1#[cfg(all(test, not(target_os = "emscripten")))]
2mod tests;
3
4use libc::{EXIT_FAILURE, EXIT_SUCCESS, c_char, c_int, gid_t, pid_t, uid_t};
5
6use crate::collections::BTreeMap;
7use crate::ffi::{CStr, CString, OsStr, OsString};
8use crate::os::unix::prelude::*;
9use crate::path::Path;
10use crate::sys::fd::FileDesc;
11use crate::sys::fs::File;
12#[cfg(not(target_os = "fuchsia"))]
13use crate::sys::fs::OpenOptions;
14use crate::sys::pipe::{self, AnonPipe};
15use crate::sys_common::process::{CommandEnv, CommandEnvs};
16use crate::sys_common::{FromInner, IntoInner};
17use crate::{fmt, io, ptr};
18
19cfg_if::cfg_if! {
20 if #[cfg(target_os = "fuchsia")] {
21 // fuchsia doesn't have /dev/null
22 } else if #[cfg(target_os = "vxworks")] {
23 const DEV_NULL: &CStr = c"/null";
24 } else {
25 const DEV_NULL: &CStr = c"/dev/null";
26 }
27}
28
29// Android with api less than 21 define sig* functions inline, so it is not
30// available for dynamic link. Implementing sigemptyset and sigaddset allow us
31// to support older Android version (independent of libc version).
32// The following implementations are based on
33// https://github.com/aosp-mirror/platform_bionic/blob/ad8dcd6023294b646e5a8288c0ed431b0845da49/libc/include/android/legacy_signal_inlines.h
34cfg_if::cfg_if! {
35 if #[cfg(target_os = "android")] {
36 #[allow(dead_code)]
37 pub unsafe fn sigemptyset(set: *mut libc::sigset_t) -> libc::c_int {
38 set.write_bytes(0u8, 1);
39 return 0;
40 }
41
42 #[allow(dead_code)]
43 pub unsafe fn sigaddset(set: *mut libc::sigset_t, signum: libc::c_int) -> libc::c_int {
44 use crate::slice;
45 use libc::{c_ulong, sigset_t};
46
47 // The implementations from bionic (android libc) type pun `sigset_t` as an
48 // array of `c_ulong`. This works, but lets add a smoke check to make sure
49 // that doesn't change.
50 const _: () = assert!(
51 align_of::<c_ulong>() == align_of::<sigset_t>()
52 && (size_of::<sigset_t>() % size_of::<c_ulong>()) == 0
53 );
54
55 let bit = (signum - 1) as usize;
56 if set.is_null() || bit >= (8 * size_of::<sigset_t>()) {
57 crate::sys::pal::os::set_errno(libc::EINVAL);
58 return -1;
59 }
60 let raw = slice::from_raw_parts_mut(
61 set as *mut c_ulong,
62 size_of::<sigset_t>() / size_of::<c_ulong>(),
63 );
64 const LONG_BIT: usize = size_of::<c_ulong>() * 8;
65 raw[bit / LONG_BIT] |= 1 << (bit % LONG_BIT);
66 return 0;
67 }
68 } else {
69 #[allow(unused_imports)]
70 pub use libc::{sigemptyset, sigaddset};
71 }
72}
73
74////////////////////////////////////////////////////////////////////////////////
75// Command
76////////////////////////////////////////////////////////////////////////////////
77
78pub struct Command {
79 program: CString,
80 args: Vec<CString>,
81 /// Exactly what will be passed to `execvp`.
82 ///
83 /// First element is a pointer to `program`, followed by pointers to
84 /// `args`, followed by a `null`. Be careful when modifying `program` or
85 /// `args` to properly update this as well.
