diff options
Diffstat (limited to 'vendor/golang.org/x/sys/windows/dll_windows.go')
| -rw-r--r-- | vendor/golang.org/x/sys/windows/dll_windows.go | 378 |
1 files changed, 378 insertions, 0 deletions
diff --git a/vendor/golang.org/x/sys/windows/dll_windows.go b/vendor/golang.org/x/sys/windows/dll_windows.go new file mode 100644 index 0000000..e92c05b --- /dev/null +++ b/vendor/golang.org/x/sys/windows/dll_windows.go @@ -0,0 +1,378 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package windows + +import ( + "sync" + "sync/atomic" + "syscall" + "unsafe" +) + +// DLLError describes reasons for DLL load failures. +type DLLError struct { + Err error + ObjName string + Msg string +} + +func (e *DLLError) Error() string { return e.Msg } + +// Implemented in runtime/syscall_windows.goc; we provide jumps to them in our assembly file. +func loadlibrary(filename *uint16) (handle uintptr, err syscall.Errno) +func getprocaddress(handle uintptr, procname *uint8) (proc uintptr, err syscall.Errno) + +// A DLL implements access to a single DLL. +type DLL struct { + Name string + Handle Handle +} + +// LoadDLL loads DLL file into memory. +// +// Warning: using LoadDLL without an absolute path name is subject to +// DLL preloading attacks. To safely load a system DLL, use LazyDLL +// with System set to true, or use LoadLibraryEx directly. +func LoadDLL(name string) (dll *DLL, err error) { + namep, err := UTF16PtrFromString(name) + if err != nil { + return nil, err + } + h, e := loadlibrary(namep) + if e != 0 { + return nil, &DLLError{ + Err: e, + ObjName: name, + Msg: "Failed to load " + name + ": " + e.Error(), + } + } + d := &DLL{ + Name: name, + Handle: Handle(h), + } + return d, nil +} + +// MustLoadDLL is like LoadDLL but panics if load operation failes. +func MustLoadDLL(name string) *DLL { + d, e := LoadDLL(name) + if e != nil { + panic(e) + } + return d +} + +// FindProc searches DLL d for procedure named name and returns *Proc +// if found. It returns an error if search fails. +func (d *DLL) FindProc(name string) (proc *Proc, err error) { + namep, err := BytePtrFromString(name) + if err != nil { + return nil, err + } + a, e := getprocaddress(uintptr(d.Handle), namep) + if e != 0 { + return nil, &DLLError{ + Err: e, + ObjName: name, + Msg: "Failed to find " + name + " procedure in " + d.Name + ": " + e.Error(), + } + } + p := &Proc{ + Dll: d, + Name: name, + addr: a, + } + return p, nil +} + +// MustFindProc is like FindProc but panics if search fails. +func (d *DLL) MustFindProc(name string) *Proc { + p, e := d.FindProc(name) + if e != nil { + panic(e) + } + return p +} + +// Release unloads DLL d from memory. +func (d *DLL) Release() (err error) { + return FreeLibrary(d.Handle) +} + +// A Proc implements access to a procedure inside a DLL. +type Proc struct { + Dll *DLL + Name string + addr uintptr +} + +// Addr returns the address of the procedure represented by p. +// The return value can be passed to Syscall to run the procedure. +func (p *Proc) Addr() uintptr { + return p.addr +} + +//go:uintptrescapes + +// Call executes procedure p with arguments a. It will panic, if more than 15 arguments +// are supplied. +// +// The returned error is always non-nil, constructed from the result of GetLastError. +// Callers must inspect the primary return value to decide whether an error occurred +// (according to the semantics of the specific function being called) before consulting +// the error. The error will be guaranteed to contain windows.Errno. +func (p *Proc) Call(a ...uintptr) (r1, r2 uintptr, lastErr error) { + switch len(a) { + case 0: + return syscall.Syscall(p.Addr(), uintptr(len(a)), 0, 0, 0) + case 1: + return syscall.Syscall(p.Addr(), uintptr(len(a)), a[0], 0, 0) + case 2: + return syscall.Syscall(p.Addr(), uintptr(len(a)), a[0], a[1], 0) + case 3: + return