/* SPDX-License-Identifier: MIT * * Copyright (C) 2019 WireGuard LLC. All Rights Reserved. */ package wintun import ( "encoding/hex" "errors" "fmt" "sync" "unsafe" "golang.org/x/crypto/blake2s" "golang.org/x/sys/windows" "golang.org/x/text/unicode/norm" "golang.zx2c4.com/wireguard/tun/wintun/namespaceapi" ) var ( wintunObjectSecurityAttributes *windows.SecurityAttributes hasInitializedNamespace bool initializingNamespace sync.Mutex ) func initializeNamespace() error { initializingNamespace.Lock() defer initializingNamespace.Unlock() if hasInitializedNamespace { return nil } sd, err := windows.SecurityDescriptorFromString("O:SYD:P(A;;GA;;;SY)") if err != nil { return fmt.Errorf("SddlToSecurityDescriptor failed: %v", err) } wintunObjectSecurityAttributes = &windows.SecurityAttributes{ Length: uint32(unsafe.Sizeof(windows.SecurityAttributes{})), SecurityDescriptor: uintptr(unsafe.Pointer(sd)), } sid, err := windows.CreateWellKnownSid(windows.WinLocalSystemSid) if err != nil { return fmt.Errorf("CreateWellKnownSid(LOCAL_SYSTEM) failed: %v", err) } boundary, err := namespaceapi.CreateBoundaryDescriptor("Wintun") if err != nil { return fmt.Errorf("CreateBoundaryDescriptor failed: %v", err) } err = boundary.AddSid(sid) if err != nil { return fmt.Errorf("AddSIDToBoundaryDescriptor failed: %v", err) } for { _, err = namespaceapi.CreatePrivateNamespace(wintunObjectSecurityAttributes, boundary, "Wintun") if err == windows.ERROR_ALREADY_EXISTS { _, err = namespaceapi.OpenPrivateNamespace(boundary, "Wintun") if err == windows.ERROR_PATH_NOT_FOUND { continue } } if err != nil { return fmt.Errorf("Create/OpenPrivateNamespace failed: %v", err) } break } hasInitializedNamespace = true return nil } func (pool Pool) takeNameMutex() (windows.Handle, error) { err := initializeNamespace() if err != nil { return 0, err } const mutexLabel = "WireGuard Adapter Name Mutex Stable Suffix v1 jason@zx2c4.com" b2, _ := blake2s.New256(nil) b2.Write([]byte(mutexLabel)) b2.Write(norm.NFC.Bytes([]byte(string(pool)))) mutexName := `Wintun\Wintun-Name-Mutex-` + hex.EncodeToString(b2.Sum(nil)) mutex, err := windows.CreateMutex(wintunObjectSecurityAttributes, false, windows.StringToUTF16Ptr(mutexName)) if err != nil { err = fmt.Errorf("Error creating name mutex: %v", err) return 0, err } event, err := windows.WaitForSingleObject(mutex, windows.INFINITE) if err != nil { windows.CloseHandle(mutex) return 0, fmt.Errorf("Error waiting on name mutex: %v", err) } if event != windows.WAIT_OBJECT_0 && event != windows.WAIT_ABANDONED { windows.CloseHandle(mutex) return 0, errors.New("Error with event trigger of name mutex") } return mutex, nil }