diff options
Diffstat (limited to 'src/syscall/exec_windows.go')
-rw-r--r-- | src/syscall/exec_windows.go | 432 |
1 files changed, 432 insertions, 0 deletions
diff --git a/src/syscall/exec_windows.go b/src/syscall/exec_windows.go new file mode 100644 index 0000000..45295de --- /dev/null +++ b/src/syscall/exec_windows.go @@ -0,0 +1,432 @@ +// Copyright 2009 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. + +// Fork, exec, wait, etc. + +package syscall + +import ( + "internal/bytealg" + "runtime" + "sync" + "unicode/utf16" + "unsafe" +) + +var ForkLock sync.RWMutex + +// EscapeArg rewrites command line argument s as prescribed +// in https://msdn.microsoft.com/en-us/library/ms880421. +// This function returns "" (2 double quotes) if s is empty. +// Alternatively, these transformations are done: +// - every back slash (\) is doubled, but only if immediately +// followed by double quote ("); +// - every double quote (") is escaped by back slash (\); +// - finally, s is wrapped with double quotes (arg -> "arg"), +// but only if there is space or tab inside s. +func EscapeArg(s string) string { + if len(s) == 0 { + return `""` + } + for i := 0; i < len(s); i++ { + switch s[i] { + case '"', '\\', ' ', '\t': + // Some escaping required. + b := make([]byte, 0, len(s)+2) + b = appendEscapeArg(b, s) + return string(b) + } + } + return s +} + +// appendEscapeArg escapes the string s, as per escapeArg, +// appends the result to b, and returns the updated slice. +func appendEscapeArg(b []byte, s string) []byte { + if len(s) == 0 { + return append(b, `""`...) + } + + needsBackslash := false + hasSpace := false + for i := 0; i < len(s); i++ { + switch s[i] { + case '"', '\\': + needsBackslash = true + case ' ', '\t': + hasSpace = true + } + } + + if !needsBackslash && !hasSpace { + // No special handling required; normal case. + return append(b, s...) + } + if !needsBackslash { + // hasSpace is true, so we need to quote the string. + b = append(b, '"') + b = append(b, s...) + return append(b, '"') + } + + if hasSpace { + b = append(b, '"') + } + slashes := 0 + for i := 0; i < len(s); i++ { + c := s[i] + switch c { + default: + slashes = 0 + case '\\': + slashes++ + case '"': + for ; slashes > 0; slashes-- { + b = append(b, '\\') + } + b = append(b, '\\') + } + b = append(b, c) + } + if hasSpace { + for ; slashes > 0; slashes-- { + b = append(b, '\\') + } + b = append(b, '"') + } + + return b +} + +// makeCmdLine builds a command line out of args by escaping "special" +// characters and joining the arguments with spaces. +func makeCmdLine(args []string) string { + var b []byte + for _, v := range args { + if len(b) > 0 { + b = append(b, ' ') + } + b = appendEscapeArg(b, v) + } + return string(b) +} + +// createEnvBlock converts an array of environment strings into +// the representation required by CreateProcess: a sequence of NUL +// terminated strings followed by a nil. +// Last bytes are two UCS-2 NULs, or four NUL bytes. +// If any string contains a NUL, it returns (nil, EINVAL). +func createEnvBlock(envv []string) (*uint16, error) { + if len(envv) == 0 { + return &utf16.Encode([]rune("\x00\x00"))[0], nil + } + length := 0 + for _, s := range envv { + if bytealg.IndexByteString(s, 0) != -1 { + return nil, EINVAL + } + length += len(s) + 1 + } + length += 1 + + b := make([]byte, length) + i := 0 + for _, s := range envv { + l := len(s) + copy(b[i:i+l], []byte(s)) + copy(b[i+l:i+l+1], []byte{0}) + i = i + l + 1 + } + copy(b[i:i+1], []byte{0}) + + return &utf16.Encode([]rune(string(b)))[0], nil +} + +func CloseOnExec(fd Handle) { + SetHandleInformation(Handle(fd), HANDLE_FLAG_INHERIT, 0) +} + +func SetNonblock(fd Handle, nonblocking bool) (err error) { + return nil +} + +// FullPath retrieves the full path of the specified file. +func FullPath(name string) (path string, err error) { + p, err := UTF16PtrFromString(name) + if err != nil { + return "", err + } + n := uint32(100) + for { + buf := make([]uint16, n) + n, err = GetFullPathName(p, uint32(len(buf)), &buf[0], nil) + if err != nil { + return "", err + } + if n <= uint32(len(buf)) { + return UTF16ToString(buf[:n]), nil + } + } +} + +func isSlash(c uint8) bool { + return c == '\\' || c == '/' +} + +func normalizeDir(dir string) (name string, err error) { + ndir, err := FullPath(dir) + if err != nil { + return "", err + } + if len(ndir) > 2 && isSlash(ndir[0]) && isSlash(ndir[1]) { + // dir cannot have \\server\share\path form + return "", EINVAL + } + return ndir, nil +} + +func volToUpper(ch int) int { + if 'a' <= ch && ch <= 'z' { + ch += 'A' - 'a' + } + return ch +} + +func joinExeDirAndFName(dir, p string) (name string, err error) { + if len(p) == 0 { + return "", EINVAL + } + if len(p) > 2 && isSlash(p[0]) && isSlash(p[1]) { + // \\server\share\path form + return p, nil + } + if len(p) > 1 && p[1] == ':' { + // has drive letter + if len(p) == 2 { + return "", EINVAL + } + if isSlash(p[2]) { + return p, nil + } else { + d, err := normalizeDir(dir) + if err != nil { + return "", err + } + if volToUpper(int(p[0])) == volToUpper(int(d[0])) { + return FullPath(d + "\\" + p[2:]) + } else { + return FullPath(p) + } + } + } else { + // no drive letter + d, err := normalizeDir(dir) + if err != nil { + return "", err + } + if isSlash(p[0]) { + return FullPath(d[:2] + p) + } else { + return FullPath(d + "\\" + p) + } + } +} + +type ProcAttr struct { + Dir string + Env []string + Files []uintptr + Sys *SysProcAttr +} + +type SysProcAttr struct { + HideWindow bool + CmdLine string // used if non-empty, else the windows command line is built by escaping the arguments passed to StartProcess + CreationFlags uint32 + Token Token // if set, runs new process in the security context represented by the token + ProcessAttributes *SecurityAttributes // if set, applies these security attributes as the descriptor for the new process + ThreadAttributes *SecurityAttributes // if set, applies these security attributes as the descriptor for the main thread of the new process + NoInheritHandles bool // if set, each inheritable handle in the calling process is not inherited by the new process + AdditionalInheritedHandles []Handle // a list of additional handles, already marked as inheritable, that will be inherited by the new process + ParentProcess Handle // if non-zero, the new process regards the process given by this handle as its parent process, and AdditionalInheritedHandles, if set, should exist in this parent process +} + +var zeroProcAttr ProcAttr +var zeroSysProcAttr SysProcAttr + +func StartProcess(argv0 string, argv []string, attr *ProcAttr) (pid int, handle uintptr, err error) { + if len(argv0) == 0 { + return 0, 0, EWINDOWS + } + if attr == nil { + attr = &zeroProcAttr + } + sys := attr.Sys + if sys == nil { + sys = &zeroSysProcAttr + } + + if len(attr.Files) > 3 { + return 0, 0, EWINDOWS + } + if len(attr.Files) < 3 { + return 0, 0, EINVAL + } + + if len(attr.Dir) != 0 { + // StartProcess assumes that argv0 is relative to attr.Dir, + // because it implies Chdir(attr.Dir) before executing argv0. + // Windows CreateProcess assumes the opposite: it looks for + // argv0 relative to the current directory, and, only once the new + // process is started, it does Chdir(attr.Dir). We are adjusting + // for that difference here by making argv0 absolute. + var err error + argv0, err = joinExeDirAndFName(attr.Dir, argv0) + if err != nil { + return 0, 0, err + } + } + argv0p, err := UTF16PtrFromString(argv0) + if err != nil { + return 0, 0, err + } + + var cmdline string + // Windows CreateProcess takes the command line as a single string: + // use attr.CmdLine if set, else build the command line by escaping + // and joining each argument with spaces + if sys.CmdLine != "" { + cmdline = sys.CmdLine + } else { + cmdline = makeCmdLine(argv) + } + + var argvp *uint16 + if len(cmdline) != 0 { + argvp, err = UTF16PtrFromString(cmdline) + if err != nil { + return 0, 