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