From d7eabfff063e286b5545226668e18857da00442f Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Tue, 3 Sep 2019 10:54:05 -0600
Subject: winipcfg: [BEGINNINGS] import undocumented iphlpapi function

---
 tunnel/winipcfg/types.go             | 25 +++++++++++++++++++++++++
 tunnel/winipcfg/winipcfg.go          |  3 +++
 tunnel/winipcfg/zwinipcfg_windows.go |  9 +++++++++
 3 files changed, 37 insertions(+)

diff --git a/tunnel/winipcfg/types.go b/tunnel/winipcfg/types.go
index 684a6c77..b7c49029 100644
--- a/tunnel/winipcfg/types.go
+++ b/tunnel/winipcfg/types.go
@@ -950,3 +950,28 @@ func (tab *mibIPforwardTable2) get() []MibIPforwardRow2 {
 func (tab *mibIPforwardTable2) free() {
 	freeMibTable(unsafe.Pointer(tab))
 }
+
+type DnsInterfaceSettings struct {
+	Version uint32
+	Flags uint64
+	Domain *uint16
+	NameServer *uint16
+	SearchList *uint16
+	RegistrationEnabled uint32
+	RegisterAdapterName uint32
+	EnableLLMNR uint32
+	QueryAdapterName uint32
+	ProfileNameServer *uint16
+}
+
+const (
+	DisVersion = 1
+
+	DisFlagsHaveNameServer = 2 << iota
+	DisFlagsHaveSearchList
+	DisFlagsHaveRegistrationEnabled
+	DisFlagsHaveDomain
+	DisFlagsHaveEnableLLMNR
+	DisFlagsHaveQueryAdapterName
+	DisFlagsHaveProfileNameServer
+)
\ No newline at end of file
diff --git a/tunnel/winipcfg/winipcfg.go b/tunnel/winipcfg/winipcfg.go
index 2fc0c875..90a96bb5 100644
--- a/tunnel/winipcfg/winipcfg.go
+++ b/tunnel/winipcfg/winipcfg.go
@@ -166,3 +166,6 @@ func GetIPForwardTable2(family AddressFamily) ([]MibIPforwardRow2, error) {
 
 // https://docs.microsoft.com/en-us/windows/desktop/api/netioapi/nf-netioapi-cancelmibchangenotify2
 //sys	cancelMibChangeNotify2(notificationHandle windows.Handle) (ret error) = iphlpapi.CancelMibChangeNotify2
+
+// Undocumented
+//sys	setInterfaceDnsSettings(guid *windows.GUID, settings *DnsInterfaceSettings) (ret error) = iphlpapi.SetInterfaceDnsSettings
\ No newline at end of file
diff --git a/tunnel/winipcfg/zwinipcfg_windows.go b/tunnel/winipcfg/zwinipcfg_windows.go
index 8f37ac26..cc4c3f70 100644
--- a/tunnel/winipcfg/zwinipcfg_windows.go
+++ b/tunnel/winipcfg/zwinipcfg_windows.go
@@ -68,6 +68,7 @@ var (
 	procNotifyUnicastIpAddressChange    = modiphlpapi.NewProc("NotifyUnicastIpAddressChange")
 	procNotifyRouteChange2              = modiphlpapi.NewProc("NotifyRouteChange2")
 	procCancelMibChangeNotify2          = modiphlpapi.NewProc("CancelMibChangeNotify2")
+	procSetInterfaceDnsSettings         = modiphlpapi.NewProc("SetInterfaceDnsSettings")
 )
 
 func freeMibTable(memory unsafe.Pointer) {
@@ -307,3 +308,11 @@ func cancelMibChangeNotify2(notificationHandle windows.Handle) (ret error) {
 	}
 	return
 }
+
+func setInterfaceDnsSettings(guid *windows.GUID, settings *DnsInterfaceSettings) (ret error) {
+	r0, _, _ := syscall.Syscall(procSetInterfaceDnsSettings.Addr(), 2, uintptr(unsafe.Pointer(guid)), uintptr(unsafe.Pointer(settings)), 0)
+	if r0 != 0 {
+		ret = syscall.Errno(r0)
+	}
+	return
+}
-- 
cgit v1.2.3-59-g8ed1b