0, err + } + } + + var dirp *uint16 + if len(attr.Dir) != 0 { + dirp, err = UTF16PtrFromString(attr.Dir) + if err != nil { + return 0, 0, err + } + } + + var maj, min, build uint32 + rtlGetNtVersionNumbers(&maj, &min, &build) + isWin7 := maj < 6 || (maj == 6 && min <= 1) + // NT kernel handles are divisible by 4, with the bottom 3 bits left as + // a tag. The fully set tag correlates with the types of handles we're + // concerned about here. Except, the kernel will interpret some + // special handle values, like -1, -2, and so forth, so kernelbase.dll + // checks to see that those bottom three bits are checked, but that top + // bit is not checked. + isLegacyWin7ConsoleHandle := func(handle Handle) bool { return isWin7 && handle&0x10000003 == 3 } + + p, _ := GetCurrentProcess() + parentProcess := p + if sys.ParentProcess != 0 { + parentProcess = sys.ParentProcess + } + fd := make([]Handle, len(attr.Files)) + for i := range attr.Files { + if attr.Files[i] > 0 { + destinationProcessHandle := parentProcess + + // On Windows 7, console handles aren't real handles, and can only be duplicated + // into the current process, not a parent one, which amounts to the same thing. + if parentProcess != p && isLegacyWin7ConsoleHandle(Handle(attr.Files[i])) { + destinationProcessHandle = p + } + + err := DuplicateHandle(p, Handle(attr.Files[i]), destinationProcessHandle, &fd[i], 0, true, DUPLICATE_SAME_ACCESS) + if err != nil { + return 0, 0, err + } + defer DuplicateHandle(parentProcess, fd[i], 0, nil, 0, false, DUPLICATE_CLOSE_SOURCE) + } + } + si := new(_STARTUPINFOEXW) + si.ProcThreadAttributeList, err = newProcThreadAttributeList(2) + if err != nil { + return 0, 0, err + } + defer deleteProcThreadAttributeList(si.ProcThreadAttributeList) + si.Cb = uint32(unsafe.Sizeof(*si)) + si.Flags = STARTF_USESTDHANDLES + if sys.HideWindow { + si.Flags |= STARTF_USESHOWWINDOW + si.ShowWindow = SW_HIDE + } + if sys.ParentProcess != 0 { + err = updateProcThreadAttribute(si.ProcThreadAttributeList, 0, _PROC_THREAD_ATTRIBUTE_PARENT_PROCESS, unsafe.Pointer(&sys.ParentProcess), unsafe.Sizeof(sys.ParentProcess), nil, nil) + if err != nil { + return 0, 0, err + } + } + si.StdInput = fd[0] + si.StdOutput = fd[1] + si.StdErr = fd[2] + + fd = append(fd, sys.AdditionalInheritedHandles...) + + // On Windows 7, console handles aren't real handles, so don't pass them + // through to PROC_THREAD_ATTRIBUTE_HANDLE_LIST. + for i := range fd { + if isLegacyWin7ConsoleHandle(fd[i]) { + fd[i] = 0 + } + } + + // The presence of a NULL handle in the list is enough to cause PROC_THREAD_ATTRIBUTE_HANDLE_LIST + // to treat the entire list as empty, so remove NULL handles. + j := 0 + for i := range fd { + if fd[i] != 0 { + fd[j] = fd[i] + j++ + } + } + fd = fd[:j] + + willInheritHandles := len(fd) > 0 && !sys.NoInheritHandles + + // Do not accidentally inherit more than these handles. + if willInheritHandles { + err = updateProcThreadAttribute(si.ProcThreadAttributeList, 0, _PROC_THREAD_ATTRIBUTE_HANDLE_LIST, unsafe.Pointer(&fd[0]), uintptr(len(fd))*unsafe.Sizeof(fd[0]), nil, nil) + if err != nil { + return 0, 0, err + } + } + + envBlock, err := createEnvBlock(attr.Env) + if err != nil { + return 0, 0, err + } + + pi := new(ProcessInformation) + flags := sys.CreationFlags | CREATE_UNICODE_ENVIRONMENT | _EXTENDED_STARTUPINFO_PRESENT + if sys.Token != 0 { + err = CreateProcessAsUser(sys.Token, argv0p, argvp, sys.ProcessAttributes, sys.ThreadAttributes, willInheritHandles, flags, envBlock, dirp, &si.StartupInfo, pi) + } else { + err = CreateProcess(argv0p, argvp, sys.ProcessAttributes, sys.ThreadAttributes, willInheritHandles, flags, envBlock, dirp, &si.StartupInfo, pi) + } + if err != nil { + return 0, 0, err + } + defer CloseHandle(Handle(pi.Thread)) + runtime.KeepAlive(fd) + runtime.KeepAlive(sys) + + return int(pi.ProcessId), uintptr(pi.Process), nil +} + +func Exec(argv0 string, argv []string, envv []string) (err error) { + return EWINDOWS +} |