Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

111 files changed, 16143 insertions, 0 deletions

diff --git a/library/std/src/os/android/fs.rs b/library/std/src/os/android/fs.rs
new file mode 100644
index 000000000..1beb3cf6e
--- /dev/null
+++ b/library/std/src/os/android/fs.rs
@@ -0,0 +1,117 @@
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+#[allow(deprecated)]
+use crate::os::android::raw;
+
+/// OS-specific extensions to [`fs::Metadata`].
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    /// Gain a reference to the underlying `stat` structure which contains
+    /// the raw information returned by the OS.
+    ///
+    /// The contents of the returned `stat` are **not** consistent across
+    /// Unix platforms. The `os::unix::fs::MetadataExt` trait contains the
+    /// cross-Unix abstractions contained within the raw stat.
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    #[deprecated(
+        since = "1.8.0",
+        note = "deprecated in favor of the accessor \
+                methods of this trait"
+    )]
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat;
+
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat {
+        unsafe { &*(self.as_inner().as_inner() as *const libc::stat as *const raw::stat) }
+    }
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        self.as_inner().as_inner().st_atime as i64
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_atime_nsec as i64
+    }
+    fn st_mtime(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime as i64
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime_nsec as i64
+    }
+    fn st_ctime(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime as i64
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime_nsec as i64
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+}
diff --git a/library/std/src/os/android/mod.rs b/library/std/src/os/android/mod.rs
new file mode 100644
index 000000000..dbb0127f3
--- /dev/null
+++ b/library/std/src/os/android/mod.rs
@@ -0,0 +1,6 @@
+//! Android-specific definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+pub mod fs;
+pub mod raw;
diff --git a/library/std/src/os/android/raw.rs b/library/std/src/os/android/raw.rs
new file mode 100644
index 000000000..a255d0320
--- /dev/null
+++ b/library/std/src/os/android/raw.rs
@@ -0,0 +1,219 @@
+//! Android-specific raw type definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.8.0",
+    note = "these type aliases are no longer supported by \
+            the standard library, the `libc` crate on \
+            crates.io should be used instead for the correct \
+            definitions"
+)]
+#![allow(deprecated)]
+
+use crate::os::raw::c_long;
+
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = c_long;
+
+#[doc(inline)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub use self::arch::{blkcnt_t, blksize_t, dev_t, ino_t, mode_t, nlink_t, off_t, stat, time_t};
+
+#[cfg(any(target_arch = "arm", target_arch = "x86"))]
+mod arch {
+    use crate::os::raw::{c_longlong, c_uchar, c_uint, c_ulong, c_ulonglong};
+    use crate::os::unix::raw::{gid_t, uid_t};
+
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type dev_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type mode_t = u32;
+
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blksize_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type nlink_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type time_t = i64;
+
+    #[repr(C)]
+    #[derive(Clone)]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub struct stat {
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_dev: c_ulonglong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad0: [c_uchar; 4],
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __st_ino: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mode: c_uint,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_nlink: c_uint,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_uid: uid_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_gid: gid_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_rdev: c_ulonglong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad3: [c_uchar; 4],
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_size: c_longlong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blksize: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blocks: c_ulonglong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime_nsec: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime_nsec: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime_nsec: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ino: c_ulonglong,
+    }
+}
+
+#[cfg(target_arch = "aarch64")]
+mod arch {
+    use crate::os::raw::{c_uchar, c_ulong};
+    use crate::os::unix::raw::{gid_t, uid_t};
+
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type dev_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type mode_t = u32;
+
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blksize_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type nlink_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type time_t = i64;
+
+    #[repr(C)]
+    #[derive(Clone)]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub struct stat {
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_dev: dev_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad0: [c_uchar; 4],
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __st_ino: ino_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mode: mode_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_nlink: nlink_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_uid: uid_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_gid: gid_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_rdev: dev_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad3: [c_uchar; 4],
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_size: off_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blksize: blksize_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blocks: blkcnt_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime: time_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime_nsec: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime: time_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime_nsec: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime: time_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime_nsec: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ino: ino_t,
+    }
+}
+
+#[cfg(target_arch = "x86_64")]
+mod arch {
+    use crate::os::raw::{c_long, c_uint, c_ulong};
+    use crate::os::unix::raw::{gid_t, uid_t};
+
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type dev_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type mode_t = u32;
+
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blksize_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type nlink_t = u32;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type time_t = i64;
+
+    #[repr(C)]
+    #[derive(Clone)]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub struct stat {
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_dev: dev_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ino: ino_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_nlink: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mode: c_uint,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_uid: uid_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_gid: gid_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_rdev: dev_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_size: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blksize: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blocks: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime_nsec: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime_nsec: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime_nsec: c_ulong,
+        __unused: [c_long; 3],
+    }
+}
diff --git a/library/std/src/os/dragonfly/fs.rs b/library/std/src/os/dragonfly/fs.rs
new file mode 100644
index 000000000..1424fc4c6
--- /dev/null
+++ b/library/std/src/os/dragonfly/fs.rs
@@ -0,0 +1,132 @@
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+#[allow(deprecated)]
+use crate::os::dragonfly::raw;
+
+/// OS-specific extensions to [`fs::Metadata`].
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    /// Gain a reference to the underlying `stat` structure which contains
+    /// the raw information returned by the OS.
+    ///
+    /// The contents of the returned `stat` are **not** consistent across
+    /// Unix platforms. The `os::unix::fs::MetadataExt` trait contains the
+    /// cross-Unix abstractions contained within the raw stat.
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    #[deprecated(
+        since = "1.8.0",
+        note = "deprecated in favor of the accessor \
+                methods of this trait"
+    )]
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat;
+
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_flags(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gen(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_lspare(&self) -> u32;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat {
+        unsafe { &*(self.as_inner().as_inner() as *const libc::stat as *const raw::stat) }
+    }
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        self.as_inner().as_inner().st_atime as i64
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_atime_nsec as i64
+    }
+    fn st_mtime(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime as i64
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime_nsec as i64
+    }
+    fn st_ctime(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime as i64
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime_nsec as i64
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+    fn st_gen(&self) -> u32 {
+        self.as_inner().as_inner().st_gen as u32
+    }
+    fn st_flags(&self) -> u32 {
+        self.as_inner().as_inner().st_flags as u32
+    }
+    fn st_lspare(&self) -> u32 {
+        self.as_inner().as_inner().st_lspare as u32
+    }
+}
diff --git a/library/std/src/os/dragonfly/mod.rs b/library/std/src/os/dragonfly/mod.rs
new file mode 100644
index 000000000..350b5fca7
--- /dev/null
+++ b/library/std/src/os/dragonfly/mod.rs
@@ -0,0 +1,6 @@
+//! Dragonfly-specific definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+pub mod fs;
+pub mod raw;
diff --git a/library/std/src/os/dragonfly/raw.rs b/library/std/src/os/dragonfly/raw.rs
new file mode 100644
index 000000000..071bf6199
--- /dev/null
+++ b/library/std/src/os/dragonfly/raw.rs
@@ -0,0 +1,83 @@
+//! Dragonfly-specific raw type definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.8.0",
+    note = "these type aliases are no longer supported by \
+            the standard library, the `libc` crate on \
+            crates.io should be used instead for the correct \
+            definitions"
+)]
+#![allow(deprecated)]
+
+use crate::os::raw::c_long;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blkcnt_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blksize_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type dev_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type fflags_t = u32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type ino_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type mode_t = u32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type nlink_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type off_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type time_t = i64;
+
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = usize;
+
+#[repr(C)]
+#[derive(Clone)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub struct stat {
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_dev: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ino: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mode: u16,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_nlink: u16,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_uid: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gid: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_rdev: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_size: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blocks: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blksize: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_flags: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gen: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_lspare: i32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_birthtime: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_birthtime_nsec: c_long,
+}
diff --git a/library/std/src/os/emscripten/fs.rs b/library/std/src/os/emscripten/fs.rs
new file mode 100644
index 000000000..d5ec8e03c
--- /dev/null
+++ b/library/std/src/os/emscripten/fs.rs
@@ -0,0 +1,117 @@
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+#[allow(deprecated)]
+use crate::os::emscripten::raw;
+
+/// OS-specific extensions to [`fs::Metadata`].
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    /// Gain a reference to the underlying `stat` structure which contains
+    /// the raw information returned by the OS.
+    ///
+    /// The contents of the returned `stat` are **not** consistent across
+    /// Unix platforms. The `os::unix::fs::MetadataExt` trait contains the
+    /// cross-Unix abstractions contained within the raw stat.
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    #[deprecated(
+        since = "1.8.0",
+        note = "deprecated in favor of the accessor \
+                methods of this trait"
+    )]
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat;
+
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat {
+        unsafe { &*(self.as_inner().as_inner() as *const libc::stat64 as *const raw::stat) }
+    }
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        self.as_inner().as_inner().st_atime as i64
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_atime_nsec as i64
+    }
+    fn st_mtime(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime as i64
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime_nsec as i64
+    }
+    fn st_ctime(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime as i64
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime_nsec as i64
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+}
diff --git a/library/std/src/os/emscripten/mod.rs b/library/std/src/os/emscripten/mod.rs
new file mode 100644
index 000000000..d35307162
--- /dev/null
+++ b/library/std/src/os/emscripten/mod.rs
@@ -0,0 +1,6 @@
+//! Linux-specific definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+pub mod fs;
+pub mod raw;
diff --git a/library/std/src/os/emscripten/raw.rs b/library/std/src/os/emscripten/raw.rs
new file mode 100644
index 000000000..d23011c73
--- /dev/null
+++ b/library/std/src/os/emscripten/raw.rs
@@ -0,0 +1,80 @@
+//! Emscripten-specific raw type definitions
+//! This is basically exactly the same as the linux definitions,
+//! except using the musl-specific stat64 structure in liblibc.
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.8.0",
+    note = "these type aliases are no longer supported by \
+            the standard library, the `libc` crate on \
+            crates.io should be used instead for the correct \
+            definitions"
+)]
+#![allow(deprecated)]
+
+use crate::os::raw::{c_long, c_short, c_uint, c_ulong};
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type dev_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type mode_t = u32;
+
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = c_ulong;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blkcnt_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blksize_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type ino_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type nlink_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type off_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type time_t = c_long;
+
+#[repr(C)]
+#[derive(Clone)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub struct stat {
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_dev: u64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub __pad1: c_short,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub __st_ino: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mode: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_nlink: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_uid: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gid: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_rdev: u64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub __pad2: c_uint,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_size: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blksize: i32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blocks: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ino: u64,
+}
diff --git a/library/std/src/os/espidf/fs.rs b/library/std/src/os/espidf/fs.rs
new file mode 100644
index 000000000..88701dafe
--- /dev/null
+++ b/library/std/src/os/espidf/fs.rs
@@ -0,0 +1,117 @@
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+#[allow(deprecated)]
+use crate::os::espidf::raw;
+
+/// OS-specific extensions to [`fs::Metadata`].
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    #[deprecated(
+        since = "1.8.0",
+        note = "deprecated in favor of the accessor \
+                methods of this trait"
+    )]
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat;
+
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_spare4(&self) -> [u32; 2];
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat {
+        unsafe { &*(self.as_inner().as_inner() as *const libc::stat as *const raw::stat) }
+    }
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        self.as_inner().as_inner().st_atime as i64
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        0
+    }
+    fn st_mtime(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime as i64
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        0
+    }
+    fn st_ctime(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime as i64
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        0
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+    fn st_spare4(&self) -> [u32; 2] {
+        let spare4 = self.as_inner().as_inner().st_spare4;
+        [spare4[0] as u32, spare4[1] as u32]
+    }
+}
diff --git a/library/std/src/os/espidf/mod.rs b/library/std/src/os/espidf/mod.rs
new file mode 100644
index 000000000..a9cef9709
--- /dev/null
+++ b/library/std/src/os/espidf/mod.rs
@@ -0,0 +1,6 @@
+//! Definitions for the ESP-IDF framework.
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+pub mod fs;
+pub mod raw;
diff --git a/library/std/src/os/espidf/raw.rs b/library/std/src/os/espidf/raw.rs
new file mode 100644
index 000000000..7df0e74b2
--- /dev/null
+++ b/library/std/src/os/espidf/raw.rs
@@ -0,0 +1,69 @@
+//! Raw type definitions for the ESP-IDF framework.
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.8.0",
+    note = "these type aliases are no longer supported by \
+            the standard library, the `libc` crate on \
+            crates.io should be used instead for the correct \
+            definitions"
+)]
+
+use crate::os::raw::c_long;
+use crate::os::unix::raw::{gid_t, uid_t};
+
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = libc::pthread_t;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blkcnt_t = libc::blkcnt_t;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blksize_t = libc::blksize_t;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type dev_t = libc::dev_t;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type ino_t = libc::ino_t;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type mode_t = libc::mode_t;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type nlink_t = libc::nlink_t;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type off_t = libc::off_t;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type time_t = libc::time_t;
+
+#[repr(C)]
+#[derive(Clone)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub struct stat {
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_dev: dev_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ino: ino_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mode: mode_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_nlink: nlink_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_uid: uid_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gid: gid_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_rdev: dev_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_size: off_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blksize: blksize_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blocks: blkcnt_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_spare4: [c_long; 2usize],
+}
diff --git a/library/std/src/os/fd/mod.rs b/library/std/src/os/fd/mod.rs
new file mode 100644
index 000000000..a45694753
--- /dev/null
+++ b/library/std/src/os/fd/mod.rs
@@ -0,0 +1,16 @@
+//! Owned and borrowed Unix-like file descriptors.
+
+#![stable(feature = "io_safety", since = "1.63.0")]
+#![deny(unsafe_op_in_unsafe_fn)]
+
+// `RawFd`, `AsRawFd`, etc.
+pub mod raw;
+
+// `OwnedFd`, `AsFd`, etc.
+pub mod owned;
+
+// Implementations for `AsRawFd` etc. for network types.
+mod net;
+
+#[cfg(test)]
+mod tests;
diff --git a/library/std/src/os/fd/net.rs b/library/std/src/os/fd/net.rs
new file mode 100644
index 000000000..843f45f7f
--- /dev/null
+++ b/library/std/src/os/fd/net.rs
@@ -0,0 +1,46 @@
+use crate::os::fd::owned::OwnedFd;
+use crate::os::fd::raw::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
+use crate::sys_common::{self, AsInner, FromInner, IntoInner};
+use crate::{net, sys};
+
+macro_rules! impl_as_raw_fd {
+    ($($t:ident)*) => {$(
+        #[stable(feature = "rust1", since = "1.0.0")]
+        impl AsRawFd for net::$t {
+            #[inline]
+            fn as_raw_fd(&self) -> RawFd {
+                self.as_inner().socket().as_raw_fd()
+            }
+        }
+    )*};
+}
+impl_as_raw_fd! { TcpStream TcpListener UdpSocket }
+
+macro_rules! impl_from_raw_fd {
+    ($($t:ident)*) => {$(
+        #[stable(feature = "from_raw_os", since = "1.1.0")]
+        impl FromRawFd for net::$t {
+            #[inline]
+            unsafe fn from_raw_fd(fd: RawFd) -> net::$t {
+                unsafe {
+                    let socket = sys::net::Socket::from_inner(FromInner::from_inner(OwnedFd::from_raw_fd(fd)));
+                    net::$t::from_inner(sys_common::net::$t::from_inner(socket))
+                }
+            }
+        }
+    )*};
+}
+impl_from_raw_fd! { TcpStream TcpListener UdpSocket }
+
+macro_rules! impl_into_raw_fd {
+    ($($t:ident)*) => {$(
+        #[stable(feature = "into_raw_os", since = "1.4.0")]
+        impl IntoRawFd for net::$t {
+            #[inline]
+            fn into_raw_fd(self) -> RawFd {
+                self.into_inner().into_socket().into_inner().into_inner().into_raw_fd()
+            }
+        }
+    )*};
+}
+impl_into_raw_fd! { TcpStream TcpListener UdpSocket }
diff --git a/library/std/src/os/fd/owned.rs b/library/std/src/os/fd/owned.rs
new file mode 100644
index 000000000..a463bc41d
--- /dev/null
+++ b/library/std/src/os/fd/owned.rs
@@ -0,0 +1,388 @@
+//! Owned and borrowed Unix-like file descriptors.
+
+#![stable(feature = "io_safety", since = "1.63.0")]
+#![deny(unsafe_op_in_unsafe_fn)]
+
+use super::raw::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
+use crate::fmt;
+use crate::fs;
+use crate::marker::PhantomData;
+use crate::mem::forget;
+#[cfg(not(any(target_arch = "wasm32", target_env = "sgx")))]
+use crate::sys::cvt;
+use crate::sys_common::{AsInner, FromInner, IntoInner};
+
+/// A borrowed file descriptor.
+///
+/// This has a lifetime parameter to tie it to the lifetime of something that
+/// owns the file descriptor.
+///
+/// This uses `repr(transparent)` and has the representation of a host file
+/// descriptor, so it can be used in FFI in places where a file descriptor is
+/// passed as an argument, it is not captured or consumed, and it never has the
+/// value `-1`.
+///
+/// This type's `.to_owned()` implementation returns another `BorrowedFd`
+/// rather than an `OwnedFd`. It just makes a trivial copy of the raw file
+/// descriptor, which is then borrowed under the same lifetime.
+#[derive(Copy, Clone)]
+#[repr(transparent)]
+#[rustc_layout_scalar_valid_range_start(0)]
+// libstd/os/raw/mod.rs assures me that every libstd-supported platform has a
+// 32-bit c_int. Below is -2, in two's complement, but that only works out
+// because c_int is 32 bits.
+#[rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE)]
+#[rustc_nonnull_optimization_guaranteed]
+#[stable(feature = "io_safety", since = "1.63.0")]
+pub struct BorrowedFd<'fd> {
+    fd: RawFd,
+    _phantom: PhantomData<&'fd OwnedFd>,
+}
+
+/// An owned file descriptor.
+///
+/// This closes the file descriptor on drop.
+///
+/// This uses `repr(transparent)` and has the representation of a host file
+/// descriptor, so it can be used in FFI in places where a file descriptor is
+/// passed as a consumed argument or returned as an owned value, and it never
+/// has the value `-1`.
+#[repr(transparent)]
+#[rustc_layout_scalar_valid_range_start(0)]
+// libstd/os/raw/mod.rs assures me that every libstd-supported platform has a
+// 32-bit c_int. Below is -2, in two's complement, but that only works out
+// because c_int is 32 bits.
+#[rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE)]
+#[rustc_nonnull_optimization_guaranteed]
+#[stable(feature = "io_safety", since = "1.63.0")]
+pub struct OwnedFd {
+    fd: RawFd,
+}
+
+impl BorrowedFd<'_> {
+    /// Return a `BorrowedFd` holding the given raw file descriptor.
+    ///
+    /// # Safety
+    ///
+    /// The resource pointed to by `fd` must remain open for the duration of
+    /// the returned `BorrowedFd`, and it must not have the value `-1`.
+    #[inline]
+    #[rustc_const_stable(feature = "io_safety", since = "1.63.0")]
+    #[stable(feature = "io_safety", since = "1.63.0")]
+    pub const unsafe fn borrow_raw(fd: RawFd) -> Self {
+        assert!(fd != u32::MAX as RawFd);
+        // SAFETY: we just asserted that the value is in the valid range and isn't `-1` (the only value bigger than `0xFF_FF_FF_FE` unsigned)
+        unsafe { Self { fd, _phantom: PhantomData } }
+    }
+}
+
+impl OwnedFd {
+    /// Creates a new `OwnedFd` instance that shares the same underlying file
+    /// description as the existing `OwnedFd` instance.
+    #[stable(feature = "io_safety", since = "1.63.0")]
+    pub fn try_clone(&self) -> crate::io::Result<Self> {
+        self.as_fd().try_clone_to_owned()
+    }
+}
+
+impl BorrowedFd<'_> {
+    /// Creates a new `OwnedFd` instance that shares the same underlying file
+    /// description as the existing `BorrowedFd` instance.
+    #[cfg(not(target_arch = "wasm32"))]
+    #[stable(feature = "io_safety", since = "1.63.0")]
+    pub fn try_clone_to_owned(&self) -> crate::io::Result<OwnedFd> {
+        // We want to atomically duplicate this file descriptor and set the
+        // CLOEXEC flag, and currently that's done via F_DUPFD_CLOEXEC. This
+        // is a POSIX flag that was added to Linux in 2.6.24.
+        #[cfg(not(target_os = "espidf"))]
+        let cmd = libc::F_DUPFD_CLOEXEC;
+
+        // For ESP-IDF, F_DUPFD is used instead, because the CLOEXEC semantics
+        // will never be supported, as this is a bare metal framework with
+        // no capabilities for multi-process execution.  While F_DUPFD is also
+        // not supported yet, it might be (currently it returns ENOSYS).
+        #[cfg(target_os = "espidf")]
+        let cmd = libc::F_DUPFD;
+
+        let fd = cvt(unsafe { libc::fcntl(self.as_raw_fd(), cmd, 0) })?;
+        Ok(unsafe { OwnedFd::from_raw_fd(fd) })
+    }
+
+    /// Creates a new `OwnedFd` instance that shares the same underlying file
+    /// description as the existing `BorrowedFd` instance.
+    #[cfg(target_arch = "wasm32")]
+    #[stable(feature = "io_safety", since = "1.63.0")]
+    pub fn try_clone_to_owned(&self) -> crate::io::Result<OwnedFd> {
+        Err(crate::io::const_io_error!(
+            crate::io::ErrorKind::Unsupported,
+            "operation not supported on WASI yet",
+        ))
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsRawFd for BorrowedFd<'_> {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        self.fd
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsRawFd for OwnedFd {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        self.fd
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl IntoRawFd for OwnedFd {
+    #[inline]
+    fn into_raw_fd(self) -> RawFd {
+        let fd = self.fd;
+        forget(self);
+        fd
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl FromRawFd for OwnedFd {
+    /// Constructs a new instance of `Self` from the given raw file descriptor.
+    ///
+    /// # Safety
+    ///
+    /// The resource pointed to by `fd` must be open and suitable for assuming
+    /// ownership. The resource must not require any cleanup other than `close`.
+    #[inline]
+    unsafe fn from_raw_fd(fd: RawFd) -> Self {
+        assert_ne!(fd, u32::MAX as RawFd);
+        // SAFETY: we just asserted that the value is in the valid range and isn't `-1` (the only value bigger than `0xFF_FF_FF_FE` unsigned)
+        unsafe { Self { fd } }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl Drop for OwnedFd {
+    #[inline]
+    fn drop(&mut self) {
+        unsafe {
+            // Note that errors are ignored when closing a file descriptor. The
+            // reason for this is that if an error occurs we don't actually know if
+            // the file descriptor was closed or not, and if we retried (for
+            // something like EINTR), we might close another valid file descriptor
+            // opened after we closed ours.
+            let _ = libc::close(self.fd);
+        }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl fmt::Debug for BorrowedFd<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("BorrowedFd").field("fd", &self.fd).finish()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl fmt::Debug for OwnedFd {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("OwnedFd").field("fd", &self.fd).finish()
+    }
+}
+
+/// A trait to borrow the file descriptor from an underlying object.
+///
+/// This is only available on unix platforms and must be imported in order to
+/// call the method. Windows platforms have a corresponding `AsHandle` and
+/// `AsSocket` set of traits.
+#[stable(feature = "io_safety", since = "1.63.0")]
+pub trait AsFd {
+    /// Borrows the file descriptor.
+    ///
+    /// # Example
+    ///
+    /// ```rust,no_run
+    /// use std::fs::File;
+    /// # use std::io;
+    /// # #[cfg(target_os = "wasi")]
+    /// # use std::os::wasi::io::{AsFd, BorrowedFd};
+    /// # #[cfg(unix)]
+    /// # use std::os::unix::io::{AsFd, BorrowedFd};
+    ///
+    /// let mut f = File::open("foo.txt")?;
+    /// # #[cfg(any(unix, target_os = "wasi"))]
+    /// let borrowed_fd: BorrowedFd<'_> = f.as_fd();
+    /// # Ok::<(), io::Error>(())
+    /// ```
+    #[stable(feature = "io_safety", since = "1.63.0")]
+    fn as_fd(&self) -> BorrowedFd<'_>;
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl<T: AsFd> AsFd for &T {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        T::as_fd(self)
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl<T: AsFd> AsFd for &mut T {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        T::as_fd(self)
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsFd for BorrowedFd<'_> {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        *self
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsFd for OwnedFd {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        // Safety: `OwnedFd` and `BorrowedFd` have the same validity
+        // invariants, and the `BorrowdFd` is bounded by the lifetime
+        // of `&self`.
+        unsafe { BorrowedFd::borrow_raw(self.as_raw_fd()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsFd for fs::File {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        self.as_inner().as_fd()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<fs::File> for OwnedFd {
+    #[inline]
+    fn from(file: fs::File) -> OwnedFd {
+        file.into_inner().into_inner().into_inner()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<OwnedFd> for fs::File {
+    #[inline]
+    fn from(owned_fd: OwnedFd) -> Self {
+        Self::from_inner(FromInner::from_inner(FromInner::from_inner(owned_fd)))
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsFd for crate::net::TcpStream {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        self.as_inner().socket().as_fd()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<crate::net::TcpStream> for OwnedFd {
+    #[inline]
+    fn from(tcp_stream: crate::net::TcpStream) -> OwnedFd {
+        tcp_stream.into_inner().into_socket().into_inner().into_inner().into()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<OwnedFd> for crate::net::TcpStream {
+    #[inline]
+    fn from(owned_fd: OwnedFd) -> Self {
+        Self::from_inner(FromInner::from_inner(FromInner::from_inner(FromInner::from_inner(
+            owned_fd,
+        ))))
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsFd for crate::net::TcpListener {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        self.as_inner().socket().as_fd()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<crate::net::TcpListener> for OwnedFd {
+    #[inline]
+    fn from(tcp_listener: crate::net::TcpListener) -> OwnedFd {
+        tcp_listener.into_inner().into_socket().into_inner().into_inner().into()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<OwnedFd> for crate::net::TcpListener {
+    #[inline]
+    fn from(owned_fd: OwnedFd) -> Self {
+        Self::from_inner(FromInner::from_inner(FromInner::from_inner(FromInner::from_inner(
+            owned_fd,
+        ))))
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsFd for crate::net::UdpSocket {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        self.as_inner().socket().as_fd()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<crate::net::UdpSocket> for OwnedFd {
+    #[inline]
+    fn from(udp_socket: crate::net::UdpSocket) -> OwnedFd {
+        udp_socket.into_inner().into_socket().into_inner().into_inner().into()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<OwnedFd> for crate::net::UdpSocket {
+    #[inline]
+    fn from(owned_fd: OwnedFd) -> Self {
+        Self::from_inner(FromInner::from_inner(FromInner::from_inner(FromInner::from_inner(
+            owned_fd,
+        ))))
+    }
+}
+
+#[stable(feature = "asfd_ptrs", since = "1.64.0")]
+/// This impl allows implementing traits that require `AsFd` on Arc.
+/// ```
+/// # #[cfg(any(unix, target_os = "wasi"))] mod group_cfg {
+/// # #[cfg(target_os = "wasi")]
+/// # use std::os::wasi::io::AsFd;
+/// # #[cfg(unix)]
+/// # use std::os::unix::io::AsFd;
+/// use std::net::UdpSocket;
+/// use std::sync::Arc;
+///
+/// trait MyTrait: AsFd {}
+/// impl MyTrait for Arc<UdpSocket> {}
+/// impl MyTrait for Box<UdpSocket> {}
+/// # }
+/// ```
+impl<T: AsFd> AsFd for crate::sync::Arc<T> {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        (**self).as_fd()
+    }
+}
+
+#[stable(feature = "asfd_ptrs", since = "1.64.0")]
+impl<T: AsFd> AsFd for Box<T> {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        (**self).as_fd()
+    }
+}
diff --git a/library/std/src/os/fd/raw.rs b/library/std/src/os/fd/raw.rs
new file mode 100644
index 000000000..081915ed1
--- /dev/null
+++ b/library/std/src/os/fd/raw.rs
@@ -0,0 +1,259 @@
+//! Raw Unix-like file descriptors.
+
+#![stable(feature = "rust1", since = "1.0.0")]
+
+use crate::fs;
+use crate::io;
+use crate::os::raw;
+#[cfg(all(doc, not(target_arch = "wasm32")))]
+use crate::os::unix::io::AsFd;
+#[cfg(unix)]
+use crate::os::unix::io::OwnedFd;
+#[cfg(target_os = "wasi")]
+use crate::os::wasi::io::OwnedFd;
+use crate::sys_common::{AsInner, IntoInner};
+
+/// Raw file descriptors.
+#[cfg_attr(not(bootstrap), rustc_allowed_through_unstable_modules)]
+#[stable(feature = "rust1", since = "1.0.0")]
+pub type RawFd = raw::c_int;
+
+/// A trait to extract the raw file descriptor from an underlying object.
+///
+/// This is only available on unix and WASI platforms and must be imported in
+/// order to call the method. Windows platforms have a corresponding
+/// `AsRawHandle` and `AsRawSocket` set of traits.
+#[cfg_attr(not(bootstrap), rustc_allowed_through_unstable_modules)]
+#[stable(feature = "rust1", since = "1.0.0")]
+pub trait AsRawFd {
+    /// Extracts the raw file descriptor.
+    ///
+    /// This function is typically used to **borrow** an owned file descriptor.
+    /// When used in this way, this method does **not** pass ownership of the
+    /// raw file descriptor to the caller, and the file descriptor is only
+    /// guaranteed to be valid while the original object has not yet been
+    /// destroyed.
+    ///
+    /// However, borrowing is not strictly required. See [`AsFd::as_fd`]
+    /// for an API which strictly borrows a file descriptor.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// use std::fs::File;
+    /// # use std::io;
+    /// #[cfg(unix)]
+    /// use std::os::unix::io::{AsRawFd, RawFd};
+    /// #[cfg(target_os = "wasi")]
+    /// use std::os::wasi::io::{AsRawFd, RawFd};
+    ///
+    /// let mut f = File::open("foo.txt")?;
+    /// // Note that `raw_fd` is only valid as long as `f` exists.
+    /// #[cfg(any(unix, target_os = "wasi"))]
+    /// let raw_fd: RawFd = f.as_raw_fd();
+    /// # Ok::<(), io::Error>(())
+    /// ```
+    #[stable(feature = "rust1", since = "1.0.0")]
+    fn as_raw_fd(&self) -> RawFd;
+}
+
+/// A trait to express the ability to construct an object from a raw file
+/// descriptor.
+#[cfg_attr(not(bootstrap), rustc_allowed_through_unstable_modules)]
+#[stable(feature = "from_raw_os", since = "1.1.0")]
+pub trait FromRawFd {
+    /// Constructs a new instance of `Self` from the given raw file
+    /// descriptor.
+    ///
+    /// This function is typically used to **consume ownership** of the
+    /// specified file descriptor. When used in this way, the returned object
+    /// will take responsibility for closing it when the object goes out of
+    /// scope.
+    ///
+    /// However, consuming ownership is not strictly required. Use a
+    /// [`From<OwnedFd>::from`] implementation for an API which strictly
+    /// consumes ownership.
+    ///
+    /// # Safety
+    ///
+    /// The `fd` passed in must be a valid and open file descriptor.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// use std::fs::File;
+    /// # use std::io;
+    /// #[cfg(unix)]
+    /// use std::os::unix::io::{FromRawFd, IntoRawFd, RawFd};
+    /// #[cfg(target_os = "wasi")]
+    /// use std::os::wasi::io::{FromRawFd, IntoRawFd, RawFd};
+    ///
+    /// let f = File::open("foo.txt")?;
+    /// # #[cfg(any(unix, target_os = "wasi"))]
+    /// let raw_fd: RawFd = f.into_raw_fd();
+    /// // SAFETY: no other functions should call `from_raw_fd`, so there
+    /// // is only one owner for the file descriptor.
+    /// # #[cfg(any(unix, target_os = "wasi"))]
+    /// let f = unsafe { File::from_raw_fd(raw_fd) };
+    /// # Ok::<(), io::Error>(())
+    /// ```
+    #[stable(feature = "from_raw_os", since = "1.1.0")]
+    unsafe fn from_raw_fd(fd: RawFd) -> Self;
+}
+
+/// A trait to express the ability to consume an object and acquire ownership of
+/// its raw file descriptor.
+#[cfg_attr(not(bootstrap), rustc_allowed_through_unstable_modules)]
+#[stable(feature = "into_raw_os", since = "1.4.0")]
+pub trait IntoRawFd {
+    /// Consumes this object, returning the raw underlying file descriptor.
+    ///
+    /// This function is typically used to **transfer ownership** of the underlying
+    /// file descriptor to the caller. When used in this way, callers are then the unique
+    /// owners of the file descriptor and must close it once it's no longer needed.
+    ///
+    /// However, transferring ownership is not strictly required. Use a
+    /// [`Into<OwnedFd>::into`] implementation for an API which strictly
+    /// transfers ownership.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// use std::fs::File;
+    /// # use std::io;
+    /// #[cfg(unix)]
+    /// use std::os::unix::io::{IntoRawFd, RawFd};
+    /// #[cfg(target_os = "wasi")]
+    /// use std::os::wasi::io::{IntoRawFd, RawFd};
+    ///
+    /// let f = File::open("foo.txt")?;
+    /// #[cfg(any(unix, target_os = "wasi"))]
+    /// let raw_fd: RawFd = f.into_raw_fd();
+    /// # Ok::<(), io::Error>(())
+    /// ```
+    #[stable(feature = "into_raw_os", since = "1.4.0")]
+    fn into_raw_fd(self) -> RawFd;
+}
+
+#[stable(feature = "raw_fd_reflexive_traits", since = "1.48.0")]
+impl AsRawFd for RawFd {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        *self
+    }
+}
+#[stable(feature = "raw_fd_reflexive_traits", since = "1.48.0")]
+impl IntoRawFd for RawFd {
+    #[inline]
+    fn into_raw_fd(self) -> RawFd {
+        self
+    }
+}
+#[stable(feature = "raw_fd_reflexive_traits", since = "1.48.0")]
+impl FromRawFd for RawFd {
+    #[inline]
+    unsafe fn from_raw_fd(fd: RawFd) -> RawFd {
+        fd
+    }
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl AsRawFd for fs::File {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        self.as_inner().as_raw_fd()
+    }
+}
+#[stable(feature = "from_raw_os", since = "1.1.0")]
+impl FromRawFd for fs::File {
+    #[inline]
+    unsafe fn from_raw_fd(fd: RawFd) -> fs::File {
+        unsafe { fs::File::from(OwnedFd::from_raw_fd(fd)) }
+    }
+}
+#[stable(feature = "into_raw_os", since = "1.4.0")]
+impl IntoRawFd for fs::File {
+    #[inline]
+    fn into_raw_fd(self) -> RawFd {
+        self.into_inner().into_inner().into_raw_fd()
+    }
+}
+
+#[stable(feature = "asraw_stdio", since = "1.21.0")]
+impl AsRawFd for io::Stdin {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        libc::STDIN_FILENO
+    }
+}
+
+#[stable(feature = "asraw_stdio", since = "1.21.0")]
+impl AsRawFd for io::Stdout {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        libc::STDOUT_FILENO
+    }
+}
+
+#[stable(feature = "asraw_stdio", since = "1.21.0")]
+impl AsRawFd for io::Stderr {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        libc::STDERR_FILENO
+    }
+}
+
+#[stable(feature = "asraw_stdio_locks", since = "1.35.0")]
+impl<'a> AsRawFd for io::StdinLock<'a> {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        libc::STDIN_FILENO
+    }
+}
+
+#[stable(feature = "asraw_stdio_locks", since = "1.35.0")]
+impl<'a> AsRawFd for io::StdoutLock<'a> {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        libc::STDOUT_FILENO
+    }
+}
+
+#[stable(feature = "asraw_stdio_locks", since = "1.35.0")]
+impl<'a> AsRawFd for io::StderrLock<'a> {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        libc::STDERR_FILENO
+    }
+}
+
+/// This impl allows implementing traits that require `AsRawFd` on Arc.
+/// ```
+/// # #[cfg(any(unix, target_os = "wasi"))] mod group_cfg {
+/// # #[cfg(target_os = "wasi")]
+/// # use std::os::wasi::io::AsRawFd;
+/// # #[cfg(unix)]
+/// # use std::os::unix::io::AsRawFd;
+/// use std::net::UdpSocket;
+/// use std::sync::Arc;
+/// trait MyTrait: AsRawFd {
+/// }
+/// impl MyTrait for Arc<UdpSocket> {}
+/// impl MyTrait for Box<UdpSocket> {}
+/// # }
+/// ```
+#[stable(feature = "asrawfd_ptrs", since = "1.63.0")]
+impl<T: AsRawFd> AsRawFd for crate::sync::Arc<T> {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        (**self).as_raw_fd()
+    }
+}
+
+#[stable(feature = "asrawfd_ptrs", since = "1.63.0")]
+impl<T: AsRawFd> AsRawFd for Box<T> {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        (**self).as_raw_fd()
+    }
+}
diff --git a/library/std/src/os/fd/tests.rs b/library/std/src/os/fd/tests.rs
new file mode 100644
index 000000000..b39863644
--- /dev/null
+++ b/library/std/src/os/fd/tests.rs
@@ -0,0 +1,53 @@
+#[cfg(any(unix, target_os = "wasi"))]
+#[test]
+fn test_raw_fd() {
+    #[cfg(unix)]
+    use crate::os::unix::io::{AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, RawFd};
+    #[cfg(target_os = "wasi")]
+    use crate::os::wasi::io::{AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, RawFd};
+
+    let raw_fd: RawFd = crate::io::stdin().as_raw_fd();
+
+    let stdin_as_file = unsafe { crate::fs::File::from_raw_fd(raw_fd) };
+    assert_eq!(stdin_as_file.as_raw_fd(), raw_fd);
+    assert_eq!(unsafe { BorrowedFd::borrow_raw(raw_fd).as_raw_fd() }, raw_fd);
+    assert_eq!(stdin_as_file.into_raw_fd(), 0);
+}
+
+#[cfg(any(unix, target_os = "wasi"))]
+#[test]
+fn test_fd() {
+    #[cfg(unix)]
+    use crate::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
+    #[cfg(target_os = "wasi")]
+    use crate::os::wasi::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
+
+    let stdin = crate::io::stdin();
+    let fd: BorrowedFd<'_> = stdin.as_fd();
+    let raw_fd: RawFd = fd.as_raw_fd();
+    let owned_fd: OwnedFd = unsafe { OwnedFd::from_raw_fd(raw_fd) };
+
+    let stdin_as_file = crate::fs::File::from(owned_fd);
+
+    assert_eq!(stdin_as_file.as_fd().as_raw_fd(), raw_fd);
+    assert_eq!(Into::<OwnedFd>::into(stdin_as_file).into_raw_fd(), raw_fd);
+}
+
+#[cfg(any(unix, target_os = "wasi"))]
+#[test]
+fn test_niche_optimizations() {
+    use crate::mem::size_of;
+    #[cfg(unix)]
+    use crate::os::unix::io::{BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
+    #[cfg(target_os = "wasi")]
+    use crate::os::wasi::io::{BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
+
+    assert_eq!(size_of::<Option<OwnedFd>>(), size_of::<RawFd>());
+    assert_eq!(size_of::<Option<BorrowedFd<'static>>>(), size_of::<RawFd>());
+    unsafe {
+        assert_eq!(OwnedFd::from_raw_fd(RawFd::MIN).into_raw_fd(), RawFd::MIN);
+        assert_eq!(OwnedFd::from_raw_fd(RawFd::MAX).into_raw_fd(), RawFd::MAX);
+        assert_eq!(Some(OwnedFd::from_raw_fd(RawFd::MIN)).unwrap().into_raw_fd(), RawFd::MIN);
+        assert_eq!(Some(OwnedFd::from_raw_fd(RawFd::MAX)).unwrap().into_raw_fd(), RawFd::MAX);
+    }
+}
diff --git a/library/std/src/os/fortanix_sgx/arch.rs b/library/std/src/os/fortanix_sgx/arch.rs
new file mode 100644
index 000000000..8358cb9e8
--- /dev/null
+++ b/library/std/src/os/fortanix_sgx/arch.rs
@@ -0,0 +1,80 @@
+//! SGX-specific access to architectural features.
+//!
+//! The functionality in this module is further documented in the Intel
+//! Software Developer's Manual, Volume 3, Chapter 40.
+#![unstable(feature = "sgx_platform", issue = "56975")]
+
+use crate::mem::MaybeUninit;
+use core::arch::asm;
+
+/// Wrapper struct to force 16-byte alignment.
+#[repr(align(16))]
+#[unstable(feature = "sgx_platform", issue = "56975")]
+pub struct Align16<T>(pub T);
+
+/// Wrapper struct to force 128-byte alignment.
+#[repr(align(128))]
+#[unstable(feature = "sgx_platform", issue = "56975")]
+pub struct Align128<T>(pub T);
+
+/// Wrapper struct to force 512-byte alignment.
+#[repr(align(512))]
+#[unstable(feature = "sgx_platform", issue = "56975")]
+pub struct Align512<T>(pub T);
+
+const ENCLU_EREPORT: u32 = 0;
+const ENCLU_EGETKEY: u32 = 1;
+
+/// Call the `EGETKEY` instruction to obtain a 128-bit secret key.
+#[unstable(feature = "sgx_platform", issue = "56975")]
+pub fn egetkey(request: &Align512<[u8; 512]>) -> Result<Align16<[u8; 16]>, u32> {
+    unsafe {
+        let mut out = MaybeUninit::uninit();
+        let error;
+
+        asm!(
+            // rbx is reserved by LLVM
+            "xchg %rbx, {0}",
+            "enclu",
+            "mov {0}, %rbx",
+            inout(reg) request => _,
+            inlateout("eax") ENCLU_EGETKEY => error,
+            in("rcx") out.as_mut_ptr(),
+            options(att_syntax, nostack),
+        );
+
+        match error {
+            0 => Ok(out.assume_init()),
+            err => Err(err),
+        }
+    }
+}
+
+/// Call the `EREPORT` instruction.
+///
+/// This creates a cryptographic report describing the contents of the current
+/// enclave. The report may be verified by the enclave described in
+/// `targetinfo`.
+#[unstable(feature = "sgx_platform", issue = "56975")]
+pub fn ereport(
+    targetinfo: &Align512<[u8; 512]>,
+    reportdata: &Align128<[u8; 64]>,
+) -> Align512<[u8; 432]> {
+    unsafe {
+        let mut report = MaybeUninit::uninit();
+
+        asm!(
+            // rbx is reserved by LLVM
+            "xchg %rbx, {0}",
+            "enclu",
+            "mov {0}, %rbx",
+            inout(reg) targetinfo => _,
+            in("eax") ENCLU_EREPORT,
+            in("rcx") reportdata,
+            in("rdx") report.as_mut_ptr(),
+            options(att_syntax, preserves_flags, nostack),
+        );
+
+        report.assume_init()
+    }
+}
diff --git a/library/std/src/os/fortanix_sgx/ffi.rs b/library/std/src/os/fortanix_sgx/ffi.rs
new file mode 100644
index 000000000..ac1db0e5e
--- /dev/null
+++ b/library/std/src/os/fortanix_sgx/ffi.rs
@@ -0,0 +1,41 @@
+//! SGX-specific extension to the primitives in the `std::ffi` module
+//!
+//! # Examples
+//!
+//! ```
+//! use std::ffi::OsString;
+//! use std::os::fortanix_sgx::ffi::OsStringExt;
+//!
+//! let bytes = b"foo".to_vec();
+//!
+//! // OsStringExt::from_vec
+//! let os_string = OsString::from_vec(bytes);
+//! assert_eq!(os_string.to_str(), Some("foo"));
+//!
+//! // OsStringExt::into_vec
+//! let bytes = os_string.into_vec();
+//! assert_eq!(bytes, b"foo");
+//! ```
+//!
+//! ```
+//! use std::ffi::OsStr;
+//! use std::os::fortanix_sgx::ffi::OsStrExt;
+//!
+//! let bytes = b"foo";
+//!
+//! // OsStrExt::from_bytes
+//! let os_str = OsStr::from_bytes(bytes);
+//! assert_eq!(os_str.to_str(), Some("foo"));
+//!
+//! // OsStrExt::as_bytes
+//! let bytes = os_str.as_bytes();
+//! assert_eq!(bytes, b"foo");
+//! ```
+
+#![unstable(feature = "sgx_platform", issue = "56975")]
+
+#[path = "../unix/ffi/os_str.rs"]
+mod os_str;
+
+#[unstable(feature = "sgx_platform", issue = "56975")]
+pub use self::os_str::{OsStrExt, OsStringExt};
diff --git a/library/std/src/os/fortanix_sgx/io.rs b/library/std/src/os/fortanix_sgx/io.rs
new file mode 100644
index 000000000..7223ade68
--- /dev/null
+++ b/library/std/src/os/fortanix_sgx/io.rs
@@ -0,0 +1,144 @@
+//! SGX-specific extensions to general I/O primitives
+//!
+//! SGX file descriptors behave differently from Unix file descriptors. See the
+//! description of [`TryIntoRawFd`] for more details.
+#![unstable(feature = "sgx_platform", issue = "56975")]
+
+use crate::net;
+pub use crate::sys::abi::usercalls::raw::Fd as RawFd;
+use crate::sys::{self, AsInner, FromInner, IntoInner, TryIntoInner};
+
+/// A trait to extract the raw SGX file descriptor from an underlying
+/// object.
+#[unstable(feature = "sgx_platform", issue = "56975")]
+pub trait AsRawFd {
+    /// Extracts the raw file descriptor.
+    ///
+    /// This method does **not** pass ownership of the raw file descriptor
+    /// to the caller. The descriptor is only guaranteed to be valid while
+    /// the original object has not yet been destroyed.
+    #[unstable(feature = "sgx_platform", issue = "56975")]
+    fn as_raw_fd(&self) -> RawFd;
+}
+
+/// A trait to express the ability to construct an object from a raw file
+/// descriptor.
+#[unstable(feature = "sgx_platform", issue = "56975")]
+pub trait FromRawFd {
+    /// An associated type that contains relevant metadata for `Self`.
+    type Metadata: Default;
+
+    /// Constructs a new instance of `Self` from the given raw file
+    /// descriptor and metadata.
+    ///
+    /// This function **consumes ownership** of the specified file
+    /// descriptor. The returned object will take responsibility for closing
+    /// it when the object goes out of scope.
+    ///
+    /// This function is also unsafe as the primitives currently returned
+    /// have the contract that they are the sole owner of the file
+    /// descriptor they are wrapping. Usage of this function could
+    /// accidentally allow violating this contract which can cause memory
+    /// unsafety in code that relies on it being true.
+    #[unstable(feature = "sgx_platform", issue = "56975")]
+    unsafe fn from_raw_fd(fd: RawFd, metadata: Self::Metadata) -> Self;
+}
+
+/// A trait to express the ability to consume an object and acquire ownership of
+/// its raw file descriptor.
+#[unstable(feature = "sgx_platform", issue = "56975")]
+pub trait TryIntoRawFd: Sized {
+    /// Consumes this object, returning the raw underlying file descriptor, if
+    /// this object is not cloned.
+    ///
+    /// This function **transfers ownership** of the underlying file descriptor
+    /// to the caller. Callers are then the unique owners of the file descriptor
+    /// and must close the descriptor once it's no longer needed.
+    ///
+    /// Unlike other platforms, on SGX, the file descriptor is shared between
+    /// all clones of an object. To avoid race conditions, this function will
+    /// only return `Ok` when called on the final clone.
+    #[unstable(feature = "sgx_platform", issue = "56975")]
+    fn try_into_raw_fd(self) -> Result<RawFd, Self>;
+}
+
+impl AsRawFd for net::TcpStream {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        *self.as_inner().as_inner().as_inner().as_inner()
+    }
+}
+
+impl AsRawFd for net::TcpListener {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        *self.as_inner().as_inner().as_inner().as_inner()
+    }
+}
+
+/// Metadata for `TcpStream`.
+#[derive(Debug, Clone, Default)]
+#[unstable(feature = "sgx_platform", issue = "56975")]
+pub struct TcpStreamMetadata {
+    /// Local address of the TCP stream
+    pub local_addr: Option<String>,
+    /// Peer address of the TCP stream
+    pub peer_addr: Option<String>,
+}
+
+impl FromRawFd for net::TcpStream {
+    type Metadata = TcpStreamMetadata;
+
+    #[inline]
+    unsafe fn from_raw_fd(fd: RawFd, metadata: Self::Metadata) -> net::TcpStream {
+        let fd = sys::fd::FileDesc::from_inner(fd);
+        let socket = sys::net::Socket::from_inner((fd, metadata.local_addr));
+        net::TcpStream::from_inner(sys::net::TcpStream::from_inner((socket, metadata.peer_addr)))
+    }
+}
+
+/// Metadata for `TcpListener`.
