src/libstd/sys/windows/process.rs

   1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 use ascii::*;
  12 use collections::HashMap;
  13 use collections;
  14 use env::split_paths;
  15 use env;
  16 use ffi::{OsString, OsStr};
  17 use fmt;
  18 use fs;
  19 use io::{self, Error, ErrorKind};
  20 use libc::c_void;
  21 use mem;
  22 use os::windows::ffi::OsStrExt;
  23 use path::Path;
  24 use ptr;
  25 use sys::mutex::Mutex;
  26 use sys::c;
  27 use sys::fs::{OpenOptions, File};
  28 use sys::handle::Handle;
  29 use sys::pipe::{self, AnonPipe};
  30 use sys::stdio;
  31 use sys::{self, cvt};
  32 use sys_common::{AsInner, FromInner};
  33
  34 ////////////////////////////////////////////////////////////////////////////////
  35 // Command
  36 ////////////////////////////////////////////////////////////////////////////////
  37
  38 fn mk_key(s: &OsStr) -> OsString {
  39     FromInner::from_inner(sys::os_str::Buf {
  40         inner: s.as_inner().inner.to_ascii_uppercase()
  41     })
  42 }
  43
  44 fn ensure_no_nuls<T: AsRef<OsStr>>(str: T) -> io::Result<T> {
  45     if str.as_ref().encode_wide().any(|b| b == 0) {
  46         Err(io::Error::new(ErrorKind::InvalidInput, "nul byte found in provided data"))
  47     } else {
  48         Ok(str)
  49     }
  50 }
  51
  52 pub struct Command {
  53     program: OsString,
  54     args: Vec<OsString>,
  55     env: Option<HashMap<OsString, OsString>>,
  56     cwd: Option<OsString>,
  57     flags: u32,
  58     detach: bool, // not currently exposed in std::process
  59     stdin: Option<Stdio>,
  60     stdout: Option<Stdio>,
  61     stderr: Option<Stdio>,
  62 }
  63
  64 pub enum Stdio {
  65     Inherit,
  66     Null,
  67     MakePipe,
  68     Handle(Handle),
  69 }
  70
  71 pub struct StdioPipes {
  72     pub stdin: Option<AnonPipe>,
  73     pub stdout: Option<AnonPipe>,
  74     pub stderr: Option<AnonPipe>,
  75 }
  76
  77 struct DropGuard<'a> {
  78     lock: &'a Mutex,
  79 }
  80
  81 impl Command {
  82     pub fn new(program: &OsStr) -> Command {
  83         Command {
  84             program: program.to_os_string(),
  85             args: Vec::new(),
  86             env: None,
  87             cwd: None,
  88             flags: 0,
  89             detach: false,
  90             stdin: None,
  91             stdout: None,
  92             stderr: None,
  93         }
  94     }
  95
  96     pub fn arg(&mut self, arg: &OsStr) {
  97         self.args.push(arg.to_os_string())
  98     }
  99     fn init_env_map(&mut self){
 100         if self.env.is_none() {
 101             self.env = Some(env::vars_os().map(|(key, val)| {
 102                 (mk_key(&key), val)
 103             }).collect());
 104         }
 105     }
 106     pub fn env(&mut self, key: &OsStr, val: &OsStr) {
 107         self.init_env_map();
 108         self.env.as_mut().unwrap().insert(mk_key(key), val.to_os_string());
 109     }
 110     pub fn env_remove(&mut self, key: &OsStr) {
 111         self.init_env_map();
 112         self.env.as_mut().unwrap().remove(&mk_key(key));
 113     }
 114     pub fn env_clear(&mut self) {
 115         self.env = Some(HashMap::new())
 116     }
 117     pub fn cwd(&mut self, dir: &OsStr) {
 118         self.cwd = Some(dir.to_os_string())
 119     }
 120     pub fn stdin(&mut self, stdin: Stdio) {
 121         self.stdin = Some(stdin);
 122     }
 123     pub fn stdout(&mut self, stdout: Stdio) {
 124         self.stdout = Some(stdout);
 125     }
 126     pub fn stderr(&mut self, stderr: Stdio) {
 127         self.stderr = Some(stderr);
 128     }
 129     pub fn creation_flags(&mut self, flags: u32) {
 130         self.flags = flags;
 131     }
 132
 133     pub fn spawn(&mut self, default: Stdio, needs_stdin: bool)
 134                  -> io::Result<(Process, StdioPipes)> {
 135         // To have the spawning semantics of unix/windows stay the same, we need
 136         // to read the *child's* PATH if one is provided. See #15149 for more
 137         // details.
