1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
|
use crate::error::*;
use std::os::unix::io::{AsRawFd as _, FromRawFd as _};
use std::os::unix::process::CommandExt as _;
pub trait Command {
fn spawn_pty(&mut self, size: Option<&crate::pty::Size>)
-> Result<Child>;
}
impl Command for std::process::Command {
fn spawn_pty(
&mut self,
size: Option<&crate::pty::Size>,
) -> Result<Child> {
let pty = crate::pty::Pty::new()?;
if let Some(size) = size {
pty.resize(size)?;
}
let pts = pty.pts()?;
let pt_fd = pty.pt().as_raw_fd();
let pts_fd = pts.as_raw_fd();
let stdin = nix::unistd::dup(pts_fd).map_err(Error::SpawnNix)?;
let stdout = nix::unistd::dup(pts_fd).map_err(Error::SpawnNix)?;
let stderr = nix::unistd::dup(pts_fd).map_err(Error::SpawnNix)?;
// safe because the fds are valid (otherwise pty.pts() or dup() would
// have returned an Err and we would have exited early) and are not
// owned by any other structure (since dup() returns a fresh copy of
// the file descriptor), allowing from_raw_fd to take ownership of it.
self.stdin(unsafe { std::process::Stdio::from_raw_fd(stdin) })
.stdout(unsafe { std::process::Stdio::from_raw_fd(stdout) })
.stderr(unsafe { std::process::Stdio::from_raw_fd(stderr) });
// safe because setsid() and close() are async-signal-safe functions
// and ioctl() is a raw syscall (which is inherently
// async-signal-safe).
unsafe {
self.pre_exec(move || {
nix::unistd::setsid().map_err(|e| e.as_errno().unwrap())?;
set_controlling_terminal(&pts)
.map_err(|e| e.as_errno().unwrap())?;
// in the parent, destructors will handle closing these file
// descriptors (other than pt, used by the parent to
// communicate with the child) when the function ends, but in
// the child, we end by calling exec(), which doesn't call
// destructors.
// XXX unwrap
nix::unistd::close(pt_fd)
.map_err(|e| e.as_errno().unwrap())?;
nix::unistd::close(pts_fd)
.map_err(|e| e.as_errno().unwrap())?;
// at this point, stdin/stdout/stderr have already been
// reopened as fds 0/1/2 in the child, so we can (and should)
// close the originals
nix::unistd::close(stdin)
.map_err(|e| e.as_errno().unwrap())?;
nix::unistd::close(stdout)
.map_err(|e| e.as_errno().unwrap())?;
nix::unistd::close(stderr)
.map_err(|e| e.as_errno().unwrap())?;
Ok(())
});
}
let child = self.spawn().map_err(Error::Spawn)?;
Ok(Child { child, pty })
}
}
pub struct Child {
child: std::process::Child,
pty: crate::pty::Pty,
}
impl Child {
pub fn pty(&self) -> &std::fs::File {
self.pty.pt()
}
pub fn pty_resize(&self, size: &crate::pty::Size) -> Result<()> {
self.pty.resize(size)
}
}
impl std::ops::Deref for Child {
type Target = std::process::Child;
fn deref(&self) -> &Self::Target {
&self.child
}
}
impl std::ops::DerefMut for Child {
fn deref_mut(&mut self) -> &mut Self::Target {
&mut self.child
}
}
nix::ioctl_write_ptr_bad!(
set_controlling_terminal_unsafe,
libc::TIOCSCTTY,
libc::c_int
);
fn set_controlling_terminal(fh: &std::fs::File) -> nix::Result<()> {
// safe because std::fs::File is required to contain a valid file
// descriptor
unsafe {
set_controlling_terminal_unsafe(fh.as_raw_fd(), std::ptr::null())
}
.map(|_| ())
}
|
