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 prelude::v1::*;
  12
  13 use ascii::*;
  14 use collections::HashMap;
  15 use collections;
  16 use env::split_paths;
  17 use env;
  18 use ffi::{OsString, OsStr};
  19 use fmt;
  20 use fs;
  21 use io::{self, Error, ErrorKind};
  22 use libc::c_void;
  23 use mem;
  24 use os::windows::ffi::OsStrExt;
  25 use path::Path;
  26 use ptr;
  27 use sync::StaticMutex;
  28 use sys::c;
  29 use sys::fs::{OpenOptions, File};
  30 use sys::handle::Handle;
  31 use sys::pipe::{self, AnonPipe};
  32 use sys::stdio;
  33 use sys::{self, cvt};
  34 use sys_common::{AsInner, FromInner};
  35
  36 ////////////////////////////////////////////////////////////////////////////////
  37 // Command
  38 ////////////////////////////////////////////////////////////////////////////////
  39
  40 fn mk_key(s: &OsStr) -> OsString {
  41     FromInner::from_inner(sys::os_str::Buf {
  42         inner: s.as_inner().inner.to_ascii_uppercase()
  43     })
  44 }
  45
  46 fn ensure_no_nuls<T: AsRef<OsStr>>(str: T) -> io::Result<T> {
  47     if str.as_ref().encode_wide().any(|b| b == 0) {
  48         Err(io::Error::new(ErrorKind::InvalidInput, "nul byte found in provided data"))
  49     } else {
  50         Ok(str)
  51     }
  52 }
  53
  54 pub struct Command {
  55     program: OsString,
  56     args: Vec<OsString>,
  57     env: Option<HashMap<OsString, OsString>>,
  58     cwd: Option<OsString>,
  59     detach: bool, // not currently exposed in std::process
  60     stdin: Option<Stdio>,
  61     stdout: Option<Stdio>,
  62     stderr: Option<Stdio>,
  63 }
  64
  65 pub enum Stdio {
  66     Inherit,
  67     Null,
  68     MakePipe,
  69     Handle(Handle),
  70 }
  71
  72 pub struct StdioPipes {
  73     pub stdin: Option<AnonPipe>,
  74     pub stdout: Option<AnonPipe>,
  75     pub stderr: Option<AnonPipe>,
  76 }
  77
  78 impl Command {
  79     pub fn new(program: &OsStr) -> Command {
  80         Command {
  81             program: program.to_os_string(),
  82             args: Vec::new(),
  83             env: None,
  84             cwd: None,
  85             detach: false,
  86             stdin: None,
  87             stdout: None,
  88             stderr: None,
  89         }
  90     }
  91
  92     pub fn arg(&mut self, arg: &OsStr) {
  93         self.args.push(arg.to_os_string())
  94     }
  95     fn init_env_map(&mut self){
  96         if self.env.is_none() {
  97             self.env = Some(env::vars_os().map(|(key, val)| {
  98                 (mk_key(&key), val)
  99             }).collect());
 100         }
 101     }
 102     pub fn env(&mut self, key: &OsStr, val: &OsStr) {
 103         self.init_env_map();
 104         self.env.as_mut().unwrap().insert(mk_key(key), val.to_os_string());
 105     }
 106     pub fn env_remove(&mut self, key: &OsStr) {
 107         self.init_env_map();
 108         self.env.as_mut().unwrap().remove(&mk_key(key));
 109     }
 110     pub fn env_clear(&mut self) {
 111         self.env = Some(HashMap::new())
 112     }
 113     pub fn cwd(&mut self, dir: &OsStr) {
 114         self.cwd = Some(dir.to_os_string())
 115     }
 116     pub fn stdin(&mut self, stdin: Stdio) {
 117         self.stdin = Some(stdin);
 118     }
 119     pub fn stdout(&mut self, stdout: Stdio) {
 120         self.stdout = Some(stdout);
 121     }
 122     pub fn stderr(&mut self, stderr: Stdio) {
 123         self.stderr = Some(stderr);
 124     }
 125
 126     pub fn spawn(&mut self, default: Stdio, needs_stdin: bool)
 127                  -> io::Result<(Process, StdioPipes)> {
 128         // To have the spawning semantics of unix/windows stay the same, we need
 129         // to read the *child's* PATH if one is provided. See #15149 for more
 130         // details.