 138         let program = self.env.as_ref().and_then(|env| {
 139             for (key, v) in env {
 140                 if OsStr::new("PATH") != &**key { continue }
 141
 142                 // Split the value and test each path to see if the
 143                 // program exists.
 144                 for path in split_paths(&v) {
 145                     let path = path.join(self.program.to_str().unwrap())
 146                                    .with_extension(env::consts::EXE_EXTENSION);
 147                     if fs::metadata(&path).is_ok() {
 148                         return Some(path.into_os_string())
 149                     }
 150                 }
 151                 break
 152             }
 153             None
 154         });
 155
 156         let mut si = zeroed_startupinfo();
 157         si.cb = mem::size_of::<c::STARTUPINFO>() as c::DWORD;
 158         si.dwFlags = c::STARTF_USESTDHANDLES;
 159
 160         let program = program.as_ref().unwrap_or(&self.program);
 161         let mut cmd_str = make_command_line(program, &self.args)?;
 162         cmd_str.push(0); // add null terminator
 163
 164         // stolen from the libuv code.
 165         let mut flags = self.flags | c::CREATE_UNICODE_ENVIRONMENT;
 166         if self.detach {
 167             flags |= c::DETACHED_PROCESS | c::CREATE_NEW_PROCESS_GROUP;
 168         }
 169
 170         let (envp, _data) = make_envp(self.env.as_ref())?;
 171         let (dirp, _data) = make_dirp(self.cwd.as_ref())?;
 172         let mut pi = zeroed_process_information();
 173
 174         // Prepare all stdio handles to be inherited by the child. This
 175         // currently involves duplicating any existing ones with the ability to
 176         // be inherited by child processes. Note, however, that once an
 177         // inheritable handle is created, *any* spawned child will inherit that
 178         // handle. We only want our own child to inherit this handle, so we wrap
 179         // the remaining portion of this spawn in a mutex.
 180         //
 181         // For more information, msdn also has an article about this race:
 182         // http://support.microsoft.com/kb/315939
 183         static CREATE_PROCESS_LOCK: Mutex = Mutex::new();
 184         let _guard = DropGuard::new(&CREATE_PROCESS_LOCK);
 185
 186         let mut pipes = StdioPipes {
 187             stdin: None,
 188             stdout: None,
 189             stderr: None,
 190         };
 191         let null = Stdio::Null;
 192         let default_stdin = if needs_stdin {&default} else {&null};
 193         let stdin = self.stdin.as_ref().unwrap_or(default_stdin);
 194         let stdout = self.stdout.as_ref().unwrap_or(&default);
 195         let stderr = self.stderr.as_ref().unwrap_or(&default);
 196         let stdin = stdin.to_handle(c::STD_INPUT_HANDLE, &mut pipes.stdin)?;
 197         let stdout = stdout.to_handle(c::STD_OUTPUT_HANDLE,
 198                                       &mut pipes.stdout)?;
 199         let stderr = stderr.to_handle(c::STD_ERROR_HANDLE,
 200                                       &mut pipes.stderr)?;
 201         si.hStdInput = stdin.raw();
 202         si.hStdOutput = stdout.raw();
 203         si.hStdError = stderr.raw();
 204
 205         unsafe {
 206             cvt(c::CreateProcessW(ptr::null(),
 207                                   cmd_str.as_mut_ptr(),
 208                                   ptr::null_mut(),
 209                                   ptr::null_mut(),
 210                                   c::TRUE, flags, envp, dirp,
 211                                   &mut si, &mut pi))
 212         }?;
 213
 214         // We close the thread handle because we don't care about keeping
 215         // the thread id valid, and we aren't keeping the thread handle
 216         // around to be able to close it later.
