Rollup merge of #93239 - Thomasdezeeuw:socketaddr_creation, r=m-ou-se

Add os::unix::net::SocketAddr::from_path

Creates a new SocketAddr from a path, supports both regular paths and
abstract namespaces.

Note that `SocketAddr::from_abstract_namespace` could be removed after this as `SocketAddr::unix` also supports abstract namespaces.

Updates #65275
Unblocks https://github.com/tokio-rs/mio/issues/1527

r? `@m-ou-se`
This commit is contained in:
Matthias Krüger 2022-01-28 15:20:23 +01:00 committed by GitHub
commit 18c8d0da64
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@ -2,7 +2,7 @@ use crate::ffi::OsStr;
use crate::os::unix::ffi::OsStrExt;
use crate::path::Path;
use crate::sys::cvt;
use crate::{ascii, fmt, io, iter, mem};
use crate::{ascii, fmt, io, mem, ptr};
// FIXME(#43348): Make libc adapt #[doc(cfg(...))] so we don't need these fake definitions here?
#[cfg(not(unix))]
@ -22,8 +22,9 @@ fn sun_path_offset(addr: &libc::sockaddr_un) -> usize {
path - base
}
pub(super) unsafe fn sockaddr_un(path: &Path) -> io::Result<(libc::sockaddr_un, libc::socklen_t)> {
let mut addr: libc::sockaddr_un = mem::zeroed();
pub(super) fn sockaddr_un(path: &Path) -> io::Result<(libc::sockaddr_un, libc::socklen_t)> {
// SAFETY: All zeros is a valid representation for `sockaddr_un`.
let mut addr: libc::sockaddr_un = unsafe { mem::zeroed() };
addr.sun_family = libc::AF_UNIX as libc::sa_family_t;
let bytes = path.as_os_str().as_bytes();
@ -41,11 +42,13 @@ pub(super) unsafe fn sockaddr_un(path: &Path) -> io::Result<(libc::sockaddr_un,
&"path must be shorter than SUN_LEN",
));
}
for (dst, src) in iter::zip(&mut addr.sun_path, bytes) {
*dst = *src as libc::c_char;
}
// null byte for pathname addresses is already there because we zeroed the
// struct
// SAFETY: `bytes` and `addr.sun_path` are not overlapping and
// both point to valid memory.
// NOTE: We zeroed the memory above, so the path is already null
// terminated.
unsafe {
ptr::copy_nonoverlapping(bytes.as_ptr(), addr.sun_path.as_mut_ptr().cast(), bytes.len())
};
let mut len = sun_path_offset(&addr) + bytes.len();
match bytes.get(0) {
@ -127,6 +130,43 @@ impl SocketAddr {
Ok(SocketAddr { addr, len })
}
/// Constructs a `SockAddr` with the family `AF_UNIX` and the provided path.
///
/// # Errors
///
/// Returns an error if the path is longer than `SUN_LEN` or if it contains
/// NULL bytes.
///
/// # Examples
///
/// ```
/// #![feature(unix_socket_creation)]
/// use std::os::unix::net::SocketAddr;
/// use std::path::Path;
///
/// # fn main() -> std::io::Result<()> {
/// let address = SocketAddr::from_path("/path/to/socket")?;
/// assert_eq!(address.as_pathname(), Some(Path::new("/path/to/socket")));
/// # Ok(())
/// # }
/// ```
///
/// Creating a `SocketAddr` with a NULL byte results in an error.
///
/// ```
/// #![feature(unix_socket_creation)]
/// use std::os::unix::net::SocketAddr;
///
/// assert!(SocketAddr::from_path("/path/with/\0/bytes").is_err());
/// ```
#[unstable(feature = "unix_socket_creation", issue = "93423")]
pub fn from_path<P>(path: P) -> io::Result<SocketAddr>
where
P: AsRef<Path>,
{
sockaddr_un(path.as_ref()).map(|(addr, len)| SocketAddr { addr, len })
}
/// Returns `true` if the address is unnamed.
///
/// # Examples