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Merged
merged 3 commits into from
Jul 4, 2025
Merged

Use OwnedFd/OwnedSocket in Socket #600

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f1c1847
Rename sys::Socket to RawSocket
Thomasdezeeuw Jul 4, 2025
3e24259
Use OwnedFd/OwnedSocket in Socket
Thomasdezeeuw Jul 4, 2025
9d775c5
Remove expected panic message from from_invalid_raw_fd_should_panic
Thomasdezeeuw Jul 4, 2025
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40 changes: 12 additions & 28 deletions src/socket.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -73,47 +73,31 @@ use crate::{MaybeUninitSlice, MsgHdr, RecvFlags};
/// # Ok(()) }
/// ```
pub struct Socket {
inner: Inner,
inner: sys::Socket,
}

/// Store a `TcpStream` internally to take advantage of its niche optimizations on Unix platforms.
pub(crate) type Inner = std::net::TcpStream;

impl Socket {
/// # Safety
///
/// The caller must ensure `raw` is a valid file descriptor/socket. NOTE:
/// this should really be marked `unsafe`, but this being an internal
/// function, often passed as mapping function, it's makes it very
/// inconvenient to mark it as `unsafe`.
pub(crate) fn from_raw(raw: sys::Socket) -> Socket {
pub(crate) fn from_raw(raw: sys::RawSocket) -> Socket {
Socket {
inner: unsafe {
// SAFETY: the caller must ensure that `raw` is a valid file
// descriptor, but when it isn't it could return I/O errors, or
// potentially close a fd it doesn't own. All of that isn't
// memory unsafe, so it's not desired but never memory unsafe or
// causes UB.
//
// However there is one exception. We use `TcpStream` to
// represent the `Socket` internally (see `Inner` type),
// `TcpStream` has a layout optimisation that doesn't allow for
// negative file descriptors (as those are always invalid).
// Violating this assumption (fd never negative) causes UB,
// something we don't want. So check for that we have this
// `assert!`.
#[cfg(unix)]
assert!(raw >= 0, "tried to create a `Socket` with an invalid fd");
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Looks like there is a test for this assertion.

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Updated the test with the error message from std lib, don't think there is value is checking it twice.

sys::socket_from_raw(raw)
},
}
}

pub(crate) fn as_raw(&self) -> sys::Socket {
// SAFETY: the caller must ensure that `raw` is a valid file
// descriptor, but when it isn't it could return I/O errors, or
// potentially close a fd it doesn't own. All of that isn't memory
// unsafe, so it's not desired but never memory unsafe or causes UB.
Comment on lines +90 to +91
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It's not immediate UB, but we consider it library UB because downstream effects can cause memory unsafety, e.g. by incorrectly touching mmap'ed fds.

https://doc.rust-lang.org/std/io/index.html#io-safety

inner: unsafe { sys::socket_from_raw(raw) },
}
}

pub(crate) fn as_raw(&self) -> sys::RawSocket {
sys::socket_as_raw(&self.inner)
}

pub(crate) fn into_raw(self) -> sys::Socket {
pub(crate) fn into_raw(self) -> sys::RawSocket {
sys::socket_into_raw(self.inner)
}

Expand Down
92 changes: 51 additions & 41 deletions src/sys/unix.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -859,35 +859,36 @@ impl SockAddr {
}
}

pub(crate) type Socket = c_int;
pub(crate) type Socket = std::os::fd::OwnedFd;
pub(crate) type RawSocket = c_int;

pub(crate) unsafe fn socket_from_raw(socket: Socket) -> crate::socket::Inner {
crate::socket::Inner::from_raw_fd(socket)
pub(crate) unsafe fn socket_from_raw(socket: RawSocket) -> Socket {
Socket::from_raw_fd(socket)
}

pub(crate) fn socket_as_raw(socket: &crate::socket::Inner) -> Socket {
pub(crate) fn socket_as_raw(socket: &Socket) -> RawSocket {
socket.as_raw_fd()
}

pub(crate) fn socket_into_raw(socket: crate::socket::Inner) -> Socket {
pub(crate) fn socket_into_raw(socket: Socket) -> RawSocket {
socket.into_raw_fd()
}

pub(crate) fn socket(family: c_int, ty: c_int, protocol: c_int) -> io::Result<Socket> {
pub(crate) fn socket(family: c_int, ty: c_int, protocol: c_int) -> io::Result<RawSocket> {
syscall!(socket(family, ty, protocol))
}