 217         drop(Handle::new(pi.hThread));
 218
 219         Ok((Process { handle: Handle::new(pi.hProcess) }, pipes))
 220     }
 221
 222 }
 223
 224 impl fmt::Debug for Command {
 225     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 226         write!(f, "{:?}", self.program)?;
 227         for arg in &self.args {
 228             write!(f, " {:?}", arg)?;
 229         }
 230         Ok(())
 231     }
 232 }
 233
 234 impl<'a> DropGuard<'a> {
 235     fn new(lock: &'a Mutex) -> DropGuard<'a> {
 236         unsafe {
 237             lock.lock();
 238             DropGuard { lock: lock }
 239         }
 240     }
 241 }
 242
 243 impl<'a> Drop for DropGuard<'a> {
 244     fn drop(&mut self) {
 245         unsafe {
 246             self.lock.unlock();
 247         }
 248     }
 249 }
 250
 251 impl Stdio {
 252     fn to_handle(&self, stdio_id: c::DWORD, pipe: &mut Option<AnonPipe>)
 253                  -> io::Result<Handle> {
 254         match *self {
 255             // If no stdio handle is available, then inherit means that it
 256             // should still be unavailable so propagate the
 257             // INVALID_HANDLE_VALUE.
 258             Stdio::Inherit => {
 259                 match stdio::get(stdio_id) {
 260                     Ok(io) => {
 261                         let io = Handle::new(io.handle());
 262                         let ret = io.duplicate(0, true,
 263                                                c::DUPLICATE_SAME_ACCESS);
 264                         io.into_raw();
 265                         return ret
 266                     }
 267                     Err(..) => Ok(Handle::new(c::INVALID_HANDLE_VALUE)),
 268                 }
 269             }
 270
 271             Stdio::MakePipe => {
 272                 let ours_readable = stdio_id != c::STD_INPUT_HANDLE;
 273                 let pipes = pipe::anon_pipe(ours_readable)?;
 274                 *pipe = Some(pipes.ours);
 275                 cvt(unsafe {
 276                     c::SetHandleInformation(pipes.theirs.handle().raw(),
 277                                             c::HANDLE_FLAG_INHERIT,
 278                                             c::HANDLE_FLAG_INHERIT)
 279                 })?;
 280                 Ok(pipes.theirs.into_handle())
 281             }
 282
 283             Stdio::Handle(ref handle) => {
 284                 handle.duplicate(0, true, c::DUPLICATE_SAME_ACCESS)
 285             }
 286
 287             // Open up a reference to NUL with appropriate read/write
 288             // permissions as well as the ability to be inherited to child
 289             // processes (as this is about to be inherited).
 290             Stdio::Null => {
 291                 let size = mem::size_of::<c::SECURITY_ATTRIBUTES>();
 292                 let mut sa = c::SECURITY_ATTRIBUTES {
 293                     nLength: size as c::DWORD,
 294                     lpSecurityDescriptor: ptr::null_mut(),
 295                     bInheritHandle: 1,
 296                 };
 297                 let mut opts = OpenOptions::new();
 298                 opts.read(stdio_id == c::STD_INPUT_HANDLE);
 299                 opts.write(stdio_id != c::STD_INPUT_HANDLE);
 300                 opts.security_attributes(&mut sa);
 301                 File::open(Path::new("NUL"), &opts).map(|file| {
 302                     file.into_handle()
 303                 })
 304             }
 305         }
 306     }
 307 }
 308
 309 impl From<AnonPipe> for Stdio {
 310     fn from(pipe: AnonPipe) -> Stdio {
 311         Stdio::Handle(pipe.into_handle())
 312     }
 313 }
 314
 315 impl From<File> for Stdio {
 316     fn from(file: File) -> Stdio {
 317         Stdio::Handle(file.into_handle())
 318     }
 319 }
 320
 321 ////////////////////////////////////////////////////////////////////////////////
 322 // Processes
 323 ////////////////////////////////////////////////////////////////////////////////
 324
 325 /// A value representing a child process.
 326 ///
 327 /// The lifetime of this value is linked to the lifetime of the actual
 328 /// process - the Process destructor calls self.finish() which waits
 329 /// for the process to terminate.
