blob: 81ac829d21bc81164006a02f55a81a32b0ad35c7 [file] [log] [blame]
use crate::ffi::OsStr;
#[cfg(any(doc, target_os = "android", target_os = "linux"))]
use crate::os::net::linux_ext;
use crate::os::unix::ffi::OsStrExt;
use crate::path::Path;
use crate::sealed::Sealed;
use crate::sys::cvt;
use crate::{fmt, io, mem, ptr};
// FIXME(#43348): Make libc adapt #[doc(cfg(...))] so we don't need these fake definitions here?
#[cfg(not(unix))]
#[allow(non_camel_case_types)]
mod libc {
pub use libc::c_int;
pub type socklen_t = u32;
pub struct sockaddr;
#[derive(Clone)]
pub struct sockaddr_un;
}
fn sun_path_offset(addr: &libc::sockaddr_un) -> usize {
// Work with an actual instance of the type since using a null pointer is UB
let base = (addr as *const libc::sockaddr_un).addr();
let path = (&addr.sun_path as *const libc::c_char).addr();
path - base
}
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();
if bytes.contains(&0) {
return Err(io::const_io_error!(
io::ErrorKind::InvalidInput,
"paths must not contain interior null bytes",
));
}
if bytes.len() >= addr.sun_path.len() {
return Err(io::const_io_error!(
io::ErrorKind::InvalidInput,
"path must be shorter than SUN_LEN",
));
}
// 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) {
Some(&0) | None => {}
Some(_) => len += 1,
}
Ok((addr, len as libc::socklen_t))
}
enum AddressKind<'a> {
Unnamed,
Pathname(&'a Path),
Abstract(&'a [u8]),
}
/// An address associated with a Unix socket.
///
/// # Examples
///
/// ```
/// use std::os::unix::net::UnixListener;
///
/// let socket = match UnixListener::bind("/tmp/sock") {
/// Ok(sock) => sock,
/// Err(e) => {
/// println!("Couldn't bind: {e:?}");
/// return
/// }
/// };
/// let addr = socket.local_addr().expect("Couldn't get local address");
/// ```
#[derive(Clone)]
#[stable(feature = "unix_socket", since = "1.10.0")]
pub struct SocketAddr {
pub(super) addr: libc::sockaddr_un,
pub(super) len: libc::socklen_t,
}
impl SocketAddr {
pub(super) fn new<F>(f: F) -> io::Result<SocketAddr>
where
F: FnOnce(*mut libc::sockaddr, *mut libc::socklen_t) -> libc::c_int,
{
unsafe {
let mut addr: libc::sockaddr_un = mem::zeroed();
let mut len = mem::size_of::<libc::sockaddr_un>() as libc::socklen_t;
cvt(f(&mut addr as *mut _ as *mut _, &mut len))?;
SocketAddr::from_parts(addr, len)
}
}
pub(super) fn from_parts(
addr: libc::sockaddr_un,
mut len: libc::socklen_t,
) -> io::Result<SocketAddr> {
if len == 0 {
// When there is a datagram from unnamed unix socket
// linux returns zero bytes of address
len = sun_path_offset(&addr) as libc::socklen_t; // i.e., zero-length address
} else if addr.sun_family != libc::AF_UNIX as libc::sa_family_t {
return Err(io::const_io_error!(
io::ErrorKind::InvalidInput,
"file descriptor did not correspond to a Unix socket",
));
}
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
///
/// ```
/// use std::os::unix::net::SocketAddr;
/// use std::path::Path;
///
/// # fn main() -> std::io::Result<()> {
/// let address = SocketAddr::from_pathname("/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.