#[cfg(all(feature = "all", unix))]
pub(crate) fn socketpair(family: c_int, ty: c_int, protocol: c_int) -> io::Result<[Socket; 2]> {
pub(crate) fn socketpair(family: c_int, ty: c_int, protocol: c_int) -> io::Result<[RawSocket; 2]> {
let mut fds = [0, 0];
syscall!(socketpair(family, ty, protocol, fds.as_mut_ptr())).map(|_| fds)
}

pub(crate) fn bind(fd: Socket, addr: &SockAddr) -> io::Result<()> {
pub(crate) fn bind(fd: RawSocket, addr: &SockAddr) -> io::Result<()> {
syscall!(bind(fd, addr.as_ptr().cast::<sockaddr>(), addr.len() as _)).map(|_| ())
}

pub(crate) fn connect(fd: Socket, addr: &SockAddr) -> io::Result<()> {
pub(crate) fn connect(fd: RawSocket, addr: &SockAddr) -> io::Result<()> {
syscall!(connect(fd, addr.as_ptr().cast::<sockaddr>(), addr.len())).map(|_| ())
}

Expand Down Expand Up @@ -933,46 +934,46 @@ pub(crate) fn poll_connect(socket: &crate::Socket, timeout: Duration) -> io::Res
}
}

pub(crate) fn listen(fd: Socket, backlog: c_int) -> io::Result<()> {
pub(crate) fn listen(fd: RawSocket, backlog: c_int) -> io::Result<()> {
syscall!(listen(fd, backlog)).map(|_| ())
}

pub(crate) fn accept(fd: Socket) -> io::Result<(Socket, SockAddr)> {
pub(crate) fn accept(fd: RawSocket) -> io::Result<(RawSocket, SockAddr)> {
// Safety: `accept` initialises the `SockAddr` for us.
unsafe { SockAddr::try_init(|storage, len| syscall!(accept(fd, storage.cast(), len))) }
}

pub(crate) fn getsockname(fd: Socket) -> io::Result<SockAddr> {
pub(crate) fn getsockname(fd: RawSocket) -> io::Result<SockAddr> {
// Safety: `accept` initialises the `SockAddr` for us.
unsafe { SockAddr::try_init(|storage, len| syscall!(getsockname(fd, storage.cast(), len))) }
.map(|(_, addr)| addr)
}

pub(crate) fn getpeername(fd: Socket) -> io::Result<SockAddr> {
pub(crate) fn getpeername(fd: RawSocket) -> io::Result<SockAddr> {
// Safety: `accept` initialises the `SockAddr` for us.
unsafe { SockAddr::try_init(|storage, len| syscall!(getpeername(fd, storage.cast(), len))) }
.map(|(_, addr)| addr)
}

pub(crate) fn try_clone(fd: Socket) -> io::Result<Socket> {
pub(crate) fn try_clone(fd: RawSocket) -> io::Result<RawSocket> {
syscall!(fcntl(fd, libc::F_DUPFD_CLOEXEC, 0))
}

#[cfg(all(feature = "all", unix, not(target_os = "vita")))]
pub(crate) fn nonblocking(fd: Socket) -> io::Result<bool> {
pub(crate) fn nonblocking(fd: RawSocket) -> io::Result<bool> {
let file_status_flags = fcntl_get(fd, libc::F_GETFL)?;
Ok((file_status_flags & libc::O_NONBLOCK) != 0)
}

#[cfg(all(feature = "all", target_os = "vita"))]
pub(crate) fn nonblocking(fd: Socket) -> io::Result<bool> {
pub(crate) fn nonblocking(fd: RawSocket) -> io::Result<bool> {
unsafe {
getsockopt::<Bool>(fd, libc::SOL_SOCKET, libc::SO_NONBLOCK).map(|non_block| non_block != 0)
}
}