+#[derive(Debug, Clone, Default)]
+#[unstable(feature = "sgx_platform", issue = "56975")]
+pub struct TcpListenerMetadata {
+    /// Local address of the TCP listener
+    pub local_addr: Option<String>,
+}
+
+impl FromRawFd for net::TcpListener {
+    type Metadata = TcpListenerMetadata;
+
+    #[inline]
+    unsafe fn from_raw_fd(fd: RawFd, metadata: Self::Metadata) -> net::TcpListener {
+        let fd = sys::fd::FileDesc::from_inner(fd);
+        let socket = sys::net::Socket::from_inner((fd, metadata.local_addr));
+        net::TcpListener::from_inner(sys::net::TcpListener::from_inner(socket))
+    }
+}
+
+impl TryIntoRawFd for net::TcpStream {
+    #[inline]
+    fn try_into_raw_fd(self) -> Result<RawFd, Self> {
+        let (socket, peer_addr) = self.into_inner().into_inner();
+        match socket.try_into_inner() {
+            Ok(fd) => Ok(fd.into_inner()),
+            Err(socket) => {
+                let sys = sys::net::TcpStream::from_inner((socket, peer_addr));
+                Err(net::TcpStream::from_inner(sys))
+            }
+        }
+    }
+}
+
+impl TryIntoRawFd for net::TcpListener {
+    #[inline]
+    fn try_into_raw_fd(self) -> Result<RawFd, Self> {
+        match self.into_inner().into_inner().try_into_inner() {
+            Ok(fd) => Ok(fd.into_inner()),
+            Err(socket) => {
+                let sys = sys::net::TcpListener::from_inner(socket);
+                Err(net::TcpListener::from_inner(sys))
+            }
+        }
+    }
+}
diff --git a/library/std/src/os/fortanix_sgx/mod.rs b/library/std/src/os/fortanix_sgx/mod.rs
new file mode 100644
index 000000000..a40dabe19
--- /dev/null
+++ b/library/std/src/os/fortanix_sgx/mod.rs
@@ -0,0 +1,53 @@
+//! Functionality specific to the `x86_64-fortanix-unknown-sgx` target.
+//!
+//! This includes functions to deal with memory isolation, usercalls, and the
+//! SGX instruction set.
+
+#![deny(missing_docs)]
+#![unstable(feature = "sgx_platform", issue = "56975")]
+
+/// Low-level interfaces to usercalls. See the [ABI documentation] for more
+/// information.
+///
+/// [ABI documentation]: https://docs.rs/fortanix-sgx-abi/
+pub mod usercalls {
+    pub use crate::sys::abi::usercalls::*;
+
+    /// Primitives for allocating memory in userspace as well as copying data
+    /// to and from user memory.
+    pub mod alloc {
+        pub use crate::sys::abi::usercalls::alloc::*;
+    }
+
+    /// Lowest-level interfaces to usercalls and usercall ABI type definitions.
+    pub mod raw {
+        pub use crate::sys::abi::usercalls::raw::{
+            accept_stream, alloc, async_queues, bind_stream, close, connect_stream, exit, flush,
+            free, insecure_time, launch_thread, read, read_alloc, send, wait, write,
+        };
+        pub use crate::sys::abi::usercalls::raw::{do_usercall, Usercalls as UsercallNrs};
+
+        // fortanix-sgx-abi re-exports
+        pub use crate::sys::abi::usercalls::raw::Error;
+        pub use crate::sys::abi::usercalls::raw::{ByteBuffer, FifoDescriptor, Return, Usercall};
+        pub use crate::sys::abi::usercalls::raw::{Fd, Result, Tcs};
+        pub use crate::sys::abi::usercalls::raw::{
+            EV_RETURNQ_NOT_EMPTY, EV_UNPARK, EV_USERCALLQ_NOT_FULL, FD_STDERR, FD_STDIN, FD_STDOUT,
+            RESULT_SUCCESS, USERCALL_USER_DEFINED, WAIT_INDEFINITE, WAIT_NO,
+        };
+    }
+}
+
+/// Functions for querying mapping information for pointers.
+pub mod mem {
+    pub use crate::sys::abi::mem::*;
+}
+
+pub mod arch;
+pub mod ffi;
+pub mod io;
+
+/// Functions for querying thread-related information.
+pub mod thread {
+    pub use crate::sys::abi::thread::current;
+}
diff --git a/library/std/src/os/freebsd/fs.rs b/library/std/src/os/freebsd/fs.rs
new file mode 100644
index 000000000..8db3a950c
--- /dev/null
+++ b/library/std/src/os/freebsd/fs.rs
@@ -0,0 +1,154 @@
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+#[allow(deprecated)]
+use crate::os::freebsd::raw;
+
+/// OS-specific extensions to [`fs::Metadata`].
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    /// Gain a reference to the underlying `stat` structure which contains
+    /// the raw information returned by the OS.
+    ///
+    /// The contents of the returned `stat` are **not** consistent across
+    /// Unix platforms. The `os::unix::fs::MetadataExt` trait contains the
+    /// cross-Unix abstractions contained within the raw stat.
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    #[deprecated(
+        since = "1.8.0",
+        note = "deprecated in favor of the accessor \
+                methods of this trait"
+    )]
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat;
+
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_birthtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_birthtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_flags(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gen(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_lspare(&self) -> u32;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat {
+        // The methods below use libc::stat, so they work fine when libc is built with FreeBSD 12 ABI.
+        // This method would just return nonsense.
+        #[cfg(freebsd12)]
+        panic!("as_raw_stat not supported with FreeBSD 12 ABI");
+        #[cfg(not(freebsd12))]
+        unsafe {
+            &*(self.as_inner().as_inner() as *const libc::stat as *const raw::stat)
+        }
+    }
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        self.as_inner().as_inner().st_atime as i64
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_atime_nsec as i64
+    }
+    fn st_mtime(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime as i64
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime_nsec as i64
+    }
+    fn st_ctime(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime as i64
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime_nsec as i64
+    }
+    fn st_birthtime(&self) -> i64 {
+        self.as_inner().as_inner().st_birthtime as i64
+    }
+    fn st_birthtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_birthtime_nsec as i64
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+    fn st_gen(&self) -> u32 {
+        self.as_inner().as_inner().st_gen as u32
+    }
+    fn st_flags(&self) -> u32 {
+        self.as_inner().as_inner().st_flags as u32
+    }
+    #[cfg(freebsd12)]
+    fn st_lspare(&self) -> u32 {
+        panic!("st_lspare not supported with FreeBSD 12 ABI");
+    }
+    #[cfg(not(freebsd12))]
+    fn st_lspare(&self) -> u32 {
+        self.as_inner().as_inner().st_lspare as u32
+    }
+}
diff --git a/library/std/src/os/freebsd/mod.rs b/library/std/src/os/freebsd/mod.rs
new file mode 100644
index 000000000..c072fae55
--- /dev/null
+++ b/library/std/src/os/freebsd/mod.rs
@@ -0,0 +1,6 @@
+//! FreeBSD-specific definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+pub mod fs;
+pub mod raw;
diff --git a/library/std/src/os/freebsd/raw.rs b/library/std/src/os/freebsd/raw.rs
new file mode 100644
index 000000000..ab0bf7923
--- /dev/null
+++ b/library/std/src/os/freebsd/raw.rs
@@ -0,0 +1,86 @@
+//! FreeBSD-specific raw type definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.8.0",
+    note = "these type aliases are no longer supported by \
+            the standard library, the `libc` crate on \
+            crates.io should be used instead for the correct \
+            definitions"
+)]
+#![allow(deprecated)]
+
+use crate::os::raw::c_long;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blkcnt_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blksize_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type dev_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type fflags_t = u32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type ino_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type mode_t = u32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type nlink_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type off_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type time_t = i64;
+
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = usize;
+
+#[repr(C)]
+#[derive(Clone)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub struct stat {
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_dev: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ino: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mode: u16,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_nlink: u16,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_uid: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gid: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_rdev: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_size: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blocks: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blksize: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_flags: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gen: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_lspare: i32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_birthtime: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_birthtime_nsec: c_long,
+    #[cfg(target_arch = "x86")]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub __unused: [u8; 8],
+}
diff --git a/library/std/src/os/fuchsia/fs.rs b/library/std/src/os/fuchsia/fs.rs
new file mode 100644
index 000000000..b48a46f91
--- /dev/null
+++ b/library/std/src/os/fuchsia/fs.rs
@@ -0,0 +1,95 @@
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+/// OS-specific extensions to [`fs::Metadata`].
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        self.as_inner().as_inner().st_atime as i64
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_atime_nsec as i64
+    }
+    fn st_mtime(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime as i64
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime_nsec as i64
+    }
+    fn st_ctime(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime as i64
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime_nsec as i64
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+}
diff --git a/library/std/src/os/fuchsia/mod.rs b/library/std/src/os/fuchsia/mod.rs
new file mode 100644
index 000000000..cd1b8233e
--- /dev/null
+++ b/library/std/src/os/fuchsia/mod.rs
@@ -0,0 +1,6 @@
+//! Fuchsia-specific definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+pub mod fs;
+pub mod raw;
diff --git a/library/std/src/os/fuchsia/raw.rs b/library/std/src/os/fuchsia/raw.rs
new file mode 100644
index 000000000..060d6e86b
--- /dev/null
+++ b/library/std/src/os/fuchsia/raw.rs
@@ -0,0 +1,293 @@
+//! Fuchsia-specific raw type definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.8.0",
+    note = "these type aliases are no longer supported by \
+            the standard library, the `libc` crate on \
+            crates.io should be used instead for the correct \
+            definitions"
+)]
+#![allow(deprecated)]
+
+use crate::os::raw::c_ulong;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type dev_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type mode_t = u32;
+
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = c_ulong;
+
+#[doc(inline)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub use self::arch::{blkcnt_t, blksize_t, ino_t, nlink_t, off_t, stat, time_t};
+
+#[cfg(any(
+    target_arch = "x86",
+    target_arch = "le32",
+    target_arch = "powerpc",
+    target_arch = "arm"
+))]
+mod arch {
+    use crate::os::raw::{c_long, c_short, c_uint};
+
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blksize_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type nlink_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type time_t = i64;
+
+    #[repr(C)]
+    #[derive(Clone)]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub struct stat {
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_dev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad1: c_short,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __st_ino: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mode: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_nlink: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_uid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_gid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_rdev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad2: c_uint,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_size: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blksize: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blocks: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ino: u64,
+    }
+}
+
+#[cfg(target_arch = "mips")]
+mod arch {
+    use crate::os::raw::{c_long, c_ulong};
+
+    #[cfg(target_env = "musl")]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = i64;
+    #[cfg(not(target_env = "musl"))]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blksize_t = u64;
+    #[cfg(target_env = "musl")]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[cfg(not(target_env = "musl"))]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type nlink_t = u64;
+    #[cfg(target_env = "musl")]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = u64;
+    #[cfg(not(target_env = "musl"))]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type time_t = i64;
+
+    #[repr(C)]
+    #[derive(Clone)]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub struct stat {
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_dev: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_pad1: [c_long; 3],
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ino: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mode: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_nlink: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_uid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_gid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_rdev: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_pad2: [c_long; 2],
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_size: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blksize: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blocks: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_pad5: [c_long; 14],
+    }
+}
+
+#[cfg(target_arch = "mips64")]
+mod arch {
+    pub use libc::{blkcnt_t, blksize_t, ino_t, nlink_t, off_t, stat, time_t};
+}
+
+#[cfg(target_arch = "aarch64")]
+mod arch {
+    use crate::os::raw::{c_int, c_long};
+
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blksize_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type nlink_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type time_t = i64;
+
+    #[repr(C)]
+    #[derive(Clone)]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub struct stat {
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_dev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ino: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mode: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_nlink: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_uid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_gid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_rdev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad1: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_size: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blksize: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad2: c_int,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blocks: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __unused: [c_int; 2],
+    }
+}
+
+#[cfg(target_arch = "x86_64")]
+mod arch {
+    use crate::os::raw::{c_int, c_long};
+
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blksize_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type nlink_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type time_t = i64;
+
+    #[repr(C)]
+    #[derive(Clone)]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub struct stat {
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_dev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ino: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_nlink: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mode: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_uid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_gid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad0: c_int,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_rdev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_size: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blksize: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blocks: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __unused: [c_long; 3],
+    }
+}
diff --git a/library/std/src/os/haiku/fs.rs b/library/std/src/os/haiku/fs.rs
new file mode 100644
index 000000000..a23a2af8f
--- /dev/null
+++ b/library/std/src/os/haiku/fs.rs
@@ -0,0 +1,127 @@
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+#[allow(deprecated)]
+use crate::os::haiku::raw;
+
+/// OS-specific extensions to [`fs::Metadata`].
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    /// Gain a reference to the underlying `stat` structure which contains
+    /// the raw information returned by the OS.
+    ///
+    /// The contents of the returned `stat` are **not** consistent across
+    /// Unix platforms. The `os::unix::fs::MetadataExt` trait contains the
+    /// cross-Unix abstractions contained within the raw stat.
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    #[deprecated(
+        since = "1.8.0",
+        note = "deprecated in favor of the accessor \
+                methods of this trait"
+    )]
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat;
+
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_crtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_crtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat {
+        unsafe { &*(self.as_inner().as_inner() as *const libc::stat as *const raw::stat) }
+    }
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        self.as_inner().as_inner().st_atime as i64
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_atime_nsec as i64
+    }
+    fn st_mtime(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime as i64
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime_nsec as i64
+    }
+    fn st_ctime(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime as i64
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime_nsec as i64
+    }
+    fn st_crtime(&self) -> i64 {
+        self.as_inner().as_inner().st_crtime as i64
+    }
+    fn st_crtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_crtime_nsec as i64
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+}
diff --git a/library/std/src/os/haiku/mod.rs b/library/std/src/os/haiku/mod.rs
new file mode 100644
index 000000000..73f500cad
--- /dev/null
+++ b/library/std/src/os/haiku/mod.rs
@@ -0,0 +1,6 @@
+//! Haiku-specific definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+pub mod fs;
+pub mod raw;
diff --git a/library/std/src/os/haiku/raw.rs b/library/std/src/os/haiku/raw.rs
new file mode 100644
index 000000000..afbb66ccb
--- /dev/null
+++ b/library/std/src/os/haiku/raw.rs
@@ -0,0 +1,79 @@
+//! Haiku-specific raw type definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.53.0",
+    note = "these type aliases are no longer supported by \
+            the standard library, the `libc` crate on \
+            crates.io should be used instead for the correct \
+            definitions"
+)]
+#![allow(deprecated)]
+
+use crate::os::raw::c_long;
+use crate::os::unix::raw::{gid_t, uid_t};
+
+// Use the direct definition of usize, instead of uintptr_t like in libc
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = usize;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blkcnt_t = i64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blksize_t = i32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type dev_t = i32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type ino_t = i64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type mode_t = u32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type nlink_t = i32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type off_t = i64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type time_t = i32;
+
+#[repr(C)]
+#[derive(Clone)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub struct stat {
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_dev: dev_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ino: ino_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mode: mode_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_nlink: nlink_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_uid: uid_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gid: gid_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_size: off_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_rdev: dev_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blksize: blksize_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_crtime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_crtime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_type: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blocks: blkcnt_t,
+}
diff --git a/library/std/src/os/hermit/ffi.rs b/library/std/src/os/hermit/ffi.rs
new file mode 100644
index 000000000..19761fd99
--- /dev/null
+++ b/library/std/src/os/hermit/ffi.rs
@@ -0,0 +1,41 @@
+//! HermitCore-specific extension to the primitives in the `std::ffi` module
+//!
+//! # Examples
+//!
+//! ```
+//! use std::ffi::OsString;
+//! use std::os::hermit::ffi::OsStringExt;
+//!
+//! let bytes = b"foo".to_vec();
+//!
+//! // OsStringExt::from_vec
+//! let os_string = OsString::from_vec(bytes);
+//! assert_eq!(os_string.to_str(), Some("foo"));
+//!
+//! // OsStringExt::into_vec
+//! let bytes = os_string.into_vec();
+//! assert_eq!(bytes, b"foo");
+//! ```
+//!
+//! ```
+//! use std::ffi::OsStr;
+//! use std::os::hermit::ffi::OsStrExt;
+//!
+//! let bytes = b"foo";
+//!
+//! // OsStrExt::from_bytes
+//! let os_str = OsStr::from_bytes(bytes);
+//! assert_eq!(os_str.to_str(), Some("foo"));
+//!
+//! // OsStrExt::as_bytes
+//! let bytes = os_str.as_bytes();
+//! assert_eq!(bytes, b"foo");
+//! ```
+
+#![stable(feature = "rust1", since = "1.0.0")]
+
+#[path = "../unix/ffi/os_str.rs"]
+mod os_str;
+
+#[stable(feature = "rust1", since = "1.0.0")]
+pub use self::os_str::{OsStrExt, OsStringExt};
diff --git a/library/std/src/os/hermit/mod.rs b/library/std/src/os/hermit/mod.rs
new file mode 100644
index 000000000..4657b545a
--- /dev/null
+++ b/library/std/src/os/hermit/mod.rs
@@ -0,0 +1,13 @@
+#![stable(feature = "rust1", since = "1.0.0")]
+
+pub mod ffi;
+
+/// A prelude for conveniently writing platform-specific code.
+///
+/// Includes all extension traits, and some important type definitions.
+#[stable(feature = "rust1", since = "1.0.0")]
+pub mod prelude {
+    #[doc(no_inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::ffi::{OsStrExt, OsStringExt};
+}
diff --git a/library/std/src/os/horizon/fs.rs b/library/std/src/os/horizon/fs.rs
new file mode 100644
index 000000000..132552210
--- /dev/null
+++ b/library/std/src/os/horizon/fs.rs
@@ -0,0 +1,95 @@
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+/// OS-specific extensions to [`fs::Metadata`].
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        self.as_inner().as_inner().st_atim.tv_sec
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_atim.tv_nsec as i64
+    }
+    fn st_mtime(&self) -> i64 {
+        self.as_inner().as_inner().st_mtim.tv_sec
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_mtim.tv_nsec as i64
+    }
+    fn st_ctime(&self) -> i64 {
+        self.as_inner().as_inner().st_ctim.tv_sec
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_ctim.tv_nsec as i64
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+}
diff --git a/library/std/src/os/horizon/mod.rs b/library/std/src/os/horizon/mod.rs
new file mode 100644
index 000000000..326d0ae9c
--- /dev/null
+++ b/library/std/src/os/horizon/mod.rs
@@ -0,0 +1,6 @@
+//! Definitions for Horizon OS
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+pub mod fs;
+pub(crate) mod raw;
diff --git a/library/std/src/os/horizon/raw.rs b/library/std/src/os/horizon/raw.rs
new file mode 100644
index 000000000..929fa7db1
--- /dev/null
+++ b/library/std/src/os/horizon/raw.rs
@@ -0,0 +1,70 @@
+//! Horizon OS raw type definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.8.0",
+    note = "these type aliases are no longer supported by \
+            the standard library, the `libc` crate on \
+            crates.io should be used instead for the correct \
+            definitions"
+)]
+#![allow(deprecated)]
+
+use crate::os::raw::c_long;
+use crate::os::unix::raw::{gid_t, uid_t};
+
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = libc::pthread_t;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blkcnt_t = libc::blkcnt_t;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blksize_t = libc::blksize_t;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type dev_t = libc::dev_t;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type ino_t = libc::ino_t;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type mode_t = libc::mode_t;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type nlink_t = libc::nlink_t;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type off_t = libc::off_t;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type time_t = libc::time_t;
+
+#[repr(C)]
+#[derive(Clone)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub struct stat {
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_dev: dev_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ino: ino_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mode: mode_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_nlink: nlink_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_uid: uid_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gid: gid_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_rdev: dev_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_size: off_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blksize: blksize_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blocks: blkcnt_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_spare4: [c_long; 2usize],
+}
diff --git a/library/std/src/os/illumos/fs.rs b/library/std/src/os/illumos/fs.rs
new file mode 100644
index 000000000..63be48b81
--- /dev/null
+++ b/library/std/src/os/illumos/fs.rs
@@ -0,0 +1,116 @@
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+#[allow(deprecated)]
+use crate::os::illumos::raw;
+
+/// OS-specific extensions to [`fs::Metadata`].
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    /// Gain a reference to the underlying `stat` structure which contains
+    /// the raw information returned by the OS.
+    ///
+    /// The contents of the returned `stat` are **not** consistent across
+    /// Unix platforms. The `os::unix::fs::MetadataExt` trait contains the
+    /// cross-Unix abstractions contained within the raw stat.
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    #[deprecated(
+        since = "1.8.0",
+        note = "deprecated in favor of the accessor methods of this trait"
+    )]
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat;
+
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat {
+        unsafe { &*(self.as_inner().as_inner() as *const libc::stat as *const raw::stat) }
+    }
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        self.as_inner().as_inner().st_atime as i64
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_atime_nsec as i64
+    }
+    fn st_mtime(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime as i64
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime_nsec as i64
+    }
+    fn st_ctime(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime as i64
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime_nsec as i64
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+}
diff --git a/library/std/src/os/illumos/mod.rs b/library/std/src/os/illumos/mod.rs
new file mode 100644
index 000000000..e61926f89
--- /dev/null
+++ b/library/std/src/os/illumos/mod.rs
@@ -0,0 +1,6 @@
+//! illumos-specific definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+pub mod fs;
+pub mod raw;
diff --git a/library/std/src/os/illumos/raw.rs b/library/std/src/os/illumos/raw.rs
new file mode 100644
index 000000000..2bea9ebb3
--- /dev/null
+++ b/library/std/src/os/illumos/raw.rs
@@ -0,0 +1,74 @@
+//! illumos-specific raw type definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.8.0",
+    note = "these type aliases are no longer supported by the standard library, the `libc` \
+    crate on crates.io should be used instead for the correct definitions"
+)]
+#![allow(deprecated)]
+
+use crate::os::raw::c_long;
+use crate::os::unix::raw::{gid_t, uid_t};
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blkcnt_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blksize_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type dev_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type fflags_t = u32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type ino_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type mode_t = u32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type nlink_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type off_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type time_t = i64;
+
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = u32;
+
+#[repr(C)]
+#[derive(Clone)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub struct stat {
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_dev: dev_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ino: ino_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mode: mode_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_nlink: nlink_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_uid: uid_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gid: gid_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_rdev: dev_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_size: off_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blksize: blksize_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blocks: blkcnt_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub __unused: [u8; 16],
+}
diff --git a/library/std/src/os/ios/fs.rs b/library/std/src/os/ios/fs.rs
new file mode 100644
index 000000000..4a4637ce0
--- /dev/null
+++ b/library/std/src/os/ios/fs.rs
@@ -0,0 +1,142 @@
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+#[allow(deprecated)]
+use crate::os::ios::raw;
+
+/// OS-specific extensions to [`fs::Metadata`].
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    /// Gain a reference to the underlying `stat` structure which contains
+    /// the raw information returned by the OS.
+    ///
+    /// The contents of the returned `stat` are **not** consistent across
+    /// Unix platforms. The `os::unix::fs::MetadataExt` trait contains the
+    /// cross-Unix abstractions contained within the raw stat.
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    #[deprecated(
+        since = "1.8.0",
+        note = "deprecated in favor of the accessor \
+                methods of this trait"
+    )]
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat;
+
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_birthtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_birthtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_flags(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gen(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_lspare(&self) -> u32;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat {
+        unsafe { &*(self.as_inner().as_inner() as *const libc::stat as *const raw::stat) }
+    }
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        self.as_inner().as_inner().st_atime as i64
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_atime_nsec as i64
+    }
+    fn st_mtime(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime as i64
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime_nsec as i64
+    }
+    fn st_ctime(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime as i64
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime_nsec as i64
+    }
+    fn st_birthtime(&self) -> i64 {
+        self.as_inner().as_inner().st_birthtime as i64
+    }
+    fn st_birthtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_birthtime_nsec as i64
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+    fn st_gen(&self) -> u32 {
+        self.as_inner().as_inner().st_gen as u32
+    }
+    fn st_flags(&self) -> u32 {
+        self.as_inner().as_inner().st_flags as u32
+    }
+    fn st_lspare(&self) -> u32 {
+        self.as_inner().as_inner().st_lspare as u32
+    }
+}
diff --git a/library/std/src/os/ios/mod.rs b/library/std/src/os/ios/mod.rs
new file mode 100644
index 000000000..fdefa1f6b
--- /dev/null
+++ b/library/std/src/os/ios/mod.rs
@@ -0,0 +1,6 @@
+//! iOS-specific definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+pub mod fs;
+pub mod raw;
diff --git a/library/std/src/os/ios/raw.rs b/library/std/src/os/ios/raw.rs
new file mode 100644
index 000000000..af12aeebe
--- /dev/null
+++ b/library/std/src/os/ios/raw.rs
@@ -0,0 +1,83 @@
+//! iOS-specific raw type definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.8.0",
+    note = "these type aliases are no longer supported by \
+            the standard library, the `libc` crate on \
+            crates.io should be used instead for the correct \
+            definitions"
+)]
+#![allow(deprecated)]
+
+use crate::os::raw::c_long;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blkcnt_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blksize_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type dev_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type ino_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type mode_t = u32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type nlink_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type off_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type time_t = i64;
+
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = usize;
+
+#[repr(C)]
+#[derive(Clone)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub struct stat {
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_dev: i32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mode: u16,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_nlink: u16,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ino: u64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_uid: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gid: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_rdev: i32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_birthtime: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_birthtime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_size: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blocks: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blksize: i32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_flags: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gen: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_lspare: i32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_qspare: [i64; 2],
+}
diff --git a/library/std/src/os/l4re/fs.rs b/library/std/src/os/l4re/fs.rs
new file mode 100644
index 000000000..6d6a535b1
--- /dev/null
+++ b/library/std/src/os/l4re/fs.rs
@@ -0,0 +1,382 @@
+//! L4Re-specific extensions to primitives in the [`std::fs`] module.
+//!
+//! [`std::fs`]: crate::fs
+
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+#[allow(deprecated)]
+use crate::os::l4re::raw;
+
+/// OS-specific extensions to [`fs::Metadata`].
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    /// Gain a reference to the underlying `stat` structure which contains
+    /// the raw information returned by the OS.
+    ///
+    /// The contents of the returned [`stat`] are **not** consistent across
+    /// Unix platforms. The `os::unix::fs::MetadataExt` trait contains the
+    /// cross-Unix abstractions contained within the raw stat.
+    ///
+    /// [`stat`]: struct@crate::os::linux::raw::stat
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let stat = meta.as_raw_stat();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    #[deprecated(since = "1.8.0", note = "other methods of this trait are now preferred")]
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat;
+
+    /// Returns the device ID on which this file resides.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_dev());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    /// Returns the inode number.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_ino());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    /// Returns the file type and mode.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_mode());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    /// Returns the number of hard links to file.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_nlink());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    /// Returns the user ID of the file owner.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_uid());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    /// Returns the group ID of the file owner.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_gid());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    /// Returns the device ID that this file represents. Only relevant for special file.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_rdev());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    /// Returns the size of the file (if it is a regular file or a symbolic link) in bytes.
+    ///
+    /// The size of a symbolic link is the length of the pathname it contains,
+    /// without a terminating null byte.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_size());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    /// Returns the last access time of the file, in seconds since Unix Epoch.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_atime());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    /// Returns the last access time of the file, in nanoseconds since [`st_atime`].
+    ///
+    /// [`st_atime`]: Self::st_atime
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_atime_nsec());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    /// Returns the last modification time of the file, in seconds since Unix Epoch.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_mtime());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    /// Returns the last modification time of the file, in nanoseconds since [`st_mtime`].
+    ///
+    /// [`st_mtime`]: Self::st_mtime
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_mtime_nsec());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    /// Returns the last status change time of the file, in seconds since Unix Epoch.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_ctime());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    /// Returns the last status change time of the file, in nanoseconds since [`st_ctime`].
+    ///
+    /// [`st_ctime`]: Self::st_ctime
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_ctime_nsec());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    /// Returns the "preferred" block size for efficient filesystem I/O.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_blksize());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    /// Returns the number of blocks allocated to the file, 512-byte units.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_blocks());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat {
+        unsafe { &*(self.as_inner().as_inner() as *const libc::stat64 as *const raw::stat) }
+    }
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        self.as_inner().as_inner().st_atime as i64
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_atime_nsec as i64
+    }
+    fn st_mtime(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime as i64
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime_nsec as i64
+    }
+    fn st_ctime(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime as i64
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime_nsec as i64
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+}
diff --git a/library/std/src/os/l4re/mod.rs b/library/std/src/os/l4re/mod.rs
new file mode 100644
index 000000000..14c2425c1
--- /dev/null
+++ b/library/std/src/os/l4re/mod.rs
@@ -0,0 +1,7 @@
+//! L4Re-specific definitions.
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![doc(cfg(target_os = "l4re"))]
+
+pub mod fs;
+pub mod raw;
diff --git a/library/std/src/os/l4re/raw.rs b/library/std/src/os/l4re/raw.rs
new file mode 100644
index 000000000..699e8be33
--- /dev/null
+++ b/library/std/src/os/l4re/raw.rs
@@ -0,0 +1,365 @@
+//! L4Re-specific raw type definitions.
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.8.0",
+    note = "these type aliases are no longer supported by \
+            the standard library, the `libc` crate on \
+            crates.io should be used instead for the correct \
+            definitions"
+)]
+#![allow(deprecated)]
+
+use crate::os::raw::c_ulong;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type dev_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type mode_t = u32;
+
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = c_ulong;
+
+#[doc(inline)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub use self::arch::{blkcnt_t, blksize_t, ino_t, nlink_t, off_t, stat, time_t};
+
+#[cfg(any(
+    target_arch = "x86",
+    target_arch = "le32",
+    target_arch = "m68k",
+    target_arch = "powerpc",
+    target_arch = "sparc",
+    target_arch = "arm",
+    target_arch = "asmjs",
+    target_arch = "wasm32"
+))]
+mod arch {
+    use crate::os::raw::{c_long, c_short, c_uint};
+
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blksize_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type nlink_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type time_t = i64;
+
+    #[repr(C)]
+    #[derive(Clone)]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub struct stat {
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_dev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad1: c_short,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __st_ino: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mode: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_nlink: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_uid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_gid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_rdev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad2: c_uint,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_size: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blksize: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blocks: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ino: u64,
+    }
+}
+
+#[cfg(target_arch = "mips")]
+mod arch {
+    use crate::os::raw::{c_long, c_ulong};
+
+    #[cfg(target_env = "musl")]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = i64;
+    #[cfg(not(target_env = "musl"))]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blksize_t = u64;
+    #[cfg(target_env = "musl")]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[cfg(not(target_env = "musl"))]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type nlink_t = u64;
+    #[cfg(target_env = "musl")]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = u64;
+    #[cfg(not(target_env = "musl"))]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type time_t = i64;
+
+    #[repr(C)]
+    #[derive(Clone)]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub struct stat {
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_dev: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_pad1: [c_long; 3],
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ino: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mode: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_nlink: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_uid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_gid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_rdev: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_pad2: [c_long; 2],
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_size: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blksize: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blocks: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_pad5: [c_long; 14],
+    }
+}
+
+#[cfg(target_arch = "hexagon")]
+mod arch {
+    use crate::os::raw::{c_int, c_long, c_uint};
+
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = i64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blksize_t = c_long;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type nlink_t = c_uint;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = i64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type time_t = i64;
+
+    #[repr(C)]
+    #[derive(Clone)]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub struct stat {
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_dev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ino: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mode: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_nlink: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_uid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_gid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_rdev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad1: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_size: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blksize: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad2: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blocks: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad3: [c_int; 2],
+    }
+}
+
+#[cfg(any(
+    target_arch = "mips64",
+    target_arch = "s390x",
+    target_arch = "sparc64",
+    target_arch = "riscv64",
+    target_arch = "riscv32"
+))]
+mod arch {
+    pub use libc::{blkcnt_t, blksize_t, ino_t, nlink_t, off_t, stat, time_t};
+}
+
+#[cfg(target_arch = "aarch64")]
+mod arch {
+    use crate::os::raw::{c_int, c_long};
+
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = i64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blksize_t = i32;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type nlink_t = u32;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = i64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type time_t = c_long;
+
+    #[repr(C)]
+    #[derive(Clone)]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub struct stat {
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_dev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ino: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mode: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_nlink: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_uid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_gid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_rdev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad1: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_size: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blksize: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad2: c_int,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blocks: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime: time_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime: time_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime: time_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __unused: [c_int; 2],
+    }
+}
+
+#[cfg(any(target_arch = "x86_64", target_arch = "powerpc64"))]
+mod arch {
+    use crate::os::raw::{c_int, c_long};
+
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blksize_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type nlink_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type time_t = i64;
+
+    #[repr(C)]
+    #[derive(Clone)]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub struct stat {
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_dev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ino: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_nlink: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mode: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_uid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_gid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad0: c_int,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_rdev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_size: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blksize: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blocks: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __unused: [c_long; 3],
+    }
+}
diff --git a/library/std/src/os/linux/fs.rs b/library/std/src/os/linux/fs.rs
new file mode 100644
index 000000000..479bbcc17
--- /dev/null
+++ b/library/std/src/os/linux/fs.rs
@@ -0,0 +1,397 @@
+//! Linux-specific extensions to primitives in the [`std::fs`] module.
+//!
+//! [`std::fs`]: crate::fs
+
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+#[allow(deprecated)]
+use crate::os::linux::raw;
+
+/// OS-specific extensions to [`fs::Metadata`].
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    /// Gain a reference to the underlying `stat` structure which contains
+    /// the raw information returned by the OS.
+    ///
+    /// The contents of the returned [`stat`] are **not** consistent across
+    /// Unix platforms. The `os::unix::fs::MetadataExt` trait contains the
+    /// cross-Unix abstractions contained within the raw stat.
+    ///
+    /// [`stat`]: struct@crate::os::linux::raw::stat
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let stat = meta.as_raw_stat();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    #[deprecated(since = "1.8.0", note = "other methods of this trait are now preferred")]
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat;
+
+    /// Returns the device ID on which this file resides.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_dev());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    /// Returns the inode number.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_ino());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    /// Returns the file type and mode.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_mode());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    /// Returns the number of hard links to file.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_nlink());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    /// Returns the user ID of the file owner.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_uid());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    /// Returns the group ID of the file owner.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_gid());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    /// Returns the device ID that this file represents. Only relevant for special file.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_rdev());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    /// Returns the size of the file (if it is a regular file or a symbolic link) in bytes.
+    ///
+    /// The size of a symbolic link is the length of the pathname it contains,
+    /// without a terminating null byte.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_size());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    /// Returns the last access time of the file, in seconds since Unix Epoch.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_atime());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    /// Returns the last access time of the file, in nanoseconds since [`st_atime`].
+    ///
+    /// [`st_atime`]: Self::st_atime
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_atime_nsec());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    /// Returns the last modification time of the file, in seconds since Unix Epoch.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_mtime());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    /// Returns the last modification time of the file, in nanoseconds since [`st_mtime`].
+    ///
+    /// [`st_mtime`]: Self::st_mtime
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_mtime_nsec());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    /// Returns the last status change time of the file, in seconds since Unix Epoch.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_ctime());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    /// Returns the last status change time of the file, in nanoseconds since [`st_ctime`].
+    ///
+    /// [`st_ctime`]: Self::st_ctime
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_ctime_nsec());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    /// Returns the "preferred" block size for efficient filesystem I/O.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_blksize());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    /// Returns the number of blocks allocated to the file, 512-byte units.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::linux::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_blocks());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat {
+        unsafe { &*(self.as_inner().as_inner() as *const libc::stat64 as *const raw::stat) }
+    }
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        let file_attr = self.as_inner();
+        #[cfg(all(target_env = "gnu", target_pointer_width = "32"))]
+        if let Some(atime) = file_attr.stx_atime() {
+            return atime.tv_sec;
+        }
+        file_attr.as_inner().st_atime as i64
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_atime_nsec as i64
+    }
+    fn st_mtime(&self) -> i64 {
+        let file_attr = self.as_inner();
+        #[cfg(all(target_env = "gnu", target_pointer_width = "32"))]
+        if let Some(mtime) = file_attr.stx_mtime() {
+            return mtime.tv_sec;
+        }
+        file_attr.as_inner().st_mtime as i64
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime_nsec as i64
+    }
+    fn st_ctime(&self) -> i64 {
+        let file_attr = self.as_inner();
+        #[cfg(all(target_env = "gnu", target_pointer_width = "32"))]
+        if let Some(ctime) = file_attr.stx_ctime() {
+            return ctime.tv_sec;
+        }
+        file_attr.as_inner().st_ctime as i64
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime_nsec as i64
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+}
diff --git a/library/std/src/os/linux/mod.rs b/library/std/src/os/linux/mod.rs
new file mode 100644
index 000000000..8e7776f66
--- /dev/null
+++ b/library/std/src/os/linux/mod.rs
@@ -0,0 +1,8 @@
+//! Linux-specific definitions.
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![doc(cfg(target_os = "linux"))]
+
+pub mod fs;
+pub mod process;
+pub mod raw;
diff --git a/library/std/src/os/linux/process.rs b/library/std/src/os/linux/process.rs
new file mode 100644
index 000000000..540363c03
--- /dev/null
+++ b/library/std/src/os/linux/process.rs
@@ -0,0 +1,165 @@
+//! Linux-specific extensions to primitives in the [`std::process`] module.
+//!
+//! [`std::process`]: crate::process
+
+#![unstable(feature = "linux_pidfd", issue = "82971")]
+
+use crate::io::Result;
+use crate::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
+use crate::process;
+use crate::sealed::Sealed;
+#[cfg(not(doc))]
+use crate::sys::fd::FileDesc;
+use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
+
+#[cfg(doc)]
+struct FileDesc;
+
+/// This type represents a file descriptor that refers to a process.
+///
+/// A `PidFd` can be obtained by setting the corresponding option on [`Command`]
+/// with [`create_pidfd`]. Subsequently, the created pidfd can be retrieved
+/// from the [`Child`] by calling [`pidfd`] or [`take_pidfd`].
+///
+/// Example:
+/// ```no_run
+/// #![feature(linux_pidfd)]
+/// use std::os::linux::process::{CommandExt, ChildExt};
+/// use std::process::Command;
+///
+/// let mut child = Command::new("echo")
+///     .create_pidfd(true)
+///     .spawn()
+///     .expect("Failed to spawn child");
+///
+/// let pidfd = child
+///     .take_pidfd()
+///     .expect("Failed to retrieve pidfd");
+///
+/// // The file descriptor will be closed when `pidfd` is dropped.
+/// ```
+/// Refer to the man page of [`pidfd_open(2)`] for further details.
+///
+/// [`Command`]: process::Command
+/// [`create_pidfd`]: CommandExt::create_pidfd
+/// [`Child`]: process::Child
+/// [`pidfd`]: fn@ChildExt::pidfd
+/// [`take_pidfd`]: ChildExt::take_pidfd
+/// [`pidfd_open(2)`]: https://man7.org/linux/man-pages/man2/pidfd_open.2.html
+#[derive(Debug)]
+pub struct PidFd {
+    inner: FileDesc,
+}
+
+impl AsInner<FileDesc> for PidFd {
+    fn as_inner(&self) -> &FileDesc {
+        &self.inner
+    }
+}
+
+impl FromInner<FileDesc> for PidFd {
+    fn from_inner(inner: FileDesc) -> PidFd {
+        PidFd { inner }
+    }
+}
+
+impl IntoInner<FileDesc> for PidFd {
+    fn into_inner(self) -> FileDesc {
+        self.inner
+    }
+}
+
+impl AsRawFd for PidFd {
+    fn as_raw_fd(&self) -> RawFd {
+        self.as_inner().as_raw_fd()
+    }
+}
+
+impl FromRawFd for PidFd {
+    unsafe fn from_raw_fd(fd: RawFd) -> Self {
+        Self::from_inner(FileDesc::from_raw_fd(fd))
+    }
+}
+
+impl IntoRawFd for PidFd {
+    fn into_raw_fd(self) -> RawFd {
+        self.into_inner().into_raw_fd()
+    }
+}
+
+impl AsFd for PidFd {
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        self.as_inner().as_fd()
+    }
+}
+
+impl From<OwnedFd> for PidFd {
+    fn from(fd: OwnedFd) -> Self {
+        Self::from_inner(FileDesc::from_inner(fd))
+    }
+}
+
+impl From<PidFd> for OwnedFd {
+    fn from(pid_fd: PidFd) -> Self {
+        pid_fd.into_inner().into_inner()
+    }
+}
+
+/// Os-specific extensions for [`Child`]
+///
+/// [`Child`]: process::Child
+pub trait ChildExt: Sealed {
+    /// Obtains a reference to the [`PidFd`] created for this [`Child`], if available.
+    ///
+    /// A pidfd will only be available if its creation was requested with
+    /// [`create_pidfd`] when the corresponding [`Command`] was created.
+    ///
+    /// Even if requested, a pidfd may not be available due to an older
+    /// version of Linux being in use, or if some other error occurred.
+    ///
+    /// [`Command`]: process::Command
+    /// [`create_pidfd`]: CommandExt::create_pidfd
+    /// [`Child`]: process::Child
+    fn pidfd(&self) -> Result<&PidFd>;
+
+    /// Takes ownership of the [`PidFd`] created for this [`Child`], if available.
+    ///
+    /// A pidfd will only be available if its creation was requested with
+    /// [`create_pidfd`] when the corresponding [`Command`] was created.
+    ///
+    /// Even if requested, a pidfd may not be available due to an older
+    /// version of Linux being in use, or if some other error occurred.
+    ///
+    /// [`Command`]: process::Command
+    /// [`create_pidfd`]: CommandExt::create_pidfd
+    /// [`Child`]: process::Child
+    fn take_pidfd(&mut self) -> Result<PidFd>;
+}
+
+/// Os-specific extensions for [`Command`]
+///
+/// [`Command`]: process::Command
+pub trait CommandExt: Sealed {
+    /// Sets whether a [`PidFd`](struct@PidFd) should be created for the [`Child`]
+    /// spawned by this [`Command`].
+    /// By default, no pidfd will be created.
+    ///
+    /// The pidfd can be retrieved from the child with [`pidfd`] or [`take_pidfd`].
+    ///
+    /// A pidfd will only be created if it is possible to do so
+    /// in a guaranteed race-free manner (e.g. if the `clone3` system call
+    /// is supported). Otherwise, [`pidfd`] will return an error.
+    ///
+    /// [`Command`]: process::Command
+    /// [`Child`]: process::Child
+    /// [`pidfd`]: fn@ChildExt::pidfd
+    /// [`take_pidfd`]: ChildExt::take_pidfd
+    fn create_pidfd(&mut self, val: bool) -> &mut process::Command;
+}
+
+impl CommandExt for process::Command {
+    fn create_pidfd(&mut self, val: bool) -> &mut process::Command {
+        self.as_inner_mut().create_pidfd(val);
+        self
+    }
+}
diff --git a/library/std/src/os/linux/raw.rs b/library/std/src/os/linux/raw.rs
new file mode 100644
index 000000000..c73791d14
--- /dev/null
+++ b/library/std/src/os/linux/raw.rs
@@ -0,0 +1,366 @@
+//! Linux-specific raw type definitions.
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.8.0",
+    note = "these type aliases are no longer supported by \
+            the standard library, the `libc` crate on \
+            crates.io should be used instead for the correct \
+            definitions"
+)]
+#![allow(deprecated)]
+
+use crate::os::raw::c_ulong;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type dev_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type mode_t = u32;
+
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = c_ulong;
+
+#[doc(inline)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub use self::arch::{blkcnt_t, blksize_t, ino_t, nlink_t, off_t, stat, time_t};
+
+#[cfg(any(
+    target_arch = "x86",
+    target_arch = "le32",
+    target_arch = "m68k",
+    target_arch = "powerpc",
+    target_arch = "sparc",
+    target_arch = "arm",
+    target_arch = "asmjs",
+    target_arch = "wasm32"
+))]
+mod arch {
+    use crate::os::raw::{c_long, c_short, c_uint};
+
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blksize_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type nlink_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type time_t = i64;
+
+    #[repr(C)]
+    #[derive(Clone)]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub struct stat {
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_dev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad1: c_short,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __st_ino: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mode: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_nlink: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_uid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_gid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_rdev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad2: c_uint,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_size: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blksize: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blocks: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ino: u64,
+    }
+}
+
+#[cfg(target_arch = "mips")]
+mod arch {
+    use crate::os::raw::{c_long, c_ulong};
+
+    #[cfg(target_env = "musl")]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = i64;
+    #[cfg(not(target_env = "musl"))]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blksize_t = u64;
+    #[cfg(target_env = "musl")]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[cfg(not(target_env = "musl"))]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type nlink_t = u64;
+    #[cfg(target_env = "musl")]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = u64;
+    #[cfg(not(target_env = "musl"))]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type time_t = i64;
+
+    #[repr(C)]
+    #[derive(Clone)]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub struct stat {
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_dev: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_pad1: [c_long; 3],
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ino: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mode: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_nlink: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_uid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_gid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_rdev: c_ulong,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_pad2: [c_long; 2],
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_size: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blksize: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blocks: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_pad5: [c_long; 14],
+    }
+}
+
+#[cfg(target_arch = "hexagon")]
+mod arch {
+    use crate::os::raw::{c_int, c_long, c_uint};
+
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = i64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blksize_t = c_long;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type nlink_t = c_uint;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = i64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type time_t = i64;
+
+    #[repr(C)]
+    #[derive(Clone)]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub struct stat {
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_dev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ino: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mode: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_nlink: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_uid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_gid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_rdev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad1: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_size: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blksize: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad2: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blocks: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad3: [c_int; 2],
+    }
+}
+
+#[cfg(any(
+    target_arch = "mips64",
+    target_arch = "s390x",
+    target_arch = "sparc64",
+    target_arch = "riscv64",
+    target_arch = "riscv32"
+))]
+mod arch {
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub use libc::{blkcnt_t, blksize_t, ino_t, nlink_t, off_t, stat, time_t};
+}
+
+#[cfg(target_arch = "aarch64")]
+mod arch {
+    use crate::os::raw::{c_int, c_long};
+
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = i64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blksize_t = i32;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type nlink_t = u32;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = i64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type time_t = c_long;
+
+    #[repr(C)]
+    #[derive(Clone)]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub struct stat {
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_dev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ino: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mode: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_nlink: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_uid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_gid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_rdev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad1: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_size: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blksize: i32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad2: c_int,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blocks: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime: time_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime: time_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime: time_t,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __unused: [c_int; 2],
+    }
+}
+
+#[cfg(any(target_arch = "x86_64", target_arch = "powerpc64"))]
+mod arch {
+    use crate::os::raw::{c_int, c_long};
+
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blkcnt_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type blksize_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type ino_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type nlink_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type off_t = u64;
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub type time_t = i64;
+
+    #[repr(C)]
+    #[derive(Clone)]
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub struct stat {
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_dev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ino: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_nlink: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mode: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_uid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_gid: u32,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __pad0: c_int,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_rdev: u64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_size: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blksize: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_blocks: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_atime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_mtime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime: i64,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub st_ctime_nsec: c_long,
+        #[stable(feature = "raw_ext", since = "1.1.0")]
+        pub __unused: [c_long; 3],
+    }
+}
diff --git a/library/std/src/os/macos/fs.rs b/library/std/src/os/macos/fs.rs
new file mode 100644
index 000000000..91915da6a
--- /dev/null
+++ b/library/std/src/os/macos/fs.rs
@@ -0,0 +1,148 @@
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+#[allow(deprecated)]
+use crate::os::macos::raw;
+
+/// OS-specific extensions to [`fs::Metadata`].
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    /// Gain a reference to the underlying `stat` structure which contains
+    /// the raw information returned by the OS.
+    ///
+    /// The contents of the returned `stat` are **not** consistent across
+    /// Unix platforms. The `os::unix::fs::MetadataExt` trait contains the
+    /// cross-Unix abstractions contained within the raw stat.
