mio/sys/unix/uds/
listener.rs

1use std::ffi::OsStr;
2use std::os::fd::{AsRawFd, FromRawFd};
3use std::os::unix::ffi::OsStrExt;
4use std::os::unix::net::{self, SocketAddr};
5use std::path::Path;
6use std::{io, mem};
7
8use crate::net::UnixStream;
9use crate::sys::unix::net::new_socket;
10use crate::sys::unix::uds::{path_offset, unix_addr};
11
12pub(crate) fn bind_addr(address: &SocketAddr) -> io::Result<net::UnixListener> {
13    let fd = new_socket(libc::AF_UNIX, libc::SOCK_STREAM)?;
14    let socket = unsafe { net::UnixListener::from_raw_fd(fd) };
15
16    let (unix_address, addrlen) = unix_addr(address);
17    let sockaddr = &unix_address as *const libc::sockaddr_un as *const libc::sockaddr;
18    syscall!(bind(fd, sockaddr, addrlen))?;
19    // Use the same backlog value as the standard libary.
20    // <https://github.com/rust-lang/rust/blob/0028f344ce9f64766259577c998a1959ca1f6a0b/library/std/src/os/unix/net/listener.rs#L75-L106>
21
22    #[cfg(any(
23        target_os = "windows",
24        target_os = "redox",
25        target_os = "espidf",
26        target_os = "horizon"
27    ))]
28    let backlog = 128;
29    #[cfg(any(
30        target_os = "linux",
31        target_os = "freebsd",
32        target_os = "openbsd",
33        target_vendor = "apple"
34    ))]
35    let backlog = -1;
36    #[cfg(not(any(
37        target_os = "linux",
38        target_os = "freebsd",
39        target_os = "openbsd",
40        target_vendor = "apple",
41        target_os = "windows",
42        target_os = "redox",
43        target_os = "espidf",
44        target_os = "horizon"
45    )))]
46    let backlog = libc::SOMAXCONN;
47
48    syscall!(listen(fd, backlog))?;
49
50    Ok(socket)
51}
52
53pub(crate) fn accept(listener: &net::UnixListener) -> io::Result<(UnixStream, SocketAddr)> {
54    // SAFETY: `libc::sockaddr_un` zero filled is properly initialized.
55    //
56    // `0` is a valid value for `sockaddr_un::sun_family`; it is
57    // `libc::AF_UNSPEC`.
58    //
59    // `[0; 108]` is a valid value for `sockaddr_un::sun_path`; it begins an
60    // abstract path.
61    let mut sockaddr = unsafe { mem::zeroed::<libc::sockaddr_un>() };
62
63    let mut socklen = mem::size_of_val(&sockaddr) as libc::socklen_t;
64
65    #[cfg(not(any(
66        target_os = "aix",
67        target_os = "haiku",
68        target_os = "ios",
69        target_os = "macos",
70        target_os = "netbsd",
71        target_os = "redox",
72        target_os = "tvos",
73        target_os = "visionos",
74        target_os = "watchos",
75        target_os = "espidf",
76        target_os = "vita",
77        target_os = "nto",
78        target_os = "horizon",
79        // Android x86's seccomp profile forbids calls to `accept4(2)`
80        // See https://github.com/tokio-rs/mio/issues/1445 for details
81        all(target_arch = "x86", target_os = "android"),
82    )))]
83    let socket = {
84        let flags = libc::SOCK_NONBLOCK | libc::SOCK_CLOEXEC;
85        syscall!(accept4(
86            listener.as_raw_fd(),
87            &mut sockaddr as *mut libc::sockaddr_un as *mut libc::sockaddr,
88            &mut socklen,
89            flags
90        ))
91        .map(|socket| unsafe { net::UnixStream::from_raw_fd(socket) })
92    };
93
94    #[cfg(any(
95        target_os = "aix",
96        target_os = "haiku",
97        target_os = "ios",
98        target_os = "macos",
99        target_os = "netbsd",
100        target_os = "redox",
101        target_os = "tvos",
102        target_os = "visionos",
103        target_os = "watchos",
104        target_os = "espidf",
105        target_os = "vita",
106        target_os = "nto",
107        target_os = "horizon",
108        all(target_arch = "x86", target_os = "android")
109    ))]
110    let socket = syscall!(accept(
111        listener.as_raw_fd(),
112        &mut sockaddr as *mut libc::sockaddr_un as *mut libc::sockaddr,
113        &mut socklen,
114    ))
115    .and_then(|socket| {
116        // Ensure the socket is closed if either of the `fcntl` calls
117        // error below.
118        let s = unsafe { net::UnixStream::from_raw_fd(socket) };
119        #[cfg(not(any(target_os = "espidf", target_os = "vita")))]
120        syscall!(fcntl(socket, libc::F_SETFD, libc::FD_CLOEXEC))?;
121
122        // See https://github.com/tokio-rs/mio/issues/1450
123        #[cfg(any(
124            all(target_arch = "x86", target_os = "android"),
125            target_os = "espidf",
126            target_os = "vita",
127            target_os = "nto",
128        ))]
129        syscall!(fcntl(socket, libc::F_SETFL, libc::O_NONBLOCK))?;
130
131        Ok(s)
132    });
133
134    let socket = socket.map(UnixStream::from_std)?;
135
136    #[allow(unused_mut)] // See below.
137    let mut path_len = socklen as usize - path_offset(&sockaddr);
138    // On FreeBSD and Darwin, it returns a length of 14/16, but an unnamed (all
139    // zero) address. Map that to a length of 0 to match other OS.
140    if sockaddr.sun_path[0] == 0 {
141        path_len = 0;
142    }
143    // SAFETY: going from i8 to u8 is fine in this context.
144    let mut path =
145        unsafe { &*(&sockaddr.sun_path[..path_len] as *const [libc::c_char] as *const [u8]) };
146    // Remove last null as `SocketAddr::from_pathname` doesn't accept it.
147    if let Some(0) = path.last() {
148        path = &path[..path.len() - 1];
149    }
150    let address = SocketAddr::from_pathname(Path::new(OsStr::from_bytes(path)))?;
151    Ok((socket, address))
152}
mio/sys/unix/uds/listener.rs

mio/sys/unix/uds/
listener.rs