 131         let program = self.env.as_ref().and_then(|env| {
 132             for (key, v) in env {
 133                 if OsStr::new("PATH") != &**key { continue }
 134
 135                 // Split the value and test each path to see if the
 136                 // program exists.
 137                 for path in split_paths(&v) {
 138                     let path = path.join(self.program.to_str().unwrap())
 139                                    .with_extension(env::consts::EXE_EXTENSION);
 140                     if fs::metadata(&path).is_ok() {
 141                         return Some(path.into_os_string())
 142                     }
 143                 }
 144                 break
 145             }
 146             None
 147         });
 148
 149         let mut si = zeroed_startupinfo();
 150         si.cb = mem::size_of::<c::STARTUPINFO>() as c::DWORD;
 151         si.dwFlags = c::STARTF_USESTDHANDLES;
 152
 153         let program = program.as_ref().unwrap_or(&self.program);
 154         let mut cmd_str = make_command_line(program, &self.args)?;
 155         cmd_str.push(0); // add null terminator
 156
 157         // stolen from the libuv code.
 158         let mut flags = c::CREATE_UNICODE_ENVIRONMENT;
 159         if self.detach {
 160             flags |= c::DETACHED_PROCESS | c::CREATE_NEW_PROCESS_GROUP;
 161         }
 162
 163         let (envp, _data) = make_envp(self.env.as_ref())?;
 164         let (dirp, _data) = make_dirp(self.cwd.as_ref())?;
 165         let mut pi = zeroed_process_information();
 166
 167         // Prepare all stdio handles to be inherited by the child. This
 168         // currently involves duplicating any existing ones with the ability to
 169         // be inherited by child processes. Note, however, that once an
 170         // inheritable handle is created, *any* spawned child will inherit that
 171         // handle. We only want our own child to inherit this handle, so we wrap
 172         // the remaining portion of this spawn in a mutex.
 173         //
 174         // For more information, msdn also has an article about this race:
 175         // http://support.microsoft.com/kb/315939
 176         static CREATE_PROCESS_LOCK: StaticMutex = StaticMutex::new();
 177         let _lock = CREATE_PROCESS_LOCK.lock();
 178
 179         let mut pipes = StdioPipes {
 180             stdin: None,
 181             stdout: None,
 182             stderr: None,
 183         };
 184         let null = Stdio::Null;
 185         let default_stdin = if needs_stdin {&default} else {&null};
 186         let stdin = self.stdin.as_ref().unwrap_or(default_stdin);
 187         let stdout = self.stdout.as_ref().unwrap_or(&default);
 188         let stderr = self.stderr.as_ref().unwrap_or(&default);
 189         let stdin = stdin.to_handle(c::STD_INPUT_HANDLE, &mut pipes.stdin)?;
 190         let stdout = stdout.to_handle(c::STD_OUTPUT_HANDLE,
 191                                       &mut pipes.stdout)?;
 192         let stderr = stderr.to_handle(c::STD_ERROR_HANDLE,
 193                                       &mut pipes.stderr)?;
 194         si.hStdInput = stdin.raw();
 195         si.hStdOutput = stdout.raw();
 196         si.hStdError = stderr.raw();
 197
 198         unsafe {
 199             cvt(c::CreateProcessW(ptr::null(),
 200                                   cmd_str.as_mut_ptr(),
 201                                   ptr::null_mut(),
 202                                   ptr::null_mut(),
 203                                   c::TRUE, flags, envp, dirp,
 204                                   &mut si, &mut pi))
 205         }?;
 206
 207         // We close the thread handle because we don't care about keeping
 208         // the thread id valid, and we aren't keeping the thread handle
 209         // around to be able to close it later.