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    #[deprecated(
+        since = "1.8.0",
+        note = "deprecated in favor of the accessor \
+                methods of this trait"
+    )]
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat;
+
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_birthtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_birthtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_flags(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gen(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_lspare(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_qspare(&self) -> [u64; 2];
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat {
+        unsafe { &*(self.as_inner().as_inner() as *const libc::stat as *const raw::stat) }
+    }
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        self.as_inner().as_inner().st_atime as i64
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_atime_nsec as i64
+    }
+    fn st_mtime(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime as i64
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime_nsec as i64
+    }
+    fn st_ctime(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime as i64
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime_nsec as i64
+    }
+    fn st_birthtime(&self) -> i64 {
+        self.as_inner().as_inner().st_birthtime as i64
+    }
+    fn st_birthtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_birthtime_nsec as i64
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+    fn st_gen(&self) -> u32 {
+        self.as_inner().as_inner().st_gen as u32
+    }
+    fn st_flags(&self) -> u32 {
+        self.as_inner().as_inner().st_flags as u32
+    }
+    fn st_lspare(&self) -> u32 {
+        self.as_inner().as_inner().st_lspare as u32
+    }
+    fn st_qspare(&self) -> [u64; 2] {
+        let qspare = self.as_inner().as_inner().st_qspare;
+        [qspare[0] as u64, qspare[1] as u64]
+    }
+}
diff --git a/library/std/src/os/macos/mod.rs b/library/std/src/os/macos/mod.rs
new file mode 100644
index 000000000..791d703b1
--- /dev/null
+++ b/library/std/src/os/macos/mod.rs
@@ -0,0 +1,6 @@
+//! macOS-specific definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+pub mod fs;
+pub mod raw;
diff --git a/library/std/src/os/macos/raw.rs b/library/std/src/os/macos/raw.rs
new file mode 100644
index 000000000..0b21f6ee5
--- /dev/null
+++ b/library/std/src/os/macos/raw.rs
@@ -0,0 +1,83 @@
+//! macOS-specific raw type definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.8.0",
+    note = "these type aliases are no longer supported by \
+            the standard library, the `libc` crate on \
+            crates.io should be used instead for the correct \
+            definitions"
+)]
+#![allow(deprecated)]
+
+use crate::os::raw::c_long;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blkcnt_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blksize_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type dev_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type ino_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type mode_t = u32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type nlink_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type off_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type time_t = i64;
+
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = usize;
+
+#[repr(C)]
+#[derive(Clone)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub struct stat {
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_dev: i32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mode: u16,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_nlink: u16,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ino: u64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_uid: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gid: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_rdev: i32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_birthtime: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_birthtime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_size: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blocks: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blksize: i32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_flags: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gen: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_lspare: i32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_qspare: [i64; 2],
+}
diff --git a/library/std/src/os/mod.rs b/library/std/src/os/mod.rs
new file mode 100644
index 000000000..6fbaa42c7
--- /dev/null
+++ b/library/std/src/os/mod.rs
@@ -0,0 +1,150 @@
+//! OS-specific functionality.
+
+#![stable(feature = "os", since = "1.0.0")]
+#![allow(missing_docs, nonstandard_style, missing_debug_implementations)]
+
+pub mod raw;
+
+// The code below could be written clearer using `cfg_if!`. However, the items below are
+// publicly exported by `std` and external tools can have trouble analysing them because of the use
+// of a macro that is not vendored by Rust and included in the toolchain.
+// See https://github.com/rust-analyzer/rust-analyzer/issues/6038.
+
+// On certain platforms right now the "main modules" modules that are
+// documented don't compile (missing things in `libc` which is empty),
+// so just omit them with an empty module and add the "unstable" attribute.
+
+// Unix, linux, wasi and windows are handled a bit differently.
+#[cfg(all(
+    doc,
+    any(
+        all(target_arch = "wasm32", not(target_os = "wasi")),
+        all(target_vendor = "fortanix", target_env = "sgx")
+    )
+))]
+#[unstable(issue = "none", feature = "std_internals")]
+pub mod unix {}
+#[cfg(all(
+    doc,
+    any(
+        all(target_arch = "wasm32", not(target_os = "wasi")),
+        all(target_vendor = "fortanix", target_env = "sgx")
+    )
+))]
+#[unstable(issue = "none", feature = "std_internals")]
+pub mod linux {}
+#[cfg(all(
+    doc,
+    any(
+        all(target_arch = "wasm32", not(target_os = "wasi")),
+        all(target_vendor = "fortanix", target_env = "sgx")
+    )
+))]
+#[unstable(issue = "none", feature = "std_internals")]
+pub mod wasi {}
+#[cfg(all(
+    doc,
+    any(
+        all(target_arch = "wasm32", not(target_os = "wasi")),
+        all(target_vendor = "fortanix", target_env = "sgx")
+    )
+))]
+#[unstable(issue = "none", feature = "std_internals")]
+pub mod windows {}
+
+// unix
+#[cfg(not(all(
+    doc,
+    any(
+        all(target_arch = "wasm32", not(target_os = "wasi")),
+        all(target_vendor = "fortanix", target_env = "sgx")
+    )
+)))]
+#[cfg(target_os = "hermit")]
+#[path = "hermit/mod.rs"]
+pub mod unix;
+#[cfg(not(all(
+    doc,
+    any(
+        all(target_arch = "wasm32", not(target_os = "wasi")),
+        all(target_vendor = "fortanix", target_env = "sgx")
+    )
+)))]
+#[cfg(all(not(target_os = "hermit"), any(unix, doc)))]
+pub mod unix;
+
+// linux
+#[cfg(not(all(
+    doc,
+    any(
+        all(target_arch = "wasm32", not(target_os = "wasi")),
+        all(target_vendor = "fortanix", target_env = "sgx")
+    )
+)))]
+#[cfg(any(target_os = "linux", doc))]
+pub mod linux;
+
+// wasi
+#[cfg(not(all(
+    doc,
+    any(
+        all(target_arch = "wasm32", not(target_os = "wasi")),
+        all(target_vendor = "fortanix", target_env = "sgx")
+    )
+)))]
+#[cfg(any(target_os = "wasi", doc))]
+pub mod wasi;
+
+// windows
+#[cfg(not(all(
+    doc,
+    any(
+        all(target_arch = "wasm32", not(target_os = "wasi")),
+        all(target_vendor = "fortanix", target_env = "sgx")
+    )
+)))]
+#[cfg(any(windows, doc))]
+pub mod windows;
+
+// Others.
+#[cfg(target_os = "android")]
+pub mod android;
+#[cfg(target_os = "dragonfly")]
+pub mod dragonfly;
+#[cfg(target_os = "emscripten")]
+pub mod emscripten;
+#[cfg(target_os = "espidf")]
+pub mod espidf;
+#[cfg(all(target_vendor = "fortanix", target_env = "sgx"))]
+pub mod fortanix_sgx;
+#[cfg(target_os = "freebsd")]
+pub mod freebsd;
+#[cfg(target_os = "fuchsia")]
+pub mod fuchsia;
+#[cfg(target_os = "haiku")]
+pub mod haiku;
+#[cfg(target_os = "horizon")]
+pub mod horizon;
+#[cfg(target_os = "illumos")]
+pub mod illumos;
+#[cfg(target_os = "ios")]
+pub mod ios;
+#[cfg(target_os = "l4re")]
+pub mod l4re;
+#[cfg(target_os = "macos")]
+pub mod macos;
+#[cfg(target_os = "netbsd")]
+pub mod netbsd;
+#[cfg(target_os = "openbsd")]
+pub mod openbsd;
+#[cfg(target_os = "redox")]
+pub mod redox;
+#[cfg(target_os = "solaris")]
+pub mod solaris;
+#[cfg(target_os = "solid_asp3")]
+pub mod solid;
+#[cfg(target_os = "vxworks")]
+pub mod vxworks;
+
+#[cfg(any(unix, target_os = "wasi", doc))]
+mod fd;
diff --git a/library/std/src/os/netbsd/fs.rs b/library/std/src/os/netbsd/fs.rs
new file mode 100644
index 000000000..fe0be069e
--- /dev/null
+++ b/library/std/src/os/netbsd/fs.rs
@@ -0,0 +1,137 @@
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+#[allow(deprecated)]
+use crate::os::netbsd::raw;
+
+/// OS-specific extensions to [`fs::Metadata`].
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    /// Gain a reference to the underlying `stat` structure which contains
+    /// the raw information returned by the OS.
+    ///
+    /// The contents of the returned `stat` are **not** consistent across
+    /// Unix platforms. The `os::unix::fs::MetadataExt` trait contains the
+    /// cross-Unix abstractions contained within the raw stat.
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    #[deprecated(
+        since = "1.8.0",
+        note = "deprecated in favor of the accessor \
+                methods of this trait"
+    )]
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat;
+
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_birthtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_birthtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_flags(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gen(&self) -> u32;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat {
+        unsafe { &*(self.as_inner().as_inner() as *const libc::stat as *const raw::stat) }
+    }
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        self.as_inner().as_inner().st_atime as i64
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_atimensec as i64
+    }
+    fn st_mtime(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime as i64
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_mtimensec as i64
+    }
+    fn st_ctime(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime as i64
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_ctimensec as i64
+    }
+    fn st_birthtime(&self) -> i64 {
+        self.as_inner().as_inner().st_birthtime as i64
+    }
+    fn st_birthtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_birthtimensec as i64
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+    fn st_gen(&self) -> u32 {
+        self.as_inner().as_inner().st_gen as u32
+    }
+    fn st_flags(&self) -> u32 {
+        self.as_inner().as_inner().st_flags as u32
+    }
+}
diff --git a/library/std/src/os/netbsd/mod.rs b/library/std/src/os/netbsd/mod.rs
new file mode 100644
index 000000000..497a51a1d
--- /dev/null
+++ b/library/std/src/os/netbsd/mod.rs
@@ -0,0 +1,6 @@
+//! OpenBSD-specific definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+pub mod fs;
+pub mod raw;
diff --git a/library/std/src/os/netbsd/raw.rs b/library/std/src/os/netbsd/raw.rs
new file mode 100644
index 000000000..18057291f
--- /dev/null
+++ b/library/std/src/os/netbsd/raw.rs
@@ -0,0 +1,83 @@
+//! NetBSD-specific raw type definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.8.0",
+    note = "these type aliases are no longer supported by \
+            the standard library, the `libc` crate on \
+            crates.io should be used instead for the correct \
+            definitions"
+)]
+#![allow(deprecated)]
+
+use crate::os::raw::c_long;
+use crate::os::unix::raw::{gid_t, uid_t};
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blkcnt_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blksize_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type dev_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type fflags_t = u32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type ino_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type mode_t = u32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type nlink_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type off_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type time_t = i64;
+
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = usize;
+
+#[repr(C)]
+#[derive(Clone)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub struct stat {
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_dev: u64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mode: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ino: u64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_nlink: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_uid: uid_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gid: gid_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_rdev: u64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_birthtime: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_birthtime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_size: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blocks: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blksize: i32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_flags: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gen: u32,
+    st_spare: [u32; 2],
+}
diff --git a/library/std/src/os/openbsd/fs.rs b/library/std/src/os/openbsd/fs.rs
new file mode 100644
index 000000000..b8d8d31c5
--- /dev/null
+++ b/library/std/src/os/openbsd/fs.rs
@@ -0,0 +1,137 @@
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+#[allow(deprecated)]
+use crate::os::openbsd::raw;
+
+/// OS-specific extensions to [`fs::Metadata`].
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    /// Gain a reference to the underlying `stat` structure which contains
+    /// the raw information returned by the OS.
+    ///
+    /// The contents of the returned `stat` are **not** consistent across
+    /// Unix platforms. The `os::unix::fs::MetadataExt` trait contains the
+    /// cross-Unix abstractions contained within the raw stat.
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    #[deprecated(
+        since = "1.8.0",
+        note = "deprecated in favor of the accessor \
+                methods of this trait"
+    )]
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat;
+
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_birthtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_birthtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_flags(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gen(&self) -> u32;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat {
+        unsafe { &*(self.as_inner().as_inner() as *const libc::stat as *const raw::stat) }
+    }
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        self.as_inner().as_inner().st_atime as i64
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_atime_nsec as i64
+    }
+    fn st_mtime(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime as i64
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime_nsec as i64
+    }
+    fn st_ctime(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime as i64
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime_nsec as i64
+    }
+    fn st_birthtime(&self) -> i64 {
+        self.as_inner().as_inner().st_birthtime as i64
+    }
+    fn st_birthtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_birthtime_nsec as i64
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+    fn st_gen(&self) -> u32 {
+        self.as_inner().as_inner().st_gen as u32
+    }
+    fn st_flags(&self) -> u32 {
+        self.as_inner().as_inner().st_flags as u32
+    }
+}
diff --git a/library/std/src/os/openbsd/mod.rs b/library/std/src/os/openbsd/mod.rs
new file mode 100644
index 000000000..497a51a1d
--- /dev/null
+++ b/library/std/src/os/openbsd/mod.rs
@@ -0,0 +1,6 @@
+//! OpenBSD-specific definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+pub mod fs;
+pub mod raw;
diff --git a/library/std/src/os/openbsd/raw.rs b/library/std/src/os/openbsd/raw.rs
new file mode 100644
index 000000000..6711fb51b
--- /dev/null
+++ b/library/std/src/os/openbsd/raw.rs
@@ -0,0 +1,81 @@
+//! OpenBSD-specific raw type definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.8.0",
+    note = "these type aliases are no longer supported by \
+            the standard library, the `libc` crate on \
+            crates.io should be used instead for the correct \
+            definitions"
+)]
+#![allow(deprecated)]
+
+use crate::os::raw::c_long;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blkcnt_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blksize_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type dev_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type fflags_t = u32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type ino_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type mode_t = u32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type nlink_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type off_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type time_t = i64;
+
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = usize;
+
+#[repr(C)]
+#[derive(Clone)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub struct stat {
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mode: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_dev: i32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ino: u64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_nlink: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_uid: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gid: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_rdev: i32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_size: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blocks: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blksize: i32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_flags: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gen: u32,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_birthtime: i64,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_birthtime_nsec: c_long,
+}
diff --git a/library/std/src/os/raw/mod.rs b/library/std/src/os/raw/mod.rs
new file mode 100644
index 000000000..19d0ffb2e
--- /dev/null
+++ b/library/std/src/os/raw/mod.rs
@@ -0,0 +1,31 @@
+//! Compatibility module for C platform-specific types. Use [`core::ffi`] instead.
+
+#![stable(feature = "raw_os", since = "1.1.0")]
+
+#[cfg(test)]
+mod tests;
+
+macro_rules! alias_core_ffi {
+    ($($t:ident)*) => {$(
+        #[stable(feature = "raw_os", since = "1.1.0")]
+        #[doc = include_str!(concat!("../../../../core/src/ffi/", stringify!($t), ".md"))]
+        // Make this type alias appear cfg-dependent so that Clippy does not suggest
+        // replacing expressions like `0 as c_char` with `0_i8`/`0_u8`. This #[cfg(all())] can be
+        // removed after the false positive in https://github.com/rust-lang/rust-clippy/issues/8093
+        // is fixed.
+        #[cfg(all())]
+        #[doc(cfg(all()))]
+        pub type $t = core::ffi::$t;
+    )*}
+}
+
+alias_core_ffi! {
+    c_char c_schar c_uchar
+    c_short c_ushort
+    c_int c_uint
+    c_long c_ulong
+    c_longlong c_ulonglong
+    c_float
+    c_double
+    c_void
+}
diff --git a/library/std/src/os/raw/tests.rs b/library/std/src/os/raw/tests.rs
new file mode 100644
index 000000000..e7bb7d7e7
--- /dev/null
+++ b/library/std/src/os/raw/tests.rs
@@ -0,0 +1,15 @@
+use crate::any::TypeId;
+
+macro_rules! ok {
+    ($($t:ident)*) => {$(
+        assert!(TypeId::of::<libc::$t>() == TypeId::of::<raw::$t>(),
+                "{} is wrong", stringify!($t));
+    )*}
+}
+
+#[test]
+fn same() {
+    use crate::os::raw;
+    ok!(c_char c_schar c_uchar c_short c_ushort c_int c_uint c_long c_ulong
+        c_longlong c_ulonglong c_float c_double);
+}
diff --git a/library/std/src/os/redox/fs.rs b/library/std/src/os/redox/fs.rs
new file mode 100644
index 000000000..682ca6a2c
--- /dev/null
+++ b/library/std/src/os/redox/fs.rs
@@ -0,0 +1,382 @@
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+#[allow(deprecated)]
+use crate::os::redox::raw;
+
+/// OS-specific extensions to [`fs::Metadata`].
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    /// Gain a reference to the underlying `stat` structure which contains
+    /// the raw information returned by the OS.
+    ///
+    /// The contents of the returned [`stat`] are **not** consistent across
+    /// Unix platforms. The `os::unix::fs::MetadataExt` trait contains the
+    /// cross-Unix abstractions contained within the raw stat.
+    ///
+    /// [`stat`]: crate::os::redox::raw::stat
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::redox::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let stat = meta.as_raw_stat();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    #[deprecated(
+        since = "1.8.0",
+        note = "deprecated in favor of the accessor \
+                methods of this trait"
+    )]
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat;
+
+    /// Returns the device ID on which this file resides.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::redox::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_dev());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    /// Returns the inode number.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::redox::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_ino());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    /// Returns the file type and mode.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::redox::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_mode());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    /// Returns the number of hard links to file.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::redox::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_nlink());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    /// Returns the user ID of the file owner.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::redox::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_uid());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    /// Returns the group ID of the file owner.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::redox::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_gid());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    /// Returns the device ID that this file represents. Only relevant for special file.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::redox::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_rdev());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    /// Returns the size of the file (if it is a regular file or a symbolic link) in bytes.
+    ///
+    /// The size of a symbolic link is the length of the pathname it contains,
+    /// without a terminating null byte.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::redox::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_size());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    /// Returns the last access time of the file, in seconds since Unix Epoch.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::redox::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_atime());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    /// Returns the last access time of the file, in nanoseconds since [`st_atime`].
+    ///
+    /// [`st_atime`]: Self::st_atime
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::redox::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_atime_nsec());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    /// Returns the last modification time of the file, in seconds since Unix Epoch.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::redox::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_mtime());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    /// Returns the last modification time of the file, in nanoseconds since [`st_mtime`].
+    ///
+    /// [`st_mtime`]: Self::st_mtime
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::redox::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_mtime_nsec());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    /// Returns the last status change time of the file, in seconds since Unix Epoch.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::redox::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_ctime());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    /// Returns the last status change time of the file, in nanoseconds since [`st_ctime`].
+    ///
+    /// [`st_ctime`]: Self::st_ctime
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::redox::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_ctime_nsec());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    /// Returns the "preferred" block size for efficient filesystem I/O.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::redox::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_blksize());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    /// Returns the number of blocks allocated to the file, 512-byte units.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::io;
+    /// use std::os::redox::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     println!("{}", meta.st_blocks());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat {
+        unsafe { &*(self.as_inner().as_inner() as *const libc::stat as *const raw::stat) }
+    }
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        self.as_inner().as_inner().st_atime as i64
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_atime_nsec as i64
+    }
+    fn st_mtime(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime as i64
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime_nsec as i64
+    }
+    fn st_ctime(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime as i64
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime_nsec as i64
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+}
diff --git a/library/std/src/os/redox/mod.rs b/library/std/src/os/redox/mod.rs
new file mode 100644
index 000000000..d786759c6
--- /dev/null
+++ b/library/std/src/os/redox/mod.rs
@@ -0,0 +1,6 @@
+//! Redox-specific definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+pub mod fs;
+pub mod raw;
diff --git a/library/std/src/os/redox/raw.rs b/library/std/src/os/redox/raw.rs
new file mode 100644
index 000000000..7b1cd8ae8
--- /dev/null
+++ b/library/std/src/os/redox/raw.rs
@@ -0,0 +1,78 @@
+//! Redox-specific raw type definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.8.0",
+    note = "these type aliases are no longer supported by \
+            the standard library, the `libc` crate on \
+            crates.io should be used instead for the correct \
+            definitions"
+)]
+#![allow(deprecated)]
+
+use crate::os::raw::{c_char, c_int, c_long, c_ulong, c_void};
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type dev_t = c_long;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type gid_t = c_int;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type mode_t = c_int;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type uid_t = c_int;
+
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = *mut c_void;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blkcnt_t = c_ulong;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blksize_t = c_ulong;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type ino_t = c_ulong;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type nlink_t = c_ulong;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type off_t = c_long;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type time_t = c_long;
+
+#[repr(C)]
+#[derive(Clone)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub struct stat {
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_dev: dev_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ino: ino_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_nlink: nlink_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mode: mode_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_uid: uid_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gid: gid_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_rdev: dev_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_size: off_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blksize: blksize_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blocks: blkcnt_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub _pad: [c_char; 24],
+}
diff --git a/library/std/src/os/solaris/fs.rs b/library/std/src/os/solaris/fs.rs
new file mode 100644
index 000000000..093143737
--- /dev/null
+++ b/library/std/src/os/solaris/fs.rs
@@ -0,0 +1,117 @@
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+#[allow(deprecated)]
+use crate::os::solaris::raw;
+
+/// OS-specific extensions to [`fs::Metadata`].
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    /// Gain a reference to the underlying `stat` structure which contains
+    /// the raw information returned by the OS.
+    ///
+    /// The contents of the returned `stat` are **not** consistent across
+    /// Unix platforms. The `os::unix::fs::MetadataExt` trait contains the
+    /// cross-Unix abstractions contained within the raw stat.
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    #[deprecated(
+        since = "1.8.0",
+        note = "deprecated in favor of the accessor \
+                methods of this trait"
+    )]
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat;
+
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    #[allow(deprecated)]
+    fn as_raw_stat(&self) -> &raw::stat {
+        unsafe { &*(self.as_inner().as_inner() as *const libc::stat as *const raw::stat) }
+    }
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        self.as_inner().as_inner().st_atime as i64
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_atime_nsec as i64
+    }
+    fn st_mtime(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime as i64
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime_nsec as i64
+    }
+    fn st_ctime(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime as i64
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime_nsec as i64
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+}
diff --git a/library/std/src/os/solaris/mod.rs b/library/std/src/os/solaris/mod.rs
new file mode 100644
index 000000000..e4cfd5329
--- /dev/null
+++ b/library/std/src/os/solaris/mod.rs
@@ -0,0 +1,6 @@
+//! Solaris-specific definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+pub mod fs;
+pub mod raw;
diff --git a/library/std/src/os/solaris/raw.rs b/library/std/src/os/solaris/raw.rs
new file mode 100644
index 000000000..63426c969
--- /dev/null
+++ b/library/std/src/os/solaris/raw.rs
@@ -0,0 +1,76 @@
+//! Solaris-specific raw type definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.8.0",
+    note = "these type aliases are no longer supported by \
+            the standard library, the `libc` crate on \
+            crates.io should be used instead for the correct \
+            definitions"
+)]
+#![allow(deprecated)]
+
+use crate::os::raw::c_long;
+use crate::os::unix::raw::{gid_t, uid_t};
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blkcnt_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type blksize_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type dev_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type fflags_t = u32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type ino_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type mode_t = u32;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type nlink_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type off_t = u64;
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type time_t = i64;
+
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = u32;
+
+#[repr(C)]
+#[derive(Clone)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub struct stat {
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_dev: dev_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ino: ino_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mode: mode_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_nlink: nlink_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_uid: uid_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_gid: gid_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_rdev: dev_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_size: off_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_atime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_mtime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime: time_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_ctime_nsec: c_long,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blksize: blksize_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub st_blocks: blkcnt_t,
+    #[stable(feature = "raw_ext", since = "1.1.0")]
+    pub __unused: [u8; 16],
+}
diff --git a/library/std/src/os/solid/ffi.rs b/library/std/src/os/solid/ffi.rs
new file mode 100644
index 000000000..aaa2070a6
--- /dev/null
+++ b/library/std/src/os/solid/ffi.rs
@@ -0,0 +1,41 @@
+//! SOLID-specific extension to the primitives in the `std::ffi` module
+//!
+//! # Examples
+//!
+//! ```
+//! use std::ffi::OsString;
+//! use std::os::solid::ffi::OsStringExt;
+//!
+//! let bytes = b"foo".to_vec();
+//!
+//! // OsStringExt::from_vec
+//! let os_string = OsString::from_vec(bytes);
+//! assert_eq!(os_string.to_str(), Some("foo"));
+//!
+//! // OsStringExt::into_vec
+//! let bytes = os_string.into_vec();
+//! assert_eq!(bytes, b"foo");
+//! ```
+//!
+//! ```
+//! use std::ffi::OsStr;
+//! use std::os::solid::ffi::OsStrExt;
+//!
+//! let bytes = b"foo";
+//!
+//! // OsStrExt::from_bytes
+//! let os_str = OsStr::from_bytes(bytes);
+//! assert_eq!(os_str.to_str(), Some("foo"));
+//!
+//! // OsStrExt::as_bytes
+//! let bytes = os_str.as_bytes();
+//! assert_eq!(bytes, b"foo");
+//! ```
+
+#![stable(feature = "rust1", since = "1.0.0")]
+
+#[path = "../unix/ffi/os_str.rs"]
+mod os_str;
+
+#[stable(feature = "rust1", since = "1.0.0")]
+pub use self::os_str::{OsStrExt, OsStringExt};
diff --git a/library/std/src/os/solid/io.rs b/library/std/src/os/solid/io.rs
new file mode 100644
index 000000000..33cc5a015
--- /dev/null
+++ b/library/std/src/os/solid/io.rs
@@ -0,0 +1,113 @@
+//! SOLID-specific extensions to general I/O primitives
+
+#![deny(unsafe_op_in_unsafe_fn)]
+#![unstable(feature = "solid_ext", issue = "none")]
+
+use crate::net;
+use crate::sys;
+use crate::sys_common::{self, AsInner, FromInner, IntoInner};
+
+/// Raw file descriptors.
+pub type RawFd = i32;
+
+/// A trait to extract the raw SOLID Sockets file descriptor from an underlying
+/// object.
+pub trait AsRawFd {
+    /// Extracts the raw file descriptor.
+    ///
+    /// This method does **not** pass ownership of the raw file descriptor
+    /// to the caller. The descriptor is only guaranteed to be valid while
+    /// the original object has not yet been destroyed.
+    fn as_raw_fd(&self) -> RawFd;
+}
+
+/// A trait to express the ability to construct an object from a raw file
+/// descriptor.
+pub trait FromRawFd {
+    /// Constructs a new instance of `Self` from the given raw file
+    /// descriptor.
+    ///
+    /// This function **consumes ownership** of the specified file
+    /// descriptor. The returned object will take responsibility for closing
+    /// it when the object goes out of scope.
+    ///
+    /// This function is also unsafe as the primitives currently returned
+    /// have the contract that they are the sole owner of the file
+    /// descriptor they are wrapping. Usage of this function could
+    /// accidentally allow violating this contract which can cause memory
+    /// unsafety in code that relies on it being true.
+    unsafe fn from_raw_fd(fd: RawFd) -> Self;
+}
+
+/// A trait to express the ability to consume an object and acquire ownership of
+/// its raw file descriptor.
+pub trait IntoRawFd {
+    /// Consumes this object, returning the raw underlying file descriptor.
+    ///
+    /// This function **transfers ownership** of the underlying file descriptor
+    /// to the caller. Callers are then the unique owners of the file descriptor
+    /// and must close the descriptor once it's no longer needed.
+    fn into_raw_fd(self) -> RawFd;
+}
+
+#[stable(feature = "raw_fd_reflexive_traits", since = "1.48.0")]
+impl AsRawFd for RawFd {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        *self
+    }
+}
+#[stable(feature = "raw_fd_reflexive_traits", since = "1.48.0")]
+impl IntoRawFd for RawFd {
+    #[inline]
+    fn into_raw_fd(self) -> RawFd {
+        self
+    }
+}
+#[stable(feature = "raw_fd_reflexive_traits", since = "1.48.0")]
+impl FromRawFd for RawFd {
+    #[inline]
+    unsafe fn from_raw_fd(fd: RawFd) -> RawFd {
+        fd
+    }
+}
+
+macro_rules! impl_as_raw_fd {
+    ($($t:ident)*) => {$(
+        #[stable(feature = "rust1", since = "1.0.0")]
+        impl AsRawFd for net::$t {
+            #[inline]
+            fn as_raw_fd(&self) -> RawFd {
+                *self.as_inner().socket().as_inner()
+            }
+        }
+    )*};
+}
+impl_as_raw_fd! { TcpStream TcpListener UdpSocket }
+
+macro_rules! impl_from_raw_fd {
+    ($($t:ident)*) => {$(
+        #[stable(feature = "from_raw_os", since = "1.1.0")]
+        impl FromRawFd for net::$t {
+            #[inline]
+            unsafe fn from_raw_fd(fd: RawFd) -> net::$t {
+                let socket = sys::net::Socket::from_inner(fd);
+                net::$t::from_inner(sys_common::net::$t::from_inner(socket))
+            }
+        }
+    )*};
+}
+impl_from_raw_fd! { TcpStream TcpListener UdpSocket }
+
+macro_rules! impl_into_raw_fd {
+    ($($t:ident)*) => {$(
+        #[stable(feature = "into_raw_os", since = "1.4.0")]
+        impl IntoRawFd for net::$t {
+            #[inline]
+            fn into_raw_fd(self) -> RawFd {
+                self.into_inner().into_socket().into_inner()
+            }
+        }
+    )*};
+}
+impl_into_raw_fd! { TcpStream TcpListener UdpSocket }
diff --git a/library/std/src/os/solid/mod.rs b/library/std/src/os/solid/mod.rs
new file mode 100644
index 000000000..4328ba7c3
--- /dev/null
+++ b/library/std/src/os/solid/mod.rs
@@ -0,0 +1,17 @@
+#![stable(feature = "rust1", since = "1.0.0")]
+
+pub mod ffi;
+pub mod io;
+
+/// A prelude for conveniently writing platform-specific code.
+///
+/// Includes all extension traits, and some important type definitions.
+#[stable(feature = "rust1", since = "1.0.0")]
+pub mod prelude {
+    #[doc(no_inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::ffi::{OsStrExt, OsStringExt};
+    #[doc(no_inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::io::{AsRawFd, FromRawFd, IntoRawFd, RawFd};
+}
diff --git a/library/std/src/os/unix/ffi/mod.rs b/library/std/src/os/unix/ffi/mod.rs
new file mode 100644
index 000000000..5b49f5076
--- /dev/null
+++ b/library/std/src/os/unix/ffi/mod.rs
@@ -0,0 +1,42 @@
+//! Unix-specific extensions to primitives in the [`std::ffi`] module.
+//!
+//! # Examples
+//!
+//! ```
+//! use std::ffi::OsString;
+//! use std::os::unix::ffi::OsStringExt;
+//!
+//! let bytes = b"foo".to_vec();
+//!
+//! // OsStringExt::from_vec
+//! let os_string = OsString::from_vec(bytes);
+//! assert_eq!(os_string.to_str(), Some("foo"));
+//!
+//! // OsStringExt::into_vec
+//! let bytes = os_string.into_vec();
+//! assert_eq!(bytes, b"foo");
+//! ```
+//!
+//! ```
+//! use std::ffi::OsStr;
+//! use std::os::unix::ffi::OsStrExt;
+//!
+//! let bytes = b"foo";
+//!
+//! // OsStrExt::from_bytes
+//! let os_str = OsStr::from_bytes(bytes);
+//! assert_eq!(os_str.to_str(), Some("foo"));
+//!
+//! // OsStrExt::as_bytes
+//! let bytes = os_str.as_bytes();
+//! assert_eq!(bytes, b"foo");
+//! ```
+//!
+//! [`std::ffi`]: crate::ffi
+
+#![stable(feature = "rust1", since = "1.0.0")]
+
+mod os_str;
+
+#[stable(feature = "rust1", since = "1.0.0")]
+pub use self::os_str::{OsStrExt, OsStringExt};
diff --git a/library/std/src/os/unix/ffi/os_str.rs b/library/std/src/os/unix/ffi/os_str.rs
new file mode 100644
index 000000000..650f712bc
--- /dev/null
+++ b/library/std/src/os/unix/ffi/os_str.rs
@@ -0,0 +1,70 @@
+use crate::ffi::{OsStr, OsString};
+use crate::mem;
+use crate::sealed::Sealed;
+use crate::sys::os_str::Buf;
+use crate::sys_common::{AsInner, FromInner, IntoInner};
+
+// Note: this file is currently reused in other `std::os::{platform}::ffi` modules to reduce duplication.
+// Keep this in mind when applying changes to this file that only apply to `unix`.
+
+/// Platform-specific extensions to [`OsString`].
+///
+/// This trait is sealed: it cannot be implemented outside the standard library.
+/// This is so that future additional methods are not breaking changes.
+#[stable(feature = "rust1", since = "1.0.0")]
+pub trait OsStringExt: Sealed {
+    /// Creates an [`OsString`] from a byte vector.
+    ///
+    /// See the module documentation for an example.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    fn from_vec(vec: Vec<u8>) -> Self;
+
+    /// Yields the underlying byte vector of this [`OsString`].
+    ///
+    /// See the module documentation for an example.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    fn into_vec(self) -> Vec<u8>;
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl OsStringExt for OsString {
+    #[inline]
+    fn from_vec(vec: Vec<u8>) -> OsString {
+        FromInner::from_inner(Buf { inner: vec })
+    }
+    #[inline]
+    fn into_vec(self) -> Vec<u8> {
+        self.into_inner().inner
+    }
+}
+
+/// Platform-specific extensions to [`OsStr`].
+///
+/// This trait is sealed: it cannot be implemented outside the standard library.
+/// This is so that future additional methods are not breaking changes.
+#[stable(feature = "rust1", since = "1.0.0")]
+pub trait OsStrExt: Sealed {
+    #[stable(feature = "rust1", since = "1.0.0")]
+    /// Creates an [`OsStr`] from a byte slice.
+    ///
+    /// See the module documentation for an example.
+    fn from_bytes(slice: &[u8]) -> &Self;
+
+    /// Gets the underlying byte view of the [`OsStr`] slice.
+    ///
+    /// See the module documentation for an example.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    fn as_bytes(&self) -> &[u8];
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl OsStrExt for OsStr {
+    #[inline]
+    fn from_bytes(slice: &[u8]) -> &OsStr {
+        unsafe { mem::transmute(slice) }
+    }
+    #[inline]
+    fn as_bytes(&self) -> &[u8] {
+        &self.as_inner().inner
+    }
+}
diff --git a/library/std/src/os/unix/fs.rs b/library/std/src/os/unix/fs.rs
new file mode 100644
index 000000000..3fc6cc44c
--- /dev/null
+++ b/library/std/src/os/unix/fs.rs
@@ -0,0 +1,1022 @@
+//! Unix-specific extensions to primitives in the [`std::fs`] module.
+//!
+//! [`std::fs`]: crate::fs
+
+#![stable(feature = "rust1", since = "1.0.0")]
+
+use super::platform::fs::MetadataExt as _;
+use crate::fs::{self, OpenOptions, Permissions};
+use crate::io;
+use crate::os::unix::io::{AsFd, AsRawFd};
+use crate::path::Path;
+use crate::sys;
+use crate::sys_common::{AsInner, AsInnerMut, FromInner};
+// Used for `File::read` on intra-doc links
+use crate::ffi::OsStr;
+use crate::sealed::Sealed;
+#[allow(unused_imports)]
+use io::{Read, Write};
+
+/// Unix-specific extensions to [`fs::File`].
+#[stable(feature = "file_offset", since = "1.15.0")]
+pub trait FileExt {
+    /// Reads a number of bytes starting from a given offset.
+    ///
+    /// Returns the number of bytes read.
+    ///
+    /// The offset is relative to the start of the file and thus independent
+    /// from the current cursor.
+    ///
+    /// The current file cursor is not affected by this function.
+    ///
+    /// Note that similar to [`File::read`], it is not an error to return with a
+    /// short read.
+    ///
+    /// [`File::read`]: fs::File::read
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::fs::File;
+    /// use std::os::unix::prelude::FileExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let mut buf = [0u8; 8];
+    ///     let file = File::open("foo.txt")?;
+    ///
+    ///     // We now read 8 bytes from the offset 10.
+    ///     let num_bytes_read = file.read_at(&mut buf, 10)?;
+    ///     println!("read {num_bytes_read} bytes: {buf:?}");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "file_offset", since = "1.15.0")]
+    fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result<usize>;
+
+    /// Reads the exact number of byte required to fill `buf` from the given offset.
+    ///
+    /// The offset is relative to the start of the file and thus independent
+    /// from the current cursor.
+    ///
+    /// The current file cursor is not affected by this function.
+    ///
+    /// Similar to [`io::Read::read_exact`] but uses [`read_at`] instead of `read`.
+    ///
+    /// [`read_at`]: FileExt::read_at
+    ///
+    /// # Errors
+    ///
+    /// If this function encounters an error of the kind
+    /// [`io::ErrorKind::Interrupted`] then the error is ignored and the operation
+    /// will continue.
+    ///
+    /// If this function encounters an "end of file" before completely filling
+    /// the buffer, it returns an error of the kind [`io::ErrorKind::UnexpectedEof`].
+    /// The contents of `buf` are unspecified in this case.
+    ///
+    /// If any other read error is encountered then this function immediately
+    /// returns. The contents of `buf` are unspecified in this case.
+    ///
+    /// If this function returns an error, it is unspecified how many bytes it
+    /// has read, but it will never read more than would be necessary to
+    /// completely fill the buffer.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::fs::File;
+    /// use std::os::unix::prelude::FileExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let mut buf = [0u8; 8];
+    ///     let file = File::open("foo.txt")?;
+    ///
+    ///     // We now read exactly 8 bytes from the offset 10.
+    ///     file.read_exact_at(&mut buf, 10)?;
+    ///     println!("read {} bytes: {:?}", buf.len(), buf);
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "rw_exact_all_at", since = "1.33.0")]
+    fn read_exact_at(&self, mut buf: &mut [u8], mut offset: u64) -> io::Result<()> {
+        while !buf.is_empty() {
+            match self.read_at(buf, offset) {
+                Ok(0) => break,
+                Ok(n) => {
+                    let tmp = buf;
+                    buf = &mut tmp[n..];
+                    offset += n as u64;
+                }
+                Err(ref e) if e.kind() == io::ErrorKind::Interrupted => {}
+                Err(e) => return Err(e),
+            }
+        }
+        if !buf.is_empty() {
+            Err(io::const_io_error!(io::ErrorKind::UnexpectedEof, "failed to fill whole buffer",))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Writes a number of bytes starting from a given offset.
+    ///
+    /// Returns the number of bytes written.
+    ///
+    /// The offset is relative to the start of the file and thus independent
+    /// from the current cursor.
+    ///
+    /// The current file cursor is not affected by this function.
+    ///
+    /// When writing beyond the end of the file, the file is appropriately
+    /// extended and the intermediate bytes are initialized with the value 0.
+    ///
+    /// Note that similar to [`File::write`], it is not an error to return a
+    /// short write.
+    ///
+    /// [`File::write`]: fs::File::write
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs::File;
+    /// use std::io;
+    /// use std::os::unix::prelude::FileExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let file = File::open("foo.txt")?;
+    ///
+    ///     // We now write at the offset 10.
+    ///     file.write_at(b"sushi", 10)?;
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "file_offset", since = "1.15.0")]
+    fn write_at(&self, buf: &[u8], offset: u64) -> io::Result<usize>;
+
+    /// Attempts to write an entire buffer starting from a given offset.
+    ///
+    /// The offset is relative to the start of the file and thus independent
+    /// from the current cursor.
+    ///
+    /// The current file cursor is not affected by this function.
+    ///
+    /// This method will continuously call [`write_at`] until there is no more data
+    /// to be written or an error of non-[`io::ErrorKind::Interrupted`] kind is
+    /// returned. This method will not return until the entire buffer has been
+    /// successfully written or such an error occurs. The first error that is
+    /// not of [`io::ErrorKind::Interrupted`] kind generated from this method will be
+    /// returned.
+    ///
+    /// # Errors
+    ///
+    /// This function will return the first error of
+    /// non-[`io::ErrorKind::Interrupted`] kind that [`write_at`] returns.
+    ///
+    /// [`write_at`]: FileExt::write_at
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs::File;
+    /// use std::io;
+    /// use std::os::unix::prelude::FileExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let file = File::open("foo.txt")?;
+    ///
+    ///     // We now write at the offset 10.
+    ///     file.write_all_at(b"sushi", 10)?;
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "rw_exact_all_at", since = "1.33.0")]
+    fn write_all_at(&self, mut buf: &[u8], mut offset: u64) -> io::Result<()> {
+        while !buf.is_empty() {
+            match self.write_at(buf, offset) {
+                Ok(0) => {
+                    return Err(io::const_io_error!(
+                        io::ErrorKind::WriteZero,
+                        "failed to write whole buffer",
+                    ));
+                }
+                Ok(n) => {
+                    buf = &buf[n..];
+                    offset += n as u64
+                }
+                Err(ref e) if e.kind() == io::ErrorKind::Interrupted => {}
+                Err(e) => return Err(e),
+            }
+        }
+        Ok(())
+    }
+}
+
+#[stable(feature = "file_offset", since = "1.15.0")]
+impl FileExt for fs::File {
+    fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result<usize> {
+        self.as_inner().read_at(buf, offset)
+    }
+    fn write_at(&self, buf: &[u8], offset: u64) -> io::Result<usize> {
+        self.as_inner().write_at(buf, offset)
+    }
+}
+
+/// Unix-specific extensions to [`fs::Permissions`].
+#[stable(feature = "fs_ext", since = "1.1.0")]
+pub trait PermissionsExt {
+    /// Returns the underlying raw `st_mode` bits that contain the standard
+    /// Unix permissions for this file.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs::File;
+    /// use std::os::unix::fs::PermissionsExt;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let f = File::create("foo.txt")?;
+    ///     let metadata = f.metadata()?;
+    ///     let permissions = metadata.permissions();
+    ///
+    ///     println!("permissions: {:o}", permissions.mode());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "fs_ext", since = "1.1.0")]
+    fn mode(&self) -> u32;
+
+    /// Sets the underlying raw bits for this set of permissions.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs::File;
+    /// use std::os::unix::fs::PermissionsExt;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let f = File::create("foo.txt")?;
+    ///     let metadata = f.metadata()?;
+    ///     let mut permissions = metadata.permissions();
+    ///
+    ///     permissions.set_mode(0o644); // Read/write for owner and read for others.
+    ///     assert_eq!(permissions.mode(), 0o644);
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "fs_ext", since = "1.1.0")]
+    fn set_mode(&mut self, mode: u32);
+
+    /// Creates a new instance of `Permissions` from the given set of Unix
+    /// permission bits.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::fs::Permissions;
+    /// use std::os::unix::fs::PermissionsExt;
+    ///
+    /// // Read/write for owner and read for others.
+    /// let permissions = Permissions::from_mode(0o644);
+    /// assert_eq!(permissions.mode(), 0o644);
+    /// ```
+    #[stable(feature = "fs_ext", since = "1.1.0")]
+    fn from_mode(mode: u32) -> Self;
+}
+
+#[stable(feature = "fs_ext", since = "1.1.0")]
+impl PermissionsExt for Permissions {
+    fn mode(&self) -> u32 {
+        self.as_inner().mode()
+    }
+
+    fn set_mode(&mut self, mode: u32) {
+        *self = Permissions::from_inner(FromInner::from_inner(mode));
+    }
+
+    fn from_mode(mode: u32) -> Permissions {
+        Permissions::from_inner(FromInner::from_inner(mode))
+    }
+}
+
+/// Unix-specific extensions to [`fs::OpenOptions`].
+#[stable(feature = "fs_ext", since = "1.1.0")]
+pub trait OpenOptionsExt {
+    /// Sets the mode bits that a new file will be created with.
+    ///
+    /// If a new file is created as part of an `OpenOptions::open` call then this
+    /// specified `mode` will be used as the permission bits for the new file.
+    /// If no `mode` is set, the default of `0o666` will be used.
+    /// The operating system masks out bits with the system's `umask`, to produce
+    /// the final permissions.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs::OpenOptions;
+    /// use std::os::unix::fs::OpenOptionsExt;
+    ///
+    /// # fn main() {
+    /// let mut options = OpenOptions::new();
+    /// options.mode(0o644); // Give read/write for owner and read for others.
+    /// let file = options.open("foo.txt");
+    /// # }
+    /// ```
+    #[stable(feature = "fs_ext", since = "1.1.0")]
+    fn mode(&mut self, mode: u32) -> &mut Self;
+
+    /// Pass custom flags to the `flags` argument of `open`.
+    ///
+    /// The bits that define the access mode are masked out with `O_ACCMODE`, to
+    /// ensure they do not interfere with the access mode set by Rusts options.
+    ///
+    /// Custom flags can only set flags, not remove flags set by Rusts options.
+    /// This options overwrites any previously set custom flags.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # #![feature(rustc_private)]
+    /// extern crate libc;
+    /// use std::fs::OpenOptions;
+    /// use std::os::unix::fs::OpenOptionsExt;
+    ///
+    /// # fn main() {
+    /// let mut options = OpenOptions::new();
+    /// options.write(true);
+    /// if cfg!(unix) {
+    ///     options.custom_flags(libc::O_NOFOLLOW);
+    /// }
+    /// let file = options.open("foo.txt");
+    /// # }
+    /// ```
+    #[stable(feature = "open_options_ext", since = "1.10.0")]
+    fn custom_flags(&mut self, flags: i32) -> &mut Self;
+}
+
+#[stable(feature = "fs_ext", since = "1.1.0")]
+impl OpenOptionsExt for OpenOptions {
+    fn mode(&mut self, mode: u32) -> &mut OpenOptions {
+        self.as_inner_mut().mode(mode);
+        self
+    }
+
+    fn custom_flags(&mut self, flags: i32) -> &mut OpenOptions {
+        self.as_inner_mut().custom_flags(flags);
+        self
+    }
+}
+
+/// Unix-specific extensions to [`fs::Metadata`].
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    /// Returns the ID of the device containing the file.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::fs;
+    /// use std::os::unix::fs::MetadataExt;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let dev_id = meta.dev();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn dev(&self) -> u64;
+    /// Returns the inode number.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::MetadataExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let inode = meta.ino();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn ino(&self) -> u64;
+    /// Returns the rights applied to this file.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::MetadataExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let mode = meta.mode();
+    ///     let user_has_write_access      = mode & 0o200;
+    ///     let user_has_read_write_access = mode & 0o600;
+    ///     let group_has_read_access      = mode & 0o040;
+    ///     let others_have_exec_access    = mode & 0o001;
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn mode(&self) -> u32;
+    /// Returns the number of hard links pointing to this file.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::MetadataExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let nb_hard_links = meta.nlink();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn nlink(&self) -> u64;
+    /// Returns the user ID of the owner of this file.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::MetadataExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let user_id = meta.uid();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn uid(&self) -> u32;
+    /// Returns the group ID of the owner of this file.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::MetadataExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let group_id = meta.gid();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn gid(&self) -> u32;
+    /// Returns the device ID of this file (if it is a special one).
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::MetadataExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let device_id = meta.rdev();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn rdev(&self) -> u64;
+    /// Returns the total size of this file in bytes.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::MetadataExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let file_size = meta.size();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn size(&self) -> u64;
+    /// Returns the last access time of the file, in seconds since Unix Epoch.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::MetadataExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let last_access_time = meta.atime();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn atime(&self) -> i64;
+    /// Returns the last access time of the file, in nanoseconds since [`atime`].
+    ///
+    /// [`atime`]: MetadataExt::atime
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::MetadataExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let nano_last_access_time = meta.atime_nsec();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn atime_nsec(&self) -> i64;
+    /// Returns the last modification time of the file, in seconds since Unix Epoch.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::MetadataExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let last_modification_time = meta.mtime();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn mtime(&self) -> i64;
+    /// Returns the last modification time of the file, in nanoseconds since [`mtime`].
+    ///
+    /// [`mtime`]: MetadataExt::mtime
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::MetadataExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let nano_last_modification_time = meta.mtime_nsec();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn mtime_nsec(&self) -> i64;
+    /// Returns the last status change time of the file, in seconds since Unix Epoch.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::MetadataExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let last_status_change_time = meta.ctime();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn ctime(&self) -> i64;
+    /// Returns the last status change time of the file, in nanoseconds since [`ctime`].
+    ///
+    /// [`ctime`]: MetadataExt::ctime
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::MetadataExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let nano_last_status_change_time = meta.ctime_nsec();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn ctime_nsec(&self) -> i64;
+    /// Returns the block size for filesystem I/O.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::MetadataExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let block_size = meta.blksize();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn blksize(&self) -> u64;
+    /// Returns the number of blocks allocated to the file, in 512-byte units.