86 argv: Argv,
87 env: CommandEnv,
88
89 program_kind: ProgramKind,
90 cwd: Option<CString>,
91 uid: Option<uid_t>,
92 gid: Option<gid_t>,
93 saw_nul: bool,
94 closures: Vec<Box<dyn FnMut() -> io::Result<()> + Send + Sync>>,
95 groups: Option<Box<[gid_t]>>,
96 stdin: Option<Stdio>,
97 stdout: Option<Stdio>,
98 stderr: Option<Stdio>,
99 #[cfg(target_os = "linux")]
100 create_pidfd: bool,
101 pgroup: Option<pid_t>,
102}
103
104// Create a new type for argv, so that we can make it `Send` and `Sync`
105struct Argv(Vec<*const c_char>);
106
107// It is safe to make `Argv` `Send` and `Sync`, because it contains
108// pointers to memory owned by `Command.args`
109unsafe impl Send for Argv {}
110unsafe impl Sync for Argv {}
111
112// passed back to std::process with the pipes connected to the child, if any
113// were requested
114pub struct StdioPipes {
115 pub stdin: Option<AnonPipe>,
116 pub stdout: Option<AnonPipe>,
117 pub stderr: Option<AnonPipe>,
118}
119
120// passed to do_exec() with configuration of what the child stdio should look
121// like
122#[cfg_attr(target_os = "vita", allow(dead_code))]
123pub struct ChildPipes {
124 pub stdin: ChildStdio,
125 pub stdout: ChildStdio,
126 pub stderr: ChildStdio,
127}
128
129pub enum ChildStdio {
130 Inherit,
131 Explicit(c_int),
132 Owned(FileDesc),
133
134 // On Fuchsia, null stdio is the default, so we simply don't specify
135 // any actions at the time of spawning.
136 #[cfg(target_os = "fuchsia")]
137 Null,
138}
139
140#[derive(Debug)]
141pub enum Stdio {
142 Inherit,
143 Null,
144 MakePipe,
145 Fd(FileDesc),
146 StaticFd(BorrowedFd<'static>),
147}
148
149#[derive(Copy, Clone, Debug, Eq, PartialEq)]
150pub enum ProgramKind {
151 /// A program that would be looked up on the PATH (e.g. `ls`)
152 PathLookup,
153 /// A relative path (e.g. `my-dir/foo`, `../foo`, `./foo`)
154 Relative,
155 /// An absolute path.
156 Absolute,
157}
158
159impl ProgramKind {
160 fn new(program: &OsStr) -> Self {
161 if program.as_encoded_bytes().starts_with(needle:b"/") {
162 Self::Absolute
163 } else if program.as_encoded_bytes().contains(&b'/') {
164 // If the program has more than one component in it, it is a relative path.
165 Self::Relative
166 } else {
167 Self::PathLookup
168 }
169 }
170}
171
172impl Command {
173 #[cfg(not(target_os = "linux"))]
174 pub fn new(program: &OsStr) -> Command {
175 let mut saw_nul = false;
176 let program_kind = ProgramKind::new(program.as_ref());
177 let program = os2c(program, &mut saw_nul);
178 Command {
179 argv: Argv(vec![program.as_ptr(), ptr::null()]),
180 args: vec![program.clone()],
181 program,
182 program_kind,
183 env: Default::default(),
184 cwd: None,
185 uid: None,
186 gid: None,
187 saw_nul,
188 closures: Vec::new(),
189 groups: None,
190 stdin: None,
191 stdout: None,
192 stderr: None,
193 pgroup: None,
194 }
195 }
196
197 #[cfg(target_os = "linux")]
198 pub fn new(program: &OsStr) -> Command {
199 let mut saw_nul = false;
200 let program_kind = ProgramKind::new(program.as_ref());
201 let program = os2c(program, &mut saw_nul);
202 Command {
203 argv: Argv(vec![program.as_ptr(), ptr::null()]),
204 args: vec![program.clone()],
205 program,
206 program_kind,
207 env: Default::default(),
208 cwd: None,
209 uid: None,
210 gid: None,
211 saw_nul,
212 closures: Vec::new(),
213 groups: None,
214 stdin: None,
215 stdout: None,
216 stderr: None,
217 create_pidfd: false,
218 pgroup: None,
219 }
220 }
221
222 pub fn set_arg_0(&mut self, arg: &OsStr) {
223 // Set a new arg0
224 let arg = os2c(arg, &mut self.saw_nul);
225 debug_assert!(self.argv.0.len() > 1);
226 self.argv.0[0] = arg.as_ptr();
227 self.args[0] = arg;
228 }
229
230 pub fn arg(&mut self, arg: &OsStr) {
231 // Overwrite the trailing null pointer in `argv` and then add a new null
232 // pointer.