 210         drop(Handle::new(pi.hThread));
 211
 212         Ok((Process { handle: Handle::new(pi.hProcess) }, pipes))
 213     }
 214
 215 }
 216
 217 impl fmt::Debug for Command {
 218     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 219         write!(f, "{:?}", self.program)?;
 220         for arg in &self.args {
 221             write!(f, " {:?}", arg)?;
 222         }
 223         Ok(())
 224     }
 225 }
 226
 227 impl Stdio {
 228     fn to_handle(&self, stdio_id: c::DWORD, pipe: &mut Option<AnonPipe>)
 229                  -> io::Result<Handle> {
 230         match *self {
 231             // If no stdio handle is available, then inherit means that it
 232             // should still be unavailable so propagate the
 233             // INVALID_HANDLE_VALUE.
 234             Stdio::Inherit => {
 235                 match stdio::get(stdio_id) {
 236                     Ok(io) => io.handle().duplicate(0, true,
 237                                                     c::DUPLICATE_SAME_ACCESS),
 238                     Err(..) => Ok(Handle::new(c::INVALID_HANDLE_VALUE)),
 239                 }
 240             }
 241
 242             Stdio::MakePipe => {
 243                 let (reader, writer) = pipe::anon_pipe()?;
 244                 let (ours, theirs) = if stdio_id == c::STD_INPUT_HANDLE {
 245                     (writer, reader)
 246                 } else {
 247                     (reader, writer)
 248                 };
 249                 *pipe = Some(ours);
 250                 cvt(unsafe {
 251                     c::SetHandleInformation(theirs.handle().raw(),
 252                                             c::HANDLE_FLAG_INHERIT,
 253                                             c::HANDLE_FLAG_INHERIT)
 254                 })?;
 255                 Ok(theirs.into_handle())
 256             }
 257
 258             Stdio::Handle(ref handle) => {
 259                 handle.duplicate(0, true, c::DUPLICATE_SAME_ACCESS)
 260             }
 261
 262             // Open up a reference to NUL with appropriate read/write
 263             // permissions as well as the ability to be inherited to child
 264             // processes (as this is about to be inherited).
 265             Stdio::Null => {
 266                 let size = mem::size_of::<c::SECURITY_ATTRIBUTES>();
 267                 let mut sa = c::SECURITY_ATTRIBUTES {
 268                     nLength: size as c::DWORD,
 269                     lpSecurityDescriptor: ptr::null_mut(),
 270                     bInheritHandle: 1,
 271                 };
 272                 let mut opts = OpenOptions::new();
 273                 opts.read(stdio_id == c::STD_INPUT_HANDLE);
 274                 opts.write(stdio_id != c::STD_INPUT_HANDLE);
 275                 opts.security_attributes(&mut sa);
 276                 File::open(Path::new("NUL"), &opts).map(|file| {
 277                     file.into_handle()
 278                 })
 279             }
 280         }
 281     }
 282 }
 283
 284 ////////////////////////////////////////////////////////////////////////////////
 285 // Processes
 286 ////////////////////////////////////////////////////////////////////////////////
 287
 288 /// A value representing a child process.
 289 ///
 290 /// The lifetime of this value is linked to the lifetime of the actual
 291 /// process - the Process destructor calls self.finish() which waits
 292 /// for the process to terminate.