+    ///
+    /// Please note that this may be smaller than `st_size / 512` when the file has holes.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::MetadataExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("some_file")?;
+    ///     let blocks = meta.blocks();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn blocks(&self) -> u64;
+    #[cfg(target_os = "vxworks")]
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn attrib(&self) -> u8;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for fs::Metadata {
+    fn dev(&self) -> u64 {
+        self.st_dev()
+    }
+    fn ino(&self) -> u64 {
+        self.st_ino()
+    }
+    fn mode(&self) -> u32 {
+        self.st_mode()
+    }
+    fn nlink(&self) -> u64 {
+        self.st_nlink()
+    }
+    fn uid(&self) -> u32 {
+        self.st_uid()
+    }
+    fn gid(&self) -> u32 {
+        self.st_gid()
+    }
+    fn rdev(&self) -> u64 {
+        self.st_rdev()
+    }
+    fn size(&self) -> u64 {
+        self.st_size()
+    }
+    fn atime(&self) -> i64 {
+        self.st_atime()
+    }
+    fn atime_nsec(&self) -> i64 {
+        self.st_atime_nsec()
+    }
+    fn mtime(&self) -> i64 {
+        self.st_mtime()
+    }
+    fn mtime_nsec(&self) -> i64 {
+        self.st_mtime_nsec()
+    }
+    fn ctime(&self) -> i64 {
+        self.st_ctime()
+    }
+    fn ctime_nsec(&self) -> i64 {
+        self.st_ctime_nsec()
+    }
+    fn blksize(&self) -> u64 {
+        self.st_blksize()
+    }
+    fn blocks(&self) -> u64 {
+        self.st_blocks()
+    }
+    #[cfg(target_os = "vxworks")]
+    fn attrib(&self) -> u8 {
+        self.st_attrib()
+    }
+}
+
+/// Unix-specific extensions for [`fs::FileType`].
+///
+/// Adds support for special Unix file types such as block/character devices,
+/// pipes, and sockets.
+#[stable(feature = "file_type_ext", since = "1.5.0")]
+pub trait FileTypeExt {
+    /// Returns `true` if this file type is a block device.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::FileTypeExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("block_device_file")?;
+    ///     let file_type = meta.file_type();
+    ///     assert!(file_type.is_block_device());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "file_type_ext", since = "1.5.0")]
+    fn is_block_device(&self) -> bool;
+    /// Returns `true` if this file type is a char device.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::FileTypeExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("char_device_file")?;
+    ///     let file_type = meta.file_type();
+    ///     assert!(file_type.is_char_device());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "file_type_ext", since = "1.5.0")]
+    fn is_char_device(&self) -> bool;
+    /// Returns `true` if this file type is a fifo.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::FileTypeExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("fifo_file")?;
+    ///     let file_type = meta.file_type();
+    ///     assert!(file_type.is_fifo());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "file_type_ext", since = "1.5.0")]
+    fn is_fifo(&self) -> bool;
+    /// Returns `true` if this file type is a socket.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs;
+    /// use std::os::unix::fs::FileTypeExt;
+    /// use std::io;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let meta = fs::metadata("unix.socket")?;
+    ///     let file_type = meta.file_type();
+    ///     assert!(file_type.is_socket());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "file_type_ext", since = "1.5.0")]
+    fn is_socket(&self) -> bool;
+}
+
+#[stable(feature = "file_type_ext", since = "1.5.0")]
+impl FileTypeExt for fs::FileType {
+    fn is_block_device(&self) -> bool {
+        self.as_inner().is(libc::S_IFBLK)
+    }
+    fn is_char_device(&self) -> bool {
+        self.as_inner().is(libc::S_IFCHR)
+    }
+    fn is_fifo(&self) -> bool {
+        self.as_inner().is(libc::S_IFIFO)
+    }
+    fn is_socket(&self) -> bool {
+        self.as_inner().is(libc::S_IFSOCK)
+    }
+}
+
+/// Unix-specific extension methods for [`fs::DirEntry`].
+#[stable(feature = "dir_entry_ext", since = "1.1.0")]
+pub trait DirEntryExt {
+    /// Returns the underlying `d_ino` field in the contained `dirent`
+    /// structure.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::fs;
+    /// use std::os::unix::fs::DirEntryExt;
+    ///
+    /// if let Ok(entries) = fs::read_dir(".") {
+    ///     for entry in entries {
+    ///         if let Ok(entry) = entry {
+    ///             // Here, `entry` is a `DirEntry`.
+    ///             println!("{:?}: {}", entry.file_name(), entry.ino());
+    ///         }
+    ///     }
+    /// }
+    /// ```
+    #[stable(feature = "dir_entry_ext", since = "1.1.0")]
+    fn ino(&self) -> u64;
+}
+
+#[stable(feature = "dir_entry_ext", since = "1.1.0")]
+impl DirEntryExt for fs::DirEntry {
+    fn ino(&self) -> u64 {
+        self.as_inner().ino()
+    }
+}
+
+/// Sealed Unix-specific extension methods for [`fs::DirEntry`].
+#[unstable(feature = "dir_entry_ext2", issue = "85573")]
+pub trait DirEntryExt2: Sealed {
+    /// Returns a reference to the underlying `OsStr` of this entry's filename.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(dir_entry_ext2)]
+    /// use std::os::unix::fs::DirEntryExt2;
+    /// use std::{fs, io};
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let mut entries = fs::read_dir(".")?.collect::<Result<Vec<_>, io::Error>>()?;
+    ///     entries.sort_unstable_by(|a, b| a.file_name_ref().cmp(b.file_name_ref()));
+    ///
+    ///     for p in entries {
+    ///         println!("{p:?}");
+    ///     }
+    ///
+    ///     Ok(())
+    /// }
+    /// ```
+    fn file_name_ref(&self) -> &OsStr;
+}
+
+/// Allows extension traits within `std`.
+#[unstable(feature = "sealed", issue = "none")]
+impl Sealed for fs::DirEntry {}
+
+#[unstable(feature = "dir_entry_ext2", issue = "85573")]
+impl DirEntryExt2 for fs::DirEntry {
+    fn file_name_ref(&self) -> &OsStr {
+        self.as_inner().file_name_os_str()
+    }
+}
+
+/// Creates a new symbolic link on the filesystem.
+///
+/// The `link` path will be a symbolic link pointing to the `original` path.
+///
+/// # Examples
+///
+/// ```no_run
+/// use std::os::unix::fs;
+///
+/// fn main() -> std::io::Result<()> {
+///     fs::symlink("a.txt", "b.txt")?;
+///     Ok(())
+/// }
+/// ```
+#[stable(feature = "symlink", since = "1.1.0")]
+pub fn symlink<P: AsRef<Path>, Q: AsRef<Path>>(original: P, link: Q) -> io::Result<()> {
+    sys::fs::symlink(original.as_ref(), link.as_ref())
+}
+
+/// Unix-specific extensions to [`fs::DirBuilder`].
+#[stable(feature = "dir_builder", since = "1.6.0")]
+pub trait DirBuilderExt {
+    /// Sets the mode to create new directories with. This option defaults to
+    /// 0o777.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs::DirBuilder;
+    /// use std::os::unix::fs::DirBuilderExt;
+    ///
+    /// let mut builder = DirBuilder::new();
+    /// builder.mode(0o755);
+    /// ```
+    #[stable(feature = "dir_builder", since = "1.6.0")]
+    fn mode(&mut self, mode: u32) -> &mut Self;
+}
+
+#[stable(feature = "dir_builder", since = "1.6.0")]
+impl DirBuilderExt for fs::DirBuilder {
+    fn mode(&mut self, mode: u32) -> &mut fs::DirBuilder {
+        self.as_inner_mut().set_mode(mode);
+        self
+    }
+}
+
+/// Change the owner and group of the specified path.
+///
+/// Specifying either the uid or gid as `None` will leave it unchanged.
+///
+/// Changing the owner typically requires privileges, such as root or a specific capability.
+/// Changing the group typically requires either being the owner and a member of the group, or
+/// having privileges.
+///
+/// If called on a symbolic link, this will change the owner and group of the link target. To
+/// change the owner and group of the link itself, see [`lchown`].
+///
+/// # Examples
+///
+/// ```no_run
+/// #![feature(unix_chown)]
+/// use std::os::unix::fs;
+///
+/// fn main() -> std::io::Result<()> {
+///     fs::chown("/sandbox", Some(0), Some(0))?;
+///     Ok(())
+/// }
+/// ```
+#[unstable(feature = "unix_chown", issue = "88989")]
+pub fn chown<P: AsRef<Path>>(dir: P, uid: Option<u32>, gid: Option<u32>) -> io::Result<()> {
+    sys::fs::chown(dir.as_ref(), uid.unwrap_or(u32::MAX), gid.unwrap_or(u32::MAX))
+}
+
+/// Change the owner and group of the file referenced by the specified open file descriptor.
+///
+/// For semantics and required privileges, see [`chown`].
+///
+/// # Examples
+///
+/// ```no_run
+/// #![feature(unix_chown)]
+/// use std::os::unix::fs;
+///
+/// fn main() -> std::io::Result<()> {
+///     let f = std::fs::File::open("/file")?;
+///     fs::fchown(&f, Some(0), Some(0))?;
+///     Ok(())
+/// }
+/// ```
+#[unstable(feature = "unix_chown", issue = "88989")]
+pub fn fchown<F: AsFd>(fd: F, uid: Option<u32>, gid: Option<u32>) -> io::Result<()> {
+    sys::fs::fchown(fd.as_fd().as_raw_fd(), uid.unwrap_or(u32::MAX), gid.unwrap_or(u32::MAX))
+}
+
+/// Change the owner and group of the specified path, without dereferencing symbolic links.
+///
+/// Identical to [`chown`], except that if called on a symbolic link, this will change the owner
+/// and group of the link itself rather than the owner and group of the link target.
+///
+/// # Examples
+///
+/// ```no_run
+/// #![feature(unix_chown)]
+/// use std::os::unix::fs;
+///
+/// fn main() -> std::io::Result<()> {
+///     fs::lchown("/symlink", Some(0), Some(0))?;
+///     Ok(())
+/// }
+/// ```
+#[unstable(feature = "unix_chown", issue = "88989")]
+pub fn lchown<P: AsRef<Path>>(dir: P, uid: Option<u32>, gid: Option<u32>) -> io::Result<()> {
+    sys::fs::lchown(dir.as_ref(), uid.unwrap_or(u32::MAX), gid.unwrap_or(u32::MAX))
+}
+
+/// Change the root directory of the current process to the specified path.
+///
+/// This typically requires privileges, such as root or a specific capability.
+///
+/// This does not change the current working directory; you should call
+/// [`std::env::set_current_dir`][`crate::env::set_current_dir`] afterwards.
+///
+/// # Examples
+///
+/// ```no_run
+/// use std::os::unix::fs;
+///
+/// fn main() -> std::io::Result<()> {
+///     fs::chroot("/sandbox")?;
+///     std::env::set_current_dir("/")?;
+///     // continue working in sandbox
+///     Ok(())
+/// }
+/// ```
+#[stable(feature = "unix_chroot", since = "1.56.0")]
+#[cfg(not(any(target_os = "fuchsia", target_os = "vxworks")))]
+pub fn chroot<P: AsRef<Path>>(dir: P) -> io::Result<()> {
+    sys::fs::chroot(dir.as_ref())
+}
diff --git a/library/std/src/os/unix/io/fd.rs b/library/std/src/os/unix/io/fd.rs
new file mode 100644
index 000000000..d4cb69645
--- /dev/null
+++ b/library/std/src/os/unix/io/fd.rs
@@ -0,0 +1,8 @@
+//! Owned and borrowed file descriptors.
+
+// Tests for this module
+#[cfg(test)]
+mod tests;
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+pub use crate::os::fd::owned::*;
diff --git a/library/std/src/os/unix/io/fd/tests.rs b/library/std/src/os/unix/io/fd/tests.rs
new file mode 100644
index 000000000..84d2a7a1a
--- /dev/null
+++ b/library/std/src/os/unix/io/fd/tests.rs
@@ -0,0 +1,11 @@
+use crate::mem::size_of;
+use crate::os::unix::io::RawFd;
+
+#[test]
+fn test_raw_fd_layout() {
+    // `OwnedFd` and `BorrowedFd` use `rustc_layout_scalar_valid_range_start`
+    // and `rustc_layout_scalar_valid_range_end`, with values that depend on
+    // the bit width of `RawFd`. If this ever changes, those values will need
+    // to be updated.
+    assert_eq!(size_of::<RawFd>(), 4);
+}
diff --git a/library/std/src/os/unix/io/mod.rs b/library/std/src/os/unix/io/mod.rs
new file mode 100644
index 000000000..3ab5606f8
--- /dev/null
+++ b/library/std/src/os/unix/io/mod.rs
@@ -0,0 +1,86 @@
+//! Unix-specific extensions to general I/O primitives.
+//!
+//! Just like raw pointers, raw file descriptors point to resources with
+//! dynamic lifetimes, and they can dangle if they outlive their resources
+//! or be forged if they're created from invalid values.
+//!
+//! This module provides three types for representing file descriptors,
+//! with different ownership properties: raw, borrowed, and owned, which are
+//! analogous to types used for representing pointers:
+//!
+//! | Type               | Analogous to |
+//! | ------------------ | ------------ |
+//! | [`RawFd`]          | `*const _`   |
+//! | [`BorrowedFd<'a>`] | `&'a _`      |
+//! | [`OwnedFd`]        | `Box<_>`     |
+//!
+//! Like raw pointers, `RawFd` values are primitive values. And in new code,
+//! they should be considered unsafe to do I/O on (analogous to dereferencing
+//! them). Rust did not always provide this guidance, so existing code in the
+//! Rust ecosystem often doesn't mark `RawFd` usage as unsafe. Once the
+//! `io_safety` feature is stable, libraries will be encouraged to migrate,
+//! either by adding `unsafe` to APIs that dereference `RawFd` values, or by
+//! using to `BorrowedFd` or `OwnedFd` instead.
+//!
+//! Like references, `BorrowedFd` values are tied to a lifetime, to ensure
+//! that they don't outlive the resource they point to. These are safe to
+//! use. `BorrowedFd` values may be used in APIs which provide safe access to
+//! any system call except for:
+//!
+//!  - `close`, because that would end the dynamic lifetime of the resource
+//!    without ending the lifetime of the file descriptor.
+//!
+//!  - `dup2`/`dup3`, in the second argument, because this argument is
+//!    closed and assigned a new resource, which may break the assumptions
+//!    other code using that file descriptor.
+//!
+//! `BorrowedFd` values may be used in APIs which provide safe access to `dup`
+//! system calls, so types implementing `AsFd` or `From<OwnedFd>` should not
+//! assume they always have exclusive access to the underlying file
+//! description.
+//!
+//! `BorrowedFd` values may also be used with `mmap`, since `mmap` uses the
+//! provided file descriptor in a manner similar to `dup` and does not require
+//! the `BorrowedFd` passed to it to live for the lifetime of the resulting
+//! mapping. That said, `mmap` is unsafe for other reasons: it operates on raw
+//! pointers, and it can have undefined behavior if the underlying storage is
+//! mutated. Mutations may come from other processes, or from the same process
+//! if the API provides `BorrowedFd` access, since as mentioned earlier,
+//! `BorrowedFd` values may be used in APIs which provide safe access to any
+//! system call. Consequently, code using `mmap` and presenting a safe API must
+//! take full responsibility for ensuring that safe Rust code cannot evoke
+//! undefined behavior through it.
+//!
+//! Like boxes, `OwnedFd` values conceptually own the resource they point to,
+//! and free (close) it when they are dropped.
+//!
+//! ## `/proc/self/mem` and similar OS features
+//!
+//! Some platforms have special files, such as `/proc/self/mem`, which
+//! provide read and write access to the process's memory. Such reads
+//! and writes happen outside the control of the Rust compiler, so they do not
+//! uphold Rust's memory safety guarantees.
+//!
+//! This does not mean that all APIs that might allow `/proc/self/mem`
+//! to be opened and read from or written must be `unsafe`. Rust's safety guarantees
+//! only cover what the program itself can do, and not what entities outside
+//! the program can do to it. `/proc/self/mem` is considered to be such an
+//! external entity, along with debugging interfaces, and people with physical access to
+//! the hardware. This is true even in cases where the program is controlling
+//! the external entity.
+//!
+//! If you desire to comprehensively prevent programs from reaching out and
+//! causing external entities to reach back in and violate memory safety, it's
+//! necessary to use *sandboxing*, which is outside the scope of `std`.
+//!
+//! [`BorrowedFd<'a>`]: crate::os::unix::io::BorrowedFd
+
+#![stable(feature = "rust1", since = "1.0.0")]
+
+mod fd;
+mod raw;
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+pub use fd::*;
+#[stable(feature = "rust1", since = "1.0.0")]
+pub use raw::*;
diff --git a/library/std/src/os/unix/io/raw.rs b/library/std/src/os/unix/io/raw.rs
new file mode 100644
index 000000000..a4d2ba797
--- /dev/null
+++ b/library/std/src/os/unix/io/raw.rs
@@ -0,0 +1,6 @@
+//! Unix-specific extensions to general I/O primitives.
+
+#![stable(feature = "rust1", since = "1.0.0")]
+
+#[stable(feature = "rust1", since = "1.0.0")]
+pub use crate::os::fd::raw::*;
diff --git a/library/std/src/os/unix/mod.rs b/library/std/src/os/unix/mod.rs
new file mode 100644
index 000000000..411cc0925
--- /dev/null
+++ b/library/std/src/os/unix/mod.rs
@@ -0,0 +1,126 @@
+//! Platform-specific extensions to `std` for Unix platforms.
+//!
+//! Provides access to platform-level information on Unix platforms, and
+//! exposes Unix-specific functions that would otherwise be inappropriate as
+//! part of the core `std` library.
+//!
+//! It exposes more ways to deal with platform-specific strings ([`OsStr`],
+//! [`OsString`]), allows to set permissions more granularly, extract low-level
+//! file descriptors from files and sockets, and has platform-specific helpers
+//! for spawning processes.
+//!
+//! # Examples
+//!
+//! ```no_run
+//! use std::fs::File;
+//! use std::os::unix::prelude::*;
+//!
+//! fn main() -> std::io::Result<()> {
+//!     let f = File::create("foo.txt")?;
+//!     let fd = f.as_raw_fd();
+//!
+//!     // use fd with native unix bindings
+//!
+//!     Ok(())
+//! }
+//! ```
+//!
+//! [`OsStr`]: crate::ffi::OsStr
+//! [`OsString`]: crate::ffi::OsString
+
+#![stable(feature = "rust1", since = "1.0.0")]
+#![doc(cfg(unix))]
+
+// Use linux as the default platform when documenting on other platforms like Windows
+#[cfg(doc)]
+use crate::os::linux as platform;
+
+#[cfg(not(doc))]
+mod platform {
+    #[cfg(target_os = "android")]
+    pub use crate::os::android::*;
+    #[cfg(target_os = "dragonfly")]
+    pub use crate::os::dragonfly::*;
+    #[cfg(target_os = "emscripten")]
+    pub use crate::os::emscripten::*;
+    #[cfg(target_os = "espidf")]
+    pub use crate::os::espidf::*;
+    #[cfg(target_os = "freebsd")]
+    pub use crate::os::freebsd::*;
+    #[cfg(target_os = "fuchsia")]
+    pub use crate::os::fuchsia::*;
+    #[cfg(target_os = "haiku")]
+    pub use crate::os::haiku::*;
+    #[cfg(target_os = "horizon")]
+    pub use crate::os::horizon::*;
+    #[cfg(target_os = "illumos")]
+    pub use crate::os::illumos::*;
+    #[cfg(target_os = "ios")]
+    pub use crate::os::ios::*;
+    #[cfg(target_os = "l4re")]
+    pub use crate::os::l4re::*;
+    #[cfg(target_os = "linux")]
+    pub use crate::os::linux::*;
+    #[cfg(target_os = "macos")]
+    pub use crate::os::macos::*;
+    #[cfg(target_os = "netbsd")]
+    pub use crate::os::netbsd::*;
+    #[cfg(target_os = "openbsd")]
+    pub use crate::os::openbsd::*;
+    #[cfg(target_os = "redox")]
+    pub use crate::os::redox::*;
+    #[cfg(target_os = "solaris")]
+    pub use crate::os::solaris::*;
+    #[cfg(target_os = "vxworks")]
+    pub use crate::os::vxworks::*;
+}
+
+pub mod ffi;
+pub mod fs;
+pub mod io;
+pub mod net;
+pub mod process;
+pub mod raw;
+pub mod thread;
+
+#[unstable(feature = "peer_credentials_unix_socket", issue = "42839", reason = "unstable")]
+#[cfg(any(
+    target_os = "android",
+    target_os = "linux",
+    target_os = "dragonfly",
+    target_os = "freebsd",
+    target_os = "ios",
+    target_os = "watchos",
+    target_os = "macos",
+    target_os = "netbsd",
+    target_os = "openbsd"
+))]
+pub mod ucred;
+
+/// A prelude for conveniently writing platform-specific code.
+///
+/// Includes all extension traits, and some important type definitions.
+#[stable(feature = "rust1", since = "1.0.0")]
+pub mod prelude {
+    #[doc(no_inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::ffi::{OsStrExt, OsStringExt};
+    #[doc(no_inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::fs::DirEntryExt;
+    #[doc(no_inline)]
+    #[stable(feature = "file_offset", since = "1.15.0")]
+    pub use super::fs::FileExt;
+    #[doc(no_inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::fs::{FileTypeExt, MetadataExt, OpenOptionsExt, PermissionsExt};
+    #[doc(no_inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
+    #[doc(no_inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::process::{CommandExt, ExitStatusExt};
+    #[doc(no_inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::thread::JoinHandleExt;
+}
diff --git a/library/std/src/os/unix/net/addr.rs b/library/std/src/os/unix/net/addr.rs
new file mode 100644
index 000000000..9aeae4b2c
--- /dev/null
+++ b/library/std/src/os/unix/net/addr.rs
@@ -0,0 +1,350 @@
+use crate::ffi::OsStr;
+use crate::os::unix::ffi::OsStrExt;
+use crate::path::Path;
+use crate::sys::cvt;
+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))]
+#[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]),
+}
+
+struct AsciiEscaped<'a>(&'a [u8]);
+
+impl<'a> fmt::Display for AsciiEscaped<'a> {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(fmt, "\"")?;
+        for byte in self.0.iter().cloned().flat_map(ascii::escape_default) {
+            write!(fmt, "{}", byte as char)?;
+        }
+        write!(fmt, "\"")
+    }
+}
+
+/// 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 }
+    }
+
+    /// Returns the contents of this address if it is an abstract namespace
+    /// without the leading null byte.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// #![feature(unix_socket_abstract)]
+    /// use std::os::unix::net::{UnixListener, SocketAddr};
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let namespace = b"hidden";
+    ///     let namespace_addr = SocketAddr::from_abstract_namespace(&namespace[..])?;
+    ///     let socket = UnixListener::bind_addr(&namespace_addr)?;
+    ///     let local_addr = socket.local_addr().expect("Couldn't get local address");
+    ///     assert_eq!(local_addr.as_abstract_namespace(), Some(&namespace[..]));
+    ///     Ok(())
+    /// }
+    /// ```
+    #[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")]
+    pub fn as_abstract_namespace(&self) -> Option<&[u8]> {
+        if let AddressKind::Abstract(name) = self.address() { Some(name) } 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())
+        }
+    }
+
+    /// Creates an abstract domain socket address from a namespace
+    ///
+    /// An abstract address does not create a file unlike traditional path-based
+    /// Unix sockets. The advantage of this is that the address will disappear when
+    /// the socket bound to it is closed, so no filesystem clean up is required.
+    ///
+    /// The leading null byte for the abstract namespace is automatically added.
+    ///
+    /// This is a Linux-specific extension. See more at [`unix(7)`].
+    ///
+    /// [`unix(7)`]: https://man7.org/linux/man-pages/man7/unix.7.html
+    ///
+    /// # Errors
+    ///
+    /// This will return an error if the given namespace is too long
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// #![feature(unix_socket_abstract)]
+    /// use std::os::unix::net::{UnixListener, SocketAddr};
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let addr = SocketAddr::from_abstract_namespace(b"hidden")?;
+    ///     let listener = match UnixListener::bind_addr(&addr) {
+    ///         Ok(sock) => sock,
+    ///         Err(err) => {
+    ///             println!("Couldn't bind: {err:?}");
+    ///             return Err(err);
+    ///         }
+    ///     };
+    ///     Ok(())
+    /// }
+    /// ```
+    #[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")]
+    pub fn from_abstract_namespace(namespace: &[u8]) -> io::Result<SocketAddr> {
+        unsafe {
+            let mut addr: libc::sockaddr_un = mem::zeroed();
+            addr.sun_family = libc::AF_UNIX as libc::sa_family_t;
+
+            if namespace.len() + 1 > addr.sun_path.len() {
+                return Err(io::const_io_error!(
+                    io::ErrorKind::InvalidInput,
+                    "namespace must be shorter than SUN_LEN",
+                ));
+            }
+
+            crate::ptr::copy_nonoverlapping(
+                namespace.as_ptr(),
+                addr.sun_path.as_mut_ptr().offset(1) as *mut u8,
+                namespace.len(),
+            );
+            let len = (sun_path_offset(&addr) + 1 + namespace.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)", AsciiEscaped(name)),
+            AddressKind::Pathname(path) => write!(fmt, "{path:?} (pathname)"),
+        }
+    }
+}
diff --git a/library/std/src/os/unix/net/ancillary.rs b/library/std/src/os/unix/net/ancillary.rs
new file mode 100644
index 000000000..7cc901a79
--- /dev/null
+++ b/library/std/src/os/unix/net/ancillary.rs
@@ -0,0 +1,674 @@
+// FIXME: This is currently disabled on *BSD.
+
+use super::{sockaddr_un, SocketAddr};
+use crate::io::{self, IoSlice, IoSliceMut};
+use crate::marker::PhantomData;
+use crate::mem::{size_of, zeroed};
+use crate::os::unix::io::RawFd;
+use crate::path::Path;
+use crate::ptr::{eq, read_unaligned};
+use crate::slice::from_raw_parts;
+use crate::sys::net::Socket;
+
+// FIXME(#43348): Make libc adapt #[doc(cfg(...))] so we don't need these fake definitions here?
+#[cfg(all(doc, not(target_os = "linux"), not(target_os = "android"), not(target_os = "netbsd")))]
+#[allow(non_camel_case_types)]
+mod libc {
+    pub use libc::c_int;
+    pub struct ucred;
+    pub struct cmsghdr;
+    pub type pid_t = i32;
+    pub type gid_t = u32;
+    pub type uid_t = u32;
+}
+
+pub(super) fn recv_vectored_with_ancillary_from(
+    socket: &Socket,
+    bufs: &mut [IoSliceMut<'_>],
+    ancillary: &mut SocketAncillary<'_>,
+) -> io::Result<(usize, bool, io::Result<SocketAddr>)> {
+    unsafe {
+        let mut msg_name: libc::sockaddr_un = zeroed();
+        let mut msg: libc::msghdr = zeroed();
+        msg.msg_name = &mut msg_name as *mut _ as *mut _;
+        msg.msg_namelen = size_of::<libc::sockaddr_un>() as libc::socklen_t;
+        msg.msg_iov = bufs.as_mut_ptr().cast();
+        msg.msg_iovlen = bufs.len() as _;
+        msg.msg_controllen = ancillary.buffer.len() as _;
+        // macos requires that the control pointer is null when the len is 0.
+        if msg.msg_controllen > 0 {
+            msg.msg_control = ancillary.buffer.as_mut_ptr().cast();
+        }
+
+        let count = socket.recv_msg(&mut msg)?;
+
+        ancillary.length = msg.msg_controllen as usize;
+        ancillary.truncated = msg.msg_flags & libc::MSG_CTRUNC == libc::MSG_CTRUNC;
+
+        let truncated = msg.msg_flags & libc::MSG_TRUNC == libc::MSG_TRUNC;
+        let addr = SocketAddr::from_parts(msg_name, msg.msg_namelen);
+
+        Ok((count, truncated, addr))
+    }
+}
+
+pub(super) fn send_vectored_with_ancillary_to(
+    socket: &Socket,
+    path: Option<&Path>,
+    bufs: &[IoSlice<'_>],
+    ancillary: &mut SocketAncillary<'_>,
+) -> io::Result<usize> {
+    unsafe {
+        let (mut msg_name, msg_namelen) =
+            if let Some(path) = path { sockaddr_un(path)? } else { (zeroed(), 0) };
+
+        let mut msg: libc::msghdr = zeroed();
+        msg.msg_name = &mut msg_name as *mut _ as *mut _;
+        msg.msg_namelen = msg_namelen;
+        msg.msg_iov = bufs.as_ptr() as *mut _;
+        msg.msg_iovlen = bufs.len() as _;
+        msg.msg_controllen = ancillary.length as _;
+        // macos requires that the control pointer is null when the len is 0.
+        if msg.msg_controllen > 0 {
+            msg.msg_control = ancillary.buffer.as_mut_ptr().cast();
+        }
+
+        ancillary.truncated = false;
+
+        socket.send_msg(&mut msg)
+    }
+}
+
+fn add_to_ancillary_data<T>(
+    buffer: &mut [u8],
+    length: &mut usize,
+    source: &[T],
+    cmsg_level: libc::c_int,
+    cmsg_type: libc::c_int,
+) -> bool {
+    let source_len = if let Some(source_len) = source.len().checked_mul(size_of::<T>()) {
+        if let Ok(source_len) = u32::try_from(source_len) {
+            source_len
+        } else {
+            return false;
+        }
+    } else {
+        return false;
+    };
+
+    unsafe {
+        let additional_space = libc::CMSG_SPACE(source_len) as usize;
+
+        let new_length = if let Some(new_length) = additional_space.checked_add(*length) {
+            new_length
+        } else {
+            return false;
+        };
+
+        if new_length > buffer.len() {
+            return false;
+        }
+
+        buffer[*length..new_length].fill(0);
+
+        *length = new_length;
+
+        let mut msg: libc::msghdr = zeroed();
+        msg.msg_control = buffer.as_mut_ptr().cast();
+        msg.msg_controllen = *length as _;
+
+        let mut cmsg = libc::CMSG_FIRSTHDR(&msg);
+        let mut previous_cmsg = cmsg;
+        while !cmsg.is_null() {
+            previous_cmsg = cmsg;
+            cmsg = libc::CMSG_NXTHDR(&msg, cmsg);
+
+            // Most operating systems, but not Linux or emscripten, return the previous pointer
+            // when its length is zero. Therefore, check if the previous pointer is the same as
+            // the current one.
+            if eq(cmsg, previous_cmsg) {
+                break;
+            }
+        }
+
+        if previous_cmsg.is_null() {
+            return false;
+        }
+
+        (*previous_cmsg).cmsg_level = cmsg_level;
+        (*previous_cmsg).cmsg_type = cmsg_type;
+        (*previous_cmsg).cmsg_len = libc::CMSG_LEN(source_len) as _;
+
+        let data = libc::CMSG_DATA(previous_cmsg).cast();
+
+        libc::memcpy(data, source.as_ptr().cast(), source_len as usize);
+    }
+    true
+}
+
+struct AncillaryDataIter<'a, T> {
+    data: &'a [u8],
+    phantom: PhantomData<T>,
+}
+
+impl<'a, T> AncillaryDataIter<'a, T> {
+    /// Create `AncillaryDataIter` struct to iterate through the data unit in the control message.
+    ///
+    /// # Safety
+    ///
+    /// `data` must contain a valid control message.
+    unsafe fn new(data: &'a [u8]) -> AncillaryDataIter<'a, T> {
+        AncillaryDataIter { data, phantom: PhantomData }
+    }
+}
+
+impl<'a, T> Iterator for AncillaryDataIter<'a, T> {
+    type Item = T;
+
+    fn next(&mut self) -> Option<T> {
+        if size_of::<T>() <= self.data.len() {
+            unsafe {
+                let unit = read_unaligned(self.data.as_ptr().cast());
+                self.data = &self.data[size_of::<T>()..];
+                Some(unit)
+            }
+        } else {
+            None
+        }
+    }
+}
+
+#[cfg(all(doc, not(target_os = "android"), not(target_os = "linux"), not(target_os = "netbsd")))]
+#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+#[derive(Clone)]
+pub struct SocketCred(());
+
+/// Unix credential.
+#[cfg(any(target_os = "android", target_os = "linux",))]
+#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+#[derive(Clone)]
+pub struct SocketCred(libc::ucred);
+
+#[cfg(target_os = "netbsd")]
+#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+#[derive(Clone)]
+pub struct SocketCred(libc::sockcred);
+
+#[doc(cfg(any(target_os = "android", target_os = "linux")))]
+#[cfg(any(target_os = "android", target_os = "linux"))]
+impl SocketCred {
+    /// Create a Unix credential struct.
+    ///
+    /// PID, UID and GID is set to 0.
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    #[must_use]
+    pub fn new() -> SocketCred {
+        SocketCred(libc::ucred { pid: 0, uid: 0, gid: 0 })
+    }
+
+    /// Set the PID.
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn set_pid(&mut self, pid: libc::pid_t) {
+        self.0.pid = pid;
+    }
+
+    /// Get the current PID.
+    #[must_use]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn get_pid(&self) -> libc::pid_t {
+        self.0.pid
+    }
+
+    /// Set the UID.
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn set_uid(&mut self, uid: libc::uid_t) {
+        self.0.uid = uid;
+    }
+
+    /// Get the current UID.
+    #[must_use]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn get_uid(&self) -> libc::uid_t {
+        self.0.uid
+    }
+
+    /// Set the GID.
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn set_gid(&mut self, gid: libc::gid_t) {
+        self.0.gid = gid;
+    }
+
+    /// Get the current GID.
+    #[must_use]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn get_gid(&self) -> libc::gid_t {
+        self.0.gid
+    }
+}
+
+#[cfg(target_os = "netbsd")]
+impl SocketCred {
+    /// Create a Unix credential struct.
+    ///
+    /// PID, UID and GID is set to 0.
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn new() -> SocketCred {
+        SocketCred(libc::sockcred {
+            sc_pid: 0,
+            sc_uid: 0,
+            sc_euid: 0,
+            sc_gid: 0,
+            sc_egid: 0,
+            sc_ngroups: 0,
+            sc_groups: [0u32; 1],
+        })
+    }
+
+    /// Set the PID.
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn set_pid(&mut self, pid: libc::pid_t) {
+        self.0.sc_pid = pid;
+    }
+
+    /// Get the current PID.
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn get_pid(&self) -> libc::pid_t {
+        self.0.sc_pid
+    }
+
+    /// Set the UID.
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn set_uid(&mut self, uid: libc::uid_t) {
+        self.0.sc_uid = uid;
+    }
+
+    /// Get the current UID.
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn get_uid(&self) -> libc::uid_t {
+        self.0.sc_uid
+    }
+
+    /// Set the GID.
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn set_gid(&mut self, gid: libc::gid_t) {
+        self.0.sc_gid = gid;
+    }
+
+    /// Get the current GID.
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn get_gid(&self) -> libc::gid_t {
+        self.0.sc_gid
+    }
+}
+
+/// This control message contains file descriptors.
+///
+/// The level is equal to `SOL_SOCKET` and the type is equal to `SCM_RIGHTS`.
+#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+pub struct ScmRights<'a>(AncillaryDataIter<'a, RawFd>);
+
+#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+impl<'a> Iterator for ScmRights<'a> {
+    type Item = RawFd;
+
+    fn next(&mut self) -> Option<RawFd> {
+        self.0.next()
+    }
+}
+
+#[cfg(all(doc, not(target_os = "android"), not(target_os = "linux"), not(target_os = "netbsd")))]
+#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+pub struct ScmCredentials<'a>(AncillaryDataIter<'a, ()>);
+
+/// This control message contains unix credentials.
+///
+/// The level is equal to `SOL_SOCKET` and the type is equal to `SCM_CREDENTIALS` or `SCM_CREDS`.
+#[cfg(any(target_os = "android", target_os = "linux",))]
+#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+pub struct ScmCredentials<'a>(AncillaryDataIter<'a, libc::ucred>);
+
+#[cfg(target_os = "netbsd")]
+#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+pub struct ScmCredentials<'a>(AncillaryDataIter<'a, libc::sockcred>);
+
+#[cfg(any(doc, target_os = "android", target_os = "linux", target_os = "netbsd",))]
+#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+impl<'a> Iterator for ScmCredentials<'a> {
+    type Item = SocketCred;
+
+    fn next(&mut self) -> Option<SocketCred> {
+        Some(SocketCred(self.0.next()?))
+    }
+}
+
+/// The error type which is returned from parsing the type a control message.
+#[non_exhaustive]
+#[derive(Debug)]
+#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+pub enum AncillaryError {
+    Unknown { cmsg_level: i32, cmsg_type: i32 },
+}
+
+/// This enum represent one control message of variable type.
+#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+pub enum AncillaryData<'a> {
+    ScmRights(ScmRights<'a>),
+    #[cfg(any(doc, target_os = "android", target_os = "linux", target_os = "netbsd",))]
+    ScmCredentials(ScmCredentials<'a>),
+}
+
+impl<'a> AncillaryData<'a> {
+    /// Create an `AncillaryData::ScmRights` variant.
+    ///
+    /// # Safety
+    ///
+    /// `data` must contain a valid control message and the control message must be type of
+    /// `SOL_SOCKET` and level of `SCM_RIGHTS`.
+    unsafe fn as_rights(data: &'a [u8]) -> Self {
+        let ancillary_data_iter = AncillaryDataIter::new(data);
+        let scm_rights = ScmRights(ancillary_data_iter);
+        AncillaryData::ScmRights(scm_rights)
+    }
+
+    /// Create an `AncillaryData::ScmCredentials` variant.
+    ///
+    /// # Safety
+    ///
+    /// `data` must contain a valid control message and the control message must be type of
+    /// `SOL_SOCKET` and level of `SCM_CREDENTIALS` or `SCM_CREDS`.
+    #[cfg(any(doc, target_os = "android", target_os = "linux", target_os = "netbsd",))]
+    unsafe fn as_credentials(data: &'a [u8]) -> Self {
+        let ancillary_data_iter = AncillaryDataIter::new(data);
+        let scm_credentials = ScmCredentials(ancillary_data_iter);
+        AncillaryData::ScmCredentials(scm_credentials)
+    }
+
+    fn try_from_cmsghdr(cmsg: &'a libc::cmsghdr) -> Result<Self, AncillaryError> {
+        unsafe {
+            let cmsg_len_zero = libc::CMSG_LEN(0) as usize;
+            let data_len = (*cmsg).cmsg_len as usize - cmsg_len_zero;
+            let data = libc::CMSG_DATA(cmsg).cast();
+            let data = from_raw_parts(data, data_len);
+
+            match (*cmsg).cmsg_level {
+                libc::SOL_SOCKET => match (*cmsg).cmsg_type {
+                    libc::SCM_RIGHTS => Ok(AncillaryData::as_rights(data)),
+                    #[cfg(any(target_os = "android", target_os = "linux",))]
+                    libc::SCM_CREDENTIALS => Ok(AncillaryData::as_credentials(data)),
+                    #[cfg(target_os = "netbsd")]
+                    libc::SCM_CREDS => Ok(AncillaryData::as_credentials(data)),
+                    cmsg_type => {
+                        Err(AncillaryError::Unknown { cmsg_level: libc::SOL_SOCKET, cmsg_type })
+                    }
+                },
+                cmsg_level => {
+                    Err(AncillaryError::Unknown { cmsg_level, cmsg_type: (*cmsg).cmsg_type })
+                }
+            }
+        }
+    }
+}
+
+/// This struct is used to iterate through the control messages.
+#[must_use = "iterators are lazy and do nothing unless consumed"]
+#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+pub struct Messages<'a> {
+    buffer: &'a [u8],
+    current: Option<&'a libc::cmsghdr>,
+}
+
+#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+impl<'a> Iterator for Messages<'a> {
+    type Item = Result<AncillaryData<'a>, AncillaryError>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        unsafe {
+            let mut msg: libc::msghdr = zeroed();
+            msg.msg_control = self.buffer.as_ptr() as *mut _;
+            msg.msg_controllen = self.buffer.len() as _;
+
+            let cmsg = if let Some(current) = self.current {
+                libc::CMSG_NXTHDR(&msg, current)
+            } else {
+                libc::CMSG_FIRSTHDR(&msg)
+            };
+
+            let cmsg = cmsg.as_ref()?;
+
+            // Most operating systems, but not Linux or emscripten, return the previous pointer
+            // when its length is zero. Therefore, check if the previous pointer is the same as
+            // the current one.
+            if let Some(current) = self.current {
+                if eq(current, cmsg) {
+                    return None;
+                }
+            }
+
+            self.current = Some(cmsg);
+            let ancillary_result = AncillaryData::try_from_cmsghdr(cmsg);
+            Some(ancillary_result)
+        }
+    }
+}
+
+/// A Unix socket Ancillary data struct.
+///
+/// # Example
+/// ```no_run
+/// #![feature(unix_socket_ancillary_data)]
+/// use std::os::unix::net::{UnixStream, SocketAncillary, AncillaryData};
+/// use std::io::IoSliceMut;
+///
+/// fn main() -> std::io::Result<()> {
+///     let sock = UnixStream::connect("/tmp/sock")?;
+///
+///     let mut fds = [0; 8];
+///     let mut ancillary_buffer = [0; 128];
+///     let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);
+///
+///     let mut buf = [1; 8];
+///     let mut bufs = &mut [IoSliceMut::new(&mut buf[..])][..];
+///     sock.recv_vectored_with_ancillary(bufs, &mut ancillary)?;
+///
+///     for ancillary_result in ancillary.messages() {
+///         if let AncillaryData::ScmRights(scm_rights) = ancillary_result.unwrap() {
+///             for fd in scm_rights {
+///                 println!("receive file descriptor: {fd}");
+///             }
+///         }
+///     }
+///     Ok(())
+/// }
+/// ```
+#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+#[derive(Debug)]
+pub struct SocketAncillary<'a> {
+    buffer: &'a mut [u8],
+    length: usize,
+    truncated: bool,
+}
+
+impl<'a> SocketAncillary<'a> {
+    /// Create an ancillary data with the given buffer.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// # #![allow(unused_mut)]
+    /// #![feature(unix_socket_ancillary_data)]
+    /// use std::os::unix::net::SocketAncillary;
+    /// let mut ancillary_buffer = [0; 128];
+    /// let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);
+    /// ```
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn new(buffer: &'a mut [u8]) -> Self {
+        SocketAncillary { buffer, length: 0, truncated: false }
+    }
+
+    /// Returns the capacity of the buffer.
+    #[must_use]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn capacity(&self) -> usize {
+        self.buffer.len()
+    }
+
+    /// Returns `true` if the ancillary data is empty.
+    #[must_use]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn is_empty(&self) -> bool {
+        self.length == 0
+    }
+
+    /// Returns the number of used bytes.
+    #[must_use]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn len(&self) -> usize {
+        self.length
+    }
+
+    /// Returns the iterator of the control messages.
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn messages(&self) -> Messages<'_> {
+        Messages { buffer: &self.buffer[..self.length], current: None }
+    }
+
+    /// Is `true` if during a recv operation the ancillary was truncated.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// #![feature(unix_socket_ancillary_data)]
+    /// use std::os::unix::net::{UnixStream, SocketAncillary};
+    /// use std::io::IoSliceMut;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixStream::connect("/tmp/sock")?;
+    ///
+    ///     let mut ancillary_buffer = [0; 128];
+    ///     let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);
+    ///
+    ///     let mut buf = [1; 8];
+    ///     let mut bufs = &mut [IoSliceMut::new(&mut buf[..])][..];
+    ///     sock.recv_vectored_with_ancillary(bufs, &mut ancillary)?;
+    ///
+    ///     println!("Is truncated: {}", ancillary.truncated());
+    ///     Ok(())
+    /// }
+    /// ```
+    #[must_use]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn truncated(&self) -> bool {
+        self.truncated
+    }
+
+    /// Add file descriptors to the ancillary data.
+    ///
+    /// The function returns `true` if there was enough space in the buffer.
+    /// If there was not enough space then no file descriptors was appended.
+    /// Technically, that means this operation adds a control message with the level `SOL_SOCKET`
+    /// and type `SCM_RIGHTS`.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// #![feature(unix_socket_ancillary_data)]
+    /// use std::os::unix::net::{UnixStream, SocketAncillary};
+    /// use std::os::unix::io::AsRawFd;
+    /// use std::io::IoSlice;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixStream::connect("/tmp/sock")?;
+    ///
+    ///     let mut ancillary_buffer = [0; 128];
+    ///     let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);
+    ///     ancillary.add_fds(&[sock.as_raw_fd()][..]);
+    ///
+    ///     let buf = [1; 8];
+    ///     let mut bufs = &mut [IoSlice::new(&buf[..])][..];
+    ///     sock.send_vectored_with_ancillary(bufs, &mut ancillary)?;
+    ///     Ok(())
+    /// }
+    /// ```
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn add_fds(&mut self, fds: &[RawFd]) -> bool {
+        self.truncated = false;
+        add_to_ancillary_data(
+            &mut self.buffer,
+            &mut self.length,
+            fds,
+            libc::SOL_SOCKET,
+            libc::SCM_RIGHTS,
+        )
+    }
+
+    /// Add credentials to the ancillary data.
+    ///
+    /// The function returns `true` if there was enough space in the buffer.
+    /// If there was not enough space then no credentials was appended.
+    /// Technically, that means this operation adds a control message with the level `SOL_SOCKET`
+    /// and type `SCM_CREDENTIALS` or `SCM_CREDS`.
+    ///
+    #[cfg(any(doc, target_os = "android", target_os = "linux", target_os = "netbsd",))]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn add_creds(&mut self, creds: &[SocketCred]) -> bool {
+        self.truncated = false;
+        add_to_ancillary_data(
+            &mut self.buffer,
+            &mut self.length,
+            creds,
+            libc::SOL_SOCKET,
+            #[cfg(not(target_os = "netbsd"))]
+            libc::SCM_CREDENTIALS,
+            #[cfg(target_os = "netbsd")]
+            libc::SCM_CREDS,
+        )
+    }
+
+    /// Clears the ancillary data, removing all values.
+    ///
+    /// # Example
+    ///
+    /// ```no_run
+    /// #![feature(unix_socket_ancillary_data)]
+    /// use std::os::unix::net::{UnixStream, SocketAncillary, AncillaryData};
+    /// use std::io::IoSliceMut;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixStream::connect("/tmp/sock")?;
+    ///
+    ///     let mut fds1 = [0; 8];
+    ///     let mut fds2 = [0; 8];
+    ///     let mut ancillary_buffer = [0; 128];
+    ///     let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);
+    ///
+    ///     let mut buf = [1; 8];
+    ///     let mut bufs = &mut [IoSliceMut::new(&mut buf[..])][..];
+    ///
+    ///     sock.recv_vectored_with_ancillary(bufs, &mut ancillary)?;
+    ///     for ancillary_result in ancillary.messages() {
+    ///         if let AncillaryData::ScmRights(scm_rights) = ancillary_result.unwrap() {
+    ///             for fd in scm_rights {
+    ///                 println!("receive file descriptor: {fd}");
+    ///             }
+    ///         }
+    ///     }
+    ///
+    ///     ancillary.clear();
+    ///
+    ///     sock.recv_vectored_with_ancillary(bufs, &mut ancillary)?;
+    ///     for ancillary_result in ancillary.messages() {
+    ///         if let AncillaryData::ScmRights(scm_rights) = ancillary_result.unwrap() {
+    ///             for fd in scm_rights {
+    ///                 println!("receive file descriptor: {fd}");
+    ///             }
+    ///         }
+    ///     }
+    ///     Ok(())
+    /// }
+    /// ```
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn clear(&mut self) {
+        self.length = 0;
+        self.truncated = false;
+    }
+}
diff --git a/library/std/src/os/unix/net/datagram.rs b/library/std/src/os/unix/net/datagram.rs
new file mode 100644
index 000000000..8008acfd1
--- /dev/null
+++ b/library/std/src/os/unix/net/datagram.rs
@@ -0,0 +1,987 @@
+#[cfg(any(doc, target_os = "android", target_os = "linux"))]
+use super::{recv_vectored_with_ancillary_from, send_vectored_with_ancillary_to, SocketAncillary};
+use super::{sockaddr_un, SocketAddr};
+#[cfg(any(doc, target_os = "android", target_os = "linux"))]
+use crate::io::{IoSlice, IoSliceMut};
+use crate::net::Shutdown;
+use crate::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
+use crate::path::Path;
+use crate::sys::cvt;
+use crate::sys::net::Socket;
+use crate::sys_common::{AsInner, FromInner, IntoInner};
+use crate::time::Duration;
+use crate::{fmt, io};
+
+#[cfg(any(
+    target_os = "linux",
+    target_os = "android",
+    target_os = "dragonfly",
+    target_os = "freebsd",
+    target_os = "openbsd",
+    target_os = "netbsd",
+    target_os = "haiku"
+))]
+use libc::MSG_NOSIGNAL;
+#[cfg(not(any(
+    target_os = "linux",
+    target_os = "android",
+    target_os = "dragonfly",
+    target_os = "freebsd",
+    target_os = "openbsd",
+    target_os = "netbsd",
+    target_os = "haiku"
+)))]
+const MSG_NOSIGNAL: libc::c_int = 0x0;
+
+/// A Unix datagram socket.