syscall.Syscall(p.Addr(), uintptr(len(a)), a[0], a[1], a[2]) + case 4: + return syscall.Syscall6(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], 0, 0) + case 5: + return syscall.Syscall6(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], 0) + case 6: + return syscall.Syscall6(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5]) + case 7: + return syscall.Syscall9(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], 0, 0) + case 8: + return syscall.Syscall9(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], 0) + case 9: + return syscall.Syscall9(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8]) + case 10: + return syscall.Syscall12(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], 0, 0) + case 11: + return syscall.Syscall12(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], a[10], 0) + case 12: + return syscall.Syscall12(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], a[10], a[11]) + case 13: + return syscall.Syscall15(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], a[10], a[11], a[12], 0, 0) + case 14: + return syscall.Syscall15(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], a[10], a[11], a[12], a[13], 0) + case 15: + return syscall.Syscall15(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], a[10], a[11], a[12], a[13], a[14]) + default: + panic("Call " + p.Name + " with too many arguments " + itoa(len(a)) + ".") + } +} + +// A LazyDLL implements access to a single DLL. +// It will delay the load of the DLL until the first +// call to its Handle method or to one of its +// LazyProc's Addr method. +type LazyDLL struct { + Name string + + // System determines whether the DLL must be loaded from the + // Windows System directory, bypassing the normal DLL search + // path. + System bool + + mu sync.Mutex + dll *DLL // non nil once DLL is loaded +} + +// Load loads DLL file d.Name into memory. It returns an error if fails. +// Load will not try to load DLL, if it is already loaded into memory. +func (d *LazyDLL) Load() error { + // Non-racy version of: + // if d.dll != nil { + if atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(&d.dll))) != nil { + return nil + } + d.mu.Lock() + defer d.mu.Unlock() + if d.dll != nil { + return nil + } + + // kernel32.dll is special, since it's where LoadLibraryEx comes from. + // The kernel already special-cases its name, so it's always + // loaded from system32. + var dll *DLL + var err error + if d.Name == "kernel32.dll" { + dll, err = LoadDLL(d.Name) + } else { + dll, err = loadLibraryEx(d.Name, d.System) + } + if err != nil { + return err + } + + // Non-racy version of: + // d.dll = dll + atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(&d.dll)), unsafe.Pointer(dll)) + return nil +} + +// mustLoad is like Load but panics if search fails. +func (d *LazyDLL) mustLoad() { + e := d.Load() + if e != nil { + panic(e) + } +} + +// Handle returns d's module handle. +func (d *LazyDLL) Handle() uintptr { + d.mustLoad() + return uintptr(d.dll.Handle) +} + +// NewProc returns a LazyProc for accessing the named procedure in the DLL d. +func (d *LazyDLL) NewProc(name string) *LazyProc { + return &LazyProc{l: d, Name: name} +} + +// NewLazyDLL creates new LazyDLL associated with DLL file. +func NewLazyDLL(name string) *LazyDLL { + return &LazyDLL{Name: name} +} + +// NewLazySystemDLL is like NewLazyDLL, but will only +// search Windows System directory for the DLL if name is +// a base name (like "advapi32.dll"). +func NewLazySystemDLL(name string) *LazyDLL { + return &LazyDLL{Name: name, System: true} +} + +// A LazyProc implements access to a procedure inside a LazyDLL. +// It delays the lookup until the Addr method is called. +type LazyProc struct { + Name string + + mu sync.Mutex + l *LazyDLL + proc *Proc +} + +// Find searches DLL for procedure named p.Name. It returns +// an error if search