	DnsInterfaceSettingsFlagQueryAdapterName            = 0x0100
+	DnsInterfaceSettingsFlagProfileNameserver           = 0x0200
+	DnsInterfaceSettingsFlagDisableUnconstrainedQueries = 0x0400 // v2 only
+	DnsInterfaceSettingsFlagSupplementalSearchList      = 0x0800 // v2 only
+	DnsInterfaceSettingsFlagDOH                         = 0x1000 // v3 only
+	DnsInterfaceSettingsFlagDOHProfile                  = 0x2000 // v3 only
 )
 
 // unsafeSlice updates the slice slicePtr to be a slice
diff --git a/tunnel/winipcfg/winipcfg.go b/tunnel/winipcfg/winipcfg.go
index dd09d3a0..558af251 100644
--- a/tunnel/winipcfg/winipcfg.go
+++ b/tunnel/winipcfg/winipcfg.go
@@ -170,18 +170,18 @@ func GetIPForwardTable2(family AddressFamily) ([]MibIPforwardRow2, error) {
 //sys	cancelMibChangeNotify2(notificationHandle windows.Handle) (ret error) = iphlpapi.CancelMibChangeNotify2
 
 //
-// Undocumented DNS API
+// DNS-related functions
 //
 
-//sys	setInterfaceDnsSettingsByPtr(guid *windows.GUID, settings *dnsInterfaceSettings) (ret error) = iphlpapi.SetInterfaceDnsSettings?
-//sys	setInterfaceDnsSettingsByQwords(guid1 uintptr, guid2 uintptr, settings *dnsInterfaceSettings) (ret error) = iphlpapi.SetInterfaceDnsSettings?
-//sys	setInterfaceDnsSettingsByDwords(guid1 uintptr, guid2 uintptr, guid3 uintptr, guid4 uintptr, settings *dnsInterfaceSettings) (ret error) = iphlpapi.SetInterfaceDnsSettings?
+//sys	setInterfaceDnsSettingsByPtr(guid *windows.GUID, settings *DnsInterfaceSettings) (ret error) = iphlpapi.SetInterfaceDnsSettings?
+//sys	setInterfaceDnsSettingsByQwords(guid1 uintptr, guid2 uintptr, settings *DnsInterfaceSettings) (ret error) = iphlpapi.SetInterfaceDnsSettings?
+//sys	setInterfaceDnsSettingsByDwords(guid1 uintptr, guid2 uintptr, guid3 uintptr, guid4 uintptr, settings *DnsInterfaceSettings) (ret error) = iphlpapi.SetInterfaceDnsSettings?
 
 // The GUID is passed by value, not by reference, which means different
 // things on different calling conventions.  On amd64, this means it's
 // passed by reference anyway, while on arm, arm64, and 386, it's split
 // into words.
-func setInterfaceDnsSettings(guid windows.GUID, settings *dnsInterfaceSettings) error {
+func SetInterfaceDnsSettings(guid windows.GUID, settings *DnsInterfaceSettings) error {
 	words := (*[4]uintptr)(unsafe.Pointer(&guid))
 	switch runtime.GOARCH {
 	case "amd64":
diff --git a/tunnel/winipcfg/zwinipcfg_windows.go b/tunnel/winipcfg/zwinipcfg_windows.go
index ac89fec1..f661cf0c 100644
--- a/tunnel/winipcfg/zwinipcfg_windows.go
+++ b/tunnel/winipcfg/zwinipcfg_windows.go
@@ -289,7 +289,7 @@ func notifyUnicastIPAddressChange(family AddressFamily, callback uintptr, caller
 	return
 }
 
-func setInterfaceDnsSettingsByDwords(guid1 uintptr, guid2 uintptr, guid3 uintptr, guid4 uintptr, settings *dnsInterfaceSettings) (ret error) {
+func setInterfaceDnsSettingsByDwords(guid1 uintptr, guid2 uintptr, guid3 uintptr, guid4 uintptr, settings *DnsInterfaceSettings) (ret error) {
 	ret = procSetInterfaceDnsSettings.Find()
 	if ret != nil {
 		return
@@ -301,7 +301,7 @@ func setInterfaceDnsSettingsByDwords(guid1 uintptr, guid2 uintptr, guid3 uintptr
 	return
 }
 
-func setInterfaceDnsSettingsByPtr(guid *windows.GUID, settings *dnsInterfaceSettings) (ret error) {
+func setInterfaceDnsSettingsByPtr(guid *windows.GUID, settings *DnsInterfaceSettings) (ret error) {
 	ret = procSetInterfaceDnsSettings.Find()
 	if ret != nil {
 		return
@@ -313,7 +313,7 @@ func setInterfaceDnsSettingsByPtr(guid *windows.GUID, settings *dnsInterfaceSett
 	return
 }
 
-func setInterfaceDnsSettingsByQwords(guid1 uintptr, guid2 uintptr, settings *dnsInterfaceSettings) (ret error) {
+func setInterfaceDnsSettingsByQwords(guid1 uintptr, guid2 uintptr, settings *DnsInterfaceSettings) (ret error) {
 	ret = procSetInterfaceDnsSettings.Find()
 	if ret != nil {
 		return