| // 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 syscall |
| |
| import ( |
| "internal/syscall/windows/sysdll" |
| "sync" |
| "sync/atomic" |
| "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.go. |
| func Syscall(trap, nargs, a1, a2, a3 uintptr) (r1, r2 uintptr, err Errno) |
| func Syscall6(trap, nargs, a1, a2, a3, a4, a5, a6 uintptr) (r1, r2 uintptr, err Errno) |
| func Syscall9(trap, nargs, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2 uintptr, err Errno) |
| func Syscall12(trap, nargs, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12 uintptr) (r1, r2 uintptr, err Errno) |
| func Syscall15(trap, nargs, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15 uintptr) (r1, r2 uintptr, err Errno) |
| func loadlibrary(filename *uint16) (handle uintptr, err Errno) |
| func loadsystemlibrary(filename *uint16) (handle uintptr, err Errno) |
| func getprocaddress(handle uintptr, procname *uint8) (proc uintptr, err Errno) |
| |
| // A DLL implements access to a single DLL. |
| type DLL struct { |
| Name string |
| Handle Handle |
| } |
| |
| // LoadDLL loads the named DLL file into memory. |
| // |
| // If name is not an absolute path and is not a known system DLL used by |
| // Go, Windows will search for the named DLL in many locations, causing |
| // potential DLL preloading attacks. |
| // |
| // Use LazyDLL in golang.org/x/sys/windows for a secure way to |
| // load system DLLs. |
| func LoadDLL(name string) (*DLL, error) { |
| namep, err := UTF16PtrFromString(name) |
| if err != nil { |
| return nil, err |
| } |
| var h uintptr |
| var e Errno |
| if sysdll.IsSystemDLL[name] { |
| h, e = loadsystemlibrary(namep) |
| } else { |
| 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 fails. |
| 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) |
| use(unsafe.Pointer(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 syscall.Errno. |
| func (p *Proc) Call(a ...uintptr) (r1, r2 uintptr, lastErr error) { |
| switch len(a) { |
| case 0: |
| return Syscall(p.Addr(), uintptr(len(a)), 0, 0, 0) |
| case 1: |
| return Syscall(p.Addr(), uintptr(len(a)), a[0], 0, 0) |
| case 2: |
| return Syscall(p.Addr(), uintptr(len(a)), a[0], a[1], 0) |
| case 3: |
| return Syscall(p.Addr(), uintptr(len(a)), a[0], a[1], a[2]) |
| case 4: |
| return Syscall6(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], 0, 0) |
| case 5: |
| return Syscall6(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], 0) |
| case 6: |
| return Syscall6(p.Addr(), uintptr(len(a)), a[0], a[1], a[2], a[3], a[4], a[5]) |
| case 7: |
| return 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 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 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 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 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 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 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 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 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)) + ".") |
| } |
| return |
| } |
| |
| // 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. |
| // |
| // LazyDLL is subject to the same DLL preloading attacks as documented |
| // on LoadDLL. |
| // |
| // Use LazyDLL in golang.org/x/sys/windows for a secure way to |
| // load system DLLs. |
| type LazyDLL struct { |
| mu sync.Mutex |
| dll *DLL // non nil once DLL is loaded |
| Name string |
| } |
| |
| // 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 { |
| d.mu.Lock() |
| defer d.mu.Unlock() |
| if d.dll == nil { |
| dll, e := LoadDLL(d.Name) |
| if e != nil { |
| return e |
| } |
| // 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} |
| } |
| |
| // A LazyProc implements access to a procedure inside a LazyDLL. |
| // It delays the lookup until the Addr method is called. |
| type LazyProc struct { |
| mu sync.Mutex |
| Name string |
| 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. |
| 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. |
| // |
| // 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 syscall.Errno. |
| func (p *LazyProc) Call(a ...uintptr) (r1, r2 uintptr, lastErr error) { |
| p.mustFind() |
| return p.proc.Call(a...) |
| } |