233 let arg = os2c(arg, &mut self.saw_nul);
234 self.argv.0[self.args.len()] = arg.as_ptr();
235 self.argv.0.push(ptr::null());
236
237 // Also make sure we keep track of the owned value to schedule a
238 // destructor for this memory.
239 self.args.push(arg);
240 }
241
242 pub fn cwd(&mut self, dir: &OsStr) {
243 self.cwd = Some(os2c(dir, &mut self.saw_nul));
244 }
245 pub fn uid(&mut self, id: uid_t) {
246 self.uid = Some(id);
247 }
248 pub fn gid(&mut self, id: gid_t) {
249 self.gid = Some(id);
250 }
251 pub fn groups(&mut self, groups: &[gid_t]) {
252 self.groups = Some(Box::from(groups));
253 }
254 pub fn pgroup(&mut self, pgroup: pid_t) {
255 self.pgroup = Some(pgroup);
256 }
257
258 #[cfg(target_os = "linux")]
259 pub fn create_pidfd(&mut self, val: bool) {
260 self.create_pidfd = val;
261 }
262
263 #[cfg(not(target_os = "linux"))]
264 #[allow(dead_code)]
265 pub fn get_create_pidfd(&self) -> bool {
266 false
267 }
268
269 #[cfg(target_os = "linux")]
270 pub fn get_create_pidfd(&self) -> bool {
271 self.create_pidfd
272 }
273
274 pub fn saw_nul(&self) -> bool {
275 self.saw_nul
276 }
277
278 pub fn get_program(&self) -> &OsStr {
279 OsStr::from_bytes(self.program.as_bytes())
280 }
281
282 #[allow(dead_code)]
283 pub fn get_program_kind(&self) -> ProgramKind {
284 self.program_kind
285 }
286
287 pub fn get_args(&self) -> CommandArgs<'_> {
288 let mut iter = self.args.iter();
289 iter.next();
290 CommandArgs { iter }
291 }
292
293 pub fn get_envs(&self) -> CommandEnvs<'_> {
294 self.env.iter()
295 }
296
297 pub fn get_current_dir(&self) -> Option<&Path> {
298 self.cwd.as_ref().map(|cs| Path::new(OsStr::from_bytes(cs.as_bytes())))
299 }
300
301 pub fn get_argv(&self) -> &Vec<*const c_char> {
302 &self.argv.0
303 }
304
305 pub fn get_program_cstr(&self) -> &CStr {
306 &*self.program
307 }
308
309 #[allow(dead_code)]
310 pub fn get_cwd(&self) -> Option<&CStr> {
311 self.cwd.as_deref()
312 }
313 #[allow(dead_code)]
314 pub fn get_uid(&self) -> Option<uid_t> {
315 self.uid
316 }
317 #[allow(dead_code)]
318 pub fn get_gid(&self) -> Option<gid_t> {
319 self.gid
320 }
321 #[allow(dead_code)]
322 pub fn get_groups(&self) -> Option<&[gid_t]> {
323 self.groups.as_deref()
324 }
325 #[allow(dead_code)]
326 pub fn get_pgroup(&self) -> Option<pid_t> {
327 self.pgroup
328 }
329
330 pub fn get_closures(&mut self) -> &mut Vec<Box<dyn FnMut() -> io::Result<()> + Send + Sync>> {
331 &mut self.closures
332 }
333
334 pub unsafe fn pre_exec(&mut self, f: Box<dyn FnMut() -> io::Result<()> + Send + Sync>) {
335 self.closures.push(f);
336 }
337
338 pub fn stdin(&mut self, stdin: Stdio) {
339 self.stdin = Some(stdin);
340 }
341
342 pub fn stdout(&mut self, stdout: Stdio) {
343 self.stdout = Some(stdout);
344 }
345
346 pub fn stderr(&mut self, stderr: Stdio) {
347 self.stderr = Some(stderr);
348 }
349
350 pub fn env_mut(&mut self) -> &mut CommandEnv {
351 &mut self.env
352 }
353
354 pub fn capture_env(&mut self) -> Option<CStringArray> {
355 let maybe_env = self.env.capture_if_changed();
356 maybe_env.map(|env| construct_envp(env, &mut self.saw_nul))
357 }
358
359 #[allow(dead_code)]