 293 pub struct Process {
 294     handle: Handle,
 295 }
 296
 297 impl Process {
 298     pub fn kill(&mut self) -> io::Result<()> {
 299         cvt(unsafe {
 300             c::TerminateProcess(self.handle.raw(), 1)
 301         })?;
 302         Ok(())
 303     }
 304
 305     pub fn id(&self) -> u32 {
 306         unsafe {
 307             c::GetProcessId(self.handle.raw()) as u32
 308         }
 309     }
 310
 311     pub fn wait(&mut self) -> io::Result<ExitStatus> {
 312         unsafe {
 313             let res = c::WaitForSingleObject(self.handle.raw(), c::INFINITE);
 314             if res != c::WAIT_OBJECT_0 {
 315                 return Err(Error::last_os_error())
 316             }
 317             let mut status = 0;
 318             cvt(c::GetExitCodeProcess(self.handle.raw(), &mut status))?;
 319             Ok(ExitStatus(status))
 320         }
 321     }
 322
 323     pub fn handle(&self) -> &Handle { &self.handle }
 324
 325     pub fn into_handle(self) -> Handle { self.handle }
 326 }
 327
 328 #[derive(PartialEq, Eq, Clone, Copy, Debug)]
 329 pub struct ExitStatus(c::DWORD);
 330
 331 impl ExitStatus {
 332     pub fn success(&self) -> bool {
 333         self.0 == 0
 334     }
 335     pub fn code(&self) -> Option<i32> {
 336         Some(self.0 as i32)
 337     }
 338 }
 339
 340 impl fmt::Display for ExitStatus {
 341     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 342         write!(f, "exit code: {}", self.0)
 343     }
 344 }
 345
 346 fn zeroed_startupinfo() -> c::STARTUPINFO {
 347     c::STARTUPINFO {
 348         cb: 0,
 349         lpReserved: ptr::null_mut(),
 350         lpDesktop: ptr::null_mut(),
 351         lpTitle: ptr::null_mut(),
 352         dwX: 0,
 353         dwY: 0,
 354         dwXSize: 0,
 355         dwYSize: 0,
 356         dwXCountChars: 0,
 357         dwYCountCharts: 0,
 358         dwFillAttribute: 0,
 359         dwFlags: 0,
 360         wShowWindow: 0,
 361         cbReserved2: 0,
 362         lpReserved2: ptr::null_mut(),
 363         hStdInput: c::INVALID_HANDLE_VALUE,
 364         hStdOutput: c::INVALID_HANDLE_VALUE,
 365         hStdError: c::INVALID_HANDLE_VALUE,
 366     }
 367 }
 368
 369 fn zeroed_process_information() -> c::PROCESS_INFORMATION {
 370     c::PROCESS_INFORMATION {
 371         hProcess: ptr::null_mut(),
 372         hThread: ptr::null_mut(),
 373         dwProcessId: 0,
 374         dwThreadId: 0
 375     }
 376 }
 377
 378 // Produces a wide string *without terminating null*; returns an error if
 379 // `prog` or any of the `args` contain a nul.
 380 fn make_command_line(prog: &OsStr, args: &[OsString]) -> io::Result<Vec<u16>> {
 381     // Encode the command and arguments in a command line string such
 382     // that the spawned process may recover them using CommandLineToArgvW.
 383     let mut cmd: Vec<u16> = Vec::new();
 384     append_arg(&mut cmd, prog)?;
 385     for arg in args {
 386         cmd.push(' ' as u16);
 387         append_arg(&mut cmd, arg)?;
 388     }
 389     return Ok(cmd);
 390
 391     fn append_arg(cmd: &mut Vec<u16>, arg: &OsStr) -> io::Result<()> {
 392         // If an argument has 0 characters then we need to quote it to ensure
 393         // that it actually gets passed through on the command line or otherwise
 394         // it will be dropped entirely when parsed on the other end.
 395         ensure_no_nuls(arg)?;
 396         let arg_bytes = &arg.as_inner().inner.as_inner();
 397         let quote = arg_bytes.iter().any(|c| *c == b' ' || *c == b'\t')
 398             || arg_bytes.is_empty();
 399         if quote {
 400             cmd.push('"' as u16);
 401         }
 402
 403         let mut iter = arg.encode_wide();
 404         let mut backslashes: usize = 0;
 405         while let Some(x) = iter.next() {
 406             if x == '\\' as u16 {
 407                 backslashes += 1;
 408             } else {
 409                 if x == '"' as u16 {
 410                     // Add n+1 backslashes to total 2n+1 before internal '"'.