+///
+/// # Examples
+///
+/// ```no_run
+/// use std::os::unix::net::UnixDatagram;
+///
+/// fn main() -> std::io::Result<()> {
+///     let socket = UnixDatagram::bind("/path/to/my/socket")?;
+///     socket.send_to(b"hello world", "/path/to/other/socket")?;
+///     let mut buf = [0; 100];
+///     let (count, address) = socket.recv_from(&mut buf)?;
+///     println!("socket {:?} sent {:?}", address, &buf[..count]);
+///     Ok(())
+/// }
+/// ```
+#[stable(feature = "unix_socket", since = "1.10.0")]
+pub struct UnixDatagram(Socket);
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl fmt::Debug for UnixDatagram {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut builder = fmt.debug_struct("UnixDatagram");
+        builder.field("fd", self.0.as_inner());
+        if let Ok(addr) = self.local_addr() {
+            builder.field("local", &addr);
+        }
+        if let Ok(addr) = self.peer_addr() {
+            builder.field("peer", &addr);
+        }
+        builder.finish()
+    }
+}
+
+impl UnixDatagram {
+    /// Creates a Unix datagram socket bound to the given path.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixDatagram;
+    ///
+    /// let sock = match UnixDatagram::bind("/path/to/the/socket") {
+    ///     Ok(sock) => sock,
+    ///     Err(e) => {
+    ///         println!("Couldn't bind: {e:?}");
+    ///         return
+    ///     }
+    /// };
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn bind<P: AsRef<Path>>(path: P) -> io::Result<UnixDatagram> {
+        unsafe {
+            let socket = UnixDatagram::unbound()?;
+            let (addr, len) = sockaddr_un(path.as_ref())?;
+
+            cvt(libc::bind(socket.as_raw_fd(), &addr as *const _ as *const _, len as _))?;
+
+            Ok(socket)
+        }
+    }
+
+    /// Creates a Unix datagram socket bound to an address.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// #![feature(unix_socket_abstract)]
+    /// use std::os::unix::net::{UnixDatagram};
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock1 = UnixDatagram::bind("path/to/socket")?;
+    ///     let addr = sock1.local_addr()?;
+    ///
+    ///     let sock2 = match UnixDatagram::bind_addr(&addr) {
+    ///         Ok(sock) => sock,
+    ///         Err(err) => {
+    ///             println!("Couldn't bind: {err:?}");
+    ///             return Err(err);
+    ///         }
+    ///     };
+    ///     Ok(())
+    /// }
+    /// ```
+    #[unstable(feature = "unix_socket_abstract", issue = "85410")]
+    pub fn bind_addr(socket_addr: &SocketAddr) -> io::Result<UnixDatagram> {
+        unsafe {
+            let socket = UnixDatagram::unbound()?;
+            cvt(libc::bind(
+                socket.as_raw_fd(),
+                &socket_addr.addr as *const _ as *const _,
+                socket_addr.len as _,
+            ))?;
+            Ok(socket)
+        }
+    }
+
+    /// Creates a Unix Datagram socket which is not bound to any address.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixDatagram;
+    ///
+    /// let sock = match UnixDatagram::unbound() {
+    ///     Ok(sock) => sock,
+    ///     Err(e) => {
+    ///         println!("Couldn't unbound: {e:?}");
+    ///         return
+    ///     }
+    /// };
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn unbound() -> io::Result<UnixDatagram> {
+        let inner = Socket::new_raw(libc::AF_UNIX, libc::SOCK_DGRAM)?;
+        Ok(UnixDatagram(inner))
+    }
+
+    /// Creates an unnamed pair of connected sockets.
+    ///
+    /// Returns two `UnixDatagrams`s which are connected to each other.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixDatagram;
+    ///
+    /// let (sock1, sock2) = match UnixDatagram::pair() {
+    ///     Ok((sock1, sock2)) => (sock1, sock2),
+    ///     Err(e) => {
+    ///         println!("Couldn't unbound: {e:?}");
+    ///         return
+    ///     }
+    /// };
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn pair() -> io::Result<(UnixDatagram, UnixDatagram)> {
+        let (i1, i2) = Socket::new_pair(libc::AF_UNIX, libc::SOCK_DGRAM)?;
+        Ok((UnixDatagram(i1), UnixDatagram(i2)))
+    }
+
+    /// Connects the socket to the specified path address.
+    ///
+    /// The [`send`] method may be used to send data to the specified address.
+    /// [`recv`] and [`recv_from`] will only receive data from that address.
+    ///
+    /// [`send`]: UnixDatagram::send
+    /// [`recv`]: UnixDatagram::recv
+    /// [`recv_from`]: UnixDatagram::recv_from
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixDatagram;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     match sock.connect("/path/to/the/socket") {
+    ///         Ok(sock) => sock,
+    ///         Err(e) => {
+    ///             println!("Couldn't connect: {e:?}");
+    ///             return Err(e)
+    ///         }
+    ///     };
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn connect<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {
+        unsafe {
+            let (addr, len) = sockaddr_un(path.as_ref())?;
+
+            cvt(libc::connect(self.as_raw_fd(), &addr as *const _ as *const _, len))?;
+        }
+        Ok(())
+    }
+
+    /// Connects the socket to an address.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// #![feature(unix_socket_abstract)]
+    /// use std::os::unix::net::{UnixDatagram};
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let bound = UnixDatagram::bind("/path/to/socket")?;
+    ///     let addr = bound.local_addr()?;
+    ///
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     match sock.connect_addr(&addr) {
+    ///         Ok(sock) => sock,
+    ///         Err(e) => {
+    ///             println!("Couldn't connect: {e:?}");
+    ///             return Err(e)
+    ///         }
+    ///     };
+    ///     Ok(())
+    /// }
+    /// ```
+    #[unstable(feature = "unix_socket_abstract", issue = "85410")]
+    pub fn connect_addr(&self, socket_addr: &SocketAddr) -> io::Result<()> {
+        unsafe {
+            cvt(libc::connect(
+                self.as_raw_fd(),
+                &socket_addr.addr as *const _ as *const _,
+                socket_addr.len,
+            ))?;
+        }
+        Ok(())
+    }
+
+    /// Creates a new independently owned handle to the underlying socket.
+    ///
+    /// The returned `UnixDatagram` is a reference to the same socket that this
+    /// object references. Both handles can be used to accept incoming
+    /// connections and options set on one side will affect the other.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixDatagram;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::bind("/path/to/the/socket")?;
+    ///     let sock_copy = sock.try_clone().expect("try_clone failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn try_clone(&self) -> io::Result<UnixDatagram> {
+        self.0.duplicate().map(UnixDatagram)
+    }
+
+    /// Returns the address of this socket.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixDatagram;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::bind("/path/to/the/socket")?;
+    ///     let addr = sock.local_addr().expect("Couldn't get local address");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn local_addr(&self) -> io::Result<SocketAddr> {
+        SocketAddr::new(|addr, len| unsafe { libc::getsockname(self.as_raw_fd(), addr, len) })
+    }
+
+    /// Returns the address of this socket's peer.
+    ///
+    /// The [`connect`] method will connect the socket to a peer.
+    ///
+    /// [`connect`]: UnixDatagram::connect
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixDatagram;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     sock.connect("/path/to/the/socket")?;
+    ///
+    ///     let addr = sock.peer_addr().expect("Couldn't get peer address");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn peer_addr(&self) -> io::Result<SocketAddr> {
+        SocketAddr::new(|addr, len| unsafe { libc::getpeername(self.as_raw_fd(), addr, len) })
+    }
+
+    fn recv_from_flags(
+        &self,
+        buf: &mut [u8],
+        flags: libc::c_int,
+    ) -> io::Result<(usize, SocketAddr)> {
+        let mut count = 0;
+        let addr = SocketAddr::new(|addr, len| unsafe {
+            count = libc::recvfrom(
+                self.as_raw_fd(),
+                buf.as_mut_ptr() as *mut _,
+                buf.len(),
+                flags,
+                addr,
+                len,
+            );
+            if count > 0 {
+                1
+            } else if count == 0 {
+                0
+            } else {
+                -1
+            }
+        })?;
+
+        Ok((count as usize, addr))
+    }
+
+    /// Receives data from the socket.
+    ///
+    /// On success, returns the number of bytes read and the address from
+    /// whence the data came.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixDatagram;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     let mut buf = vec![0; 10];
+    ///     let (size, sender) = sock.recv_from(buf.as_mut_slice())?;
+    ///     println!("received {size} bytes from {sender:?}");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn recv_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
+        self.recv_from_flags(buf, 0)
+    }
+
+    /// Receives data from the socket.
+    ///
+    /// On success, returns the number of bytes read.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixDatagram;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::bind("/path/to/the/socket")?;
+    ///     let mut buf = vec![0; 10];
+    ///     sock.recv(buf.as_mut_slice()).expect("recv function failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn recv(&self, buf: &mut [u8]) -> io::Result<usize> {
+        self.0.read(buf)
+    }
+
+    /// Receives data and ancillary data from socket.
+    ///
+    /// On success, returns the number of bytes read, if the data was truncated and the address from whence the msg came.
+    ///
+    /// # Examples
+    ///
+    #[cfg_attr(any(target_os = "android", target_os = "linux"), doc = "```no_run")]
+    #[cfg_attr(not(any(target_os = "android", target_os = "linux")), doc = "```ignore")]
+    /// #![feature(unix_socket_ancillary_data)]
+    /// use std::os::unix::net::{UnixDatagram, SocketAncillary, AncillaryData};
+    /// use std::io::IoSliceMut;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     let mut buf1 = [1; 8];
+    ///     let mut buf2 = [2; 16];
+    ///     let mut buf3 = [3; 8];
+    ///     let mut bufs = &mut [
+    ///         IoSliceMut::new(&mut buf1),
+    ///         IoSliceMut::new(&mut buf2),
+    ///         IoSliceMut::new(&mut buf3),
+    ///     ][..];
+    ///     let mut fds = [0; 8];
+    ///     let mut ancillary_buffer = [0; 128];
+    ///     let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);
+    ///     let (size, _truncated, sender) = sock.recv_vectored_with_ancillary_from(bufs, &mut ancillary)?;
+    ///     println!("received {size}");
+    ///     for ancillary_result in ancillary.messages() {
+    ///         if let AncillaryData::ScmRights(scm_rights) = ancillary_result.unwrap() {
+    ///             for fd in scm_rights {
+    ///                 println!("receive file descriptor: {fd}");
+    ///             }
+    ///         }
+    ///     }
+    ///     Ok(())
+    /// }
+    /// ```
+    #[cfg(any(doc, target_os = "android", target_os = "linux"))]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn recv_vectored_with_ancillary_from(
+        &self,
+        bufs: &mut [IoSliceMut<'_>],
+        ancillary: &mut SocketAncillary<'_>,
+    ) -> io::Result<(usize, bool, SocketAddr)> {
+        let (count, truncated, addr) = recv_vectored_with_ancillary_from(&self.0, bufs, ancillary)?;
+        let addr = addr?;
+
+        Ok((count, truncated, addr))
+    }
+
+    /// Receives data and ancillary data from socket.
+    ///
+    /// On success, returns the number of bytes read and if the data was truncated.
+    ///
+    /// # Examples
+    ///
+    #[cfg_attr(any(target_os = "android", target_os = "linux"), doc = "```no_run")]
+    #[cfg_attr(not(any(target_os = "android", target_os = "linux")), doc = "```ignore")]
+    /// #![feature(unix_socket_ancillary_data)]
+    /// use std::os::unix::net::{UnixDatagram, SocketAncillary, AncillaryData};
+    /// use std::io::IoSliceMut;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     let mut buf1 = [1; 8];
+    ///     let mut buf2 = [2; 16];
+    ///     let mut buf3 = [3; 8];
+    ///     let mut bufs = &mut [
+    ///         IoSliceMut::new(&mut buf1),
+    ///         IoSliceMut::new(&mut buf2),
+    ///         IoSliceMut::new(&mut buf3),
+    ///     ][..];
+    ///     let mut fds = [0; 8];
+    ///     let mut ancillary_buffer = [0; 128];
+    ///     let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);
+    ///     let (size, _truncated) = sock.recv_vectored_with_ancillary(bufs, &mut ancillary)?;
+    ///     println!("received {size}");
+    ///     for ancillary_result in ancillary.messages() {
+    ///         if let AncillaryData::ScmRights(scm_rights) = ancillary_result.unwrap() {
+    ///             for fd in scm_rights {
+    ///                 println!("receive file descriptor: {fd}");
+    ///             }
+    ///         }
+    ///     }
+    ///     Ok(())
+    /// }
+    /// ```
+    #[cfg(any(doc, target_os = "android", target_os = "linux"))]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn recv_vectored_with_ancillary(
+        &self,
+        bufs: &mut [IoSliceMut<'_>],
+        ancillary: &mut SocketAncillary<'_>,
+    ) -> io::Result<(usize, bool)> {
+        let (count, truncated, addr) = recv_vectored_with_ancillary_from(&self.0, bufs, ancillary)?;
+        addr?;
+
+        Ok((count, truncated))
+    }
+
+    /// Sends data on the socket to the specified address.
+    ///
+    /// On success, returns the number of bytes written.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixDatagram;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     sock.send_to(b"omelette au fromage", "/some/sock").expect("send_to function failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn send_to<P: AsRef<Path>>(&self, buf: &[u8], path: P) -> io::Result<usize> {
+        unsafe {
+            let (addr, len) = sockaddr_un(path.as_ref())?;
+
+            let count = cvt(libc::sendto(
+                self.as_raw_fd(),
+                buf.as_ptr() as *const _,
+                buf.len(),
+                MSG_NOSIGNAL,
+                &addr as *const _ as *const _,
+                len,
+            ))?;
+            Ok(count as usize)
+        }
+    }
+
+    /// Sends data on the socket to the specified [SocketAddr].
+    ///
+    /// On success, returns the number of bytes written.
+    ///
+    /// [SocketAddr]: crate::os::unix::net::SocketAddr
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// #![feature(unix_socket_abstract)]
+    /// use std::os::unix::net::{UnixDatagram};
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let bound = UnixDatagram::bind("/path/to/socket")?;
+    ///     let addr = bound.local_addr()?;
+    ///
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     sock.send_to_addr(b"bacon egg and cheese", &addr).expect("send_to_addr function failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[unstable(feature = "unix_socket_abstract", issue = "85410")]
+    pub fn send_to_addr(&self, buf: &[u8], socket_addr: &SocketAddr) -> io::Result<usize> {
+        unsafe {
+            let count = cvt(libc::sendto(
+                self.as_raw_fd(),
+                buf.as_ptr() as *const _,
+                buf.len(),
+                MSG_NOSIGNAL,
+                &socket_addr.addr as *const _ as *const _,
+                socket_addr.len,
+            ))?;
+            Ok(count as usize)
+        }
+    }
+
+    /// Sends data on the socket to the socket's peer.
+    ///
+    /// The peer address may be set by the `connect` method, and this method
+    /// will return an error if the socket has not already been connected.
+    ///
+    /// On success, returns the number of bytes written.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixDatagram;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     sock.connect("/some/sock").expect("Couldn't connect");
+    ///     sock.send(b"omelette au fromage").expect("send_to function failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn send(&self, buf: &[u8]) -> io::Result<usize> {
+        self.0.write(buf)
+    }
+
+    /// Sends data and ancillary data on the socket to the specified address.
+    ///
+    /// On success, returns the number of bytes written.
+    ///
+    /// # Examples
+    ///
+    #[cfg_attr(any(target_os = "android", target_os = "linux"), doc = "```no_run")]
+    #[cfg_attr(not(any(target_os = "android", target_os = "linux")), doc = "```ignore")]
+    /// #![feature(unix_socket_ancillary_data)]
+    /// use std::os::unix::net::{UnixDatagram, SocketAncillary};
+    /// use std::io::IoSlice;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     let buf1 = [1; 8];
+    ///     let buf2 = [2; 16];
+    ///     let buf3 = [3; 8];
+    ///     let bufs = &[
+    ///         IoSlice::new(&buf1),
+    ///         IoSlice::new(&buf2),
+    ///         IoSlice::new(&buf3),
+    ///     ][..];
+    ///     let fds = [0, 1, 2];
+    ///     let mut ancillary_buffer = [0; 128];
+    ///     let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);
+    ///     ancillary.add_fds(&fds[..]);
+    ///     sock.send_vectored_with_ancillary_to(bufs, &mut ancillary, "/some/sock")
+    ///         .expect("send_vectored_with_ancillary_to function failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[cfg(any(doc, target_os = "android", target_os = "linux"))]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn send_vectored_with_ancillary_to<P: AsRef<Path>>(
+        &self,
+        bufs: &[IoSlice<'_>],
+        ancillary: &mut SocketAncillary<'_>,
+        path: P,
+    ) -> io::Result<usize> {
+        send_vectored_with_ancillary_to(&self.0, Some(path.as_ref()), bufs, ancillary)
+    }
+
+    /// Sends data and ancillary data on the socket.
+    ///
+    /// On success, returns the number of bytes written.
+    ///
+    /// # Examples
+    ///
+    #[cfg_attr(any(target_os = "android", target_os = "linux"), doc = "```no_run")]
+    #[cfg_attr(not(any(target_os = "android", target_os = "linux")), doc = "```ignore")]
+    /// #![feature(unix_socket_ancillary_data)]
+    /// use std::os::unix::net::{UnixDatagram, SocketAncillary};
+    /// use std::io::IoSlice;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     let buf1 = [1; 8];
+    ///     let buf2 = [2; 16];
+    ///     let buf3 = [3; 8];
+    ///     let bufs = &[
+    ///         IoSlice::new(&buf1),
+    ///         IoSlice::new(&buf2),
+    ///         IoSlice::new(&buf3),
+    ///     ][..];
+    ///     let fds = [0, 1, 2];
+    ///     let mut ancillary_buffer = [0; 128];
+    ///     let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);
+    ///     ancillary.add_fds(&fds[..]);
+    ///     sock.send_vectored_with_ancillary(bufs, &mut ancillary)
+    ///         .expect("send_vectored_with_ancillary function failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[cfg(any(doc, target_os = "android", target_os = "linux"))]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn send_vectored_with_ancillary(
+        &self,
+        bufs: &[IoSlice<'_>],
+        ancillary: &mut SocketAncillary<'_>,
+    ) -> io::Result<usize> {
+        send_vectored_with_ancillary_to(&self.0, None, bufs, ancillary)
+    }
+
+    /// Sets the read timeout for the socket.
+    ///
+    /// If the provided value is [`None`], then [`recv`] and [`recv_from`] calls will
+    /// block indefinitely. An [`Err`] is returned if the zero [`Duration`]
+    /// is passed to this method.
+    ///
+    /// [`recv`]: UnixDatagram::recv
+    /// [`recv_from`]: UnixDatagram::recv_from
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::os::unix::net::UnixDatagram;
+    /// use std::time::Duration;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     sock.set_read_timeout(Some(Duration::new(1, 0)))
+    ///         .expect("set_read_timeout function failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    ///
+    /// An [`Err`] is returned if the zero [`Duration`] is passed to this
+    /// method:
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::os::unix::net::UnixDatagram;
+    /// use std::time::Duration;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixDatagram::unbound()?;
+    ///     let result = socket.set_read_timeout(Some(Duration::new(0, 0)));
+    ///     let err = result.unwrap_err();
+    ///     assert_eq!(err.kind(), io::ErrorKind::InvalidInput);
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn set_read_timeout(&self, timeout: Option<Duration>) -> io::Result<()> {
+        self.0.set_timeout(timeout, libc::SO_RCVTIMEO)
+    }
+
+    /// Sets the write timeout for the socket.
+    ///
+    /// If the provided value is [`None`], then [`send`] and [`send_to`] calls will
+    /// block indefinitely. An [`Err`] is returned if the zero [`Duration`] is passed to this
+    /// method.
+    ///
+    /// [`send`]: UnixDatagram::send
+    /// [`send_to`]: UnixDatagram::send_to
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::os::unix::net::UnixDatagram;
+    /// use std::time::Duration;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     sock.set_write_timeout(Some(Duration::new(1, 0)))
+    ///         .expect("set_write_timeout function failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    ///
+    /// An [`Err`] is returned if the zero [`Duration`] is passed to this
+    /// method:
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::os::unix::net::UnixDatagram;
+    /// use std::time::Duration;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixDatagram::unbound()?;
+    ///     let result = socket.set_write_timeout(Some(Duration::new(0, 0)));
+    ///     let err = result.unwrap_err();
+    ///     assert_eq!(err.kind(), io::ErrorKind::InvalidInput);
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn set_write_timeout(&self, timeout: Option<Duration>) -> io::Result<()> {
+        self.0.set_timeout(timeout, libc::SO_SNDTIMEO)
+    }
+
+    /// Returns the read timeout of this socket.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::os::unix::net::UnixDatagram;
+    /// use std::time::Duration;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     sock.set_read_timeout(Some(Duration::new(1, 0)))
+    ///         .expect("set_read_timeout function failed");
+    ///     assert_eq!(sock.read_timeout()?, Some(Duration::new(1, 0)));
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn read_timeout(&self) -> io::Result<Option<Duration>> {
+        self.0.timeout(libc::SO_RCVTIMEO)
+    }
+
+    /// Returns the write timeout of this socket.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::os::unix::net::UnixDatagram;
+    /// use std::time::Duration;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     sock.set_write_timeout(Some(Duration::new(1, 0)))
+    ///         .expect("set_write_timeout function failed");
+    ///     assert_eq!(sock.write_timeout()?, Some(Duration::new(1, 0)));
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn write_timeout(&self) -> io::Result<Option<Duration>> {
+        self.0.timeout(libc::SO_SNDTIMEO)
+    }
+
+    /// Moves the socket into or out of nonblocking mode.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::os::unix::net::UnixDatagram;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     sock.set_nonblocking(true).expect("set_nonblocking function failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
+        self.0.set_nonblocking(nonblocking)
+    }
+
+    /// Moves the socket to pass unix credentials as control message in [`SocketAncillary`].
+    ///
+    /// Set the socket option `SO_PASSCRED`.
+    ///
+    /// # Examples
+    ///
+    #[cfg_attr(any(target_os = "android", target_os = "linux"), doc = "```no_run")]
+    #[cfg_attr(not(any(target_os = "android", target_os = "linux")), doc = "```ignore")]
+    /// #![feature(unix_socket_ancillary_data)]
+    /// use std::os::unix::net::UnixDatagram;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     sock.set_passcred(true).expect("set_passcred function failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[cfg(any(doc, target_os = "android", target_os = "linux", target_os = "netbsd",))]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn set_passcred(&self, passcred: bool) -> io::Result<()> {
+        self.0.set_passcred(passcred)
+    }
+
+    /// Get the current value of the socket for passing unix credentials in [`SocketAncillary`].
+    /// This value can be change by [`set_passcred`].
+    ///
+    /// Get the socket option `SO_PASSCRED`.
+    ///
+    /// [`set_passcred`]: UnixDatagram::set_passcred
+    #[cfg(any(doc, target_os = "android", target_os = "linux", target_os = "netbsd",))]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn passcred(&self) -> io::Result<bool> {
+        self.0.passcred()
+    }
+
+    /// Returns the value of the `SO_ERROR` option.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixDatagram;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     if let Ok(Some(err)) = sock.take_error() {
+    ///         println!("Got error: {err:?}");
+    ///     }
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn take_error(&self) -> io::Result<Option<io::Error>> {
+        self.0.take_error()
+    }
+
+    /// Shut down the read, write, or both halves of this connection.
+    ///
+    /// This function will cause all pending and future I/O calls on the
+    /// specified portions to immediately return with an appropriate value
+    /// (see the documentation of [`Shutdown`]).
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixDatagram;
+    /// use std::net::Shutdown;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let sock = UnixDatagram::unbound()?;
+    ///     sock.shutdown(Shutdown::Both).expect("shutdown function failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn shutdown(&self, how: Shutdown) -> io::Result<()> {
+        self.0.shutdown(how)
+    }
+
+    /// Receives data on the socket from the remote address to which it is
+    /// connected, without removing that data from the queue. On success,
+    /// returns the number of bytes peeked.
+    ///
+    /// Successive calls return the same data. This is accomplished by passing
+    /// `MSG_PEEK` as a flag to the underlying `recv` system call.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// #![feature(unix_socket_peek)]
+    ///
+    /// use std::os::unix::net::UnixDatagram;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixDatagram::bind("/tmp/sock")?;
+    ///     let mut buf = [0; 10];
+    ///     let len = socket.peek(&mut buf).expect("peek failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[unstable(feature = "unix_socket_peek", issue = "76923")]
+    pub fn peek(&self, buf: &mut [u8]) -> io::Result<usize> {
+        self.0.peek(buf)
+    }
+
+    /// Receives a single datagram message on the socket, without removing it from the
+    /// queue. On success, returns the number of bytes read and the origin.
+    ///
+    /// The function must be called with valid byte array `buf` of sufficient size to
+    /// hold the message bytes. If a message is too long to fit in the supplied buffer,
+    /// excess bytes may be discarded.
+    ///
+    /// Successive calls return the same data. This is accomplished by passing
+    /// `MSG_PEEK` as a flag to the underlying `recvfrom` system call.
+    ///
+    /// Do not use this function to implement busy waiting, instead use `libc::poll` to
+    /// synchronize IO events on one or more sockets.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// #![feature(unix_socket_peek)]
+    ///
+    /// use std::os::unix::net::UnixDatagram;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixDatagram::bind("/tmp/sock")?;
+    ///     let mut buf = [0; 10];
+    ///     let (len, addr) = socket.peek_from(&mut buf).expect("peek failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[unstable(feature = "unix_socket_peek", issue = "76923")]
+    pub fn peek_from(&self, buf: &mut [u8]) -> io::Result<(usize, SocketAddr)> {
+        self.recv_from_flags(buf, libc::MSG_PEEK)
+    }
+}
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl AsRawFd for UnixDatagram {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        self.0.as_inner().as_raw_fd()
+    }
+}
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl FromRawFd for UnixDatagram {
+    #[inline]
+    unsafe fn from_raw_fd(fd: RawFd) -> UnixDatagram {
+        UnixDatagram(Socket::from_inner(FromInner::from_inner(OwnedFd::from_raw_fd(fd))))
+    }
+}
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl IntoRawFd for UnixDatagram {
+    #[inline]
+    fn into_raw_fd(self) -> RawFd {
+        self.0.into_inner().into_inner().into_raw_fd()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsFd for UnixDatagram {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        self.0.as_inner().as_fd()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<UnixDatagram> for OwnedFd {
+    #[inline]
+    fn from(unix_datagram: UnixDatagram) -> OwnedFd {
+        unsafe { OwnedFd::from_raw_fd(unix_datagram.into_raw_fd()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<OwnedFd> for UnixDatagram {
+    #[inline]
+    fn from(owned: OwnedFd) -> Self {
+        unsafe { Self::from_raw_fd(owned.into_raw_fd()) }
+    }
+}
diff --git a/library/std/src/os/unix/net/listener.rs b/library/std/src/os/unix/net/listener.rs
new file mode 100644
index 000000000..7c0d53950
--- /dev/null
+++ b/library/std/src/os/unix/net/listener.rs
@@ -0,0 +1,385 @@
+use super::{sockaddr_un, SocketAddr, UnixStream};
+use crate::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
+use crate::path::Path;
+use crate::sys::cvt;
+use crate::sys::net::Socket;
+use crate::sys_common::{AsInner, FromInner, IntoInner};
+use crate::{fmt, io, mem};
+
+/// A structure representing a Unix domain socket server.
+///
+/// # Examples
+///
+/// ```no_run
+/// use std::thread;
+/// use std::os::unix::net::{UnixStream, UnixListener};
+///
+/// fn handle_client(stream: UnixStream) {
+///     // ...
+/// }
+///
+/// fn main() -> std::io::Result<()> {
+///     let listener = UnixListener::bind("/path/to/the/socket")?;
+///
+///     // accept connections and process them, spawning a new thread for each one
+///     for stream in listener.incoming() {
+///         match stream {
+///             Ok(stream) => {
+///                 /* connection succeeded */
+///                 thread::spawn(|| handle_client(stream));
+///             }
+///             Err(err) => {
+///                 /* connection failed */
+///                 break;
+///             }
+///         }
+///     }
+///     Ok(())
+/// }
+/// ```
+#[stable(feature = "unix_socket", since = "1.10.0")]
+pub struct UnixListener(Socket);
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl fmt::Debug for UnixListener {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut builder = fmt.debug_struct("UnixListener");
+        builder.field("fd", self.0.as_inner());
+        if let Ok(addr) = self.local_addr() {
+            builder.field("local", &addr);
+        }
+        builder.finish()
+    }
+}
+
+impl UnixListener {
+    /// Creates a new `UnixListener` bound to the specified socket.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixListener;
+    ///
+    /// let listener = match UnixListener::bind("/path/to/the/socket") {
+    ///     Ok(sock) => sock,
+    ///     Err(e) => {
+    ///         println!("Couldn't connect: {e:?}");
+    ///         return
+    ///     }
+    /// };
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn bind<P: AsRef<Path>>(path: P) -> io::Result<UnixListener> {
+        unsafe {
+            let inner = Socket::new_raw(libc::AF_UNIX, libc::SOCK_STREAM)?;
+            let (addr, len) = sockaddr_un(path.as_ref())?;
+
+            cvt(libc::bind(inner.as_inner().as_raw_fd(), &addr as *const _ as *const _, len as _))?;
+            cvt(libc::listen(inner.as_inner().as_raw_fd(), 128))?;
+
+            Ok(UnixListener(inner))
+        }
+    }
+
+    /// Creates a new `UnixListener` bound to the specified [`socket address`].
+    ///
+    /// [`socket address`]: crate::os::unix::net::SocketAddr
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// #![feature(unix_socket_abstract)]
+    /// use std::os::unix::net::{UnixListener};
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let listener1 = UnixListener::bind("path/to/socket")?;
+    ///     let addr = listener1.local_addr()?;
+    ///
+    ///     let listener2 = match UnixListener::bind_addr(&addr) {
+    ///         Ok(sock) => sock,
+    ///         Err(err) => {
+    ///             println!("Couldn't bind: {err:?}");
+    ///             return Err(err);
+    ///         }
+    ///     };
+    ///     Ok(())
+    /// }
+    /// ```
+    #[unstable(feature = "unix_socket_abstract", issue = "85410")]
+    pub fn bind_addr(socket_addr: &SocketAddr) -> io::Result<UnixListener> {
+        unsafe {
+            let inner = Socket::new_raw(libc::AF_UNIX, libc::SOCK_STREAM)?;
+            cvt(libc::bind(
+                inner.as_raw_fd(),
+                &socket_addr.addr as *const _ as *const _,
+                socket_addr.len as _,
+            ))?;
+            cvt(libc::listen(inner.as_raw_fd(), 128))?;
+            Ok(UnixListener(inner))
+        }
+    }
+
+    /// Accepts a new incoming connection to this listener.
+    ///
+    /// This function will block the calling thread until a new Unix connection
+    /// is established. When established, the corresponding [`UnixStream`] and
+    /// the remote peer's address will be returned.
+    ///
+    /// [`UnixStream`]: crate::os::unix::net::UnixStream
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixListener;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let listener = UnixListener::bind("/path/to/the/socket")?;
+    ///
+    ///     match listener.accept() {
+    ///         Ok((socket, addr)) => println!("Got a client: {addr:?}"),
+    ///         Err(e) => println!("accept function failed: {e:?}"),
+    ///     }
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn accept(&self) -> io::Result<(UnixStream, SocketAddr)> {
+        let mut storage: libc::sockaddr_un = unsafe { mem::zeroed() };
+        let mut len = mem::size_of_val(&storage) as libc::socklen_t;
+        let sock = self.0.accept(&mut storage as *mut _ as *mut _, &mut len)?;
+        let addr = SocketAddr::from_parts(storage, len)?;
+        Ok((UnixStream(sock), addr))
+    }
+
+    /// Creates a new independently owned handle to the underlying socket.
+    ///
+    /// The returned `UnixListener` is a reference to the same socket that this
+    /// object references. Both handles can be used to accept incoming
+    /// connections and options set on one listener will affect the other.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixListener;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let listener = UnixListener::bind("/path/to/the/socket")?;
+    ///     let listener_copy = listener.try_clone().expect("try_clone failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn try_clone(&self) -> io::Result<UnixListener> {
+        self.0.duplicate().map(UnixListener)
+    }
+
+    /// Returns the local socket address of this listener.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixListener;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let listener = UnixListener::bind("/path/to/the/socket")?;
+    ///     let addr = listener.local_addr().expect("Couldn't get local address");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn local_addr(&self) -> io::Result<SocketAddr> {
+        SocketAddr::new(|addr, len| unsafe { libc::getsockname(self.as_raw_fd(), addr, len) })
+    }
+
+    /// Moves the socket into or out of nonblocking mode.
+    ///
+    /// This will result in the `accept` operation becoming nonblocking,
+    /// i.e., immediately returning from their calls. If the IO operation is
+    /// successful, `Ok` is returned and no further action is required. If the
+    /// IO operation could not be completed and needs to be retried, an error
+    /// with kind [`io::ErrorKind::WouldBlock`] is returned.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixListener;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let listener = UnixListener::bind("/path/to/the/socket")?;
+    ///     listener.set_nonblocking(true).expect("Couldn't set non blocking");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
+        self.0.set_nonblocking(nonblocking)
+    }
+
+    /// Returns the value of the `SO_ERROR` option.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixListener;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let listener = UnixListener::bind("/tmp/sock")?;
+    ///
+    ///     if let Ok(Some(err)) = listener.take_error() {
+    ///         println!("Got error: {err:?}");
+    ///     }
+    ///     Ok(())
+    /// }
+    /// ```
+    ///
+    /// # Platform specific
+    /// On Redox this always returns `None`.
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn take_error(&self) -> io::Result<Option<io::Error>> {
+        self.0.take_error()
+    }
+
+    /// Returns an iterator over incoming connections.
+    ///
+    /// The iterator will never return [`None`] and will also not yield the
+    /// peer's [`SocketAddr`] structure.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::thread;
+    /// use std::os::unix::net::{UnixStream, UnixListener};
+    ///
+    /// fn handle_client(stream: UnixStream) {
+    ///     // ...
+    /// }
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let listener = UnixListener::bind("/path/to/the/socket")?;
+    ///
+    ///     for stream in listener.incoming() {
+    ///         match stream {
+    ///             Ok(stream) => {
+    ///                 thread::spawn(|| handle_client(stream));
+    ///             }
+    ///             Err(err) => {
+    ///                 break;
+    ///             }
+    ///         }
+    ///     }
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn incoming(&self) -> Incoming<'_> {
+        Incoming { listener: self }
+    }
+}
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl AsRawFd for UnixListener {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        self.0.as_inner().as_raw_fd()
+    }
+}
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl FromRawFd for UnixListener {
+    #[inline]
+    unsafe fn from_raw_fd(fd: RawFd) -> UnixListener {
+        UnixListener(Socket::from_inner(FromInner::from_inner(OwnedFd::from_raw_fd(fd))))
+    }
+}
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl IntoRawFd for UnixListener {
+    #[inline]
+    fn into_raw_fd(self) -> RawFd {
+        self.0.into_inner().into_inner().into_raw_fd()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsFd for UnixListener {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        self.0.as_inner().as_fd()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<OwnedFd> for UnixListener {
+    #[inline]
+    fn from(fd: OwnedFd) -> UnixListener {
+        UnixListener(Socket::from_inner(FromInner::from_inner(fd)))
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<UnixListener> for OwnedFd {
+    #[inline]
+    fn from(listener: UnixListener) -> OwnedFd {
+        listener.0.into_inner().into_inner()
+    }
+}
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl<'a> IntoIterator for &'a UnixListener {
+    type Item = io::Result<UnixStream>;
+    type IntoIter = Incoming<'a>;
+
+    fn into_iter(self) -> Incoming<'a> {
+        self.incoming()
+    }
+}
+
+/// An iterator over incoming connections to a [`UnixListener`].
+///
+/// It will never return [`None`].
+///
+/// # Examples
+///
+/// ```no_run
+/// use std::thread;
+/// use std::os::unix::net::{UnixStream, UnixListener};
+///
+/// fn handle_client(stream: UnixStream) {
+///     // ...
+/// }
+///
+/// fn main() -> std::io::Result<()> {
+///     let listener = UnixListener::bind("/path/to/the/socket")?;
+///
+///     for stream in listener.incoming() {
+///         match stream {
+///             Ok(stream) => {
+///                 thread::spawn(|| handle_client(stream));
+///             }
+///             Err(err) => {
+///                 break;
+///             }
+///         }
+///     }
+///     Ok(())
+/// }
+/// ```
+#[derive(Debug)]
+#[must_use = "iterators are lazy and do nothing unless consumed"]
+#[stable(feature = "unix_socket", since = "1.10.0")]
+pub struct Incoming<'a> {
+    listener: &'a UnixListener,
+}
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl<'a> Iterator for Incoming<'a> {
+    type Item = io::Result<UnixStream>;
+
+    fn next(&mut self) -> Option<io::Result<UnixStream>> {
+        Some(self.listener.accept().map(|s| s.0))
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        (usize::MAX, None)
+    }
+}
diff --git a/library/std/src/os/unix/net/mod.rs b/library/std/src/os/unix/net/mod.rs
new file mode 100644
index 000000000..6da3e350b
--- /dev/null
+++ b/library/std/src/os/unix/net/mod.rs
@@ -0,0 +1,26 @@
+//! Unix-specific networking functionality.
+
+#![allow(irrefutable_let_patterns)]
+#![stable(feature = "unix_socket", since = "1.10.0")]
+
+mod addr;
+#[doc(cfg(any(target_os = "android", target_os = "linux")))]
+#[cfg(any(doc, target_os = "android", target_os = "linux"))]
+mod ancillary;
+mod datagram;
+mod listener;
+mod stream;
+#[cfg(all(test, not(target_os = "emscripten")))]
+mod tests;
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+pub use self::addr::*;
+#[cfg(any(doc, target_os = "android", target_os = "linux"))]
+#[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+pub use self::ancillary::*;
+#[stable(feature = "unix_socket", since = "1.10.0")]
+pub use self::datagram::*;
+#[stable(feature = "unix_socket", since = "1.10.0")]
+pub use self::listener::*;
+#[stable(feature = "unix_socket", since = "1.10.0")]
+pub use self::stream::*;
diff --git a/library/std/src/os/unix/net/stream.rs b/library/std/src/os/unix/net/stream.rs
new file mode 100644
index 000000000..cc3a88587
--- /dev/null
+++ b/library/std/src/os/unix/net/stream.rs
@@ -0,0 +1,711 @@
+#[cfg(any(doc, target_os = "android", target_os = "linux"))]
+use super::{recv_vectored_with_ancillary_from, send_vectored_with_ancillary_to, SocketAncillary};
+use super::{sockaddr_un, SocketAddr};
+use crate::fmt;
+use crate::io::{self, IoSlice, IoSliceMut};
+use crate::net::Shutdown;
+use crate::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
+#[cfg(any(
+    target_os = "android",
+    target_os = "linux",
+    target_os = "dragonfly",
+    target_os = "freebsd",
+    target_os = "ios",
+    target_os = "macos",
+    target_os = "watchos",
+    target_os = "netbsd",
+    target_os = "openbsd"
+))]
+use crate::os::unix::ucred;
+use crate::path::Path;
+use crate::sys::cvt;
+use crate::sys::net::Socket;
+use crate::sys_common::{AsInner, FromInner};
+use crate::time::Duration;
+
+#[unstable(feature = "peer_credentials_unix_socket", issue = "42839", reason = "unstable")]
+#[cfg(any(
+    target_os = "android",
+    target_os = "linux",
+    target_os = "dragonfly",
+    target_os = "freebsd",
+    target_os = "ios",
+    target_os = "macos",
+    target_os = "watchos",
+    target_os = "netbsd",
+    target_os = "openbsd"
+))]
+pub use ucred::UCred;
+
+/// A Unix stream socket.
+///
+/// # Examples
+///
+/// ```no_run
+/// use std::os::unix::net::UnixStream;
+/// use std::io::prelude::*;
+///
+/// fn main() -> std::io::Result<()> {
+///     let mut stream = UnixStream::connect("/path/to/my/socket")?;
+///     stream.write_all(b"hello world")?;
+///     let mut response = String::new();
+///     stream.read_to_string(&mut response)?;
+///     println!("{response}");
+///     Ok(())
+/// }
+/// ```
+#[stable(feature = "unix_socket", since = "1.10.0")]
+pub struct UnixStream(pub(super) Socket);
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl fmt::Debug for UnixStream {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut builder = fmt.debug_struct("UnixStream");
+        builder.field("fd", self.0.as_inner());
+        if let Ok(addr) = self.local_addr() {
+            builder.field("local", &addr);
+        }
+        if let Ok(addr) = self.peer_addr() {
+            builder.field("peer", &addr);
+        }
+        builder.finish()
+    }
+}
+
+impl UnixStream {
+    /// Connects to the socket named by `path`.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixStream;
+    ///
+    /// let socket = match UnixStream::connect("/tmp/sock") {
+    ///     Ok(sock) => sock,
+    ///     Err(e) => {
+    ///         println!("Couldn't connect: {e:?}");
+    ///         return
+    ///     }
+    /// };
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn connect<P: AsRef<Path>>(path: P) -> io::Result<UnixStream> {
+        unsafe {
+            let inner = Socket::new_raw(libc::AF_UNIX, libc::SOCK_STREAM)?;
+            let (addr, len) = sockaddr_un(path.as_ref())?;
+
+            cvt(libc::connect(inner.as_raw_fd(), &addr as *const _ as *const _, len))?;
+            Ok(UnixStream(inner))
+        }
+    }
+
+    /// Connects to the socket specified by [`address`].
+    ///
+    /// [`address`]: crate::os::unix::net::SocketAddr
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// #![feature(unix_socket_abstract)]
+    /// use std::os::unix::net::{UnixListener, UnixStream};
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let listener = UnixListener::bind("/path/to/the/socket")?;
+    ///     let addr = listener.local_addr()?;
+    ///
+    ///     let sock = match UnixStream::connect_addr(&addr) {
+    ///         Ok(sock) => sock,
+    ///         Err(e) => {
+    ///             println!("Couldn't connect: {e:?}");
+    ///             return Err(e)
+    ///         }
+    ///     };
+    ///     Ok(())
+    /// }
+    /// ````
+    #[unstable(feature = "unix_socket_abstract", issue = "85410")]
+    pub fn connect_addr(socket_addr: &SocketAddr) -> io::Result<UnixStream> {
+        unsafe {
+            let inner = Socket::new_raw(libc::AF_UNIX, libc::SOCK_STREAM)?;
+            cvt(libc::connect(
+                inner.as_raw_fd(),
+                &socket_addr.addr as *const _ as *const _,
+                socket_addr.len,
+            ))?;
+            Ok(UnixStream(inner))
+        }
+    }
+
+    /// Creates an unnamed pair of connected sockets.
+    ///
+    /// Returns two `UnixStream`s which are connected to each other.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixStream;
+    ///
+    /// let (sock1, sock2) = match UnixStream::pair() {
+    ///     Ok((sock1, sock2)) => (sock1, sock2),
+    ///     Err(e) => {
+    ///         println!("Couldn't create a pair of sockets: {e:?}");
+    ///         return
+    ///     }
+    /// };
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn pair() -> io::Result<(UnixStream, UnixStream)> {
+        let (i1, i2) = Socket::new_pair(libc::AF_UNIX, libc::SOCK_STREAM)?;
+        Ok((UnixStream(i1), UnixStream(i2)))
+    }
+
+    /// Creates a new independently owned handle to the underlying socket.
+    ///
+    /// The returned `UnixStream` is a reference to the same stream that this
+    /// object references. Both handles will read and write the same stream of
+    /// data, and options set on one stream will be propagated to the other
+    /// stream.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixStream;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixStream::connect("/tmp/sock")?;
+    ///     let sock_copy = socket.try_clone().expect("Couldn't clone socket");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn try_clone(&self) -> io::Result<UnixStream> {
+        self.0.duplicate().map(UnixStream)
+    }
+
+    /// Returns the socket address of the local half of this connection.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixStream;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixStream::connect("/tmp/sock")?;
+    ///     let addr = socket.local_addr().expect("Couldn't get local address");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn local_addr(&self) -> io::Result<SocketAddr> {
+        SocketAddr::new(|addr, len| unsafe { libc::getsockname(self.as_raw_fd(), addr, len) })
+    }
+
+    /// Returns the socket address of the remote half of this connection.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixStream;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixStream::connect("/tmp/sock")?;
+    ///     let addr = socket.peer_addr().expect("Couldn't get peer address");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn peer_addr(&self) -> io::Result<SocketAddr> {
+        SocketAddr::new(|addr, len| unsafe { libc::getpeername(self.as_raw_fd(), addr, len) })
+    }
+
+    /// Gets the peer credentials for this Unix domain socket.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// #![feature(peer_credentials_unix_socket)]
+    /// use std::os::unix::net::UnixStream;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixStream::connect("/tmp/sock")?;
+    ///     let peer_cred = socket.peer_cred().expect("Couldn't get peer credentials");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[unstable(feature = "peer_credentials_unix_socket", issue = "42839", reason = "unstable")]
+    #[cfg(any(
+        target_os = "android",
+        target_os = "linux",
+        target_os = "dragonfly",
+        target_os = "freebsd",
+        target_os = "ios",
+        target_os = "macos",
+        target_os = "watchos",
+        target_os = "netbsd",
+        target_os = "openbsd"
+    ))]
+    pub fn peer_cred(&self) -> io::Result<UCred> {
+        ucred::peer_cred(self)
+    }
+
+    /// Sets the read timeout for the socket.
+    ///
+    /// If the provided value is [`None`], then [`read`] calls will block
+    /// indefinitely. An [`Err`] is returned if the zero [`Duration`] is passed to this
+    /// method.
+    ///
+    /// [`read`]: io::Read::read
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixStream;
+    /// use std::time::Duration;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixStream::connect("/tmp/sock")?;
+    ///     socket.set_read_timeout(Some(Duration::new(1, 0))).expect("Couldn't set read timeout");
+    ///     Ok(())
+    /// }
+    /// ```
+    ///
+    /// An [`Err`] is returned if the zero [`Duration`] is passed to this
+    /// method:
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::os::unix::net::UnixStream;
+    /// use std::time::Duration;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixStream::connect("/tmp/sock")?;
+    ///     let result = socket.set_read_timeout(Some(Duration::new(0, 0)));
+    ///     let err = result.unwrap_err();
+    ///     assert_eq!(err.kind(), io::ErrorKind::InvalidInput);
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn set_read_timeout(&self, timeout: Option<Duration>) -> io::Result<()> {
+        self.0.set_timeout(timeout, libc::SO_RCVTIMEO)
+    }
+
+    /// Sets the write timeout for the socket.
+    ///
+    /// If the provided value is [`None`], then [`write`] calls will block
+    /// indefinitely. An [`Err`] is returned if the zero [`Duration`] is
+    /// passed to this method.