360 pub fn env_saw_path(&self) -> bool {
361 self.env.have_changed_path()
362 }
363
364 #[allow(dead_code)]
365 pub fn program_is_path(&self) -> bool {
366 self.program.to_bytes().contains(&b'/')
367 }
368
369 pub fn setup_io(
370 &self,
371 default: Stdio,
372 needs_stdin: bool,
373 ) -> io::Result<(StdioPipes, ChildPipes)> {
374 let null = Stdio::Null;
375 let default_stdin = if needs_stdin { &default } else { &null };
376 let stdin = self.stdin.as_ref().unwrap_or(default_stdin);
377 let stdout = self.stdout.as_ref().unwrap_or(&default);
378 let stderr = self.stderr.as_ref().unwrap_or(&default);
379 let (their_stdin, our_stdin) = stdin.to_child_stdio(true)?;
380 let (their_stdout, our_stdout) = stdout.to_child_stdio(false)?;
381 let (their_stderr, our_stderr) = stderr.to_child_stdio(false)?;
382 let ours = StdioPipes { stdin: our_stdin, stdout: our_stdout, stderr: our_stderr };
383 let theirs = ChildPipes { stdin: their_stdin, stdout: their_stdout, stderr: their_stderr };
384 Ok((ours, theirs))
385 }
386}
387
388fn os2c(s: &OsStr, saw_nul: &mut bool) -> CString {
389 CString::new(s.as_bytes()).unwrap_or_else(|_e: NulError| {
390 *saw_nul = true;
391 c"<string-with-nul>".to_owned()
392 })
393}
394
395// Helper type to manage ownership of the strings within a C-style array.
396pub struct CStringArray {
397 items: Vec<CString>,
398 ptrs: Vec<*const c_char>,
399}
400
401impl CStringArray {
402 pub fn with_capacity(capacity: usize) -> Self {
403 let mut result: CStringArray = CStringArray {
404 items: Vec::with_capacity(capacity),
405 ptrs: Vec::with_capacity(capacity + 1),
406 };
407 result.ptrs.push(ptr::null());
408 result
409 }
410 pub fn push(&mut self, item: CString) {
411 let l: usize = self.ptrs.len();
412 self.ptrs[l - 1] = item.as_ptr();
413 self.ptrs.push(ptr::null());
414 self.items.push(item);
415 }
416 pub fn as_ptr(&self) -> *const *const c_char {
417 self.ptrs.as_ptr()
418 }
419}
420
421fn construct_envp(env: BTreeMap<OsString, OsString>, saw_nul: &mut bool) -> CStringArray {
422 let mut result: CStringArray = CStringArray::with_capacity(env.len());
423 for (mut k: OsString, v: OsString) in env {
424 // Reserve additional space for '=' and null terminator
425 k.reserve_exact(additional:v.len() + 2);
426 k.push("=");
427 k.push(&v);
428
429 // Add the new entry into the array
430 if let Ok(item: CString) = CString::new(k.into_vec()) {
431 result.push(item);
432 } else {
433 *saw_nul = true;
434 }
435 }
436
437 result
438}
439
440impl Stdio {
441 pub fn to_child_stdio(&self, readable: bool) -> io::Result<(ChildStdio, Option<AnonPipe>)> {
442 match *self {
443 Stdio::Inherit => Ok((ChildStdio::Inherit, None)),
444
445 // Make sure that the source descriptors are not an stdio
446 // descriptor, otherwise the order which we set the child's
447 // descriptors may blow away a descriptor which we are hoping to
448 // save. For example, suppose we want the child's stderr to be the
449 // parent's stdout, and the child's stdout to be the parent's
450 // stderr. No matter which we dup first, the second will get
451 // overwritten prematurely.