 330 pub struct Process {
 331     handle: Handle,
 332 }
 333
 334 impl Process {
 335     pub fn kill(&mut self) -> io::Result<()> {
 336         cvt(unsafe {
 337             c::TerminateProcess(self.handle.raw(), 1)
 338         })?;
 339         Ok(())
 340     }
 341
 342     pub fn id(&self) -> u32 {
 343         unsafe {
 344             c::GetProcessId(self.handle.raw()) as u32
 345         }
 346     }
 347
 348     pub fn wait(&mut self) -> io::Result<ExitStatus> {
 349         unsafe {
 350             let res = c::WaitForSingleObject(self.handle.raw(), c::INFINITE);
 351             if res != c::WAIT_OBJECT_0 {
 352                 return Err(Error::last_os_error())
 353             }
 354             let mut status = 0;
 355             cvt(c::GetExitCodeProcess(self.handle.raw(), &mut status))?;
 356             Ok(ExitStatus(status))
 357         }
 358     }
 359
 360     pub fn try_wait(&mut self) -> io::Result<Option<ExitStatus>> {
 361         unsafe {
 362             match c::WaitForSingleObject(self.handle.raw(), 0) {
 363                 c::WAIT_OBJECT_0 => {}
 364                 c::WAIT_TIMEOUT => {
 365                     return Ok(None);
 366                 }
 367                 _ => return Err(io::Error::last_os_error()),
 368             }
 369             let mut status = 0;
 370             cvt(c::GetExitCodeProcess(self.handle.raw(), &mut status))?;
 371             Ok(Some(ExitStatus(status)))
 372         }
 373     }
 374
 375     pub fn handle(&self) -> &Handle { &self.handle }
 376
 377     pub fn into_handle(self) -> Handle { self.handle }
 378 }
 379
 380 #[derive(PartialEq, Eq, Clone, Copy, Debug)]
 381 pub struct ExitStatus(c::DWORD);
 382
 383 impl ExitStatus {
 384     pub fn success(&self) -> bool {
 385         self.0 == 0
 386     }
 387     pub fn code(&self) -> Option<i32> {
 388         Some(self.0 as i32)
 389     }
 390 }
 391
 392 impl From<c::DWORD> for ExitStatus {
 393     fn from(u: c::DWORD) -> ExitStatus {
 394         ExitStatus(u)
 395     }
 396 }
 397
 398 impl fmt::Display for ExitStatus {
 399     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 400         write!(f, "exit code: {}", self.0)
 401     }
 402 }
 403
 404 fn zeroed_startupinfo() -> c::STARTUPINFO {
 405     c::STARTUPINFO {
 406         cb: 0,
 407         lpReserved: ptr::null_mut(),
 408         lpDesktop: ptr::null_mut(),
 409         lpTitle: ptr::null_mut(),
 410         dwX: 0,
 411         dwY: 0,
 412         dwXSize: 0,
 413         dwYSize: 0,
 414         dwXCountChars: 0,
 415         dwYCountCharts: 0,
 416         dwFillAttribute: 0,
 417         dwFlags: 0,
 418         wShowWindow: 0,
 419         cbReserved2: 0,
 420         lpReserved2: ptr::null_mut(),
 421         hStdInput: c::INVALID_HANDLE_VALUE,
 422         hStdOutput: c::INVALID_HANDLE_VALUE,
 423         hStdError: c::INVALID_HANDLE_VALUE,
 424     }
 425 }
 426
 427 fn zeroed_process_information() -> c::PROCESS_INFORMATION {
 428     c::PROCESS_INFORMATION {
 429         hProcess: ptr::null_mut(),
 430         hThread: ptr::null_mut(),
 431         dwProcessId: 0,
 432         dwThreadId: 0
 433     }
 434 }
 435
 436 // Produces a wide string *without terminating null*; returns an error if
 437 // `prog` or any of the `args` contain a nul.
 438 fn make_command_line(prog: &OsStr, args: &[OsString]) -> io::Result<Vec<u16>> {
 439     // Encode the command and arguments in a command line string such
 440     // that the spawned process may recover them using CommandLineToArgvW.
 441     let mut cmd: Vec<u16> = Vec::new();
 442     // Always quote the program name so CreateProcess doesn't interpret args as
 443     // part of the name if the binary wasn't found first time.
 444     append_arg(&mut cmd, prog, true)?;
 445     for arg in args {
 446         cmd.push(' ' as u16);
 447         append_arg(&mut cmd, arg, false)?;
 448     }
 449     return Ok(cmd);
 450
 451     fn append_arg(cmd: &mut Vec<u16>, arg: &OsStr, force_quotes: bool) -> io::Result<()> {
 452         // If an argument has 0 characters then we need to quote it to ensure
 453         // that it actually gets passed through on the command line or otherwise
 454         // it will be dropped entirely when parsed on the other end.