+    ///
+    /// [`read`]: io::Read::read
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixStream;
+    /// use std::time::Duration;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixStream::connect("/tmp/sock")?;
+    ///     socket.set_write_timeout(Some(Duration::new(1, 0)))
+    ///         .expect("Couldn't set write timeout");
+    ///     Ok(())
+    /// }
+    /// ```
+    ///
+    /// An [`Err`] is returned if the zero [`Duration`] is passed to this
+    /// method:
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::net::UdpSocket;
+    /// use std::time::Duration;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UdpSocket::bind("127.0.0.1:34254")?;
+    ///     let result = socket.set_write_timeout(Some(Duration::new(0, 0)));
+    ///     let err = result.unwrap_err();
+    ///     assert_eq!(err.kind(), io::ErrorKind::InvalidInput);
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn set_write_timeout(&self, timeout: Option<Duration>) -> io::Result<()> {
+        self.0.set_timeout(timeout, libc::SO_SNDTIMEO)
+    }
+
+    /// Returns the read timeout of this socket.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixStream;
+    /// use std::time::Duration;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixStream::connect("/tmp/sock")?;
+    ///     socket.set_read_timeout(Some(Duration::new(1, 0))).expect("Couldn't set read timeout");
+    ///     assert_eq!(socket.read_timeout()?, Some(Duration::new(1, 0)));
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn read_timeout(&self) -> io::Result<Option<Duration>> {
+        self.0.timeout(libc::SO_RCVTIMEO)
+    }
+
+    /// Returns the write timeout of this socket.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixStream;
+    /// use std::time::Duration;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixStream::connect("/tmp/sock")?;
+    ///     socket.set_write_timeout(Some(Duration::new(1, 0)))
+    ///         .expect("Couldn't set write timeout");
+    ///     assert_eq!(socket.write_timeout()?, Some(Duration::new(1, 0)));
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn write_timeout(&self) -> io::Result<Option<Duration>> {
+        self.0.timeout(libc::SO_SNDTIMEO)
+    }
+
+    /// Moves the socket into or out of nonblocking mode.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixStream;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixStream::connect("/tmp/sock")?;
+    ///     socket.set_nonblocking(true).expect("Couldn't set nonblocking");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> {
+        self.0.set_nonblocking(nonblocking)
+    }
+
+    /// Moves the socket to pass unix credentials as control message in [`SocketAncillary`].
+    ///
+    /// Set the socket option `SO_PASSCRED`.
+    ///
+    /// # Examples
+    ///
+    #[cfg_attr(any(target_os = "android", target_os = "linux"), doc = "```no_run")]
+    #[cfg_attr(not(any(target_os = "android", target_os = "linux")), doc = "```ignore")]
+    /// #![feature(unix_socket_ancillary_data)]
+    /// use std::os::unix::net::UnixStream;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixStream::connect("/tmp/sock")?;
+    ///     socket.set_passcred(true).expect("Couldn't set passcred");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[cfg(any(doc, target_os = "android", target_os = "linux", target_os = "netbsd",))]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn set_passcred(&self, passcred: bool) -> io::Result<()> {
+        self.0.set_passcred(passcred)
+    }
+
+    /// Get the current value of the socket for passing unix credentials in [`SocketAncillary`].
+    /// This value can be change by [`set_passcred`].
+    ///
+    /// Get the socket option `SO_PASSCRED`.
+    ///
+    /// [`set_passcred`]: UnixStream::set_passcred
+    #[cfg(any(doc, target_os = "android", target_os = "linux", target_os = "netbsd",))]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn passcred(&self) -> io::Result<bool> {
+        self.0.passcred()
+    }
+
+    /// Returns the value of the `SO_ERROR` option.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixStream;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixStream::connect("/tmp/sock")?;
+    ///     if let Ok(Some(err)) = socket.take_error() {
+    ///         println!("Got error: {err:?}");
+    ///     }
+    ///     Ok(())
+    /// }
+    /// ```
+    ///
+    /// # Platform specific
+    /// On Redox this always returns `None`.
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn take_error(&self) -> io::Result<Option<io::Error>> {
+        self.0.take_error()
+    }
+
+    /// Shuts down the read, write, or both halves of this connection.
+    ///
+    /// This function will cause all pending and future I/O calls on the
+    /// specified portions to immediately return with an appropriate value
+    /// (see the documentation of [`Shutdown`]).
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::os::unix::net::UnixStream;
+    /// use std::net::Shutdown;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixStream::connect("/tmp/sock")?;
+    ///     socket.shutdown(Shutdown::Both).expect("shutdown function failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "unix_socket", since = "1.10.0")]
+    pub fn shutdown(&self, how: Shutdown) -> io::Result<()> {
+        self.0.shutdown(how)
+    }
+
+    /// Receives data on the socket from the remote address to which it is
+    /// connected, without removing that data from the queue. On success,
+    /// returns the number of bytes peeked.
+    ///
+    /// Successive calls return the same data. This is accomplished by passing
+    /// `MSG_PEEK` as a flag to the underlying `recv` system call.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// #![feature(unix_socket_peek)]
+    ///
+    /// use std::os::unix::net::UnixStream;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixStream::connect("/tmp/sock")?;
+    ///     let mut buf = [0; 10];
+    ///     let len = socket.peek(&mut buf).expect("peek failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[unstable(feature = "unix_socket_peek", issue = "76923")]
+    pub fn peek(&self, buf: &mut [u8]) -> io::Result<usize> {
+        self.0.peek(buf)
+    }
+
+    /// Receives data and ancillary data from socket.
+    ///
+    /// On success, returns the number of bytes read.
+    ///
+    /// # Examples
+    ///
+    #[cfg_attr(any(target_os = "android", target_os = "linux"), doc = "```no_run")]
+    #[cfg_attr(not(any(target_os = "android", target_os = "linux")), doc = "```ignore")]
+    /// #![feature(unix_socket_ancillary_data)]
+    /// use std::os::unix::net::{UnixStream, SocketAncillary, AncillaryData};
+    /// use std::io::IoSliceMut;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixStream::connect("/tmp/sock")?;
+    ///     let mut buf1 = [1; 8];
+    ///     let mut buf2 = [2; 16];
+    ///     let mut buf3 = [3; 8];
+    ///     let mut bufs = &mut [
+    ///         IoSliceMut::new(&mut buf1),
+    ///         IoSliceMut::new(&mut buf2),
+    ///         IoSliceMut::new(&mut buf3),
+    ///     ][..];
+    ///     let mut fds = [0; 8];
+    ///     let mut ancillary_buffer = [0; 128];
+    ///     let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);
+    ///     let size = socket.recv_vectored_with_ancillary(bufs, &mut ancillary)?;
+    ///     println!("received {size}");
+    ///     for ancillary_result in ancillary.messages() {
+    ///         if let AncillaryData::ScmRights(scm_rights) = ancillary_result.unwrap() {
+    ///             for fd in scm_rights {
+    ///                 println!("receive file descriptor: {fd}");
+    ///             }
+    ///         }
+    ///     }
+    ///     Ok(())
+    /// }
+    /// ```
+    #[cfg(any(doc, target_os = "android", target_os = "linux"))]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn recv_vectored_with_ancillary(
+        &self,
+        bufs: &mut [IoSliceMut<'_>],
+        ancillary: &mut SocketAncillary<'_>,
+    ) -> io::Result<usize> {
+        let (count, _, _) = recv_vectored_with_ancillary_from(&self.0, bufs, ancillary)?;
+
+        Ok(count)
+    }
+
+    /// Sends data and ancillary data on the socket.
+    ///
+    /// On success, returns the number of bytes written.
+    ///
+    /// # Examples
+    ///
+    #[cfg_attr(any(target_os = "android", target_os = "linux"), doc = "```no_run")]
+    #[cfg_attr(not(any(target_os = "android", target_os = "linux")), doc = "```ignore")]
+    /// #![feature(unix_socket_ancillary_data)]
+    /// use std::os::unix::net::{UnixStream, SocketAncillary};
+    /// use std::io::IoSlice;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let socket = UnixStream::connect("/tmp/sock")?;
+    ///     let buf1 = [1; 8];
+    ///     let buf2 = [2; 16];
+    ///     let buf3 = [3; 8];
+    ///     let bufs = &[
+    ///         IoSlice::new(&buf1),
+    ///         IoSlice::new(&buf2),
+    ///         IoSlice::new(&buf3),
+    ///     ][..];
+    ///     let fds = [0, 1, 2];
+    ///     let mut ancillary_buffer = [0; 128];
+    ///     let mut ancillary = SocketAncillary::new(&mut ancillary_buffer[..]);
+    ///     ancillary.add_fds(&fds[..]);
+    ///     socket.send_vectored_with_ancillary(bufs, &mut ancillary)
+    ///         .expect("send_vectored_with_ancillary function failed");
+    ///     Ok(())
+    /// }
+    /// ```
+    #[cfg(any(doc, target_os = "android", target_os = "linux"))]
+    #[unstable(feature = "unix_socket_ancillary_data", issue = "76915")]
+    pub fn send_vectored_with_ancillary(
+        &self,
+        bufs: &[IoSlice<'_>],
+        ancillary: &mut SocketAncillary<'_>,
+    ) -> io::Result<usize> {
+        send_vectored_with_ancillary_to(&self.0, None, bufs, ancillary)
+    }
+}
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl io::Read for UnixStream {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        io::Read::read(&mut &*self, buf)
+    }
+
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
+        io::Read::read_vectored(&mut &*self, bufs)
+    }
+
+    #[inline]
+    fn is_read_vectored(&self) -> bool {
+        io::Read::is_read_vectored(&&*self)
+    }
+}
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl<'a> io::Read for &'a UnixStream {
+    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+        self.0.read(buf)
+    }
+
+    fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
+        self.0.read_vectored(bufs)
+    }
+
+    #[inline]
+    fn is_read_vectored(&self) -> bool {
+        self.0.is_read_vectored()
+    }
+}
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl io::Write for UnixStream {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        io::Write::write(&mut &*self, buf)
+    }
+
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
+        io::Write::write_vectored(&mut &*self, bufs)
+    }
+
+    #[inline]
+    fn is_write_vectored(&self) -> bool {
+        io::Write::is_write_vectored(&&*self)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        io::Write::flush(&mut &*self)
+    }
+}
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl<'a> io::Write for &'a UnixStream {
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        self.0.write(buf)
+    }
+
+    fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
+        self.0.write_vectored(bufs)
+    }
+
+    #[inline]
+    fn is_write_vectored(&self) -> bool {
+        self.0.is_write_vectored()
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl AsRawFd for UnixStream {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        self.0.as_raw_fd()
+    }
+}
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl FromRawFd for UnixStream {
+    #[inline]
+    unsafe fn from_raw_fd(fd: RawFd) -> UnixStream {
+        UnixStream(Socket::from_inner(FromInner::from_inner(OwnedFd::from_raw_fd(fd))))
+    }
+}
+
+#[stable(feature = "unix_socket", since = "1.10.0")]
+impl IntoRawFd for UnixStream {
+    #[inline]
+    fn into_raw_fd(self) -> RawFd {
+        self.0.into_raw_fd()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsFd for UnixStream {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        self.0.as_fd()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<UnixStream> for OwnedFd {
+    #[inline]
+    fn from(unix_stream: UnixStream) -> OwnedFd {
+        unsafe { OwnedFd::from_raw_fd(unix_stream.into_raw_fd()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<OwnedFd> for UnixStream {
+    #[inline]
+    fn from(owned: OwnedFd) -> Self {
+        unsafe { Self::from_raw_fd(owned.into_raw_fd()) }
+    }
+}
diff --git a/library/std/src/os/unix/net/tests.rs b/library/std/src/os/unix/net/tests.rs
new file mode 100644
index 000000000..e4499f9b6
--- /dev/null
+++ b/library/std/src/os/unix/net/tests.rs
@@ -0,0 +1,753 @@
+use super::*;
+use crate::io::prelude::*;
+use crate::io::{self, ErrorKind, IoSlice, IoSliceMut};
+#[cfg(any(target_os = "android", target_os = "linux"))]
+use crate::os::unix::io::AsRawFd;
+use crate::sys_common::io::test::tmpdir;
+use crate::thread;
+use crate::time::Duration;
+
+macro_rules! or_panic {
+    ($e:expr) => {
+        match $e {
+            Ok(e) => e,
+            Err(e) => panic!("{e}"),
+        }
+    };
+}
+
+#[test]
+fn basic() {
+    let dir = tmpdir();
+    let socket_path = dir.path().join("sock");
+    let msg1 = b"hello";
+    let msg2 = b"world!";
+
+    let listener = or_panic!(UnixListener::bind(&socket_path));
+    let thread = thread::spawn(move || {
+        let mut stream = or_panic!(listener.accept()).0;
+        let mut buf = [0; 5];
+        or_panic!(stream.read(&mut buf));
+        assert_eq!(&msg1[..], &buf[..]);
+        or_panic!(stream.write_all(msg2));
+    });
+
+    let mut stream = or_panic!(UnixStream::connect(&socket_path));
+    assert_eq!(Some(&*socket_path), stream.peer_addr().unwrap().as_pathname());
+    or_panic!(stream.write_all(msg1));
+    let mut buf = vec![];
+    or_panic!(stream.read_to_end(&mut buf));
+    assert_eq!(&msg2[..], &buf[..]);
+    drop(stream);
+
+    thread.join().unwrap();
+}
+
+#[test]
+fn vectored() {
+    let (mut s1, mut s2) = or_panic!(UnixStream::pair());
+
+    let len = or_panic!(s1.write_vectored(&[
+        IoSlice::new(b"hello"),
+        IoSlice::new(b" "),
+        IoSlice::new(b"world!")
+    ],));
+    assert_eq!(len, 12);
+
+    let mut buf1 = [0; 6];
+    let mut buf2 = [0; 7];
+    let len =
+        or_panic!(s2.read_vectored(&mut [IoSliceMut::new(&mut buf1), IoSliceMut::new(&mut buf2)],));
+    assert_eq!(len, 12);
+    assert_eq!(&buf1, b"hello ");
+    assert_eq!(&buf2, b"world!\0");
+}
+
+#[test]
+fn pair() {
+    let msg1 = b"hello";
+    let msg2 = b"world!";
+
+    let (mut s1, mut s2) = or_panic!(UnixStream::pair());
+    let thread = thread::spawn(move || {
+        // s1 must be moved in or the test will hang!
+        let mut buf = [0; 5];
+        or_panic!(s1.read(&mut buf));
+        assert_eq!(&msg1[..], &buf[..]);
+        or_panic!(s1.write_all(msg2));
+    });
+
+    or_panic!(s2.write_all(msg1));
+    let mut buf = vec![];
+    or_panic!(s2.read_to_end(&mut buf));
+    assert_eq!(&msg2[..], &buf[..]);
+    drop(s2);
+
+    thread.join().unwrap();
+}
+
+#[test]
+fn try_clone() {
+    let dir = tmpdir();
+    let socket_path = dir.path().join("sock");
+    let msg1 = b"hello";
+    let msg2 = b"world";
+
+    let listener = or_panic!(UnixListener::bind(&socket_path));
+    let thread = thread::spawn(move || {
+        let mut stream = or_panic!(listener.accept()).0;
+        or_panic!(stream.write_all(msg1));
+        or_panic!(stream.write_all(msg2));
+    });
+
+    let mut stream = or_panic!(UnixStream::connect(&socket_path));
+    let mut stream2 = or_panic!(stream.try_clone());
+
+    let mut buf = [0; 5];
+    or_panic!(stream.read(&mut buf));
+    assert_eq!(&msg1[..], &buf[..]);
+    or_panic!(stream2.read(&mut buf));
+    assert_eq!(&msg2[..], &buf[..]);
+
+    thread.join().unwrap();
+}
+
+#[test]
+fn iter() {
+    let dir = tmpdir();
+    let socket_path = dir.path().join("sock");
+
+    let listener = or_panic!(UnixListener::bind(&socket_path));
+    let thread = thread::spawn(move || {
+        for stream in listener.incoming().take(2) {
+            let mut stream = or_panic!(stream);
+            let mut buf = [0];
+            or_panic!(stream.read(&mut buf));
+        }
+    });
+
+    for _ in 0..2 {
+        let mut stream = or_panic!(UnixStream::connect(&socket_path));
+        or_panic!(stream.write_all(&[0]));
+    }
+
+    thread.join().unwrap();
+}
+
+#[test]
+fn long_path() {
+    let dir = tmpdir();
+    let socket_path = dir.path().join(
+        "asdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfasdfa\
+                                sasdfasdfasdasdfasdfasdfadfasdfasdfasdfasdfasdf",
+    );
+    match UnixStream::connect(&socket_path) {
+        Err(ref e) if e.kind() == io::ErrorKind::InvalidInput => {}
+        Err(e) => panic!("unexpected error {e}"),
+        Ok(_) => panic!("unexpected success"),
+    }
+
+    match UnixListener::bind(&socket_path) {
+        Err(ref e) if e.kind() == io::ErrorKind::InvalidInput => {}
+        Err(e) => panic!("unexpected error {e}"),
+        Ok(_) => panic!("unexpected success"),
+    }
+
+    match UnixDatagram::bind(&socket_path) {
+        Err(ref e) if e.kind() == io::ErrorKind::InvalidInput => {}
+        Err(e) => panic!("unexpected error {e}"),
+        Ok(_) => panic!("unexpected success"),
+    }
+}
+
+#[test]
+fn timeouts() {
+    let dir = tmpdir();
+    let socket_path = dir.path().join("sock");
+
+    let _listener = or_panic!(UnixListener::bind(&socket_path));
+
+    let stream = or_panic!(UnixStream::connect(&socket_path));
+    let dur = Duration::new(15410, 0);
+
+    assert_eq!(None, or_panic!(stream.read_timeout()));
+
+    or_panic!(stream.set_read_timeout(Some(dur)));
+    assert_eq!(Some(dur), or_panic!(stream.read_timeout()));
+
+    assert_eq!(None, or_panic!(stream.write_timeout()));
+
+    or_panic!(stream.set_write_timeout(Some(dur)));
+    assert_eq!(Some(dur), or_panic!(stream.write_timeout()));
+
+    or_panic!(stream.set_read_timeout(None));
+    assert_eq!(None, or_panic!(stream.read_timeout()));
+
+    or_panic!(stream.set_write_timeout(None));
+    assert_eq!(None, or_panic!(stream.write_timeout()));
+}
+
+#[test]
+fn test_read_timeout() {
+    let dir = tmpdir();
+    let socket_path = dir.path().join("sock");
+
+    let _listener = or_panic!(UnixListener::bind(&socket_path));
+
+    let mut stream = or_panic!(UnixStream::connect(&socket_path));
+    or_panic!(stream.set_read_timeout(Some(Duration::from_millis(1000))));
+
+    let mut buf = [0; 10];
+    let kind = stream.read_exact(&mut buf).err().expect("expected error").kind();
+    assert!(
+        kind == ErrorKind::WouldBlock || kind == ErrorKind::TimedOut,
+        "unexpected_error: {:?}",
+        kind
+    );
+}
+
+#[test]
+fn test_read_with_timeout() {
+    let dir = tmpdir();
+    let socket_path = dir.path().join("sock");
+
+    let listener = or_panic!(UnixListener::bind(&socket_path));
+
+    let mut stream = or_panic!(UnixStream::connect(&socket_path));
+    or_panic!(stream.set_read_timeout(Some(Duration::from_millis(1000))));
+
+    let mut other_end = or_panic!(listener.accept()).0;
+    or_panic!(other_end.write_all(b"hello world"));
+
+    let mut buf = [0; 11];
+    or_panic!(stream.read(&mut buf));
+    assert_eq!(b"hello world", &buf[..]);
+
+    let kind = stream.read_exact(&mut buf).err().expect("expected error").kind();
+    assert!(
+        kind == ErrorKind::WouldBlock || kind == ErrorKind::TimedOut,
+        "unexpected_error: {:?}",
+        kind
+    );
+}
+
+// Ensure the `set_read_timeout` and `set_write_timeout` calls return errors
+// when passed zero Durations
+#[test]
+fn test_unix_stream_timeout_zero_duration() {
+    let dir = tmpdir();
+    let socket_path = dir.path().join("sock");
+
+    let listener = or_panic!(UnixListener::bind(&socket_path));
+    let stream = or_panic!(UnixStream::connect(&socket_path));
+
+    let result = stream.set_write_timeout(Some(Duration::new(0, 0)));
+    let err = result.unwrap_err();
+    assert_eq!(err.kind(), ErrorKind::InvalidInput);
+
+    let result = stream.set_read_timeout(Some(Duration::new(0, 0)));
+    let err = result.unwrap_err();
+    assert_eq!(err.kind(), ErrorKind::InvalidInput);
+
+    drop(listener);
+}
+
+#[test]
+fn test_unix_datagram() {
+    let dir = tmpdir();
+    let path1 = dir.path().join("sock1");
+    let path2 = dir.path().join("sock2");
+
+    let sock1 = or_panic!(UnixDatagram::bind(&path1));
+    let sock2 = or_panic!(UnixDatagram::bind(&path2));
+
+    let msg = b"hello world";
+    or_panic!(sock1.send_to(msg, &path2));
+    let mut buf = [0; 11];
+    or_panic!(sock2.recv_from(&mut buf));
+    assert_eq!(msg, &buf[..]);
+}
+
+#[test]
+fn test_unnamed_unix_datagram() {
+    let dir = tmpdir();
+    let path1 = dir.path().join("sock1");
+
+    let sock1 = or_panic!(UnixDatagram::bind(&path1));
+    let sock2 = or_panic!(UnixDatagram::unbound());
+
+    let msg = b"hello world";
+    or_panic!(sock2.send_to(msg, &path1));
+    let mut buf = [0; 11];
+    let (usize, addr) = or_panic!(sock1.recv_from(&mut buf));
+    assert_eq!(usize, 11);
+    assert!(addr.is_unnamed());
+    assert_eq!(msg, &buf[..]);
+}
+
+#[test]
+fn test_unix_datagram_connect_to_recv_addr() {
+    let dir = tmpdir();
+    let path1 = dir.path().join("sock1");
+    let path2 = dir.path().join("sock2");
+
+    let sock1 = or_panic!(UnixDatagram::bind(&path1));
+    let sock2 = or_panic!(UnixDatagram::bind(&path2));
+
+    let msg = b"hello world";
+    let sock1_addr = or_panic!(sock1.local_addr());
+    or_panic!(sock2.send_to_addr(msg, &sock1_addr));
+    let mut buf = [0; 11];
+    let (_, addr) = or_panic!(sock1.recv_from(&mut buf));
+
+    let new_msg = b"hello back";
+    let mut new_buf = [0; 10];
+    or_panic!(sock2.connect_addr(&addr));
+    or_panic!(sock2.send(new_msg)); // set by connect_addr
+    let usize = or_panic!(sock2.recv(&mut new_buf));
+    assert_eq!(usize, 10);
+    assert_eq!(new_msg, &new_buf[..]);
+}
+
+#[test]
+fn test_connect_unix_datagram() {
+    let dir = tmpdir();
+    let path1 = dir.path().join("sock1");
+    let path2 = dir.path().join("sock2");
+
+    let bsock1 = or_panic!(UnixDatagram::bind(&path1));
+    let bsock2 = or_panic!(UnixDatagram::bind(&path2));
+    let sock = or_panic!(UnixDatagram::unbound());
+    or_panic!(sock.connect(&path1));
+
+    // Check send()
+    let msg = b"hello there";
+    or_panic!(sock.send(msg));
+    let mut buf = [0; 11];
+    let (usize, addr) = or_panic!(bsock1.recv_from(&mut buf));
+    assert_eq!(usize, 11);
+    assert!(addr.is_unnamed());
+    assert_eq!(msg, &buf[..]);
+
+    // Changing default socket works too
+    or_panic!(sock.connect(&path2));
+    or_panic!(sock.send(msg));
+    or_panic!(bsock2.recv_from(&mut buf));
+}
+
+#[test]
+fn test_unix_datagram_recv() {
+    let dir = tmpdir();
+    let path1 = dir.path().join("sock1");
+
+    let sock1 = or_panic!(UnixDatagram::bind(&path1));
+    let sock2 = or_panic!(UnixDatagram::unbound());
+    or_panic!(sock2.connect(&path1));
+
+    let msg = b"hello world";
+    or_panic!(sock2.send(msg));
+    let mut buf = [0; 11];
+    let size = or_panic!(sock1.recv(&mut buf));
+    assert_eq!(size, 11);
+    assert_eq!(msg, &buf[..]);
+}
+
+#[test]
+fn datagram_pair() {
+    let msg1 = b"hello";
+    let msg2 = b"world!";
+
+    let (s1, s2) = or_panic!(UnixDatagram::pair());
+    let thread = thread::spawn(move || {
+        // s1 must be moved in or the test will hang!
+        let mut buf = [0; 5];
+        or_panic!(s1.recv(&mut buf));
+        assert_eq!(&msg1[..], &buf[..]);
+        or_panic!(s1.send(msg2));
+    });
+
+    or_panic!(s2.send(msg1));
+    let mut buf = [0; 6];
+    or_panic!(s2.recv(&mut buf));
+    assert_eq!(&msg2[..], &buf[..]);
+    drop(s2);
+
+    thread.join().unwrap();
+}
+
+// Ensure the `set_read_timeout` and `set_write_timeout` calls return errors
+// when passed zero Durations
+#[test]
+fn test_unix_datagram_timeout_zero_duration() {
+    let dir = tmpdir();
+    let path = dir.path().join("sock");
+
+    let datagram = or_panic!(UnixDatagram::bind(&path));
+
+    let result = datagram.set_write_timeout(Some(Duration::new(0, 0)));
+    let err = result.unwrap_err();
+    assert_eq!(err.kind(), ErrorKind::InvalidInput);
+
+    let result = datagram.set_read_timeout(Some(Duration::new(0, 0)));
+    let err = result.unwrap_err();
+    assert_eq!(err.kind(), ErrorKind::InvalidInput);
+}
+
+#[test]
+fn abstract_namespace_not_allowed_connect() {
+    assert!(UnixStream::connect("\0asdf").is_err());
+}
+
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[test]
+fn test_abstract_stream_connect() {
+    let msg1 = b"hello";
+    let msg2 = b"world";
+
+    let socket_addr = or_panic!(SocketAddr::from_abstract_namespace(b"namespace"));
+    let listener = or_panic!(UnixListener::bind_addr(&socket_addr));
+
+    let thread = thread::spawn(move || {
+        let mut stream = or_panic!(listener.accept()).0;
+        let mut buf = [0; 5];
+        or_panic!(stream.read(&mut buf));
+        assert_eq!(&msg1[..], &buf[..]);
+        or_panic!(stream.write_all(msg2));
+    });
+
+    let mut stream = or_panic!(UnixStream::connect_addr(&socket_addr));
+
+    let peer = or_panic!(stream.peer_addr());
+    assert_eq!(peer.as_abstract_namespace().unwrap(), b"namespace");
+
+    or_panic!(stream.write_all(msg1));
+    let mut buf = vec![];
+    or_panic!(stream.read_to_end(&mut buf));
+    assert_eq!(&msg2[..], &buf[..]);
+    drop(stream);
+
+    thread.join().unwrap();
+}
+
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[test]
+fn test_abstract_stream_iter() {
+    let addr = or_panic!(SocketAddr::from_abstract_namespace(b"hidden"));
+    let listener = or_panic!(UnixListener::bind_addr(&addr));
+
+    let thread = thread::spawn(move || {
+        for stream in listener.incoming().take(2) {
+            let mut stream = or_panic!(stream);
+            let mut buf = [0];
+            or_panic!(stream.read(&mut buf));
+        }
+    });
+
+    for _ in 0..2 {
+        let mut stream = or_panic!(UnixStream::connect_addr(&addr));
+        or_panic!(stream.write_all(&[0]));
+    }
+
+    thread.join().unwrap();
+}
+
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[test]
+fn test_abstract_datagram_bind_send_to_addr() {
+    let addr1 = or_panic!(SocketAddr::from_abstract_namespace(b"ns1"));
+    let sock1 = or_panic!(UnixDatagram::bind_addr(&addr1));
+
+    let local = or_panic!(sock1.local_addr());
+    assert_eq!(local.as_abstract_namespace().unwrap(), b"ns1");
+
+    let addr2 = or_panic!(SocketAddr::from_abstract_namespace(b"ns2"));
+    let sock2 = or_panic!(UnixDatagram::bind_addr(&addr2));
+
+    let msg = b"hello world";
+    or_panic!(sock1.send_to_addr(msg, &addr2));
+    let mut buf = [0; 11];
+    let (len, addr) = or_panic!(sock2.recv_from(&mut buf));
+    assert_eq!(msg, &buf[..]);
+    assert_eq!(len, 11);
+    assert_eq!(addr.as_abstract_namespace().unwrap(), b"ns1");
+}
+
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[test]
+fn test_abstract_datagram_connect_addr() {
+    let addr1 = or_panic!(SocketAddr::from_abstract_namespace(b"ns3"));
+    let bsock1 = or_panic!(UnixDatagram::bind_addr(&addr1));
+
+    let sock = or_panic!(UnixDatagram::unbound());
+    or_panic!(sock.connect_addr(&addr1));
+
+    let msg = b"hello world";
+    or_panic!(sock.send(msg));
+    let mut buf = [0; 11];
+    let (len, addr) = or_panic!(bsock1.recv_from(&mut buf));
+    assert_eq!(len, 11);
+    assert_eq!(addr.is_unnamed(), true);
+    assert_eq!(msg, &buf[..]);
+
+    let addr2 = or_panic!(SocketAddr::from_abstract_namespace(b"ns4"));
+    let bsock2 = or_panic!(UnixDatagram::bind_addr(&addr2));
+
+    or_panic!(sock.connect_addr(&addr2));
+    or_panic!(sock.send(msg));
+    or_panic!(bsock2.recv_from(&mut buf));
+}
+
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[test]
+fn test_abstract_namespace_too_long() {
+    match SocketAddr::from_abstract_namespace(
+        b"abcdefghijklmnopqrstuvwxyzabcdefghijklmn\
+        opqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghi\
+        jklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz",
+    ) {
+        Err(ref e) if e.kind() == io::ErrorKind::InvalidInput => {}
+        Err(e) => panic!("unexpected error {e}"),
+        Ok(_) => panic!("unexpected success"),
+    }
+}
+
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[test]
+fn test_abstract_namespace_no_pathname_and_not_unnamed() {
+    let namespace = b"local";
+    let addr = or_panic!(SocketAddr::from_abstract_namespace(&namespace[..]));
+    assert_eq!(addr.as_pathname(), None);
+    assert_eq!(addr.as_abstract_namespace(), Some(&namespace[..]));
+    assert_eq!(addr.is_unnamed(), false);
+}
+
+#[test]
+fn test_unix_stream_peek() {
+    let (txdone, rxdone) = crate::sync::mpsc::channel();
+
+    let dir = tmpdir();
+    let path = dir.path().join("sock");
+
+    let listener = or_panic!(UnixListener::bind(&path));
+    let thread = thread::spawn(move || {
+        let mut stream = or_panic!(listener.accept()).0;
+        or_panic!(stream.write_all(&[1, 3, 3, 7]));
+        or_panic!(rxdone.recv());
+    });
+
+    let mut stream = or_panic!(UnixStream::connect(&path));
+    let mut buf = [0; 10];
+    for _ in 0..2 {
+        assert_eq!(or_panic!(stream.peek(&mut buf)), 4);
+    }
+    assert_eq!(or_panic!(stream.read(&mut buf)), 4);
+
+    or_panic!(stream.set_nonblocking(true));
+    match stream.peek(&mut buf) {
+        Ok(_) => panic!("expected error"),
+        Err(ref e) if e.kind() == ErrorKind::WouldBlock => {}
+        Err(e) => panic!("unexpected error: {e}"),
+    }
+
+    or_panic!(txdone.send(()));
+    thread.join().unwrap();
+}
+
+#[test]
+fn test_unix_datagram_peek() {
+    let dir = tmpdir();
+    let path1 = dir.path().join("sock");
+
+    let sock1 = or_panic!(UnixDatagram::bind(&path1));
+    let sock2 = or_panic!(UnixDatagram::unbound());
+    or_panic!(sock2.connect(&path1));
+
+    let msg = b"hello world";
+    or_panic!(sock2.send(msg));
+    for _ in 0..2 {
+        let mut buf = [0; 11];
+        let size = or_panic!(sock1.peek(&mut buf));
+        assert_eq!(size, 11);
+        assert_eq!(msg, &buf[..]);
+    }
+
+    let mut buf = [0; 11];
+    let size = or_panic!(sock1.recv(&mut buf));
+    assert_eq!(size, 11);
+    assert_eq!(msg, &buf[..]);
+}
+
+#[test]
+fn test_unix_datagram_peek_from() {
+    let dir = tmpdir();
+    let path1 = dir.path().join("sock");
+
+    let sock1 = or_panic!(UnixDatagram::bind(&path1));
+    let sock2 = or_panic!(UnixDatagram::unbound());
+    or_panic!(sock2.connect(&path1));
+
+    let msg = b"hello world";
+    or_panic!(sock2.send(msg));
+    for _ in 0..2 {
+        let mut buf = [0; 11];
+        let (size, _) = or_panic!(sock1.peek_from(&mut buf));
+        assert_eq!(size, 11);
+        assert_eq!(msg, &buf[..]);
+    }
+
+    let mut buf = [0; 11];
+    let size = or_panic!(sock1.recv(&mut buf));
+    assert_eq!(size, 11);
+    assert_eq!(msg, &buf[..]);
+}
+
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[test]
+fn test_send_vectored_fds_unix_stream() {
+    let (s1, s2) = or_panic!(UnixStream::pair());
+
+    let buf1 = [1; 8];
+    let bufs_send = &[IoSlice::new(&buf1[..])][..];
+
+    let mut ancillary1_buffer = [0; 128];
+    let mut ancillary1 = SocketAncillary::new(&mut ancillary1_buffer[..]);
+    assert!(ancillary1.add_fds(&[s1.as_raw_fd()][..]));
+
+    let usize = or_panic!(s1.send_vectored_with_ancillary(&bufs_send, &mut ancillary1));
+    assert_eq!(usize, 8);
+
+    let mut buf2 = [0; 8];
+    let mut bufs_recv = &mut [IoSliceMut::new(&mut buf2[..])][..];
+
+    let mut ancillary2_buffer = [0; 128];
+    let mut ancillary2 = SocketAncillary::new(&mut ancillary2_buffer[..]);
+
+    let usize = or_panic!(s2.recv_vectored_with_ancillary(&mut bufs_recv, &mut ancillary2));
+    assert_eq!(usize, 8);
+    assert_eq!(buf1, buf2);
+
+    let mut ancillary_data_vec = Vec::from_iter(ancillary2.messages());
+    assert_eq!(ancillary_data_vec.len(), 1);
+    if let AncillaryData::ScmRights(scm_rights) = ancillary_data_vec.pop().unwrap().unwrap() {
+        let fd_vec = Vec::from_iter(scm_rights);
+        assert_eq!(fd_vec.len(), 1);
+        unsafe {
+            libc::close(fd_vec[0]);
+        }
+    } else {
+        unreachable!("must be ScmRights");
+    }
+}
+
+#[cfg(any(target_os = "android", target_os = "linux",))]
+#[test]
+fn test_send_vectored_with_ancillary_to_unix_datagram() {
+    fn getpid() -> libc::pid_t {
+        unsafe { libc::getpid() }
+    }
+
+    fn getuid() -> libc::uid_t {
+        unsafe { libc::getuid() }
+    }
+
+    fn getgid() -> libc::gid_t {
+        unsafe { libc::getgid() }
+    }
+
+    let dir = tmpdir();
+    let path1 = dir.path().join("sock1");
+    let path2 = dir.path().join("sock2");
+
+    let bsock1 = or_panic!(UnixDatagram::bind(&path1));
+    let bsock2 = or_panic!(UnixDatagram::bind(&path2));
+
+    or_panic!(bsock2.set_passcred(true));
+
+    let buf1 = [1; 8];
+    let bufs_send = &[IoSlice::new(&buf1[..])][..];
+
+    let mut ancillary1_buffer = [0; 128];
+    let mut ancillary1 = SocketAncillary::new(&mut ancillary1_buffer[..]);
+    let mut cred1 = SocketCred::new();
+    cred1.set_pid(getpid());
+    cred1.set_uid(getuid());
+    cred1.set_gid(getgid());
+    assert!(ancillary1.add_creds(&[cred1.clone()][..]));
+
+    let usize =
+        or_panic!(bsock1.send_vectored_with_ancillary_to(&bufs_send, &mut ancillary1, &path2));
+    assert_eq!(usize, 8);
+
+    let mut buf2 = [0; 8];
+    let mut bufs_recv = &mut [IoSliceMut::new(&mut buf2[..])][..];
+
+    let mut ancillary2_buffer = [0; 128];
+    let mut ancillary2 = SocketAncillary::new(&mut ancillary2_buffer[..]);
+
+    let (usize, truncated, _addr) =
+        or_panic!(bsock2.recv_vectored_with_ancillary_from(&mut bufs_recv, &mut ancillary2));
+    assert_eq!(ancillary2.truncated(), false);
+    assert_eq!(usize, 8);
+    assert_eq!(truncated, false);
+    assert_eq!(buf1, buf2);
+
+    let mut ancillary_data_vec = Vec::from_iter(ancillary2.messages());
+    assert_eq!(ancillary_data_vec.len(), 1);
+    if let AncillaryData::ScmCredentials(scm_credentials) =
+        ancillary_data_vec.pop().unwrap().unwrap()
+    {
+        let cred_vec = Vec::from_iter(scm_credentials);
+        assert_eq!(cred_vec.len(), 1);
+        assert_eq!(cred1.get_pid(), cred_vec[0].get_pid());
+        assert_eq!(cred1.get_uid(), cred_vec[0].get_uid());
+        assert_eq!(cred1.get_gid(), cred_vec[0].get_gid());
+    } else {
+        unreachable!("must be ScmCredentials");
+    }
+}
+
+#[cfg(any(target_os = "android", target_os = "linux"))]
+#[test]
+fn test_send_vectored_with_ancillary_unix_datagram() {
+    let dir = tmpdir();
+    let path1 = dir.path().join("sock1");
+    let path2 = dir.path().join("sock2");
+
+    let bsock1 = or_panic!(UnixDatagram::bind(&path1));
+    let bsock2 = or_panic!(UnixDatagram::bind(&path2));
+
+    let buf1 = [1; 8];
+    let bufs_send = &[IoSlice::new(&buf1[..])][..];
+
+    let mut ancillary1_buffer = [0; 128];
+    let mut ancillary1 = SocketAncillary::new(&mut ancillary1_buffer[..]);
+    assert!(ancillary1.add_fds(&[bsock1.as_raw_fd()][..]));
+
+    or_panic!(bsock1.connect(&path2));
+    let usize = or_panic!(bsock1.send_vectored_with_ancillary(&bufs_send, &mut ancillary1));
+    assert_eq!(usize, 8);
+
+    let mut buf2 = [0; 8];
+    let mut bufs_recv = &mut [IoSliceMut::new(&mut buf2[..])][..];
+
+    let mut ancillary2_buffer = [0; 128];
+    let mut ancillary2 = SocketAncillary::new(&mut ancillary2_buffer[..]);
+
+    let (usize, truncated) =
+        or_panic!(bsock2.recv_vectored_with_ancillary(&mut bufs_recv, &mut ancillary2));
+    assert_eq!(usize, 8);
+    assert_eq!(truncated, false);
+    assert_eq!(buf1, buf2);
+
+    let mut ancillary_data_vec = Vec::from_iter(ancillary2.messages());
+    assert_eq!(ancillary_data_vec.len(), 1);
+    if let AncillaryData::ScmRights(scm_rights) = ancillary_data_vec.pop().unwrap().unwrap() {
+        let fd_vec = Vec::from_iter(scm_rights);
+        assert_eq!(fd_vec.len(), 1);
+        unsafe {
+            libc::close(fd_vec[0]);
+        }
+    } else {
+        unreachable!("must be ScmRights");
+    }
+}
diff --git a/library/std/src/os/unix/process.rs b/library/std/src/os/unix/process.rs
new file mode 100644
index 000000000..09b2bfe39
--- /dev/null
+++ b/library/std/src/os/unix/process.rs
@@ -0,0 +1,466 @@
+//! Unix-specific extensions to primitives in the [`std::process`] module.
+//!
+//! [`std::process`]: crate::process
+
+#![stable(feature = "rust1", since = "1.0.0")]
+
+use crate::ffi::OsStr;
+use crate::io;
+use crate::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
+use crate::process;
+use crate::sealed::Sealed;
+use crate::sys;
+use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
+
+#[cfg(not(any(target_os = "vxworks", target_os = "espidf", target_os = "horizon")))]
+type UserId = u32;
+#[cfg(not(any(target_os = "vxworks", target_os = "espidf", target_os = "horizon")))]
+type GroupId = u32;
+
+#[cfg(any(target_os = "vxworks", target_os = "espidf", target_os = "horizon"))]
+type UserId = u16;
+#[cfg(any(target_os = "vxworks", target_os = "espidf", target_os = "horizon"))]
+type GroupId = u16;
+
+/// Unix-specific extensions to the [`process::Command`] builder.
+///
+/// This trait is sealed: it cannot be implemented outside the standard library.
+/// This is so that future additional methods are not breaking changes.
+#[stable(feature = "rust1", since = "1.0.0")]
+pub trait CommandExt: Sealed {
+    /// Sets the child process's user ID. This translates to a
+    /// `setuid` call in the child process. Failure in the `setuid`
+    /// call will cause the spawn to fail.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    fn uid(&mut self, id: UserId) -> &mut process::Command;
+
+    /// Similar to `uid`, but sets the group ID of the child process. This has
+    /// the same semantics as the `uid` field.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    fn gid(&mut self, id: GroupId) -> &mut process::Command;
+
+    /// Sets the supplementary group IDs for the calling process. Translates to
+    /// a `setgroups` call in the child process.
+    #[unstable(feature = "setgroups", issue = "90747")]
+    fn groups(&mut self, groups: &[GroupId]) -> &mut process::Command;
+
+    /// Schedules a closure to be run just before the `exec` function is
+    /// invoked.
+    ///
+    /// The closure is allowed to return an I/O error whose OS error code will
+    /// be communicated back to the parent and returned as an error from when
+    /// the spawn was requested.
+    ///
+    /// Multiple closures can be registered and they will be called in order of
+    /// their registration. If a closure returns `Err` then no further closures
+    /// will be called and the spawn operation will immediately return with a
+    /// failure.
+    ///
+    /// # Notes and Safety
+    ///
+    /// This closure will be run in the context of the child process after a
+    /// `fork`. This primarily means that any modifications made to memory on
+    /// behalf of this closure will **not** be visible to the parent process.
+    /// This is often a very constrained environment where normal operations
+    /// like `malloc`, accessing environment variables through [`std::env`]
+    /// or acquiring a mutex are not guaranteed to work (due to
+    /// other threads perhaps still running when the `fork` was run).
+    ///
+    /// For further details refer to the [POSIX fork() specification]
+    /// and the equivalent documentation for any targeted
+    /// platform, especially the requirements around *async-signal-safety*.
+    ///
+    /// This also means that all resources such as file descriptors and
+    /// memory-mapped regions got duplicated. It is your responsibility to make
+    /// sure that the closure does not violate library invariants by making
+    /// invalid use of these duplicates.
+    ///
+    /// Panicking in the closure is safe only if all the format arguments for the
+    /// panic message can be safely formatted; this is because although
+    /// `Command` calls [`std::panic::always_abort`](crate::panic::always_abort)
+    /// before calling the pre_exec hook, panic will still try to format the
+    /// panic message.
+    ///
+    /// When this closure is run, aspects such as the stdio file descriptors and
+    /// working directory have successfully been changed, so output to these
+    /// locations might not appear where intended.
+    ///
+    /// [POSIX fork() specification]:
+    ///     https://pubs.opengroup.org/onlinepubs/9699919799/functions/fork.html
+    /// [`std::env`]: mod@crate::env
+    #[stable(feature = "process_pre_exec", since = "1.34.0")]
+    unsafe fn pre_exec<F>(&mut self, f: F) -> &mut process::Command
+    where
+        F: FnMut() -> io::Result<()> + Send + Sync + 'static;
+
+    /// Schedules a closure to be run just before the `exec` function is
+    /// invoked.
+    ///
+    /// This method is stable and usable, but it should be unsafe. To fix
+    /// that, it got deprecated in favor of the unsafe [`pre_exec`].
+    ///
+    /// [`pre_exec`]: CommandExt::pre_exec
+    #[stable(feature = "process_exec", since = "1.15.0")]
+    #[deprecated(since = "1.37.0", note = "should be unsafe, use `pre_exec` instead")]
+    fn before_exec<F>(&mut self, f: F) -> &mut process::Command
+    where
+        F: FnMut() -> io::Result<()> + Send + Sync + 'static,
+    {
+        unsafe { self.pre_exec(f) }
+    }
+
+    /// Performs all the required setup by this `Command`, followed by calling
+    /// the `execvp` syscall.
+    ///
+    /// On success this function will not return, and otherwise it will return
+    /// an error indicating why the exec (or another part of the setup of the
+    /// `Command`) failed.
+    ///
+    /// `exec` not returning has the same implications as calling
+    /// [`process::exit`] – no destructors on the current stack or any other
+    /// thread’s stack will be run. Therefore, it is recommended to only call
+    /// `exec` at a point where it is fine to not run any destructors. Note,
+    /// that the `execvp` syscall independently guarantees that all memory is
+    /// freed and all file descriptors with the `CLOEXEC` option (set by default
+    /// on all file descriptors opened by the standard library) are closed.
+    ///
+    /// This function, unlike `spawn`, will **not** `fork` the process to create
+    /// a new child. Like spawn, however, the default behavior for the stdio
+    /// descriptors will be to inherited from the current process.
+    ///
+    /// # Notes
+    ///
+    /// The process may be in a "broken state" if this function returns in
+    /// error. For example the working directory, environment variables, signal
+    /// handling settings, various user/group information, or aspects of stdio
+    /// file descriptors may have changed. If a "transactional spawn" is
+    /// required to gracefully handle errors it is recommended to use the
+    /// cross-platform `spawn` instead.
+    #[stable(feature = "process_exec2", since = "1.9.0")]
+    fn exec(&mut self) -> io::Error;
+
+    /// Set executable argument
+    ///
+    /// Set the first process argument, `argv[0]`, to something other than the
+    /// default executable path.
+    #[stable(feature = "process_set_argv0", since = "1.45.0")]
+    fn arg0<S>(&mut self, arg: S) -> &mut process::Command
+    where
+        S: AsRef<OsStr>;
+
+    /// Sets the process group ID (PGID) of the child process. Equivalent to a
+    /// `setpgid` call in the child process, but may be more efficient.
+    ///
+    /// Process groups determine which processes receive signals.
+    ///
+    /// # Examples
+    ///
+    /// Pressing Ctrl-C in a terminal will send SIGINT to all processes in
+    /// the current foreground process group. By spawning the `sleep`
+    /// subprocess in a new process group, it will not receive SIGINT from the
+    /// terminal.
+    ///
+    /// The parent process could install a signal handler and manage the
+    /// subprocess on its own terms.
+    ///
+    /// A process group ID of 0 will use the process ID as the PGID.
+    ///
+    /// ```no_run
+    /// use std::process::Command;
+    /// use std::os::unix::process::CommandExt;
+    ///
+    /// Command::new("sleep")
+    ///     .arg("10")
+    ///     .process_group(0)
+    ///     .spawn()?
+    ///     .wait()?;
+    /// #
+    /// # Ok::<_, Box<dyn std::error::Error>>(())
+    /// ```
+    #[stable(feature = "process_set_process_group", since = "1.64.0")]
+    fn process_group(&mut self, pgroup: i32) -> &mut process::Command;
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl CommandExt for process::Command {
+    fn uid(&mut self, id: UserId) -> &mut process::Command {
+        self.as_inner_mut().uid(id);
+        self
+    }
+
+    fn gid(&mut self, id: GroupId) -> &mut process::Command {
+        self.as_inner_mut().gid(id);
+        self
+    }
+
+    fn groups(&mut self, groups: &[GroupId]) -> &mut process::Command {
+        self.as_inner_mut().groups(groups);
+        self
+    }
+
+    unsafe fn pre_exec<F>(&mut self, f: F) -> &mut process::Command
+    where
+        F: FnMut() -> io::Result<()> + Send + Sync + 'static,
+    {
+        self.as_inner_mut().pre_exec(Box::new(f));
+        self
+    }
+
+    fn exec(&mut self) -> io::Error {
+        // NOTE: This may *not* be safe to call after `libc::fork`, because it
+        // may allocate. That may be worth fixing at some point in the future.
+        self.as_inner_mut().exec(sys::process::Stdio::Inherit)
+    }
+
+    fn arg0<S>(&mut self, arg: S) -> &mut process::Command
+    where
+        S: AsRef<OsStr>,
+    {
+        self.as_inner_mut().set_arg_0(arg.as_ref());
+        self
+    }
+
+    fn process_group(&mut self, pgroup: i32) -> &mut process::Command {
+        self.as_inner_mut().pgroup(pgroup);
+        self
+    }
+}
+
+/// Unix-specific extensions to [`process::ExitStatus`] and
+/// [`ExitStatusError`](process::ExitStatusError).