#[cfg(not(target_os = "vita"))]
pub(crate) fn set_nonblocking(fd: Socket, nonblocking: bool) -> io::Result<()> {
pub(crate) fn set_nonblocking(fd: RawSocket, nonblocking: bool) -> io::Result<()> {
if nonblocking {
fcntl_add(fd, libc::F_GETFL, libc::F_SETFL, libc::O_NONBLOCK)
} else {
Expand All @@ -981,7 +982,7 @@ pub(crate) fn set_nonblocking(fd: Socket, nonblocking: bool) -> io::Result<()> {
}

#[cfg(target_os = "vita")]
pub(crate) fn set_nonblocking(fd: Socket, nonblocking: bool) -> io::Result<()> {
pub(crate) fn set_nonblocking(fd: RawSocket, nonblocking: bool) -> io::Result<()> {
unsafe {
setsockopt(
fd,
Expand All @@ -992,7 +993,7 @@ pub(crate) fn set_nonblocking(fd: Socket, nonblocking: bool) -> io::Result<()> {
}
}

pub(crate) fn shutdown(fd: Socket, how: Shutdown) -> io::Result<()> {
pub(crate) fn shutdown(fd: RawSocket, how: Shutdown) -> io::Result<()> {
let how = match how {
Shutdown::Write => libc::SHUT_WR,
Shutdown::Read => libc::SHUT_RD,
Expand All @@ -1001,7 +1002,7 @@ pub(crate) fn shutdown(fd: Socket, how: Shutdown) -> io::Result<()> {
syscall!(shutdown(fd, how)).map(|_| ())
}

pub(crate) fn recv(fd: Socket, buf: &mut [MaybeUninit<u8>], flags: c_int) -> io::Result<usize> {
pub(crate) fn recv(fd: RawSocket, buf: &mut [MaybeUninit<u8>], flags: c_int) -> io::Result<usize> {
syscall!(recv(
fd,
buf.as_mut_ptr().cast(),
Expand All @@ -1012,7 +1013,7 @@ pub(crate) fn recv(fd: Socket, buf: &mut [MaybeUninit<u8>], flags: c_int) -> io:
}

pub(crate) fn recv_from(
fd: Socket,
fd: RawSocket,
buf: &mut [MaybeUninit<u8>],
flags: c_int,
) -> io::Result<(usize, SockAddr)> {
Expand All @@ -1032,7 +1033,7 @@ pub(crate) fn recv_from(
}
}

pub(crate) fn peek_sender(fd: Socket) -> io::Result<SockAddr> {
pub(crate) fn peek_sender(fd: RawSocket) -> io::Result<SockAddr> {
// Unix-like platforms simply truncate the returned data, so this implementation is trivial.
// However, for Windows this requires suppressing the `WSAEMSGSIZE` error,
// so that requires a different approach.
Expand All @@ -1043,7 +1044,7 @@ pub(crate) fn peek_sender(fd: Socket) -> io::Result<SockAddr> {

#[cfg(not(target_os = "redox"))]
pub(crate) fn recv_vectored(
fd: Socket,
fd: RawSocket,
bufs: &mut [crate::MaybeUninitSlice<'_>],
flags: c_int,
) -> io::Result<(usize, RecvFlags)> {
Expand All @@ -1054,7 +1055,7 @@ pub(crate) fn recv_vectored(

#[cfg(not(target_os = "redox"))]
pub(crate) fn recv_from_vectored(
fd: Socket,
fd: RawSocket,
bufs: &mut [crate::MaybeUninitSlice<'_>],
flags: c_int,
) -> io::Result<(usize, RecvFlags, SockAddr)> {
Expand All @@ -1076,14 +1077,14 @@ pub(crate) fn recv_from_vectored(