452 Stdio::Fd(ref fd) => {
453 if fd.as_raw_fd() >= 0 && fd.as_raw_fd() <= libc::STDERR_FILENO {
454 Ok((ChildStdio::Owned(fd.duplicate()?), None))
455 } else {
456 Ok((ChildStdio::Explicit(fd.as_raw_fd()), None))
457 }
458 }
459
460 Stdio::StaticFd(fd) => {
461 let fd = FileDesc::from_inner(fd.try_clone_to_owned()?);
462 Ok((ChildStdio::Owned(fd), None))
463 }
464
465 Stdio::MakePipe => {
466 let (reader, writer) = pipe::anon_pipe()?;
467 let (ours, theirs) = if readable { (writer, reader) } else { (reader, writer) };
468 Ok((ChildStdio::Owned(theirs.into_inner()), Some(ours)))
469 }
470
471 #[cfg(not(target_os = "fuchsia"))]
472 Stdio::Null => {
473 let mut opts = OpenOptions::new();
474 opts.read(readable);
475 opts.write(!readable);
476 let fd = File::open_c(DEV_NULL, &opts)?;
477 Ok((ChildStdio::Owned(fd.into_inner()), None))
478 }
479
480 #[cfg(target_os = "fuchsia")]
481 Stdio::Null => Ok((ChildStdio::Null, None)),
482 }
483 }
484}
485
486impl From<AnonPipe> for Stdio {
487 fn from(pipe: AnonPipe) -> Stdio {
488 Stdio::Fd(pipe.into_inner())
489 }
490}
491
492impl From<FileDesc> for Stdio {
493 fn from(fd: FileDesc) -> Stdio {
494 Stdio::Fd(fd)
495 }
496}
497
498impl From<File> for Stdio {
499 fn from(file: File) -> Stdio {
500 Stdio::Fd(file.into_inner())
501 }
502}
503
504impl From<io::Stdout> for Stdio {
505 fn from(_: io::Stdout) -> Stdio {
506 // This ought really to be is Stdio::StaticFd(input_argument.as_fd()).
507 // But AsFd::as_fd takes its argument by reference, and yields
508 // a bounded lifetime, so it's no use here. There is no AsStaticFd.
509 //
510 // Additionally AsFd is only implemented for the *locked* versions.
511 // We don't want to lock them here. (The implications of not locking
512 // are the same as those for process::Stdio::inherit().)
513 //
514 // Arguably the hypothetical AsStaticFd and AsFd<'static>
515 // should be implemented for io::Stdout, not just for StdoutLocked.