///
/// ```
/// use std::os::unix::net::SocketAddr;
///
/// assert!(SocketAddr::from_pathname("/path/with/\0/bytes").is_err());
/// ```
#[stable(feature = "unix_socket_creation", since = "1.61.0")]
pub fn from_pathname<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
///
/// A named address:
///
/// ```no_run
/// use std::os::unix::net::UnixListener;
///
/// fn main() -> std::io::Result<()> {
/// let socket = UnixListener::bind("/tmp/sock")?;
/// let addr = socket.local_addr().expect("Couldn't get local address");
/// assert_eq!(addr.is_unnamed(), false);
/// Ok(())
/// }
/// ```
///
/// An unnamed address:
///
/// ```
/// use std::os::unix::net::UnixDatagram;
///
/// fn main() -> std::io::Result<()> {
/// let socket = UnixDatagram::unbound()?;
/// let addr = socket.local_addr().expect("Couldn't get local address");
/// assert_eq!(addr.is_unnamed(), true);
/// Ok(())
/// }
/// ```
#[must_use]
#[stable(feature = "unix_socket", since = "1.10.0")]
pub fn is_unnamed(&self) -> bool {
matches!(self.address(), AddressKind::Unnamed)
}
/// Returns the contents of this address if it is a `pathname` address.
///
/// # Examples
///
/// With a pathname:
///
/// ```no_run
/// use std::os::unix::net::UnixListener;
/// use std::path::Path;
///
/// fn main() -> std::io::Result<()> {
/// let socket = UnixListener::bind("/tmp/sock")?;
/// let addr = socket.local_addr().expect("Couldn't get local address");
/// assert_eq!(addr.as_pathname(), Some(Path::new("/tmp/sock")));
/// Ok(())
/// }
/// ```
///
/// Without a pathname:
///
/// ```
/// use std::os::unix::net::UnixDatagram;
///
/// fn main() -> std::io::Result<()> {
/// let socket = UnixDatagram::unbound()?;
/// let addr = socket.local_addr().expect("Couldn't get local address");
/// assert_eq!(addr.as_pathname(), None);
/// Ok(())
/// }
/// ```
#[stable(feature = "unix_socket", since = "1.10.0")]
#[must_use]
pub fn as_pathname(&self) -> Option<&Path> {
if let AddressKind::Pathname(path) = self.address() { Some(path) } else { None }
}
fn address(&self) -> AddressKind<'_> {
let len = self.len as usize - sun_path_offset(&self.addr);
let path = unsafe { mem::transmute::<&[libc::c_char], &[u8]>(&self.addr.sun_path) };
// macOS seems to return a len of 16 and a zeroed sun_path for unnamed addresses
if len == 0
|| (cfg!(not(any(target_os = "linux", target_os = "android")))
&& self.addr.sun_path[0] == 0)
{
AddressKind::Unnamed
} else if self.addr.sun_path[0] == 0 {
AddressKind::Abstract(&path[1..len])
} else {
AddressKind::Pathname(OsStr::from_bytes(&path[..len - 1]).as_ref())
}
}
}
#[unstable(feature = "unix_socket_abstract", issue = "85410")]
impl Sealed for SocketAddr {}
#[doc(cfg(any(target_os = "android", target_os = "linux")))]
#[cfg(any(doc, target_os = "android", target_os = "linux"))]
#[unstable(feature = "unix_socket_abstract", issue = "85410")]
impl linux_ext::addr::SocketAddrExt for SocketAddr {
fn as_abstract_name(&self) -> Option<&[u8]> {
if let AddressKind::Abstract(name) = self.address() { Some(name) } else { None }
}
fn from_abstract_name<N>(name: &N) -> crate::io::Result<Self>
where
N: AsRef<[u8]>,
{
let name = name.as_ref();
unsafe {
let mut addr: libc::sockaddr_un = mem::zeroed();
addr.sun_family = libc::AF_UNIX as libc::sa_family_t;
if name.len() + 1 > addr.sun_path.len() {
return Err(io::const_io_error!(
io::ErrorKind::InvalidInput,
"abstract socket name must be shorter than SUN_LEN",
));
}
crate::ptr::copy_nonoverlapping(
name.as_ptr(),
addr.sun_path.as_mut_ptr().add(1) as *mut u8,
name.len(),
);
let len = (sun_path_offset(&addr) + 1 + name.len()) as libc::socklen_t;
SocketAddr::from_parts(addr, len)
}
}
}
#[stable(feature = "unix_socket", since = "1.10.0")]
impl fmt::Debug for SocketAddr {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
match self.address() {
AddressKind::Unnamed => write!(fmt, "(unnamed)"),
AddressKind::Abstract(name) => write!(fmt, "\"{}\" (abstract)", name.escape_ascii()),
AddressKind::Pathname(path) => write!(fmt, "{path:?} (pathname)"),
}
}
}