#[cfg(not(target_os = "redox"))]
pub(crate) fn recvmsg(
fd: Socket,
fd: RawSocket,
msg: &mut MsgHdrMut<'_, '_, '_>,
flags: c_int,
) -> io::Result<usize> {
syscall!(recvmsg(fd, &mut msg.inner, flags)).map(|n| n as usize)
}

pub(crate) fn send(fd: Socket, buf: &[u8], flags: c_int) -> io::Result<usize> {
pub(crate) fn send(fd: RawSocket, buf: &[u8], flags: c_int) -> io::Result<usize> {
syscall!(send(
fd,
buf.as_ptr().cast(),
Expand All @@ -1094,12 +1095,21 @@ pub(crate) fn send(fd: Socket, buf: &[u8], flags: c_int) -> io::Result<usize> {
}

#[cfg(not(target_os = "redox"))]
pub(crate) fn send_vectored(fd: Socket, bufs: &[IoSlice<'_>], flags: c_int) -> io::Result<usize> {
pub(crate) fn send_vectored(
fd: RawSocket,
bufs: &[IoSlice<'_>],
flags: c_int,
) -> io::Result<usize> {
let msg = MsgHdr::new().with_buffers(bufs);
sendmsg(fd, &msg, flags)
}

pub(crate) fn send_to(fd: Socket, buf: &[u8], addr: &SockAddr, flags: c_int) -> io::Result<usize> {
pub(crate) fn send_to(
fd: RawSocket,
buf: &[u8],
addr: &SockAddr,
flags: c_int,
) -> io::Result<usize> {
syscall!(sendto(
fd,
buf.as_ptr().cast(),
Expand All @@ -1113,7 +1123,7 @@ pub(crate) fn send_to(fd: Socket, buf: &[u8], addr: &SockAddr, flags: c_int) ->

#[cfg(not(target_os = "redox"))]
pub(crate) fn send_to_vectored(
fd: Socket,
fd: RawSocket,
bufs: &[IoSlice<'_>],
addr: &SockAddr,
flags: c_int,
Expand All @@ -1123,12 +1133,12 @@ pub(crate) fn send_to_vectored(
}

#[cfg(not(target_os = "redox"))]
pub(crate) fn sendmsg(fd: Socket, msg: &MsgHdr<'_, '_, '_>, flags: c_int) -> io::Result<usize> {
pub(crate) fn sendmsg(fd: RawSocket, msg: &MsgHdr<'_, '_, '_>, flags: c_int) -> io::Result<usize> {
syscall!(sendmsg(fd, &msg.inner, flags)).map(|n| n as usize)
}

/// Wrapper around `getsockopt` to deal with platform specific timeouts.
pub(crate) fn timeout_opt(fd: Socket, opt: c_int, val: c_int) -> io::Result<Option<Duration>> {
pub(crate) fn timeout_opt(fd: RawSocket, opt: c_int, val: c_int) -> io::Result<Option<Duration>> {
unsafe { getsockopt(fd, opt, val).map(from_timeval) }
}

Expand All @@ -1144,7 +1154,7 @@ const fn from_timeval(duration: libc::timeval) -> Option<Duration> {

/// Wrapper around `setsockopt` to deal with platform specific timeouts.
pub(crate) fn set_timeout_opt(
fd: Socket,
fd: RawSocket,
opt: c_int,
val: c_int,
duration: Option<Duration>,
Expand Down Expand Up @@ -1172,15 +1182,15 @@ fn into_timeval(duration: Option<Duration>) -> libc::timeval {
feature = "all",
not(any(target_os = "haiku", target_os = "openbsd", target_os = "vita"))
))]
pub(crate) fn tcp_keepalive_time(fd: Socket) -> io::Result<Duration> {
pub(crate) fn tcp_keepalive_time(fd: RawSocket) -> io::Result<Duration> {
unsafe {
getsockopt::<c_int>(fd, IPPROTO_TCP, KEEPALIVE_TIME)
.map(|secs| Duration::from_secs(secs as u64))
}
}

#[allow(unused_variables)]
pub(crate) fn set_tcp_keepalive(fd: Socket, keepalive: &TcpKeepalive) -> io::Result<()> {
pub(crate) fn set_tcp_keepalive(fd: RawSocket, keepalive: &TcpKeepalive) -> io::Result<()> {
#[cfg(not(any(
target_os = "haiku",
target_os = "openbsd",
Expand Down Expand Up @@ -1241,13 +1251,13 @@ fn into_secs(duration: Duration) -> c_int {