516 Stdio::StaticFd(unsafe { BorrowedFd::borrow_raw(fd:libc::STDOUT_FILENO) })
517 }
518}
519
520impl From<io::Stderr> for Stdio {
521 fn from(_: io::Stderr) -> Stdio {
522 Stdio::StaticFd(unsafe { BorrowedFd::borrow_raw(fd:libc::STDERR_FILENO) })
523 }
524}
525
526impl ChildStdio {
527 pub fn fd(&self) -> Option<c_int> {
528 match *self {
529 ChildStdio::Inherit => None,
530 ChildStdio::Explicit(fd: i32) => Some(fd),
531 ChildStdio::Owned(ref fd: &FileDesc) => Some(fd.as_raw_fd()),
532
533 #[cfg(target_os = "fuchsia")]
534 ChildStdio::Null => None,
535 }
536 }
537}
538
539impl fmt::Debug for Command {
540 // show all attributes but `self.closures` which does not implement `Debug`
541 // and `self.argv` which is not useful for debugging
542 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
543 if f.alternate() {
544 let mut debug_command = f.debug_struct("Command");
545 debug_command.field("program", &self.program).field("args", &self.args);
546 if !self.env.is_unchanged() {
547 debug_command.field("env", &self.env);
548 }
549
550 if self.cwd.is_some() {
551 debug_command.field("cwd", &self.cwd);
552 }
553 if self.uid.is_some() {
554 debug_command.field("uid", &self.uid);
555 }
556 if self.gid.is_some() {
557 debug_command.field("gid", &self.gid);
558 }
559
560 if self.groups.is_some() {
561 debug_command.field("groups", &self.groups);
562 }
563
564 if self.stdin.is_some() {
565 debug_command.field("stdin", &self.stdin);
566 }
567 if self.stdout.is_some() {
568 debug_command.field("stdout", &self.stdout);
569 }
570 if self.stderr.is_some() {
571 debug_command.field("stderr", &self.stderr);
572 }
573 if self.pgroup.is_some() {
574 debug_command.field("pgroup", &self.pgroup);
575 }
576
577 #[cfg(target_os = "linux")]
578 {
579 debug_command.field("create_pidfd", &self.create_pidfd);
580 }
581
582 debug_command.finish()
583 } else {
584 if let Some(ref cwd) = self.cwd {
585 write!(f, "cd {cwd:?} && ")?;
586 }
587 if self.env.does_clear() {
588 write!(f, "env -i ")?;
589 // Altered env vars will be printed next, that should exactly work as expected.
590 } else {
591 // Removed env vars need the command to be wrapped in `env`.
592 let mut any_removed = false;
593 for (key, value_opt) in self.get_envs() {
594 if value_opt.is_none() {
595 if !any_removed {
596 write!(f, "env ")?;
597 any_removed = true;
598 }
599 write!(f, "-u {} ", key.to_string_lossy())?;
600 }
601 }
602 }
603 // Altered env vars can just be added in front of the program.
604 for (key, value_opt) in self.get_envs() {
605 if let Some(value) = value_opt {
606 write!(f, "{}={value:?} ", key.to_string_lossy())?;
607 }
608 }
609 if self.program != self.args[0] {
610 write!(f, "[{:?}] ", self.program)?;
611 }
612 write!(f, "{:?}", self.args[0])?;
613
614 for arg in &self.args[1..] {
615 write!(f, " {:?}", arg)?;
616 }
617 Ok(())
618 }
619 }
620}
621
622#[derive(PartialEq, Eq, Clone, Copy)]
623pub struct ExitCode(u8);
624
625impl fmt::Debug for ExitCode {
626 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
627 f.debug_tuple(name:"unix_exit_status").field(&self.0).finish()
628 }
629}
630
631impl ExitCode {
632 pub const SUCCESS: ExitCode = ExitCode(EXIT_SUCCESS as _);
633 pub const FAILURE: ExitCode = ExitCode(EXIT_FAILURE as _);
634
635 #[inline]
636 pub fn as_i32(&self) -> i32 {
637 self.0 as i32
638 }
639}
640
641impl From<u8> for ExitCode {
642 fn from(code: u8) -> Self {
643 Self(code)
644 }
645}
646
647pub struct CommandArgs<'a> {
648 iter: crate::slice::Iter<'a, CString>,
649}
650
651impl<'a> Iterator for CommandArgs<'a> {
652 type Item = &'a OsStr;
653 fn next(&mut self) -> Option<&'a OsStr> {
654 self.iter.next().map(|cs: &'a CString| OsStr::from_bytes(slice:cs.as_bytes()))
655 }
656 fn size_hint(&self) -> (usize, Option<usize>) {
657 self.iter.size_hint()
658 }
659}
660
661impl<'a> ExactSizeIterator for CommandArgs<'a> {
662 fn len(&self) -> usize {
663 self.iter.len()
664 }
665 fn is_empty(&self) -> bool {
666 self.iter.is_empty()
667 }
668}
669
670impl<'a> fmt::Debug for CommandArgs<'a> {
671 fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
672 f.debug_list().entries(self.iter.clone()).finish()
673 }
674}
675