memmod: fix import loading function usage

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

5 files changed, 10 insertions, 32 deletions

diff --git a/go.mod b/go.mod
index ccecad8..22e0b95 100644
--- a/go.mod
+++ b/go.mod
@@ -3,7 +3,7 @@ module golang.zx2c4.com/wireguard
 go 1.13
 
 require (
-	golang.org/x/crypto v0.0.0-20201117144127-c1f2f97bffc9
+	golang.org/x/crypto v0.0.0-20201124201722-c8d3bf9c5392
 	golang.org/x/net v0.0.0-20201110031124-69a78807bb2b
-	golang.org/x/sys v0.0.0-20201117222635-ba5294a509c7
+	golang.org/x/sys v0.0.0-20201126233918-771906719818
 )
diff --git a/go.sum b/go.sum
index 54bd85b..96e4ae0 100644
--- a/go.sum
+++ b/go.sum
@@ -1,7 +1,7 @@
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
-golang.org/x/crypto v0.0.0-20201117144127-c1f2f97bffc9 h1:phUcVbl53swtrUN8kQEXFhUxPlIlWyBfKmidCu7P95o=
-golang.org/x/crypto v0.0.0-20201117144127-c1f2f97bffc9/go.mod h1:jdWPYTVW3xRLrWPugEBEK3UY2ZEsg3UU495nc5E+M+I=
+golang.org/x/crypto v0.0.0-20201124201722-c8d3bf9c5392 h1:xYJJ3S178yv++9zXV/hnr29plCAGO9vAFG9dorqaFQc=
+golang.org/x/crypto v0.0.0-20201124201722-c8d3bf9c5392/go.mod h1:jdWPYTVW3xRLrWPugEBEK3UY2ZEsg3UU495nc5E+M+I=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20201110031124-69a78807bb2b h1:uwuIcX0g4Yl1NC5XAz37xsr2lTtcqevgzYNVt49waME=
 golang.org/x/net v0.0.0-20201110031124-69a78807bb2b/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
@@ -9,8 +9,8 @@ golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5h
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20201117222635-ba5294a509c7 h1:s330+6z/Ko3J0o6rvOcwXe5nzs7UT9tLKHoOXYn6uE0=
-golang.org/x/sys v0.0.0-20201117222635-ba5294a509c7/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20201126233918-771906719818 h1:f1CIuDlJhwANEC2MM87MBEVMr3jl5bifgsfj90XAF9c=
+golang.org/x/sys v0.0.0-20201126233918-771906719818/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
diff --git a/tun/wintun/memmod/memmod_windows.go b/tun/wintun/memmod/memmod_windows.go
index 13f28ef..b9d7783 100644
--- a/tun/wintun/memmod/memmod_windows.go
+++ b/tun/wintun/memmod/memmod_windows.go
@@ -313,7 +313,7 @@ func (module *Module) buildImportTable() error {
 	module.modules = make([]windows.Handle, 0, 16)
 	importDesc := (*IMAGE_IMPORT_DESCRIPTOR)(a2p(module.codeBase + uintptr(directory.VirtualAddress)))
 	for !isBadReadPtr(uintptr(unsafe.Pointer(importDesc)), unsafe.Sizeof(*importDesc)) && importDesc.Name != 0 {
-		handle, err := loadLibraryA((*byte)(a2p(module.codeBase + uintptr(importDesc.Name))))
+		handle, err := windows.LoadLibraryEx(windows.BytePtrToString((*byte)(a2p(module.codeBase + uintptr(importDesc.Name)))), 0, windows.LOAD_LIBRARY_SEARCH_SYSTEM32)
 		if err != nil {
 			return fmt.Errorf("Error loading module: %w", err)
 		}
@@ -328,10 +328,10 @@ func (module *Module) buildImportTable() error {
 		}
 		for *thunkRef != 0 {
 			if IMAGE_SNAP_BY_ORDINAL(*thunkRef) {
-				*funcRef, err = getProcAddress(handle, (*byte)(a2p(IMAGE_ORDINAL(*thunkRef))))
+				*funcRef, err = windows.GetProcAddressByOrdinal(handle, IMAGE_ORDINAL(*thunkRef))
 			} else {
 				thunkData := (*IMAGE_IMPORT_BY_NAME)(a2p(module.codeBase + *thunkRef))
-				*funcRef, err = getProcAddress(handle, &thunkData.Name[0])
+				*funcRef, err = windows.GetProcAddress(handle, windows.BytePtrToString(&thunkData.Name[0]))
 			}
 			if err != nil {
 				windows.FreeLibrary(handle)
diff --git a/tun/wintun/memmod/syscall_windows.go b/tun/wintun/memmod/syscall_windows.go
index beae415..0b29cb9 100644
--- a/tun/wintun/memmod/syscall_windows.go
+++ b/tun/wintun/memmod/syscall_windows.go
@@ -324,8 +324,6 @@ const (
 	DLL_PROCESS_DETACH = 0
 )
 
-//sys	loadLibraryA(libFileName *byte) (module windows.Handle, err error) = kernel32.LoadLibraryA
-//sys	getProcAddress(module windows.Handle, procName *byte) (addr uintptr, err error) = kernel32.GetProcAddress
 //sys	isBadReadPtr(addr uintptr, ucb uintptr) (ret bool) = kernel32.IsBadReadPtr
 
 type SYSTEM_INFO struct {
diff --git a/tun/wintun/memmod/zsyscall_windows.go b/tun/wintun/memmod/zsyscall_windows.go
index c56b650..6a5b76f 100644
--- a/tun/wintun/memmod/zsyscall_windows.go
+++ b/tun/wintun/memmod/zsyscall_windows.go
@@ -40,31 +40,11 @@ func errnoErr(e syscall.Errno) error {
 var (
 	modkernel32 = windows.NewLazySystemDLL("kernel32.dll")
 
-	procGetProcAddress = modkernel32.NewProc("GetProcAddress")
-	procIsBadReadPtr   = modkernel32.NewProc("IsBadReadPtr")
-	procLoadLibraryA   = modkernel32.NewProc("LoadLibraryA")
+	procIsBadReadPtr = modkernel32.NewProc("IsBadReadPtr")
 )
 
-func getProcAddress(module windows.Handle, procName *byte) (addr uintptr, err error) {
-	r0, _, e1 := syscall.Syscall(procGetProcAddress.Addr(), 2, uintptr(module), uintptr(unsafe.Pointer(procName)), 0)
-	addr = uintptr(r0)
-	if addr == 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
 func isBadReadPtr(addr uintptr, ucb uintptr) (ret bool) {
 	r0, _, _ := syscall.Syscall(procIsBadReadPtr.Addr(), 2, uintptr(addr), uintptr(ucb), 0)
 	ret = r0 != 0
 	return
 }
-
-func loadLibraryA(libFileName *byte) (module windows.Handle, err error) {
-	r0, _, e1 := syscall.Syscall(procLoadLibraryA.Addr(), 1, uintptr(unsafe.Pointer(libFileName)), 0, 0)
-	module = windows.Handle(r0)
-	if module == 0 {
-		err = errnoErr(e1)
-	}
-	return
-}