/// Get the flags using `cmd`.
#[cfg(not(target_os = "vita"))]
fn fcntl_get(fd: Socket, cmd: c_int) -> io::Result<c_int> {
fn fcntl_get(fd: RawSocket, cmd: c_int) -> io::Result<c_int> {
syscall!(fcntl(fd, cmd))
}

/// Add `flag` to the current set flags of `F_GETFD`.
#[cfg(not(target_os = "vita"))]
fn fcntl_add(fd: Socket, get_cmd: c_int, set_cmd: c_int, flag: c_int) -> io::Result<()> {
fn fcntl_add(fd: RawSocket, get_cmd: c_int, set_cmd: c_int, flag: c_int) -> io::Result<()> {
let previous = fcntl_get(fd, get_cmd)?;
let new = previous | flag;
if new != previous {
Expand All @@ -1260,7 +1270,7 @@ fn fcntl_add(fd: Socket, get_cmd: c_int, set_cmd: c_int, flag: c_int) -> io::Res

/// Remove `flag` to the current set flags of `F_GETFD`.
#[cfg(not(target_os = "vita"))]
fn fcntl_remove(fd: Socket, get_cmd: c_int, set_cmd: c_int, flag: c_int) -> io::Result<()> {
fn fcntl_remove(fd: RawSocket, get_cmd: c_int, set_cmd: c_int, flag: c_int) -> io::Result<()> {
let previous = fcntl_get(fd, get_cmd)?;
let new = previous & !flag;
if new != previous {
Expand All @@ -1272,7 +1282,7 @@ fn fcntl_remove(fd: Socket, get_cmd: c_int, set_cmd: c_int, flag: c_int) -> io::
}

/// Caller must ensure `T` is the correct type for `opt` and `val`.
pub(crate) unsafe fn getsockopt<T>(fd: Socket, opt: c_int, val: c_int) -> io::Result<T> {
pub(crate) unsafe fn getsockopt<T>(fd: RawSocket, opt: c_int, val: c_int) -> io::Result<T> {
let mut payload: MaybeUninit<T> = MaybeUninit::uninit();
let mut len = size_of::<T>() as libc::socklen_t;
syscall!(getsockopt(
Expand All @@ -1291,7 +1301,7 @@ pub(crate) unsafe fn getsockopt<T>(fd: Socket, opt: c_int, val: c_int) -> io::Re

/// Caller must ensure `T` is the correct type for `opt` and `val`.
pub(crate) unsafe fn setsockopt<T>(
fd: Socket,
fd: RawSocket,
opt: c_int,
val: c_int,
payload: T,
Expand Down Expand Up @@ -1365,7 +1375,7 @@ pub(crate) const fn to_mreqn(
feature = "all",
any(target_os = "android", target_os = "fuchsia", target_os = "linux")
))]
pub(crate) fn original_dst_v4(fd: Socket) -> io::Result<SockAddr> {
pub(crate) fn original_dst_v4(fd: RawSocket) -> io::Result<SockAddr> {
// Safety: `getsockopt` initialises the `SockAddr` for us.
unsafe {
SockAddr::try_init(|storage, len| {
Expand All @@ -1386,7 +1396,7 @@ pub(crate) fn original_dst_v4(fd: Socket) -> io::Result<SockAddr> {
/// This value contains the original destination IPv6 address of the connection
/// redirected using `ip6tables` `REDIRECT` or `TPROXY`.
#[cfg(all(feature = "all", any(target_os = "android", target_os = "linux")))]
pub(crate) fn original_dst_v6(fd: Socket) -> io::Result<SockAddr> {
pub(crate) fn original_dst_v6(fd: RawSocket) -> io::Result<SockAddr> {
// Safety: `getsockopt` initialises the `SockAddr` for us.
unsafe {
SockAddr::try_init(|storage, len| {
Expand Down
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