+///
+/// On Unix, `ExitStatus` **does not necessarily represent an exit status**, as
+/// passed to the `_exit` system call or returned by
+/// [`ExitStatus::code()`](crate::process::ExitStatus::code).  It represents **any wait status**
+/// as returned by one of the `wait` family of system
+/// calls.
+///
+/// A Unix wait status (a Rust `ExitStatus`) can represent a Unix exit status, but can also
+/// represent other kinds of process event.
+///
+/// This trait is sealed: it cannot be implemented outside the standard library.
+/// This is so that future additional methods are not breaking changes.
+#[stable(feature = "rust1", since = "1.0.0")]
+pub trait ExitStatusExt: Sealed {
+    /// Creates a new `ExitStatus` or `ExitStatusError` from the raw underlying integer status
+    /// value from `wait`
+    ///
+    /// The value should be a **wait status, not an exit status**.
+    ///
+    /// # Panics
+    ///
+    /// Panics on an attempt to make an `ExitStatusError` from a wait status of `0`.
+    ///
+    /// Making an `ExitStatus` always succeeds and never panics.
+    #[stable(feature = "exit_status_from", since = "1.12.0")]
+    fn from_raw(raw: i32) -> Self;
+
+    /// If the process was terminated by a signal, returns that signal.
+    ///
+    /// In other words, if `WIFSIGNALED`, this returns `WTERMSIG`.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    fn signal(&self) -> Option<i32>;
+
+    /// If the process was terminated by a signal, says whether it dumped core.
+    #[stable(feature = "unix_process_wait_more", since = "1.58.0")]
+    fn core_dumped(&self) -> bool;
+
+    /// If the process was stopped by a signal, returns that signal.
+    ///
+    /// In other words, if `WIFSTOPPED`, this returns `WSTOPSIG`.  This is only possible if the status came from
+    /// a `wait` system call which was passed `WUNTRACED`, and was then converted into an `ExitStatus`.
+    #[stable(feature = "unix_process_wait_more", since = "1.58.0")]
+    fn stopped_signal(&self) -> Option<i32>;
+
+    /// Whether the process was continued from a stopped status.
+    ///
+    /// Ie, `WIFCONTINUED`.  This is only possible if the status came from a `wait` system call
+    /// which was passed `WCONTINUED`, and was then converted into an `ExitStatus`.
+    #[stable(feature = "unix_process_wait_more", since = "1.58.0")]
+    fn continued(&self) -> bool;
+
+    /// Returns the underlying raw `wait` status.
+    ///
+    /// The returned integer is a **wait status, not an exit status**.
+    #[stable(feature = "unix_process_wait_more", since = "1.58.0")]
+    fn into_raw(self) -> i32;
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl ExitStatusExt for process::ExitStatus {
+    fn from_raw(raw: i32) -> Self {
+        process::ExitStatus::from_inner(From::from(raw))
+    }
+
+    fn signal(&self) -> Option<i32> {
+        self.as_inner().signal()
+    }
+
+    fn core_dumped(&self) -> bool {
+        self.as_inner().core_dumped()
+    }
+
+    fn stopped_signal(&self) -> Option<i32> {
+        self.as_inner().stopped_signal()
+    }
+
+    fn continued(&self) -> bool {
+        self.as_inner().continued()
+    }
+
+    fn into_raw(self) -> i32 {
+        self.as_inner().into_raw().into()
+    }
+}
+
+#[unstable(feature = "exit_status_error", issue = "84908")]
+impl ExitStatusExt for process::ExitStatusError {
+    fn from_raw(raw: i32) -> Self {
+        process::ExitStatus::from_raw(raw)
+            .exit_ok()
+            .expect_err("<ExitStatusError as ExitStatusExt>::from_raw(0) but zero is not an error")
+    }
+
+    fn signal(&self) -> Option<i32> {
+        self.into_status().signal()
+    }
+
+    fn core_dumped(&self) -> bool {
+        self.into_status().core_dumped()
+    }
+
+    fn stopped_signal(&self) -> Option<i32> {
+        self.into_status().stopped_signal()
+    }
+
+    fn continued(&self) -> bool {
+        self.into_status().continued()
+    }
+
+    fn into_raw(self) -> i32 {
+        self.into_status().into_raw()
+    }
+}
+
+#[stable(feature = "process_extensions", since = "1.2.0")]
+impl FromRawFd for process::Stdio {
+    #[inline]
+    unsafe fn from_raw_fd(fd: RawFd) -> process::Stdio {
+        let fd = sys::fd::FileDesc::from_raw_fd(fd);
+        let io = sys::process::Stdio::Fd(fd);
+        process::Stdio::from_inner(io)
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<OwnedFd> for process::Stdio {
+    #[inline]
+    fn from(fd: OwnedFd) -> process::Stdio {
+        let fd = sys::fd::FileDesc::from_inner(fd);
+        let io = sys::process::Stdio::Fd(fd);
+        process::Stdio::from_inner(io)
+    }
+}
+
+#[stable(feature = "process_extensions", since = "1.2.0")]
+impl AsRawFd for process::ChildStdin {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        self.as_inner().as_raw_fd()
+    }
+}
+
+#[stable(feature = "process_extensions", since = "1.2.0")]
+impl AsRawFd for process::ChildStdout {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        self.as_inner().as_raw_fd()
+    }
+}
+
+#[stable(feature = "process_extensions", since = "1.2.0")]
+impl AsRawFd for process::ChildStderr {
+    #[inline]
+    fn as_raw_fd(&self) -> RawFd {
+        self.as_inner().as_raw_fd()
+    }
+}
+
+#[stable(feature = "into_raw_os", since = "1.4.0")]
+impl IntoRawFd for process::ChildStdin {
+    #[inline]
+    fn into_raw_fd(self) -> RawFd {
+        self.into_inner().into_inner().into_raw_fd()
+    }
+}
+
+#[stable(feature = "into_raw_os", since = "1.4.0")]
+impl IntoRawFd for process::ChildStdout {
+    #[inline]
+    fn into_raw_fd(self) -> RawFd {
+        self.into_inner().into_inner().into_raw_fd()
+    }
+}
+
+#[stable(feature = "into_raw_os", since = "1.4.0")]
+impl IntoRawFd for process::ChildStderr {
+    #[inline]
+    fn into_raw_fd(self) -> RawFd {
+        self.into_inner().into_inner().into_raw_fd()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsFd for crate::process::ChildStdin {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        self.as_inner().as_fd()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<crate::process::ChildStdin> for OwnedFd {
+    #[inline]
+    fn from(child_stdin: crate::process::ChildStdin) -> OwnedFd {
+        child_stdin.into_inner().into_inner().into_inner()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsFd for crate::process::ChildStdout {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        self.as_inner().as_fd()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<crate::process::ChildStdout> for OwnedFd {
+    #[inline]
+    fn from(child_stdout: crate::process::ChildStdout) -> OwnedFd {
+        child_stdout.into_inner().into_inner().into_inner()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsFd for crate::process::ChildStderr {
+    #[inline]
+    fn as_fd(&self) -> BorrowedFd<'_> {
+        self.as_inner().as_fd()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<crate::process::ChildStderr> for OwnedFd {
+    #[inline]
+    fn from(child_stderr: crate::process::ChildStderr) -> OwnedFd {
+        child_stderr.into_inner().into_inner().into_inner()
+    }
+}
+
+/// Returns the OS-assigned process identifier associated with this process's parent.
+#[must_use]
+#[stable(feature = "unix_ppid", since = "1.27.0")]
+pub fn parent_id() -> u32 {
+    crate::sys::os::getppid()
+}
diff --git a/library/std/src/os/unix/raw.rs b/library/std/src/os/unix/raw.rs
new file mode 100644
index 000000000..fe761627b
--- /dev/null
+++ b/library/std/src/os/unix/raw.rs
@@ -0,0 +1,33 @@
+//! Unix-specific primitives available on all unix platforms.
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+#![deprecated(
+    since = "1.8.0",
+    note = "these type aliases are no longer supported by \
+            the standard library, the `libc` crate on \
+            crates.io should be used instead for the correct \
+            definitions"
+)]
+#![allow(deprecated)]
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+#[allow(non_camel_case_types)]
+pub type uid_t = u32;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+#[allow(non_camel_case_types)]
+pub type gid_t = u32;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+#[allow(non_camel_case_types)]
+pub type pid_t = i32;
+
+#[doc(inline)]
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub use super::platform::raw::pthread_t;
+#[doc(inline)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub use super::platform::raw::{blkcnt_t, time_t};
+#[doc(inline)]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub use super::platform::raw::{blksize_t, dev_t, ino_t, mode_t, nlink_t, off_t};
diff --git a/library/std/src/os/unix/thread.rs b/library/std/src/os/unix/thread.rs
new file mode 100644
index 000000000..03dcc3a4f
--- /dev/null
+++ b/library/std/src/os/unix/thread.rs
@@ -0,0 +1,41 @@
+//! Unix-specific extensions to primitives in the [`std::thread`] module.
+//!
+//! [`std::thread`]: crate::thread
+
+#![stable(feature = "thread_extensions", since = "1.9.0")]
+
+#[allow(deprecated)]
+use crate::os::unix::raw::pthread_t;
+use crate::sys_common::{AsInner, IntoInner};
+use crate::thread::JoinHandle;
+
+#[stable(feature = "thread_extensions", since = "1.9.0")]
+#[allow(deprecated)]
+pub type RawPthread = pthread_t;
+
+/// Unix-specific extensions to [`JoinHandle`].
+#[stable(feature = "thread_extensions", since = "1.9.0")]
+pub trait JoinHandleExt {
+    /// Extracts the raw pthread_t without taking ownership
+    #[stable(feature = "thread_extensions", since = "1.9.0")]
+    fn as_pthread_t(&self) -> RawPthread;
+
+    /// Consumes the thread, returning the raw pthread_t
+    ///
+    /// This function **transfers ownership** of the underlying pthread_t to
+    /// the caller. Callers are then the unique owners of the pthread_t and
+    /// must either detach or join the pthread_t once it's no longer needed.
+    #[stable(feature = "thread_extensions", since = "1.9.0")]
+    fn into_pthread_t(self) -> RawPthread;
+}
+
+#[stable(feature = "thread_extensions", since = "1.9.0")]
+impl<T> JoinHandleExt for JoinHandle<T> {
+    fn as_pthread_t(&self) -> RawPthread {
+        self.as_inner().id() as RawPthread
+    }
+
+    fn into_pthread_t(self) -> RawPthread {
+        self.into_inner().into_id() as RawPthread
+    }
+}
diff --git a/library/std/src/os/unix/ucred.rs b/library/std/src/os/unix/ucred.rs
new file mode 100644
index 000000000..ae4faf27b
--- /dev/null
+++ b/library/std/src/os/unix/ucred.rs
@@ -0,0 +1,136 @@
+//! Unix peer credentials.
+
+// NOTE: Code in this file is heavily based on work done in PR 13 from the tokio-uds repository on
+//       GitHub.
+//
+//       For reference, the link is here: https://github.com/tokio-rs/tokio-uds/pull/13
+//       Credit to Martin Habovštiak (GitHub username Kixunil) and contributors for this work.
+
+use libc::{gid_t, pid_t, uid_t};
+
+/// Credentials for a UNIX process for credentials passing.
+#[unstable(feature = "peer_credentials_unix_socket", issue = "42839", reason = "unstable")]
+#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
+pub struct UCred {
+    /// The UID part of the peer credential. This is the effective UID of the process at the domain
+    /// socket's endpoint.
+    pub uid: uid_t,
+    /// The GID part of the peer credential. This is the effective GID of the process at the domain
+    /// socket's endpoint.
+    pub gid: gid_t,
+    /// The PID part of the peer credential. This field is optional because the PID part of the
+    /// peer credentials is not supported on every platform. On platforms where the mechanism to
+    /// discover the PID exists, this field will be populated to the PID of the process at the
+    /// domain socket's endpoint. Otherwise, it will be set to None.
+    pub pid: Option<pid_t>,
+}
+
+#[cfg(any(target_os = "android", target_os = "linux"))]
+pub use self::impl_linux::peer_cred;
+
+#[cfg(any(
+    target_os = "dragonfly",
+    target_os = "freebsd",
+    target_os = "openbsd",
+    target_os = "netbsd"
+))]
+pub use self::impl_bsd::peer_cred;
+
+#[cfg(any(target_os = "macos", target_os = "ios", target_os = "watchos"))]
+pub use self::impl_mac::peer_cred;
+
+#[cfg(any(target_os = "linux", target_os = "android"))]
+pub mod impl_linux {
+    use super::UCred;
+    use crate::os::unix::io::AsRawFd;
+    use crate::os::unix::net::UnixStream;
+    use crate::{io, mem};
+    use libc::{c_void, getsockopt, socklen_t, ucred, SOL_SOCKET, SO_PEERCRED};
+
+    pub fn peer_cred(socket: &UnixStream) -> io::Result<UCred> {
+        let ucred_size = mem::size_of::<ucred>();
+
+        // Trivial sanity checks.
+        assert!(mem::size_of::<u32>() <= mem::size_of::<usize>());
+        assert!(ucred_size <= u32::MAX as usize);
+
+        let mut ucred_size = ucred_size as socklen_t;
+        let mut ucred: ucred = ucred { pid: 1, uid: 1, gid: 1 };
+
+        unsafe {
+            let ret = getsockopt(
+                socket.as_raw_fd(),
+                SOL_SOCKET,
+                SO_PEERCRED,
+                &mut ucred as *mut ucred as *mut c_void,
+                &mut ucred_size,
+            );
+
+            if ret == 0 && ucred_size as usize == mem::size_of::<ucred>() {
+                Ok(UCred { uid: ucred.uid, gid: ucred.gid, pid: Some(ucred.pid) })
+            } else {
+                Err(io::Error::last_os_error())
+            }
+        }
+    }
+}
+
+#[cfg(any(
+    target_os = "dragonfly",
+    target_os = "freebsd",
+    target_os = "openbsd",
+    target_os = "netbsd"
+))]
+pub mod impl_bsd {
+    use super::UCred;
+    use crate::io;
+    use crate::os::unix::io::AsRawFd;
+    use crate::os::unix::net::UnixStream;
+
+    pub fn peer_cred(socket: &UnixStream) -> io::Result<UCred> {
+        let mut cred = UCred { uid: 1, gid: 1, pid: None };
+        unsafe {
+            let ret = libc::getpeereid(socket.as_raw_fd(), &mut cred.uid, &mut cred.gid);
+
+            if ret == 0 { Ok(cred) } else { Err(io::Error::last_os_error()) }
+        }
+    }
+}
+
+#[cfg(any(target_os = "macos", target_os = "ios", target_os = "watchos"))]
+pub mod impl_mac {
+    use super::UCred;
+    use crate::os::unix::io::AsRawFd;
+    use crate::os::unix::net::UnixStream;
+    use crate::{io, mem};
+    use libc::{c_void, getpeereid, getsockopt, pid_t, socklen_t, LOCAL_PEERPID, SOL_LOCAL};
+
+    pub fn peer_cred(socket: &UnixStream) -> io::Result<UCred> {
+        let mut cred = UCred { uid: 1, gid: 1, pid: None };
+        unsafe {
+            let ret = getpeereid(socket.as_raw_fd(), &mut cred.uid, &mut cred.gid);
+
+            if ret != 0 {
+                return Err(io::Error::last_os_error());
+            }
+
+            let mut pid: pid_t = 1;
+            let mut pid_size = mem::size_of::<pid_t>() as socklen_t;
+
+            let ret = getsockopt(
+                socket.as_raw_fd(),
+                SOL_LOCAL,
+                LOCAL_PEERPID,
+                &mut pid as *mut pid_t as *mut c_void,
+                &mut pid_size,
+            );
+
+            if ret == 0 && pid_size as usize == mem::size_of::<pid_t>() {
+                cred.pid = Some(pid);
+                Ok(cred)
+            } else {
+                Err(io::Error::last_os_error())
+            }
+        }
+    }
+}
diff --git a/library/std/src/os/unix/ucred/tests.rs b/library/std/src/os/unix/ucred/tests.rs
new file mode 100644
index 000000000..e63a2fc24
--- /dev/null
+++ b/library/std/src/os/unix/ucred/tests.rs
@@ -0,0 +1,39 @@
+use crate::os::unix::net::UnixStream;
+use libc::{getegid, geteuid, getpid};
+
+#[test]
+#[cfg(any(
+    target_os = "android",
+    target_os = "linux",
+    target_os = "dragonfly",
+    target_os = "freebsd",
+    target_os = "ios",
+    target_os = "macos",
+    target_os = "watchos",
+    target_os = "openbsd"
+))]
+fn test_socket_pair() {
+    // Create two connected sockets and get their peer credentials. They should be equal.
+    let (sock_a, sock_b) = UnixStream::pair().unwrap();
+    let (cred_a, cred_b) = (sock_a.peer_cred().unwrap(), sock_b.peer_cred().unwrap());
+    assert_eq!(cred_a, cred_b);
+
+    // Check that the UID and GIDs match up.
+    let uid = unsafe { geteuid() };
+    let gid = unsafe { getegid() };
+    assert_eq!(cred_a.uid, uid);
+    assert_eq!(cred_a.gid, gid);
+}
+
+#[test]
+#[cfg(any(target_os = "linux", target_os = "ios", target_os = "macos", target_os = "watchos"))]
+fn test_socket_pair_pids(arg: Type) -> RetType {
+    // Create two connected sockets and get their peer credentials.
+    let (sock_a, sock_b) = UnixStream::pair().unwrap();
+    let (cred_a, cred_b) = (sock_a.peer_cred().unwrap(), sock_b.peer_cred().unwrap());
+
+    // On supported platforms (see the cfg above), the credentials should always include the PID.
+    let pid = unsafe { getpid() };
+    assert_eq!(cred_a.pid, Some(pid));
+    assert_eq!(cred_b.pid, Some(pid));
+}
diff --git a/library/std/src/os/vxworks/fs.rs b/library/std/src/os/vxworks/fs.rs
new file mode 100644
index 000000000..77e6238ca
--- /dev/null
+++ b/library/std/src/os/vxworks/fs.rs
@@ -0,0 +1,99 @@
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::fs::Metadata;
+use crate::sys_common::AsInner;
+
+///
+/// [`fs::Metadata`]: crate::fs::Metadata
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_dev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ino(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mode(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_nlink(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_uid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_gid(&self) -> u32;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_rdev(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_size(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_atime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_mtime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_ctime_nsec(&self) -> i64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blksize(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_blocks(&self) -> u64;
+    #[stable(feature = "metadata_ext2", since = "1.8.0")]
+    fn st_attrib(&self) -> u8;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    fn st_dev(&self) -> u64 {
+        self.as_inner().as_inner().st_dev as u64
+    }
+    fn st_ino(&self) -> u64 {
+        self.as_inner().as_inner().st_ino as u64
+    }
+    fn st_mode(&self) -> u32 {
+        self.as_inner().as_inner().st_mode as u32
+    }
+    fn st_nlink(&self) -> u64 {
+        self.as_inner().as_inner().st_nlink as u64
+    }
+    fn st_uid(&self) -> u32 {
+        self.as_inner().as_inner().st_uid as u32
+    }
+    fn st_gid(&self) -> u32 {
+        self.as_inner().as_inner().st_gid as u32
+    }
+    fn st_rdev(&self) -> u64 {
+        self.as_inner().as_inner().st_rdev as u64
+    }
+    fn st_size(&self) -> u64 {
+        self.as_inner().as_inner().st_size as u64
+    }
+    fn st_atime(&self) -> i64 {
+        self.as_inner().as_inner().st_atime as i64
+    }
+    fn st_atime_nsec(&self) -> i64 {
+        0
+    }
+    fn st_mtime(&self) -> i64 {
+        self.as_inner().as_inner().st_mtime as i64
+    }
+    fn st_mtime_nsec(&self) -> i64 {
+        0
+    }
+    fn st_ctime(&self) -> i64 {
+        self.as_inner().as_inner().st_ctime as i64
+    }
+    fn st_ctime_nsec(&self) -> i64 {
+        0
+    }
+    fn st_blksize(&self) -> u64 {
+        self.as_inner().as_inner().st_blksize as u64
+    }
+    fn st_blocks(&self) -> u64 {
+        self.as_inner().as_inner().st_blocks as u64
+    }
+    fn st_attrib(&self) -> u8 {
+        self.as_inner().as_inner().st_attrib as u8
+    }
+}
diff --git a/library/std/src/os/vxworks/mod.rs b/library/std/src/os/vxworks/mod.rs
new file mode 100644
index 000000000..0a7ac641d
--- /dev/null
+++ b/library/std/src/os/vxworks/mod.rs
@@ -0,0 +1,6 @@
+//! VxWorks-specific definitions
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+pub mod fs;
+pub mod raw;
diff --git a/library/std/src/os/vxworks/raw.rs b/library/std/src/os/vxworks/raw.rs
new file mode 100644
index 000000000..cb41ddfe2
--- /dev/null
+++ b/library/std/src/os/vxworks/raw.rs
@@ -0,0 +1,10 @@
+//! VxWorks-specific raw type definitions
+#![stable(feature = "metadata_ext", since = "1.1.0")]
+
+use crate::os::raw::c_ulong;
+
+#[stable(feature = "pthread_t", since = "1.8.0")]
+pub type pthread_t = c_ulong;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub use libc::{blkcnt_t, blksize_t, dev_t, ino_t, mode_t, nlink_t, off_t, time_t};
diff --git a/library/std/src/os/wasi/ffi.rs b/library/std/src/os/wasi/ffi.rs
new file mode 100644
index 000000000..41dd8702e
--- /dev/null
+++ b/library/std/src/os/wasi/ffi.rs
@@ -0,0 +1,11 @@
+//! WASI-specific extensions to primitives in the [`std::ffi`] module
+//!
+//! [`std::ffi`]: crate::ffi
+
+#![stable(feature = "rust1", since = "1.0.0")]
+
+#[path = "../unix/ffi/os_str.rs"]
+mod os_str;
+
+#[stable(feature = "rust1", since = "1.0.0")]
+pub use self::os_str::{OsStrExt, OsStringExt};
diff --git a/library/std/src/os/wasi/fs.rs b/library/std/src/os/wasi/fs.rs
new file mode 100644
index 000000000..160c8f1ec
--- /dev/null
+++ b/library/std/src/os/wasi/fs.rs
@@ -0,0 +1,558 @@
+//! WASI-specific extensions to primitives in the [`std::fs`] module.
+//!
+//! [`std::fs`]: crate::fs
+
+#![deny(unsafe_op_in_unsafe_fn)]
+#![unstable(feature = "wasi_ext", issue = "71213")]
+
+use crate::ffi::OsStr;
+use crate::fs::{self, File, Metadata, OpenOptions};
+use crate::io::{self, IoSlice, IoSliceMut};
+use crate::path::{Path, PathBuf};
+use crate::sys_common::{AsInner, AsInnerMut, FromInner};
+// Used for `File::read` on intra-doc links
+#[allow(unused_imports)]
+use io::{Read, Write};
+
+/// WASI-specific extensions to [`File`].
+pub trait FileExt {
+    /// Reads a number of bytes starting from a given offset.
+    ///
+    /// Returns the number of bytes read.
+    ///
+    /// The offset is relative to the start of the file and thus independent
+    /// from the current cursor.
+    ///
+    /// The current file cursor is not affected by this function.
+    ///
+    /// Note that similar to [`File::read`], it is not an error to return with a
+    /// short read.
+    fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result<usize> {
+        let bufs = &mut [IoSliceMut::new(buf)];
+        self.read_vectored_at(bufs, offset)
+    }
+
+    /// Reads a number of bytes starting from a given offset.
+    ///
+    /// Returns the number of bytes read.
+    ///
+    /// The offset is relative to the start of the file and thus independent
+    /// from the current cursor.
+    ///
+    /// The current file cursor is not affected by this function.
+    ///
+    /// Note that similar to [`File::read_vectored`], it is not an error to
+    /// return with a short read.
+    fn read_vectored_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize>;
+
+    /// Reads the exact number of byte required to fill `buf` from the given offset.
+    ///
+    /// The offset is relative to the start of the file and thus independent
+    /// from the current cursor.
+    ///
+    /// The current file cursor is not affected by this function.
+    ///
+    /// Similar to [`Read::read_exact`] but uses [`read_at`] instead of `read`.
+    ///
+    /// [`read_at`]: FileExt::read_at
+    ///
+    /// # Errors
+    ///
+    /// If this function encounters an error of the kind
+    /// [`io::ErrorKind::Interrupted`] then the error is ignored and the operation
+    /// will continue.
+    ///
+    /// If this function encounters an "end of file" before completely filling
+    /// the buffer, it returns an error of the kind [`io::ErrorKind::UnexpectedEof`].
+    /// The contents of `buf` are unspecified in this case.
+    ///
+    /// If any other read error is encountered then this function immediately
+    /// returns. The contents of `buf` are unspecified in this case.
+    ///
+    /// If this function returns an error, it is unspecified how many bytes it
+    /// has read, but it will never read more than would be necessary to
+    /// completely fill the buffer.
+    #[stable(feature = "rw_exact_all_at", since = "1.33.0")]
+    fn read_exact_at(&self, mut buf: &mut [u8], mut offset: u64) -> io::Result<()> {
+        while !buf.is_empty() {
+            match self.read_at(buf, offset) {
+                Ok(0) => break,
+                Ok(n) => {
+                    let tmp = buf;
+                    buf = &mut tmp[n..];
+                    offset += n as u64;
+                }
+                Err(ref e) if e.kind() == io::ErrorKind::Interrupted => {}
+                Err(e) => return Err(e),
+            }
+        }
+        if !buf.is_empty() {
+            Err(io::const_io_error!(io::ErrorKind::UnexpectedEof, "failed to fill whole buffer"))
+        } else {
+            Ok(())
+        }
+    }
+
+    /// Writes a number of bytes starting from a given offset.
+    ///
+    /// Returns the number of bytes written.
+    ///
+    /// The offset is relative to the start of the file and thus independent
+    /// from the current cursor.
+    ///
+    /// The current file cursor is not affected by this function.
+    ///
+    /// When writing beyond the end of the file, the file is appropriately
+    /// extended and the intermediate bytes are initialized with the value 0.
+    ///
+    /// Note that similar to [`File::write`], it is not an error to return a
+    /// short write.
+    fn write_at(&self, buf: &[u8], offset: u64) -> io::Result<usize> {
+        let bufs = &[IoSlice::new(buf)];
+        self.write_vectored_at(bufs, offset)
+    }
+
+    /// Writes a number of bytes starting from a given offset.
+    ///
+    /// Returns the number of bytes written.
+    ///
+    /// The offset is relative to the start of the file and thus independent
+    /// from the current cursor.
+    ///
+    /// The current file cursor is not affected by this function.
+    ///
+    /// When writing beyond the end of the file, the file is appropriately
+    /// extended and the intermediate bytes are initialized with the value 0.
+    ///
+    /// Note that similar to [`File::write_vectored`], it is not an error to return a
+    /// short write.
+    fn write_vectored_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize>;
+
+    /// Attempts to write an entire buffer starting from a given offset.
+    ///
+    /// The offset is relative to the start of the file and thus independent
+    /// from the current cursor.
+    ///
+    /// The current file cursor is not affected by this function.
+    ///
+    /// This method will continuously call [`write_at`] until there is no more data
+    /// to be written or an error of non-[`io::ErrorKind::Interrupted`] kind is
+    /// returned. This method will not return until the entire buffer has been
+    /// successfully written or such an error occurs. The first error that is
+    /// not of [`io::ErrorKind::Interrupted`] kind generated from this method will be
+    /// returned.
+    ///
+    /// # Errors
+    ///
+    /// This function will return the first error of
+    /// non-[`io::ErrorKind::Interrupted`] kind that [`write_at`] returns.
+    ///
+    /// [`write_at`]: FileExt::write_at
+    #[stable(feature = "rw_exact_all_at", since = "1.33.0")]
+    fn write_all_at(&self, mut buf: &[u8], mut offset: u64) -> io::Result<()> {
+        while !buf.is_empty() {
+            match self.write_at(buf, offset) {
+                Ok(0) => {
+                    return Err(io::const_io_error!(
+                        io::ErrorKind::WriteZero,
+                        "failed to write whole buffer",
+                    ));
+                }
+                Ok(n) => {
+                    buf = &buf[n..];
+                    offset += n as u64
+                }
+                Err(ref e) if e.kind() == io::ErrorKind::Interrupted => {}
+                Err(e) => return Err(e),
+            }
+        }
+        Ok(())
+    }
+
+    /// Returns the current position within the file.
+    ///
+    /// This corresponds to the `fd_tell` syscall and is similar to
+    /// `seek` where you offset 0 bytes from the current position.
+    fn tell(&self) -> io::Result<u64>;
+
+    /// Adjust the flags associated with this file.
+    ///
+    /// This corresponds to the `fd_fdstat_set_flags` syscall.
+    fn fdstat_set_flags(&self, flags: u16) -> io::Result<()>;
+
+    /// Adjust the rights associated with this file.
+    ///
+    /// This corresponds to the `fd_fdstat_set_rights` syscall.
+    fn fdstat_set_rights(&self, rights: u64, inheriting: u64) -> io::Result<()>;
+
+    /// Provide file advisory information on a file descriptor.
+    ///
+    /// This corresponds to the `fd_advise` syscall.
+    fn advise(&self, offset: u64, len: u64, advice: u8) -> io::Result<()>;
+
+    /// Force the allocation of space in a file.
+    ///
+    /// This corresponds to the `fd_allocate` syscall.
+    fn allocate(&self, offset: u64, len: u64) -> io::Result<()>;
+
+    /// Create a directory.
+    ///
+    /// This corresponds to the `path_create_directory` syscall.
+    fn create_directory<P: AsRef<Path>>(&self, dir: P) -> io::Result<()>;
+
+    /// Read the contents of a symbolic link.
+    ///
+    /// This corresponds to the `path_readlink` syscall.
+    fn read_link<P: AsRef<Path>>(&self, path: P) -> io::Result<PathBuf>;
+
+    /// Return the attributes of a file or directory.
+    ///
+    /// This corresponds to the `path_filestat_get` syscall.
+    fn metadata_at<P: AsRef<Path>>(&self, lookup_flags: u32, path: P) -> io::Result<Metadata>;
+
+    /// Unlink a file.
+    ///
+    /// This corresponds to the `path_unlink_file` syscall.
+    fn remove_file<P: AsRef<Path>>(&self, path: P) -> io::Result<()>;
+
+    /// Remove a directory.
+    ///
+    /// This corresponds to the `path_remove_directory` syscall.
+    fn remove_directory<P: AsRef<Path>>(&self, path: P) -> io::Result<()>;
+}
+
+// FIXME: bind fd_fdstat_get - need to define a custom return type
+// FIXME: bind fd_readdir - can't return `ReadDir` since we only have entry name
+// FIXME: bind fd_filestat_set_times maybe? - on crates.io for unix
+// FIXME: bind path_filestat_set_times maybe? - on crates.io for unix
+// FIXME: bind poll_oneoff maybe? - probably should wait for I/O to settle
+// FIXME: bind random_get maybe? - on crates.io for unix
+
+impl FileExt for fs::File {
+    fn read_vectored_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize> {
+        self.as_inner().as_inner().pread(bufs, offset)
+    }
+
+    fn write_vectored_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize> {
+        self.as_inner().as_inner().pwrite(bufs, offset)
+    }
+
+    fn tell(&self) -> io::Result<u64> {
+        self.as_inner().as_inner().tell()
+    }
+
+    fn fdstat_set_flags(&self, flags: u16) -> io::Result<()> {
+        self.as_inner().as_inner().set_flags(flags)
+    }
+
+    fn fdstat_set_rights(&self, rights: u64, inheriting: u64) -> io::Result<()> {
+        self.as_inner().as_inner().set_rights(rights, inheriting)
+    }
+
+    fn advise(&self, offset: u64, len: u64, advice: u8) -> io::Result<()> {
+        let advice = match advice {
+            a if a == wasi::ADVICE_NORMAL.raw() => wasi::ADVICE_NORMAL,
+            a if a == wasi::ADVICE_SEQUENTIAL.raw() => wasi::ADVICE_SEQUENTIAL,
+            a if a == wasi::ADVICE_RANDOM.raw() => wasi::ADVICE_RANDOM,
+            a if a == wasi::ADVICE_WILLNEED.raw() => wasi::ADVICE_WILLNEED,
+            a if a == wasi::ADVICE_DONTNEED.raw() => wasi::ADVICE_DONTNEED,
+            a if a == wasi::ADVICE_NOREUSE.raw() => wasi::ADVICE_NOREUSE,
+            _ => {
+                return Err(io::const_io_error!(
+                    io::ErrorKind::InvalidInput,
+                    "invalid parameter 'advice'",
+                ));
+            }
+        };
+
+        self.as_inner().as_inner().advise(offset, len, advice)
+    }
+
+    fn allocate(&self, offset: u64, len: u64) -> io::Result<()> {
+        self.as_inner().as_inner().allocate(offset, len)
+    }
+
+    fn create_directory<P: AsRef<Path>>(&self, dir: P) -> io::Result<()> {
+        self.as_inner().as_inner().create_directory(osstr2str(dir.as_ref().as_ref())?)
+    }
+
+    fn read_link<P: AsRef<Path>>(&self, path: P) -> io::Result<PathBuf> {
+        self.as_inner().read_link(path.as_ref())
+    }
+
+    fn metadata_at<P: AsRef<Path>>(&self, lookup_flags: u32, path: P) -> io::Result<Metadata> {
+        let m = self.as_inner().metadata_at(lookup_flags, path.as_ref())?;
+        Ok(FromInner::from_inner(m))
+    }
+
+    fn remove_file<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {
+        self.as_inner().as_inner().unlink_file(osstr2str(path.as_ref().as_ref())?)
+    }
+
+    fn remove_directory<P: AsRef<Path>>(&self, path: P) -> io::Result<()> {
+        self.as_inner().as_inner().remove_directory(osstr2str(path.as_ref().as_ref())?)
+    }
+}
+
+/// WASI-specific extensions to [`fs::OpenOptions`].
+pub trait OpenOptionsExt {
+    /// Pass custom `dirflags` argument to `path_open`.
+    ///
+    /// This option configures the `dirflags` argument to the
+    /// `path_open` syscall which `OpenOptions` will eventually call. The
+    /// `dirflags` argument configures how the file is looked up, currently
+    /// primarily affecting whether symlinks are followed or not.
+    ///
+    /// By default this value is `__WASI_LOOKUP_SYMLINK_FOLLOW`, or symlinks are
+    /// followed. You can call this method with 0 to disable following symlinks
+    fn lookup_flags(&mut self, flags: u32) -> &mut Self;
+
+    /// Indicates whether `OpenOptions` must open a directory or not.
+    ///
+    /// This method will configure whether the `__WASI_O_DIRECTORY` flag is
+    /// passed when opening a file. When passed it will require that the opened
+    /// path is a directory.
+    ///
+    /// This option is by default `false`
+    fn directory(&mut self, dir: bool) -> &mut Self;
+
+    /// Indicates whether `__WASI_FDFLAG_DSYNC` is passed in the `fs_flags`
+    /// field of `path_open`.
+    ///
+    /// This option is by default `false`
+    fn dsync(&mut self, dsync: bool) -> &mut Self;
+
+    /// Indicates whether `__WASI_FDFLAG_NONBLOCK` is passed in the `fs_flags`
+    /// field of `path_open`.
+    ///
+    /// This option is by default `false`
+    fn nonblock(&mut self, nonblock: bool) -> &mut Self;
+
+    /// Indicates whether `__WASI_FDFLAG_RSYNC` is passed in the `fs_flags`
+    /// field of `path_open`.
+    ///
+    /// This option is by default `false`
+    fn rsync(&mut self, rsync: bool) -> &mut Self;
+
+    /// Indicates whether `__WASI_FDFLAG_SYNC` is passed in the `fs_flags`
+    /// field of `path_open`.
+    ///
+    /// This option is by default `false`
+    fn sync(&mut self, sync: bool) -> &mut Self;
+
+    /// Indicates the value that should be passed in for the `fs_rights_base`
+    /// parameter of `path_open`.
+    ///
+    /// This option defaults based on the `read` and `write` configuration of
+    /// this `OpenOptions` builder. If this method is called, however, the
+    /// exact mask passed in will be used instead.
+    fn fs_rights_base(&mut self, rights: u64) -> &mut Self;
+
+    /// Indicates the value that should be passed in for the
+    /// `fs_rights_inheriting` parameter of `path_open`.
+    ///
+    /// The default for this option is the same value as what will be passed
+    /// for the `fs_rights_base` parameter but if this method is called then
+    /// the specified value will be used instead.
+    fn fs_rights_inheriting(&mut self, rights: u64) -> &mut Self;
+
+    /// Open a file or directory.
+    ///
+    /// This corresponds to the `path_open` syscall.
+    fn open_at<P: AsRef<Path>>(&self, file: &File, path: P) -> io::Result<File>;
+}
+
+impl OpenOptionsExt for OpenOptions {
+    fn lookup_flags(&mut self, flags: u32) -> &mut OpenOptions {
+        self.as_inner_mut().lookup_flags(flags);
+        self
+    }
+
+    fn directory(&mut self, dir: bool) -> &mut OpenOptions {
+        self.as_inner_mut().directory(dir);
+        self
+    }
+
+    fn dsync(&mut self, enabled: bool) -> &mut OpenOptions {
+        self.as_inner_mut().dsync(enabled);
+        self
+    }
+
+    fn nonblock(&mut self, enabled: bool) -> &mut OpenOptions {
+        self.as_inner_mut().nonblock(enabled);
+        self
+    }
+
+    fn rsync(&mut self, enabled: bool) -> &mut OpenOptions {
+        self.as_inner_mut().rsync(enabled);
+        self
+    }
+
+    fn sync(&mut self, enabled: bool) -> &mut OpenOptions {
+        self.as_inner_mut().sync(enabled);
+        self
+    }
+
+    fn fs_rights_base(&mut self, rights: u64) -> &mut OpenOptions {
+        self.as_inner_mut().fs_rights_base(rights);
+        self
+    }
+
+    fn fs_rights_inheriting(&mut self, rights: u64) -> &mut OpenOptions {
+        self.as_inner_mut().fs_rights_inheriting(rights);
+        self
+    }
+
+    fn open_at<P: AsRef<Path>>(&self, file: &File, path: P) -> io::Result<File> {
+        let inner = file.as_inner().open_at(path.as_ref(), self.as_inner())?;
+        Ok(File::from_inner(inner))
+    }
+}
+
+/// WASI-specific extensions to [`fs::Metadata`].
+pub trait MetadataExt {
+    /// Returns the `st_dev` field of the internal `filestat_t`
+    fn dev(&self) -> u64;
+    /// Returns the `st_ino` field of the internal `filestat_t`
+    fn ino(&self) -> u64;
+    /// Returns the `st_nlink` field of the internal `filestat_t`
+    fn nlink(&self) -> u64;
+    /// Returns the `st_size` field of the internal `filestat_t`
+    fn size(&self) -> u64;
+    /// Returns the `st_atim` field of the internal `filestat_t`
+    fn atim(&self) -> u64;
+    /// Returns the `st_mtim` field of the internal `filestat_t`
+    fn mtim(&self) -> u64;
+    /// Returns the `st_ctim` field of the internal `filestat_t`
+    fn ctim(&self) -> u64;
+}
+
+impl MetadataExt for fs::Metadata {
+    fn dev(&self) -> u64 {
+        self.as_inner().as_wasi().dev
+    }
+    fn ino(&self) -> u64 {
+        self.as_inner().as_wasi().ino
+    }
+    fn nlink(&self) -> u64 {
+        self.as_inner().as_wasi().nlink
+    }
+    fn size(&self) -> u64 {
+        self.as_inner().as_wasi().size
+    }
+    fn atim(&self) -> u64 {
+        self.as_inner().as_wasi().atim
+    }
+    fn mtim(&self) -> u64 {
+        self.as_inner().as_wasi().mtim
+    }
+    fn ctim(&self) -> u64 {
+        self.as_inner().as_wasi().ctim
+    }
+}
+
+/// WASI-specific extensions for [`fs::FileType`].
+///
+/// Adds support for special WASI file types such as block/character devices,
+/// pipes, and sockets.
+pub trait FileTypeExt {
+    /// Returns `true` if this file type is a block device.
+    fn is_block_device(&self) -> bool;
+    /// Returns `true` if this file type is a character device.
+    fn is_char_device(&self) -> bool;
+    /// Returns `true` if this file type is a socket datagram.
+    fn is_socket_dgram(&self) -> bool;
+    /// Returns `true` if this file type is a socket stream.
+    fn is_socket_stream(&self) -> bool;
+    /// Returns `true` if this file type is any type of socket.
+    fn is_socket(&self) -> bool {
+        self.is_socket_stream() || self.is_socket_dgram()
+    }
+}
+
+impl FileTypeExt for fs::FileType {
+    fn is_block_device(&self) -> bool {
+        self.as_inner().bits() == wasi::FILETYPE_BLOCK_DEVICE
+    }
+    fn is_char_device(&self) -> bool {
+        self.as_inner().bits() == wasi::FILETYPE_CHARACTER_DEVICE
+    }
+    fn is_socket_dgram(&self) -> bool {
+        self.as_inner().bits() == wasi::FILETYPE_SOCKET_DGRAM
+    }
+    fn is_socket_stream(&self) -> bool {
+        self.as_inner().bits() == wasi::FILETYPE_SOCKET_STREAM
+    }
+}
+
+/// WASI-specific extension methods for [`fs::DirEntry`].
+pub trait DirEntryExt {
+    /// Returns the underlying `d_ino` field of the `dirent_t`
+    fn ino(&self) -> u64;
+}
+
+impl DirEntryExt for fs::DirEntry {
+    fn ino(&self) -> u64 {
+        self.as_inner().ino()
+    }
+}
+
+/// Create a hard link.
+///
+/// This corresponds to the `path_link` syscall.
+pub fn link<P: AsRef<Path>, U: AsRef<Path>>(
+    old_fd: &File,
+    old_flags: u32,
+    old_path: P,
+    new_fd: &File,
+    new_path: U,
+) -> io::Result<()> {
+    old_fd.as_inner().as_inner().link(
+        old_flags,
+        osstr2str(old_path.as_ref().as_ref())?,
+        new_fd.as_inner().as_inner(),
+        osstr2str(new_path.as_ref().as_ref())?,
+    )
+}
+
+/// Rename a file or directory.
+///
+/// This corresponds to the `path_rename` syscall.
+pub fn rename<P: AsRef<Path>, U: AsRef<Path>>(
+    old_fd: &File,
+    old_path: P,
+    new_fd: &File,
+    new_path: U,
+) -> io::Result<()> {
+    old_fd.as_inner().as_inner().rename(
+        osstr2str(old_path.as_ref().as_ref())?,
+        new_fd.as_inner().as_inner(),
+        osstr2str(new_path.as_ref().as_ref())?,
+    )
+}
+
+/// Create a symbolic link.
+///
+/// This corresponds to the `path_symlink` syscall.
+pub fn symlink<P: AsRef<Path>, U: AsRef<Path>>(
+    old_path: P,
+    fd: &File,
+    new_path: U,
+) -> io::Result<()> {
+    fd.as_inner()
+        .as_inner()
+        .symlink(osstr2str(old_path.as_ref().as_ref())?, osstr2str(new_path.as_ref().as_ref())?)
+}
+
+/// Create a symbolic link.
+///
+/// This is a convenience API similar to `std::os::unix::fs::symlink` and
+/// `std::os::windows::fs::symlink_file` and `std::os::windows::fs::symlink_dir`.
+pub fn symlink_path<P: AsRef<Path>, U: AsRef<Path>>(old_path: P, new_path: U) -> io::Result<()> {
+    crate::sys::fs::symlink(old_path.as_ref(), new_path.as_ref())
+}
+
+fn osstr2str(f: &OsStr) -> io::Result<&str> {
+    f.to_str()
+        .ok_or_else(|| io::const_io_error!(io::ErrorKind::Uncategorized, "input must be utf-8"))
+}
diff --git a/library/std/src/os/wasi/io/fd.rs b/library/std/src/os/wasi/io/fd.rs
new file mode 100644
index 000000000..930aca887
--- /dev/null
+++ b/library/std/src/os/wasi/io/fd.rs
@@ -0,0 +1,9 @@
+//! Owned and borrowed file descriptors.
+
+#![unstable(feature = "wasi_ext", issue = "71213")]
+
+// Tests for this module
+#[cfg(test)]
+mod tests;
+
+pub use crate::os::fd::owned::*;
diff --git a/library/std/src/os/wasi/io/fd/tests.rs b/library/std/src/os/wasi/io/fd/tests.rs
new file mode 100644
index 000000000..418274752
--- /dev/null
+++ b/library/std/src/os/wasi/io/fd/tests.rs
@@ -0,0 +1,11 @@
+use crate::mem::size_of;
+use crate::os::wasi::io::RawFd;
+
+#[test]
+fn test_raw_fd_layout() {
+    // `OwnedFd` and `BorrowedFd` use `rustc_layout_scalar_valid_range_start`
+    // and `rustc_layout_scalar_valid_range_end`, with values that depend on
+    // the bit width of `RawFd`. If this ever changes, those values will need
+    // to be updated.
+    assert_eq!(size_of::<RawFd>(), 4);
+}
diff --git a/library/std/src/os/wasi/io/mod.rs b/library/std/src/os/wasi/io/mod.rs
new file mode 100644
index 000000000..6c884e2ea
--- /dev/null
+++ b/library/std/src/os/wasi/io/mod.rs
@@ -0,0 +1,12 @@
+//! WASI-specific extensions to general I/O primitives.
+
+#![deny(unsafe_op_in_unsafe_fn)]
+#![unstable(feature = "wasi_ext", issue = "71213")]
+
+mod fd;
+mod raw;
+
+#[unstable(feature = "wasi_ext", issue = "71213")]
+pub use fd::*;
+#[unstable(feature = "wasi_ext", issue = "71213")]
+pub use raw::*;
diff --git a/library/std/src/os/wasi/io/raw.rs b/library/std/src/os/wasi/io/raw.rs
new file mode 100644
index 000000000..da3b36ada
--- /dev/null
+++ b/library/std/src/os/wasi/io/raw.rs
@@ -0,0 +1,20 @@
+//! WASI-specific extensions to general I/O primitives.
+
+#![unstable(feature = "wasi_ext", issue = "71213")]
+
+// NOTE: despite the fact that this module is unstable,
+// stable Rust had the capability to access the stable
+// re-exported items from os::fd::raw through this
+// unstable module.
+// In PR #95956 the stability checker was changed to check
+// all path segments of an item rather than just the last,
+// which caused the aforementioned stable usage to regress
+// (see issue #99502).
+// As a result, the items in os::fd::raw were given the
+// rustc_allowed_through_unstable_modules attribute.
+// No regression tests were added to ensure this property,
+// as CI is not configured to test wasm32-wasi.
+// If this module is stabilized,
+// you may want to remove those attributes
+// (assuming no other unstable modules need them).
+pub use crate::os::fd::raw::*;
diff --git a/library/std/src/os/wasi/mod.rs b/library/std/src/os/wasi/mod.rs
new file mode 100644
index 000000000..bbaf328f4
--- /dev/null
+++ b/library/std/src/os/wasi/mod.rs
@@ -0,0 +1,57 @@
+//! Platform-specific extensions to `std` for the WebAssembly System Interface (WASI).
+//!
+//! Provides access to platform-level information on WASI, and exposes
+//! WASI-specific functions that would otherwise be inappropriate as
+//! part of the core `std` library.
+//!
+//! It exposes more ways to deal with platform-specific strings (`OsStr`,
+//! `OsString`), allows to set permissions more granularly, extract low-level
+//! file descriptors from files and sockets, and has platform-specific helpers
+//! for spawning processes.
+//!
+//! # Examples
+//!
+//! ```no_run
+//! use std::fs::File;
+//! use std::os::wasi::prelude::*;
+//!
+//! fn main() -> std::io::Result<()> {
+//!     let f = File::create("foo.txt")?;
+//!     let fd = f.as_raw_fd();
+//!
+//!     // use fd with native WASI bindings
+//!
+//!     Ok(())
+//! }
+//! ```
+//!