 411                     for _ in 0..(backslashes+1) {
 412                         cmd.push('\\' as u16);
 413                     }
 414                 }
 415                 backslashes = 0;
 416             }
 417             cmd.push(x);
 418         }
 419
 420         if quote {
 421             // Add n backslashes to total 2n before ending '"'.
 422             for _ in 0..backslashes {
 423                 cmd.push('\\' as u16);
 424             }
 425             cmd.push('"' as u16);
 426         }
 427         Ok(())
 428     }
 429 }
 430
 431 fn make_envp(env: Option<&collections::HashMap<OsString, OsString>>)
 432              -> io::Result<(*mut c_void, Vec<u16>)> {
 433     // On Windows we pass an "environment block" which is not a char**, but
 434     // rather a concatenation of null-terminated k=v\0 sequences, with a final
 435     // \0 to terminate.
 436     match env {
 437         Some(env) => {
 438             let mut blk = Vec::new();
 439
 440             for pair in env {
 441                 blk.extend(ensure_no_nuls(pair.0)?.encode_wide());
 442                 blk.push('=' as u16);
 443                 blk.extend(ensure_no_nuls(pair.1)?.encode_wide());
 444                 blk.push(0);
 445             }
 446             blk.push(0);
 447             Ok((blk.as_mut_ptr() as *mut c_void, blk))
 448         }
 449         _ => Ok((ptr::null_mut(), Vec::new()))
 450     }
 451 }
 452
 453 fn make_dirp(d: Option<&OsString>) -> io::Result<(*const u16, Vec<u16>)> {
 454
 455     match d {
 456         Some(dir) => {
 457             let mut dir_str: Vec<u16> = ensure_no_nuls(dir)?.encode_wide().collect();
 458             dir_str.push(0);
 459             Ok((dir_str.as_ptr(), dir_str))
 460         },
 461         None => Ok((ptr::null(), Vec::new()))
 462     }
 463 }
 464
 465 #[cfg(test)]
 466 mod tests {
 467     use prelude::v1::*;
 468     use ffi::{OsStr, OsString};
 469     use super::make_command_line;
 470
 471     #[test]
 472     fn test_make_command_line() {
 473         fn test_wrapper(prog: &str, args: &[&str]) -> String {
 474             let command_line = &make_command_line(OsStr::new(prog),
 475                                                   &args.iter()
 476                                                        .map(|a| OsString::from(a))
 477                                                        .collect::<Vec<OsString>>())
 478                                     .unwrap();
 479             String::from_utf16(command_line).unwrap()
 480         }
 481
 482         assert_eq!(
 483             test_wrapper("prog", &["aaa", "bbb", "ccc"]),
 484             "prog aaa bbb ccc"
 485         );
 486
 487         assert_eq!(
 488             test_wrapper("C:\\Program Files\\blah\\blah.exe", &["aaa"]),
 489             "\"C:\\Program Files\\blah\\blah.exe\" aaa"
 490         );
 491         assert_eq!(
 492             test_wrapper("C:\\Program Files\\test", &["aa\"bb"]),
 493             "\"C:\\Program Files\\test\" aa\\\"bb"
 494         );
 495         assert_eq!(
 496             test_wrapper("echo", &["a b c"]),
 497             "echo \"a b c\""
 498         );
 499         assert_eq!(
 500             test_wrapper("echo", &["\" \\\" \\", "\\"]),
 501             "echo \"\\\" \\\\\\\" \\\\\" \\"
 502         );
 503         assert_eq!(
 504             test_wrapper("\u{03c0}\u{042f}\u{97f3}\u{00e6}\u{221e}", &[]),
 505             "\u{03c0}\u{042f}\u{97f3}\u{00e6}\u{221e}"
 506         );
 507     }
 508 }