fails. Find will not search procedure, +// if it is already found and loaded into memory. +func (p *LazyProc) Find() error { + // Non-racy version of: + // if p.proc == nil { + if atomic.LoadPointer((*unsafe.Pointer)(unsafe.Pointer(&p.proc))) == nil { + p.mu.Lock() + defer p.mu.Unlock() + if p.proc == nil { + e := p.l.Load() + if e != nil { + return e + } + proc, e := p.l.dll.FindProc(p.Name) + if e != nil { + return e + } + // Non-racy version of: + // p.proc = proc + atomic.StorePointer((*unsafe.Pointer)(unsafe.Pointer(&p.proc)), unsafe.Pointer(proc)) + } + } + return nil +} + +// mustFind is like Find but panics if search fails. +func (p *LazyProc) mustFind() { + e := p.Find() + if e != nil { + panic(e) + } +} + +// Addr returns the address of the procedure represented by p. +// The return value can be passed to Syscall to run the procedure. +// It will panic if the procedure cannot be found. +func (p *LazyProc) Addr() uintptr { + p.mustFind() + return p.proc.Addr() +} + +//go:uintptrescapes + +// Call executes procedure p with arguments a. It will panic, if more than 15 arguments +// are supplied. It will also panic if the procedure cannot be found. +// +// The returned error is always non-nil, constructed from the result of GetLastError. +// Callers must inspect the primary return value to decide whether an error occurred +// (according to the semantics of the specific function being called) before consulting +// the error. The error will be guaranteed to contain windows.Errno. +func (p *LazyProc) Call(a ...uintptr) (r1, r2 uintptr, lastErr error) { + p.mustFind() + return p.proc.Call(a...) +} + +var canDoSearchSystem32Once struct { + sync.Once + v bool +} + +func initCanDoSearchSystem32() { + // https://msdn.microsoft.com/en-us/library/ms684179(v=vs.85).aspx says: + // "Windows 7, Windows Server 2008 R2, Windows Vista, and Windows + // Server 2008: The LOAD_LIBRARY_SEARCH_* flags are available on + // systems that have KB2533623 installed. To determine whether the + // flags are available, use GetProcAddress to get the address of the + // AddDllDirectory, RemoveDllDirectory, or SetDefaultDllDirectories + // function. If GetProcAddress succeeds, the LOAD_LIBRARY_SEARCH_* + // flags can be used with LoadLibraryEx." + canDoSearchSystem32Once.v = (modkernel32.NewProc("AddDllDirectory").Find() == nil) +} + +func canDoSearchSystem32() bool { + canDoSearchSystem32Once.Do(initCanDoSearchSystem32) + return canDoSearchSystem32Once.v +} + +func isBaseName(name string) bool { + for _, c := range name { + if c == ':' || c == '/' || c == '\\' { + return false + } + } + return true +} + +// loadLibraryEx wraps the Windows LoadLibraryEx function. +// +// See https://msdn.microsoft.com/en-us/library/windows/desktop/ms684179(v=vs.85).aspx +// +// If name is not an absolute path, LoadLibraryEx searches for the DLL +// in a variety of automatic locations unless constrained by flags. +// See: https://msdn.microsoft.com/en-us/library/ff919712%28VS.85%29.aspx +func loadLibraryEx(name string, system bool) (*DLL, error) { + loadDLL := name + var flags uintptr + if system { + if canDoSearchSystem32() { + const LOAD_LIBRARY_SEARCH_SYSTEM32 = 0x00000800 + flags = LOAD_LIBRARY_SEARCH_SYSTEM32 + } else if isBaseName(name) { + // WindowsXP or unpatched Windows machine + // trying to load "foo.dll" out of the system + // folder, but LoadLibraryEx doesn't support + // that yet on their system, so emulate it. + windir, _ := Getenv("WINDIR") // old var; apparently works on XP + if windir == "" { + return nil, errString("%WINDIR% not defined") + } + loadDLL = windir + "\\System32\\" + name + } + } + h, err := LoadLibraryEx(loadDLL, 0, flags) + if err != nil { + return nil, err + } + return &DLL{Name: name, Handle: h}, nil +} + +type errString string + +func (s errString) Error() string { return string(s) } |