 455         ensure_no_nuls(arg)?;
 456         let arg_bytes = &arg.as_inner().inner.as_inner();
 457         let quote = force_quotes || arg_bytes.iter().any(|c| *c == b' ' || *c == b'\t')
 458             || arg_bytes.is_empty();
 459         if quote {
 460             cmd.push('"' as u16);
 461         }
 462
 463         let mut iter = arg.encode_wide();
 464         let mut backslashes: usize = 0;
 465         while let Some(x) = iter.next() {
 466             if x == '\\' as u16 {
 467                 backslashes += 1;
 468             } else {
 469                 if x == '"' as u16 {
 470                     // Add n+1 backslashes to total 2n+1 before internal '"'.
 471                     for _ in 0..(backslashes+1) {
 472                         cmd.push('\\' as u16);
 473                     }
 474                 }
 475                 backslashes = 0;
 476             }
 477             cmd.push(x);
 478         }
 479
 480         if quote {
 481             // Add n backslashes to total 2n before ending '"'.
 482             for _ in 0..backslashes {
 483                 cmd.push('\\' as u16);
 484             }
 485             cmd.push('"' as u16);
 486         }
 487         Ok(())
 488     }
 489 }
 490
 491 fn make_envp(env: Option<&collections::HashMap<OsString, OsString>>)
 492              -> io::Result<(*mut c_void, Vec<u16>)> {
 493     // On Windows we pass an "environment block" which is not a char**, but
 494     // rather a concatenation of null-terminated k=v\0 sequences, with a final
 495     // \0 to terminate.
 496     match env {
 497         Some(env) => {
 498             let mut blk = Vec::new();
 499
 500             for pair in env {
 501                 blk.extend(ensure_no_nuls(pair.0)?.encode_wide());
 502                 blk.push('=' as u16);
 503                 blk.extend(ensure_no_nuls(pair.1)?.encode_wide());
 504                 blk.push(0);
 505             }
 506             blk.push(0);
 507             Ok((blk.as_mut_ptr() as *mut c_void, blk))
 508         }
 509         _ => Ok((ptr::null_mut(), Vec::new()))
 510     }
 511 }
 512
 513 fn make_dirp(d: Option<&OsString>) -> io::Result<(*const u16, Vec<u16>)> {
 514
 515     match d {
 516         Some(dir) => {
 517             let mut dir_str: Vec<u16> = ensure_no_nuls(dir)?.encode_wide().collect();
 518             dir_str.push(0);
 519             Ok((dir_str.as_ptr(), dir_str))
 520         },
 521         None => Ok((ptr::null(), Vec::new()))
 522     }
 523 }
 524
 525 #[cfg(test)]
 526 mod tests {
 527     use ffi::{OsStr, OsString};
 528     use super::make_command_line;
 529
 530     #[test]
 531     fn test_make_command_line() {
 532         fn test_wrapper(prog: &str, args: &[&str]) -> String {
 533             let command_line = &make_command_line(OsStr::new(prog),
 534                                                   &args.iter()
 535                                                        .map(|a| OsString::from(a))
 536                                                        .collect::<Vec<OsString>>())
 537                                     .unwrap();
 538             String::from_utf16(command_line).unwrap()
 539         }
 540
 541         assert_eq!(
 542             test_wrapper("prog", &["aaa", "bbb", "ccc"]),
 543             "\"prog\" aaa bbb ccc"
 544         );
 545
 546         assert_eq!(
 547             test_wrapper("C:\\Program Files\\blah\\blah.exe", &["aaa"]),
 548             "\"C:\\Program Files\\blah\\blah.exe\" aaa"
 549         );
 550         assert_eq!(
 551             test_wrapper("C:\\Program Files\\test", &["aa\"bb"]),
 552             "\"C:\\Program Files\\test\" aa\\\"bb"
 553         );
 554         assert_eq!(
 555             test_wrapper("echo", &["a b c"]),
 556             "\"echo\" \"a b c\""
 557         );
 558         assert_eq!(
 559             test_wrapper("echo", &["\" \\\" \\", "\\"]),
 560             "\"echo\" \"\\\" \\\\\\\" \\\\\" \\"
 561         );
 562         assert_eq!(
 563             test_wrapper("\u{03c0}\u{042f}\u{97f3}\u{00e6}\u{221e}", &[]),
 564             "\"\u{03c0}\u{042f}\u{97f3}\u{00e6}\u{221e}\""
 565         );
 566     }
 567 }