1use crate::PipeReader;
2use crate::PipeWriter;
3use libc::c_int;
4use std::fs::File;
5use std::io;
6use std::os::unix::prelude::*;
7
8// We need to atomically create pipes and set the CLOEXEC flag on them. This is
9// done with the pipe2() API. However, macOS doesn't support pipe2. There, all
10// we can do is call pipe() followed by fcntl(), and hope that no other threads
11// fork() in between. The following code is copied from the nix crate, where it
12// works but is deprecated.
13#[cfg(not(any(
14 target_os = "aix",
15 target_os = "ios",
16 target_os = "visionos",
17 target_os = "macos",
18 target_os = "haiku"
19)))]
20fn pipe2_cloexec() -> io::Result<(OwnedFd, OwnedFd)> {
21 let mut fds: [c_int; 2] = [0; 2];
22 let res: i32 = unsafe { libc::pipe2(fds.as_mut_ptr(), flags:libc::O_CLOEXEC) };
23 if res != 0 {
24 return Err(io::Error::last_os_error());
25 }
26 unsafe { Ok((OwnedFd::from_raw_fd(fds[0]), OwnedFd::from_raw_fd(fds[1]))) }
27}
28
29#[cfg(any(
30 target_os = "aix",
31 target_os = "ios",
32 target_os = "visionos",
33 target_os = "macos",
34 target_os = "haiku"
35))]
36fn pipe2_cloexec() -> io::Result<(OwnedFd, OwnedFd)> {
37 let mut fds: [c_int; 2] = [0; 2];
38 let res = unsafe { libc::pipe(fds.as_mut_ptr()) };
39 if res != 0 {
40 return Err(io::Error::last_os_error());
41 }
42 // Wrap the fds immediately, so that we'll drop them and close them in the unlikely event that
43 // any of the following fcntls fails.
44 let owned_fds = unsafe { (OwnedFd::from_raw_fd(fds[0]), OwnedFd::from_raw_fd(fds[1])) };
45 let res = unsafe { libc::fcntl(fds[0], libc::F_SETFD, libc::FD_CLOEXEC) };
46 if res != 0 {
47 return Err(io::Error::last_os_error());
48 }
49 let res = unsafe { libc::fcntl(fds[1], libc::F_SETFD, libc::FD_CLOEXEC) };
50 if res != 0 {
51 return Err(io::Error::last_os_error());
52 }
53 Ok(owned_fds)
54}
55
56pub(crate) fn pipe() -> io::Result<(PipeReader, PipeWriter)> {
57 let (read_fd: OwnedFd, write_fd: OwnedFd) = pipe2_cloexec()?;
58 Ok((read_fd.into(), write_fd.into()))
59}
60
61pub(crate) fn dup(handle: impl AsFd) -> io::Result<OwnedFd> {
62 handle.as_fd().try_clone_to_owned()
63}
64
65impl IntoRawFd for PipeReader {
66 fn into_raw_fd(self) -> RawFd {
67 self.0.into_raw_fd()
68 }
69}
70
71impl AsRawFd for PipeReader {
72 fn as_raw_fd(&self) -> RawFd {
73 self.0.as_raw_fd()
74 }
75}
76
77impl FromRawFd for PipeReader {
78 unsafe fn from_raw_fd(fd: RawFd) -> PipeReader {
79 PipeReader(File::from_raw_fd(fd))
80 }
81}
82
83impl From<PipeReader> for OwnedFd {
84 fn from(pr: PipeReader) -> Self {
85 pr.0.into()
86 }
87}
88
89impl AsFd for PipeReader {
90 fn as_fd(&self) -> BorrowedFd<'_> {
91 self.0.as_fd()
92 }
93}
94
95impl From<OwnedFd> for PipeReader {
96 fn from(fd: OwnedFd) -> Self {
97 PipeReader(fd.into())
98 }
99}
100
101impl IntoRawFd for PipeWriter {
102 fn into_raw_fd(self) -> RawFd {
103 self.0.into_raw_fd()
104 }
105}
106
107impl AsRawFd for PipeWriter {
108 fn as_raw_fd(&self) -> RawFd {
109 self.0.as_raw_fd()
110 }
111}
112
113impl FromRawFd for PipeWriter {
114 unsafe fn from_raw_fd(fd: RawFd) -> PipeWriter {
115 PipeWriter(File::from_raw_fd(fd))
116 }
117}
118
119impl From<PipeWriter> for OwnedFd {
120 fn from(pw: PipeWriter) -> Self {
121 pw.0.into()
122 }
123}
124
125impl AsFd for PipeWriter {
126 fn as_fd(&self) -> BorrowedFd<'_> {
127 self.0.as_fd()
128 }
129}
130
131impl From<OwnedFd> for PipeWriter {
132 fn from(fd: OwnedFd) -> Self {
133 PipeWriter(fd.into())
134 }
135}
136