+//! [`OsStr`]: crate::ffi::OsStr
+//! [`OsString`]: crate::ffi::OsString
+
+#![stable(feature = "rust1", since = "1.0.0")]
+#![deny(unsafe_op_in_unsafe_fn)]
+#![doc(cfg(target_os = "wasi"))]
+
+pub mod ffi;
+pub mod fs;
+pub mod io;
+pub mod net;
+
+/// A prelude for conveniently writing platform-specific code.
+///
+/// Includes all extension traits, and some important type definitions.
+#[stable(feature = "rust1", since = "1.0.0")]
+pub mod prelude {
+    #[doc(no_inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::ffi::{OsStrExt, OsStringExt};
+    #[doc(no_inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::fs::FileTypeExt;
+    #[doc(no_inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::fs::{DirEntryExt, FileExt, MetadataExt, OpenOptionsExt};
+    #[doc(no_inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd};
+}
diff --git a/library/std/src/os/wasi/net/mod.rs b/library/std/src/os/wasi/net/mod.rs
new file mode 100644
index 000000000..73c097d4a
--- /dev/null
+++ b/library/std/src/os/wasi/net/mod.rs
@@ -0,0 +1,23 @@
+//! WASI-specific networking functionality
+
+#![unstable(feature = "wasi_ext", issue = "71213")]
+
+use crate::io;
+use crate::net;
+use crate::sys_common::AsInner;
+
+/// WASI-specific extensions to [`std::net::TcpListener`].
+///
+/// [`std::net::TcpListener`]: crate::net::TcpListener
+pub trait TcpListenerExt {
+    /// Accept a socket.
+    ///
+    /// This corresponds to the `sock_accept` syscall.
+    fn sock_accept(&self, flags: u16) -> io::Result<u32>;
+}
+
+impl TcpListenerExt for net::TcpListener {
+    fn sock_accept(&self, flags: u16) -> io::Result<u32> {
+        self.as_inner().as_inner().as_inner().sock_accept(flags)
+    }
+}
diff --git a/library/std/src/os/windows/ffi.rs b/library/std/src/os/windows/ffi.rs
new file mode 100644
index 000000000..96bab59d3
--- /dev/null
+++ b/library/std/src/os/windows/ffi.rs
@@ -0,0 +1,136 @@
+//! Windows-specific extensions to primitives in the [`std::ffi`] module.
+//!
+//! # Overview
+//!
+//! For historical reasons, the Windows API uses a form of potentially
+//! ill-formed UTF-16 encoding for strings. Specifically, the 16-bit
+//! code units in Windows strings may contain [isolated surrogate code
+//! points which are not paired together][ill-formed-utf-16]. The
+//! Unicode standard requires that surrogate code points (those in the
+//! range U+D800 to U+DFFF) always be *paired*, because in the UTF-16
+//! encoding a *surrogate code unit pair* is used to encode a single
+//! character. For compatibility with code that does not enforce
+//! these pairings, Windows does not enforce them, either.
+//!
+//! While it is not always possible to convert such a string losslessly into
+//! a valid UTF-16 string (or even UTF-8), it is often desirable to be
+//! able to round-trip such a string from and to Windows APIs
+//! losslessly. For example, some Rust code may be "bridging" some
+//! Windows APIs together, just passing `WCHAR` strings among those
+//! APIs without ever really looking into the strings.
+//!
+//! If Rust code *does* need to look into those strings, it can
+//! convert them to valid UTF-8, possibly lossily, by substituting
+//! invalid sequences with [`U+FFFD REPLACEMENT CHARACTER`][U+FFFD], as is
+//! conventionally done in other Rust APIs that deal with string
+//! encodings.
+//!
+//! # `OsStringExt` and `OsStrExt`
+//!
+//! [`OsString`] is the Rust wrapper for owned strings in the
+//! preferred representation of the operating system. On Windows,
+//! this struct gets augmented with an implementation of the
+//! [`OsStringExt`] trait, which has an [`OsStringExt::from_wide`] method. This
+//! lets you create an [`OsString`] from a `&[u16]` slice; presumably
+//! you get such a slice out of a `WCHAR` Windows API.
+//!
+//! Similarly, [`OsStr`] is the Rust wrapper for borrowed strings from
+//! preferred representation of the operating system. On Windows, the
+//! [`OsStrExt`] trait provides the [`OsStrExt::encode_wide`] method, which
+//! outputs an [`EncodeWide`] iterator. You can [`collect`] this
+//! iterator, for example, to obtain a `Vec<u16>`; you can later get a
+//! pointer to this vector's contents and feed it to Windows APIs.
+//!
+//! These traits, along with [`OsString`] and [`OsStr`], work in
+//! conjunction so that it is possible to **round-trip** strings from
+//! Windows and back, with no loss of data, even if the strings are
+//! ill-formed UTF-16.
+//!
+//! [ill-formed-utf-16]: https://simonsapin.github.io/wtf-8/#ill-formed-utf-16
+//! [`collect`]: crate::iter::Iterator::collect
+//! [U+FFFD]: crate::char::REPLACEMENT_CHARACTER
+//! [`std::ffi`]: crate::ffi
+
+#![stable(feature = "rust1", since = "1.0.0")]
+
+use crate::ffi::{OsStr, OsString};
+use crate::sealed::Sealed;
+use crate::sys::os_str::Buf;
+use crate::sys_common::wtf8::Wtf8Buf;
+use crate::sys_common::{AsInner, FromInner};
+
+#[stable(feature = "rust1", since = "1.0.0")]
+pub use crate::sys_common::wtf8::EncodeWide;
+
+/// Windows-specific extensions to [`OsString`].
+///
+/// This trait is sealed: it cannot be implemented outside the standard library.
+/// This is so that future additional methods are not breaking changes.
+#[stable(feature = "rust1", since = "1.0.0")]
+pub trait OsStringExt: Sealed {
+    /// Creates an `OsString` from a potentially ill-formed UTF-16 slice of
+    /// 16-bit code units.
+    ///
+    /// This is lossless: calling [`OsStrExt::encode_wide`] on the resulting string
+    /// will always return the original code units.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::ffi::OsString;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// // UTF-16 encoding for "Unicode".
+    /// let source = [0x0055, 0x006E, 0x0069, 0x0063, 0x006F, 0x0064, 0x0065];
+    ///
+    /// let string = OsString::from_wide(&source[..]);
+    /// ```
+    #[stable(feature = "rust1", since = "1.0.0")]
+    fn from_wide(wide: &[u16]) -> Self;
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl OsStringExt for OsString {
+    fn from_wide(wide: &[u16]) -> OsString {
+        FromInner::from_inner(Buf { inner: Wtf8Buf::from_wide(wide) })
+    }
+}
+
+/// Windows-specific extensions to [`OsStr`].
+///
+/// This trait is sealed: it cannot be implemented outside the standard library.
+/// This is so that future additional methods are not breaking changes.
+#[stable(feature = "rust1", since = "1.0.0")]
+pub trait OsStrExt: Sealed {
+    /// Re-encodes an `OsStr` as a wide character sequence, i.e., potentially
+    /// ill-formed UTF-16.
+    ///
+    /// This is lossless: calling [`OsStringExt::from_wide`] and then
+    /// `encode_wide` on the result will yield the original code units.
+    /// Note that the encoding does not add a final null terminator.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use std::ffi::OsString;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// // UTF-16 encoding for "Unicode".
+    /// let source = [0x0055, 0x006E, 0x0069, 0x0063, 0x006F, 0x0064, 0x0065];
+    ///
+    /// let string = OsString::from_wide(&source[..]);
+    ///
+    /// let result: Vec<u16> = string.encode_wide().collect();
+    /// assert_eq!(&source[..], &result[..]);
+    /// ```
+    #[stable(feature = "rust1", since = "1.0.0")]
+    fn encode_wide(&self) -> EncodeWide<'_>;
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl OsStrExt for OsStr {
+    #[inline]
+    fn encode_wide(&self) -> EncodeWide<'_> {
+        self.as_inner().inner.encode_wide()
+    }
+}
diff --git a/library/std/src/os/windows/fs.rs b/library/std/src/os/windows/fs.rs
new file mode 100644
index 000000000..a091f06dd
--- /dev/null
+++ b/library/std/src/os/windows/fs.rs
@@ -0,0 +1,605 @@
+//! Windows-specific extensions to primitives in the [`std::fs`] module.
+//!
+//! [`std::fs`]: crate::fs
+
+#![stable(feature = "rust1", since = "1.0.0")]
+
+use crate::fs::{self, Metadata, OpenOptions};
+use crate::io;
+use crate::path::Path;
+use crate::sealed::Sealed;
+use crate::sys;
+use crate::sys_common::{AsInner, AsInnerMut};
+
+/// Windows-specific extensions to [`fs::File`].
+#[stable(feature = "file_offset", since = "1.15.0")]
+pub trait FileExt {
+    /// Seeks to a given position and reads a number of bytes.
+    ///
+    /// Returns the number of bytes read.
+    ///
+    /// The offset is relative to the start of the file and thus independent
+    /// from the current cursor. The current cursor **is** affected by this
+    /// function, it is set to the end of the read.
+    ///
+    /// Reading beyond the end of the file will always return with a length of
+    /// 0\.
+    ///
+    /// Note that similar to `File::read`, it is not an error to return with a
+    /// short read. When returning from such a short read, the file pointer is
+    /// still updated.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::fs::File;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let mut file = File::open("foo.txt")?;
+    ///     let mut buffer = [0; 10];
+    ///
+    ///     // Read 10 bytes, starting 72 bytes from the
+    ///     // start of the file.
+    ///     file.seek_read(&mut buffer[..], 72)?;
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "file_offset", since = "1.15.0")]
+    fn seek_read(&self, buf: &mut [u8], offset: u64) -> io::Result<usize>;
+
+    /// Seeks to a given position and writes a number of bytes.
+    ///
+    /// Returns the number of bytes written.
+    ///
+    /// The offset is relative to the start of the file and thus independent
+    /// from the current cursor. The current cursor **is** affected by this
+    /// function, it is set to the end of the write.
+    ///
+    /// When writing beyond the end of the file, the file is appropriately
+    /// extended and the intermediate bytes are left uninitialized.
+    ///
+    /// Note that similar to `File::write`, it is not an error to return a
+    /// short write. When returning from such a short write, the file pointer
+    /// is still updated.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs::File;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// fn main() -> std::io::Result<()> {
+    ///     let mut buffer = File::create("foo.txt")?;
+    ///
+    ///     // Write a byte string starting 72 bytes from
+    ///     // the start of the file.
+    ///     buffer.seek_write(b"some bytes", 72)?;
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "file_offset", since = "1.15.0")]
+    fn seek_write(&self, buf: &[u8], offset: u64) -> io::Result<usize>;
+}
+
+#[stable(feature = "file_offset", since = "1.15.0")]
+impl FileExt for fs::File {
+    fn seek_read(&self, buf: &mut [u8], offset: u64) -> io::Result<usize> {
+        self.as_inner().read_at(buf, offset)
+    }
+
+    fn seek_write(&self, buf: &[u8], offset: u64) -> io::Result<usize> {
+        self.as_inner().write_at(buf, offset)
+    }
+}
+
+/// Windows-specific extensions to [`fs::OpenOptions`].
+#[stable(feature = "open_options_ext", since = "1.10.0")]
+pub trait OpenOptionsExt {
+    /// Overrides the `dwDesiredAccess` argument to the call to [`CreateFile`]
+    /// with the specified value.
+    ///
+    /// This will override the `read`, `write`, and `append` flags on the
+    /// `OpenOptions` structure. This method provides fine-grained control over
+    /// the permissions to read, write and append data, attributes (like hidden
+    /// and system), and extended attributes.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs::OpenOptions;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// // Open without read and write permission, for example if you only need
+    /// // to call `stat` on the file
+    /// let file = OpenOptions::new().access_mode(0).open("foo.txt");
+    /// ```
+    ///
+    /// [`CreateFile`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilea
+    #[stable(feature = "open_options_ext", since = "1.10.0")]
+    fn access_mode(&mut self, access: u32) -> &mut Self;
+
+    /// Overrides the `dwShareMode` argument to the call to [`CreateFile`] with
+    /// the specified value.
+    ///
+    /// By default `share_mode` is set to
+    /// `FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE`. This allows
+    /// other processes to read, write, and delete/rename the same file
+    /// while it is open. Removing any of the flags will prevent other
+    /// processes from performing the corresponding operation until the file
+    /// handle is closed.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::fs::OpenOptions;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// // Do not allow others to read or modify this file while we have it open
+    /// // for writing.
+    /// let file = OpenOptions::new()
+    ///     .write(true)
+    ///     .share_mode(0)
+    ///     .open("foo.txt");
+    /// ```
+    ///
+    /// [`CreateFile`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilea
+    #[stable(feature = "open_options_ext", since = "1.10.0")]
+    fn share_mode(&mut self, val: u32) -> &mut Self;
+
+    /// Sets extra flags for the `dwFileFlags` argument to the call to
+    /// [`CreateFile2`] to the specified value (or combines it with
+    /// `attributes` and `security_qos_flags` to set the `dwFlagsAndAttributes`
+    /// for [`CreateFile`]).
+    ///
+    /// Custom flags can only set flags, not remove flags set by Rust's options.
+    /// This option overwrites any previously set custom flags.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # #![allow(unexpected_cfgs)]
+    /// # #[cfg(for_demonstration_only)]
+    /// extern crate winapi;
+    /// # mod winapi { pub const FILE_FLAG_DELETE_ON_CLOSE: u32 = 0x04000000; }
+    ///
+    /// use std::fs::OpenOptions;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// let file = OpenOptions::new()
+    ///     .create(true)
+    ///     .write(true)
+    ///     .custom_flags(winapi::FILE_FLAG_DELETE_ON_CLOSE)
+    ///     .open("foo.txt");
+    /// ```
+    ///
+    /// [`CreateFile`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilea
+    /// [`CreateFile2`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfile2
+    #[stable(feature = "open_options_ext", since = "1.10.0")]
+    fn custom_flags(&mut self, flags: u32) -> &mut Self;
+
+    /// Sets the `dwFileAttributes` argument to the call to [`CreateFile2`] to
+    /// the specified value (or combines it with `custom_flags` and
+    /// `security_qos_flags` to set the `dwFlagsAndAttributes` for
+    /// [`CreateFile`]).
+    ///
+    /// If a _new_ file is created because it does not yet exist and
+    /// `.create(true)` or `.create_new(true)` are specified, the new file is
+    /// given the attributes declared with `.attributes()`.
+    ///
+    /// If an _existing_ file is opened with `.create(true).truncate(true)`, its
+    /// existing attributes are preserved and combined with the ones declared
+    /// with `.attributes()`.
+    ///
+    /// In all other cases the attributes get ignored.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # #![allow(unexpected_cfgs)]
+    /// # #[cfg(for_demonstration_only)]
+    /// extern crate winapi;
+    /// # mod winapi { pub const FILE_ATTRIBUTE_HIDDEN: u32 = 2; }
+    ///
+    /// use std::fs::OpenOptions;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// let file = OpenOptions::new()
+    ///     .write(true)
+    ///     .create(true)
+    ///     .attributes(winapi::FILE_ATTRIBUTE_HIDDEN)
+    ///     .open("foo.txt");
+    /// ```
+    ///
+    /// [`CreateFile`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilea
+    /// [`CreateFile2`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfile2
+    #[stable(feature = "open_options_ext", since = "1.10.0")]
+    fn attributes(&mut self, val: u32) -> &mut Self;
+
+    /// Sets the `dwSecurityQosFlags` argument to the call to [`CreateFile2`] to
+    /// the specified value (or combines it with `custom_flags` and `attributes`
+    /// to set the `dwFlagsAndAttributes` for [`CreateFile`]).
+    ///
+    /// By default `security_qos_flags` is not set. It should be specified when
+    /// opening a named pipe, to control to which degree a server process can
+    /// act on behalf of a client process (security impersonation level).
+    ///
+    /// When `security_qos_flags` is not set, a malicious program can gain the
+    /// elevated privileges of a privileged Rust process when it allows opening
+    /// user-specified paths, by tricking it into opening a named pipe. So
+    /// arguably `security_qos_flags` should also be set when opening arbitrary
+    /// paths. However the bits can then conflict with other flags, specifically
+    /// `FILE_FLAG_OPEN_NO_RECALL`.
+    ///
+    /// For information about possible values, see [Impersonation Levels] on the
+    /// Windows Dev Center site. The `SECURITY_SQOS_PRESENT` flag is set
+    /// automatically when using this method.
+
+    /// # Examples
+    ///
+    /// ```no_run
+    /// # #![allow(unexpected_cfgs)]
+    /// # #[cfg(for_demonstration_only)]
+    /// extern crate winapi;
+    /// # mod winapi { pub const SECURITY_IDENTIFICATION: u32 = 0; }
+    /// use std::fs::OpenOptions;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// let file = OpenOptions::new()
+    ///     .write(true)
+    ///     .create(true)
+    ///
+    ///     // Sets the flag value to `SecurityIdentification`.
+    ///     .security_qos_flags(winapi::SECURITY_IDENTIFICATION)
+    ///
+    ///     .open(r"\\.\pipe\MyPipe");
+    /// ```
+    ///
+    /// [`CreateFile`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilea
+    /// [`CreateFile2`]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfile2
+    /// [Impersonation Levels]:
+    ///     https://docs.microsoft.com/en-us/windows/win32/api/winnt/ne-winnt-security_impersonation_level
+    #[stable(feature = "open_options_ext", since = "1.10.0")]
+    fn security_qos_flags(&mut self, flags: u32) -> &mut Self;
+}
+
+#[stable(feature = "open_options_ext", since = "1.10.0")]
+impl OpenOptionsExt for OpenOptions {
+    fn access_mode(&mut self, access: u32) -> &mut OpenOptions {
+        self.as_inner_mut().access_mode(access);
+        self
+    }
+
+    fn share_mode(&mut self, share: u32) -> &mut OpenOptions {
+        self.as_inner_mut().share_mode(share);
+        self
+    }
+
+    fn custom_flags(&mut self, flags: u32) -> &mut OpenOptions {
+        self.as_inner_mut().custom_flags(flags);
+        self
+    }
+
+    fn attributes(&mut self, attributes: u32) -> &mut OpenOptions {
+        self.as_inner_mut().attributes(attributes);
+        self
+    }
+
+    fn security_qos_flags(&mut self, flags: u32) -> &mut OpenOptions {
+        self.as_inner_mut().security_qos_flags(flags);
+        self
+    }
+}
+
+/// Windows-specific extensions to [`fs::Metadata`].
+///
+/// The data members that this trait exposes correspond to the members
+/// of the [`BY_HANDLE_FILE_INFORMATION`] structure.
+///
+/// [`BY_HANDLE_FILE_INFORMATION`]:
+///     https://docs.microsoft.com/en-us/windows/win32/api/fileapi/ns-fileapi-by_handle_file_information
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+pub trait MetadataExt {
+    /// Returns the value of the `dwFileAttributes` field of this metadata.
+    ///
+    /// This field contains the file system attribute information for a file
+    /// or directory. For possible values and their descriptions, see
+    /// [File Attribute Constants] in the Windows Dev Center.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::fs;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let metadata = fs::metadata("foo.txt")?;
+    ///     let attributes = metadata.file_attributes();
+    ///     Ok(())
+    /// }
+    /// ```
+    ///
+    /// [File Attribute Constants]:
+    ///     https://docs.microsoft.com/en-us/windows/win32/fileio/file-attribute-constants
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn file_attributes(&self) -> u32;
+
+    /// Returns the value of the `ftCreationTime` field of this metadata.
+    ///
+    /// The returned 64-bit value is equivalent to a [`FILETIME`] struct,
+    /// which represents the number of 100-nanosecond intervals since
+    /// January 1, 1601 (UTC). The struct is automatically
+    /// converted to a `u64` value, as that is the recommended way
+    /// to use it.
+    ///
+    /// If the underlying filesystem does not support creation time, the
+    /// returned value is 0.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::fs;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let metadata = fs::metadata("foo.txt")?;
+    ///     let creation_time = metadata.creation_time();
+    ///     Ok(())
+    /// }
+    /// ```
+    ///
+    /// [`FILETIME`]: https://docs.microsoft.com/en-us/windows/win32/api/minwinbase/ns-minwinbase-filetime
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn creation_time(&self) -> u64;
+
+    /// Returns the value of the `ftLastAccessTime` field of this metadata.
+    ///
+    /// The returned 64-bit value is equivalent to a [`FILETIME`] struct,
+    /// which represents the number of 100-nanosecond intervals since
+    /// January 1, 1601 (UTC). The struct is automatically
+    /// converted to a `u64` value, as that is the recommended way
+    /// to use it.
+    ///
+    /// For a file, the value specifies the last time that a file was read
+    /// from or written to. For a directory, the value specifies when
+    /// the directory was created. For both files and directories, the
+    /// specified date is correct, but the time of day is always set to
+    /// midnight.
+    ///
+    /// If the underlying filesystem does not support last access time, the
+    /// returned value is 0.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::fs;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let metadata = fs::metadata("foo.txt")?;
+    ///     let last_access_time = metadata.last_access_time();
+    ///     Ok(())
+    /// }
+    /// ```
+    ///
+    /// [`FILETIME`]: https://docs.microsoft.com/en-us/windows/win32/api/minwinbase/ns-minwinbase-filetime
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn last_access_time(&self) -> u64;
+
+    /// Returns the value of the `ftLastWriteTime` field of this metadata.
+    ///
+    /// The returned 64-bit value is equivalent to a [`FILETIME`] struct,
+    /// which represents the number of 100-nanosecond intervals since
+    /// January 1, 1601 (UTC). The struct is automatically
+    /// converted to a `u64` value, as that is the recommended way
+    /// to use it.
+    ///
+    /// For a file, the value specifies the last time that a file was written
+    /// to. For a directory, the structure specifies when the directory was
+    /// created.
+    ///
+    /// If the underlying filesystem does not support the last write time,
+    /// the returned value is 0.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::fs;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let metadata = fs::metadata("foo.txt")?;
+    ///     let last_write_time = metadata.last_write_time();
+    ///     Ok(())
+    /// }
+    /// ```
+    ///
+    /// [`FILETIME`]: https://docs.microsoft.com/en-us/windows/win32/api/minwinbase/ns-minwinbase-filetime
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn last_write_time(&self) -> u64;
+
+    /// Returns the value of the `nFileSize{High,Low}` fields of this
+    /// metadata.
+    ///
+    /// The returned value does not have meaning for directories.
+    ///
+    /// # Examples
+    ///
+    /// ```no_run
+    /// use std::io;
+    /// use std::fs;
+    /// use std::os::windows::prelude::*;
+    ///
+    /// fn main() -> io::Result<()> {
+    ///     let metadata = fs::metadata("foo.txt")?;
+    ///     let file_size = metadata.file_size();
+    ///     Ok(())
+    /// }
+    /// ```
+    #[stable(feature = "metadata_ext", since = "1.1.0")]
+    fn file_size(&self) -> u64;
+
+    /// Returns the value of the `dwVolumeSerialNumber` field of this
+    /// metadata.
+    ///
+    /// This will return `None` if the `Metadata` instance was created from a
+    /// call to `DirEntry::metadata`. If this `Metadata` was created by using
+    /// `fs::metadata` or `File::metadata`, then this will return `Some`.
+    #[unstable(feature = "windows_by_handle", issue = "63010")]
+    fn volume_serial_number(&self) -> Option<u32>;
+
+    /// Returns the value of the `nNumberOfLinks` field of this
+    /// metadata.
+    ///
+    /// This will return `None` if the `Metadata` instance was created from a
+    /// call to `DirEntry::metadata`. If this `Metadata` was created by using
+    /// `fs::metadata` or `File::metadata`, then this will return `Some`.
+    #[unstable(feature = "windows_by_handle", issue = "63010")]
+    fn number_of_links(&self) -> Option<u32>;
+
+    /// Returns the value of the `nFileIndex{Low,High}` fields of this
+    /// metadata.
+    ///
+    /// This will return `None` if the `Metadata` instance was created from a
+    /// call to `DirEntry::metadata`. If this `Metadata` was created by using
+    /// `fs::metadata` or `File::metadata`, then this will return `Some`.
+    #[unstable(feature = "windows_by_handle", issue = "63010")]
+    fn file_index(&self) -> Option<u64>;
+}
+
+#[stable(feature = "metadata_ext", since = "1.1.0")]
+impl MetadataExt for Metadata {
+    fn file_attributes(&self) -> u32 {
+        self.as_inner().attrs()
+    }
+    fn creation_time(&self) -> u64 {
+        self.as_inner().created_u64()
+    }
+    fn last_access_time(&self) -> u64 {
+        self.as_inner().accessed_u64()
+    }
+    fn last_write_time(&self) -> u64 {
+        self.as_inner().modified_u64()
+    }
+    fn file_size(&self) -> u64 {
+        self.as_inner().size()
+    }
+    fn volume_serial_number(&self) -> Option<u32> {
+        self.as_inner().volume_serial_number()
+    }
+    fn number_of_links(&self) -> Option<u32> {
+        self.as_inner().number_of_links()
+    }
+    fn file_index(&self) -> Option<u64> {
+        self.as_inner().file_index()
+    }
+}
+
+/// Windows-specific extensions to [`fs::FileType`].
+///
+/// On Windows, a symbolic link knows whether it is a file or directory.
+#[stable(feature = "windows_file_type_ext", since = "1.64.0")]
+pub trait FileTypeExt: Sealed {
+    /// Returns `true` if this file type is a symbolic link that is also a directory.
+    #[stable(feature = "windows_file_type_ext", since = "1.64.0")]
+    fn is_symlink_dir(&self) -> bool;
+    /// Returns `true` if this file type is a symbolic link that is also a file.
+    #[stable(feature = "windows_file_type_ext", since = "1.64.0")]
+    fn is_symlink_file(&self) -> bool;
+}
+
+#[stable(feature = "windows_file_type_ext", since = "1.64.0")]
+impl Sealed for fs::FileType {}
+
+#[stable(feature = "windows_file_type_ext", since = "1.64.0")]
+impl FileTypeExt for fs::FileType {
+    fn is_symlink_dir(&self) -> bool {
+        self.as_inner().is_symlink_dir()
+    }
+    fn is_symlink_file(&self) -> bool {
+        self.as_inner().is_symlink_file()
+    }
+}
+
+/// Creates a new symlink to a non-directory file on the filesystem.
+///
+/// The `link` path will be a file symbolic link pointing to the `original`
+/// path.
+///
+/// The `original` path should not be a directory or a symlink to a directory,
+/// otherwise the symlink will be broken. Use [`symlink_dir`] for directories.
+///
+/// This function currently corresponds to [`CreateSymbolicLinkW`][CreateSymbolicLinkW].
+/// Note that this [may change in the future][changes].
+///
+/// [CreateSymbolicLinkW]: https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-createsymboliclinkw
+/// [changes]: io#platform-specific-behavior
+///
+/// # Examples
+///
+/// ```no_run
+/// use std::os::windows::fs;
+///
+/// fn main() -> std::io::Result<()> {
+///     fs::symlink_file("a.txt", "b.txt")?;
+///     Ok(())
+/// }
+/// ```
+///
+/// # Limitations
+///
+/// Windows treats symlink creation as a [privileged action][symlink-security],
+/// therefore this function is likely to fail unless the user makes changes to
+/// their system to permit symlink creation. Users can try enabling Developer
+/// Mode, granting the `SeCreateSymbolicLinkPrivilege` privilege, or running
+/// the process as an administrator.
+///
+/// [symlink-security]: https://docs.microsoft.com/en-us/windows/security/threat-protection/security-policy-settings/create-symbolic-links
+#[stable(feature = "symlink", since = "1.1.0")]
+pub fn symlink_file<P: AsRef<Path>, Q: AsRef<Path>>(original: P, link: Q) -> io::Result<()> {
+    sys::fs::symlink_inner(original.as_ref(), link.as_ref(), false)
+}
+
+/// Creates a new symlink to a directory on the filesystem.
+///
+/// The `link` path will be a directory symbolic link pointing to the `original`
+/// path.
+///
+/// The `original` path must be a directory or a symlink to a directory,
+/// otherwise the symlink will be broken. Use [`symlink_file`] for other files.
+///
+/// This function currently corresponds to [`CreateSymbolicLinkW`][CreateSymbolicLinkW].
+/// Note that this [may change in the future][changes].
+///
+/// [CreateSymbolicLinkW]: https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-createsymboliclinkw
+/// [changes]: io#platform-specific-behavior
+///
+/// # Examples
+///
+/// ```no_run
+/// use std::os::windows::fs;
+///
+/// fn main() -> std::io::Result<()> {
+///     fs::symlink_dir("a", "b")?;
+///     Ok(())
+/// }
+/// ```
+///
+/// # Limitations
+///
+/// Windows treats symlink creation as a [privileged action][symlink-security],
+/// therefore this function is likely to fail unless the user makes changes to
+/// their system to permit symlink creation. Users can try enabling Developer
+/// Mode, granting the `SeCreateSymbolicLinkPrivilege` privilege, or running
+/// the process as an administrator.
+///
+/// [symlink-security]: https://docs.microsoft.com/en-us/windows/security/threat-protection/security-policy-settings/create-symbolic-links
+#[stable(feature = "symlink", since = "1.1.0")]
+pub fn symlink_dir<P: AsRef<Path>, Q: AsRef<Path>>(original: P, link: Q) -> io::Result<()> {
+    sys::fs::symlink_inner(original.as_ref(), link.as_ref(), true)
+}
diff --git a/library/std/src/os/windows/io/handle.rs b/library/std/src/os/windows/io/handle.rs
new file mode 100644
index 000000000..16cc8fa27
--- /dev/null
+++ b/library/std/src/os/windows/io/handle.rs
@@ -0,0 +1,576 @@
+//! Owned and borrowed OS handles.
+
+#![stable(feature = "io_safety", since = "1.63.0")]
+
+use super::raw::{AsRawHandle, FromRawHandle, IntoRawHandle, RawHandle};
+use crate::fmt;
+use crate::fs;
+use crate::io;
+use crate::marker::PhantomData;
+use crate::mem::forget;
+use crate::ptr;
+use crate::sys::c;
+use crate::sys::cvt;
+use crate::sys_common::{AsInner, FromInner, IntoInner};
+
+/// A borrowed handle.
+///
+/// This has a lifetime parameter to tie it to the lifetime of something that
+/// owns the handle.
+///
+/// This uses `repr(transparent)` and has the representation of a host handle,
+/// so it can be used in FFI in places where a handle is passed as an argument,
+/// it is not captured or consumed.
+///
+/// Note that it *may* have the value `-1`, which in `BorrowedHandle` always
+/// represents a valid handle value, such as [the current process handle], and
+/// not `INVALID_HANDLE_VALUE`, despite the two having the same value. See
+/// [here] for the full story.
+///
+/// And, it *may* have the value `NULL` (0), which can occur when consoles are
+/// detached from processes, or when `windows_subsystem` is used.
+///
+/// This type's `.to_owned()` implementation returns another `BorrowedHandle`
+/// rather than an `OwnedHandle`. It just makes a trivial copy of the raw
+/// handle, which is then borrowed under the same lifetime.
+///
+/// [here]: https://devblogs.microsoft.com/oldnewthing/20040302-00/?p=40443
+/// [the current process handle]: https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-getcurrentprocess#remarks
+#[derive(Copy, Clone)]
+#[repr(transparent)]
+#[stable(feature = "io_safety", since = "1.63.0")]
+pub struct BorrowedHandle<'handle> {
+    handle: RawHandle,
+    _phantom: PhantomData<&'handle OwnedHandle>,
+}
+
+/// An owned handle.
+///
+/// This closes the handle on drop.
+///
+/// Note that it *may* have the value `-1`, which in `OwnedHandle` always
+/// represents a valid handle value, such as [the current process handle], and
+/// not `INVALID_HANDLE_VALUE`, despite the two having the same value. See
+/// [here] for the full story.
+///
+/// And, it *may* have the value `NULL` (0), which can occur when consoles are
+/// detached from processes, or when `windows_subsystem` is used.
+///
+/// `OwnedHandle` uses [`CloseHandle`] to close its handle on drop. As such,
+/// it must not be used with handles to open registry keys which need to be
+/// closed with [`RegCloseKey`] instead.
+///
+/// [`CloseHandle`]: https://docs.microsoft.com/en-us/windows/win32/api/handleapi/nf-handleapi-closehandle
+/// [`RegCloseKey`]: https://docs.microsoft.com/en-us/windows/win32/api/winreg/nf-winreg-regclosekey
+///
+/// [here]: https://devblogs.microsoft.com/oldnewthing/20040302-00/?p=40443
+/// [the current process handle]: https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-getcurrentprocess#remarks
+#[repr(transparent)]
+#[stable(feature = "io_safety", since = "1.63.0")]
+pub struct OwnedHandle {
+    handle: RawHandle,
+}
+
+/// FFI type for handles in return values or out parameters, where `NULL` is used
+/// as a sentry value to indicate errors, such as in the return value of `CreateThread`. This uses
+/// `repr(transparent)` and has the representation of a host handle, so that it can be used in such
+/// FFI declarations.
+///
+/// The only thing you can usefully do with a `HandleOrNull` is to convert it into an
+/// `OwnedHandle` using its [`TryFrom`] implementation; this conversion takes care of the check for
+/// `NULL`. This ensures that such FFI calls cannot start using the handle without
+/// checking for `NULL` first.
+///
+/// This type may hold any handle value that [`OwnedHandle`] may hold. As with `OwnedHandle`, when
+/// it holds `-1`, that value is interpreted as a valid handle value, such as
+/// [the current process handle], and not `INVALID_HANDLE_VALUE`.
+///
+/// If this holds a non-null handle, it will close the handle on drop.
+///
+/// [the current process handle]: https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-getcurrentprocess#remarks
+#[repr(transparent)]
+#[stable(feature = "io_safety", since = "1.63.0")]
+#[derive(Debug)]
+pub struct HandleOrNull(OwnedHandle);
+
+/// FFI type for handles in return values or out parameters, where `INVALID_HANDLE_VALUE` is used
+/// as a sentry value to indicate errors, such as in the return value of `CreateFileW`. This uses
+/// `repr(transparent)` and has the representation of a host handle, so that it can be used in such
+/// FFI declarations.
+///
+/// The only thing you can usefully do with a `HandleOrInvalid` is to convert it into an
+/// `OwnedHandle` using its [`TryFrom`] implementation; this conversion takes care of the check for
+/// `INVALID_HANDLE_VALUE`. This ensures that such FFI calls cannot start using the handle without
+/// checking for `INVALID_HANDLE_VALUE` first.
+///
+/// This type may hold any handle value that [`OwnedHandle`] may hold, except that when it holds
+/// `-1`, that value is interpreted to mean `INVALID_HANDLE_VALUE`.
+///
+/// If holds a handle other than `INVALID_HANDLE_VALUE`, it will close the handle on drop.
+#[repr(transparent)]
+#[stable(feature = "io_safety", since = "1.63.0")]
+#[derive(Debug)]
+pub struct HandleOrInvalid(OwnedHandle);
+
+// The Windows [`HANDLE`] type may be transferred across and shared between
+// thread boundaries (despite containing a `*mut void`, which in general isn't
+// `Send` or `Sync`).
+//
+// [`HANDLE`]: std::os::windows::raw::HANDLE
+#[stable(feature = "io_safety", since = "1.63.0")]
+unsafe impl Send for OwnedHandle {}
+#[stable(feature = "io_safety", since = "1.63.0")]
+unsafe impl Send for HandleOrNull {}
+#[stable(feature = "io_safety", since = "1.63.0")]
+unsafe impl Send for HandleOrInvalid {}
+#[stable(feature = "io_safety", since = "1.63.0")]
+unsafe impl Send for BorrowedHandle<'_> {}
+#[stable(feature = "io_safety", since = "1.63.0")]
+unsafe impl Sync for OwnedHandle {}
+#[stable(feature = "io_safety", since = "1.63.0")]
+unsafe impl Sync for HandleOrNull {}
+#[stable(feature = "io_safety", since = "1.63.0")]
+unsafe impl Sync for HandleOrInvalid {}
+#[stable(feature = "io_safety", since = "1.63.0")]
+unsafe impl Sync for BorrowedHandle<'_> {}
+
+impl BorrowedHandle<'_> {
+    /// Return a `BorrowedHandle` holding the given raw handle.
+    ///
+    /// # Safety
+    ///
+    /// The resource pointed to by `handle` must be a valid open handle, it
+    /// must remain open for the duration of the returned `BorrowedHandle`.
+    ///
+    /// Note that it *may* have the value `INVALID_HANDLE_VALUE` (-1), which is
+    /// sometimes a valid handle value. See [here] for the full story.
+    ///
+    /// And, it *may* have the value `NULL` (0), which can occur when consoles are
+    /// detached from processes, or when `windows_subsystem` is used.
+    ///
+    /// [here]: https://devblogs.microsoft.com/oldnewthing/20040302-00/?p=40443
+    #[inline]
+    #[rustc_const_stable(feature = "io_safety", since = "1.63.0")]
+    #[stable(feature = "io_safety", since = "1.63.0")]
+    pub const unsafe fn borrow_raw(handle: RawHandle) -> Self {
+        Self { handle, _phantom: PhantomData }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl TryFrom<HandleOrNull> for OwnedHandle {
+    type Error = NullHandleError;
+
+    #[inline]
+    fn try_from(handle_or_null: HandleOrNull) -> Result<Self, NullHandleError> {
+        let owned_handle = handle_or_null.0;
+        if owned_handle.handle.is_null() {
+            // Don't call `CloseHandle`; it'd be harmless, except that it could
+            // overwrite the `GetLastError` error.
+            forget(owned_handle);
+
+            Err(NullHandleError(()))
+        } else {
+            Ok(owned_handle)
+        }
+    }
+}
+
+impl OwnedHandle {
+    /// Creates a new `OwnedHandle` instance that shares the same underlying
+    /// object as the existing `OwnedHandle` instance.
+    #[stable(feature = "io_safety", since = "1.63.0")]
+    pub fn try_clone(&self) -> crate::io::Result<Self> {
+        self.as_handle().try_clone_to_owned()
+    }
+}
+
+impl BorrowedHandle<'_> {
+    /// Creates a new `OwnedHandle` instance that shares the same underlying
+    /// object as the existing `BorrowedHandle` instance.
+    #[stable(feature = "io_safety", since = "1.63.0")]
+    pub fn try_clone_to_owned(&self) -> crate::io::Result<OwnedHandle> {
+        self.duplicate(0, false, c::DUPLICATE_SAME_ACCESS)
+    }
+
+    pub(crate) fn duplicate(
+        &self,
+        access: c::DWORD,
+        inherit: bool,
+        options: c::DWORD,
+    ) -> io::Result<OwnedHandle> {
+        let handle = self.as_raw_handle();
+
+        // `Stdin`, `Stdout`, and `Stderr` can all hold null handles, such as
+        // in a process with a detached console. `DuplicateHandle` would fail
+        // if we passed it a null handle, but we can treat null as a valid
+        // handle which doesn't do any I/O, and allow it to be duplicated.
+        if handle.is_null() {
+            return unsafe { Ok(OwnedHandle::from_raw_handle(handle)) };
+        }
+
+        let mut ret = ptr::null_mut();
+        cvt(unsafe {
+            let cur_proc = c::GetCurrentProcess();
+            c::DuplicateHandle(
+                cur_proc,
+                handle,
+                cur_proc,
+                &mut ret,
+                access,
+                inherit as c::BOOL,
+                options,
+            )
+        })?;
+        unsafe { Ok(OwnedHandle::from_raw_handle(ret)) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl TryFrom<HandleOrInvalid> for OwnedHandle {
+    type Error = InvalidHandleError;
+
+    #[inline]
+    fn try_from(handle_or_invalid: HandleOrInvalid) -> Result<Self, InvalidHandleError> {
+        let owned_handle = handle_or_invalid.0;
+        if owned_handle.handle == c::INVALID_HANDLE_VALUE {
+            // Don't call `CloseHandle`; it'd be harmless, except that it could
+            // overwrite the `GetLastError` error.
+            forget(owned_handle);
+
+            Err(InvalidHandleError(()))
+        } else {
+            Ok(owned_handle)
+        }
+    }
+}
+
+/// This is the error type used by [`HandleOrNull`] when attempting to convert
+/// into a handle, to indicate that the value is null.
+// The empty field prevents constructing this, and allows extending it in the future.
+#[stable(feature = "io_safety", since = "1.63.0")]
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct NullHandleError(());
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl fmt::Display for NullHandleError {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        "A HandleOrNull could not be converted to a handle because it was null".fmt(fmt)
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl crate::error::Error for NullHandleError {}
+
+/// This is the error type used by [`HandleOrInvalid`] when attempting to
+/// convert into a handle, to indicate that the value is
+/// `INVALID_HANDLE_VALUE`.
+// The empty field prevents constructing this, and allows extending it in the future.
+#[stable(feature = "io_safety", since = "1.63.0")]
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct InvalidHandleError(());
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl fmt::Display for InvalidHandleError {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        "A HandleOrInvalid could not be converted to a handle because it was INVALID_HANDLE_VALUE"
+            .fmt(fmt)
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl crate::error::Error for InvalidHandleError {}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsRawHandle for BorrowedHandle<'_> {
+    #[inline]
+    fn as_raw_handle(&self) -> RawHandle {
+        self.handle
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsRawHandle for OwnedHandle {
+    #[inline]
+    fn as_raw_handle(&self) -> RawHandle {
+        self.handle
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl IntoRawHandle for OwnedHandle {
+    #[inline]
+    fn into_raw_handle(self) -> RawHandle {
+        let handle = self.handle;
+        forget(self);
+        handle
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl FromRawHandle for OwnedHandle {
+    #[inline]
+    unsafe fn from_raw_handle(handle: RawHandle) -> Self {
+        Self { handle }
+    }
+}
+
+impl HandleOrNull {
+    /// Constructs a new instance of `Self` from the given `RawHandle` returned
+    /// from a Windows API that uses null to indicate failure, such as
+    /// `CreateThread`.
+    ///
+    /// Use `HandleOrInvalid` instead of `HandleOrNull` for APIs that
+    /// use `INVALID_HANDLE_VALUE` to indicate failure.
+    ///
+    /// # Safety
+    ///
+    /// The passed `handle` value must either satisfy the safety requirements
+    /// of [`FromRawHandle::from_raw_handle`], or be null. Note that not all
+    /// Windows APIs use null for errors; see [here] for the full story.
+    ///
+    /// [here]: https://devblogs.microsoft.com/oldnewthing/20040302-00/?p=40443
+    #[stable(feature = "io_safety", since = "1.63.0")]
+    #[inline]
+    pub unsafe fn from_raw_handle(handle: RawHandle) -> Self {
+        Self(OwnedHandle::from_raw_handle(handle))
+    }
+}
+
+impl HandleOrInvalid {
+    /// Constructs a new instance of `Self` from the given `RawHandle` returned
+    /// from a Windows API that uses `INVALID_HANDLE_VALUE` to indicate
+    /// failure, such as `CreateFileW`.
+    ///
+    /// Use `HandleOrNull` instead of `HandleOrInvalid` for APIs that
+    /// use null to indicate failure.
+    ///
+    /// # Safety
+    ///
+    /// The passed `handle` value must either satisfy the safety requirements
+    /// of [`FromRawHandle::from_raw_handle`], or be
+    /// `INVALID_HANDLE_VALUE` (-1). Note that not all Windows APIs use
+    /// `INVALID_HANDLE_VALUE` for errors; see [here] for the full story.
+    ///
+    /// [here]: https://devblogs.microsoft.com/oldnewthing/20040302-00/?p=40443
+    #[stable(feature = "io_safety", since = "1.63.0")]
+    #[inline]
+    pub unsafe fn from_raw_handle(handle: RawHandle) -> Self {
+        Self(OwnedHandle::from_raw_handle(handle))
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl Drop for OwnedHandle {
+    #[inline]
+    fn drop(&mut self) {
+        unsafe {
+            let _ = c::CloseHandle(self.handle);
+        }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl fmt::Debug for BorrowedHandle<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("BorrowedHandle").field("handle", &self.handle).finish()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl fmt::Debug for OwnedHandle {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("OwnedHandle").field("handle", &self.handle).finish()
+    }
+}
+
+/// A trait to borrow the handle from an underlying object.
+#[stable(feature = "io_safety", since = "1.63.0")]
+pub trait AsHandle {
+    /// Borrows the handle.
+    ///
+    /// # Example
+    ///
+    /// ```rust,no_run
+    /// use std::fs::File;
+    /// # use std::io;
+    /// use std::os::windows::io::{AsHandle, BorrowedHandle};
+    ///
+    /// let mut f = File::open("foo.txt")?;
+    /// let borrowed_handle: BorrowedHandle<'_> = f.as_handle();
+    /// # Ok::<(), io::Error>(())
+    /// ```
+    #[stable(feature = "io_safety", since = "1.63.0")]
+    fn as_handle(&self) -> BorrowedHandle<'_>;
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl<T: AsHandle> AsHandle for &T {
+    #[inline]
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        T::as_handle(self)
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl<T: AsHandle> AsHandle for &mut T {
+    #[inline]
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        T::as_handle(self)
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsHandle for BorrowedHandle<'_> {
+    #[inline]
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        *self
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsHandle for OwnedHandle {
+    #[inline]
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        // Safety: `OwnedHandle` and `BorrowedHandle` have the same validity
+        // invariants, and the `BorrowdHandle` is bounded by the lifetime
+        // of `&self`.
+        unsafe { BorrowedHandle::borrow_raw(self.as_raw_handle()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsHandle for fs::File {
+    #[inline]
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        self.as_inner().as_handle()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<fs::File> for OwnedHandle {
+    #[inline]
+    fn from(file: fs::File) -> OwnedHandle {
+        file.into_inner().into_inner().into_inner().into()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<OwnedHandle> for fs::File {
+    #[inline]
+    fn from(owned: OwnedHandle) -> Self {
+        Self::from_inner(FromInner::from_inner(FromInner::from_inner(owned)))
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsHandle for crate::io::Stdin {
+    #[inline]
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        unsafe { BorrowedHandle::borrow_raw(self.as_raw_handle()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl<'a> AsHandle for crate::io::StdinLock<'a> {
+    #[inline]
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        unsafe { BorrowedHandle::borrow_raw(self.as_raw_handle()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsHandle for crate::io::Stdout {
+    #[inline]
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        unsafe { BorrowedHandle::borrow_raw(self.as_raw_handle()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl<'a> AsHandle for crate::io::StdoutLock<'a> {
+    #[inline]
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        unsafe { BorrowedHandle::borrow_raw(self.as_raw_handle()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsHandle for crate::io::Stderr {
+    #[inline]
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        unsafe { BorrowedHandle::borrow_raw(self.as_raw_handle()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl<'a> AsHandle for crate::io::StderrLock<'a> {
+    #[inline]
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        unsafe { BorrowedHandle::borrow_raw(self.as_raw_handle()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsHandle for crate::process::ChildStdin {
+    #[inline]
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        unsafe { BorrowedHandle::borrow_raw(self.as_raw_handle()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<crate::process::ChildStdin> for OwnedHandle {
+    #[inline]
+    fn from(child_stdin: crate::process::ChildStdin) -> OwnedHandle {
+        unsafe { OwnedHandle::from_raw_handle(child_stdin.into_raw_handle()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsHandle for crate::process::ChildStdout {
+    #[inline]
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        unsafe { BorrowedHandle::borrow_raw(self.as_raw_handle()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<crate::process::ChildStdout> for OwnedHandle {
+    #[inline]
+    fn from(child_stdout: crate::process::ChildStdout) -> OwnedHandle {
+        unsafe { OwnedHandle::from_raw_handle(child_stdout.into_raw_handle()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsHandle for crate::process::ChildStderr {
+    #[inline]
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        unsafe { BorrowedHandle::borrow_raw(self.as_raw_handle()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<crate::process::ChildStderr> for OwnedHandle {
+    #[inline]
+    fn from(child_stderr: crate::process::ChildStderr) -> OwnedHandle {
+        unsafe { OwnedHandle::from_raw_handle(child_stderr.into_raw_handle()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl<T> AsHandle for crate::thread::JoinHandle<T> {
+    #[inline]
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        unsafe { BorrowedHandle::borrow_raw(self.as_raw_handle()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl<T> From<crate::thread::JoinHandle<T>> for OwnedHandle {
+    #[inline]
+    fn from(join_handle: crate::thread::JoinHandle<T>) -> OwnedHandle {
+        join_handle.into_inner().into_handle().into_inner()
+    }
+}
diff --git a/library/std/src/os/windows/io/mod.rs b/library/std/src/os/windows/io/mod.rs
new file mode 100644
index 000000000..e2a401fb6
--- /dev/null
+++ b/library/std/src/os/windows/io/mod.rs
@@ -0,0 +1,65 @@
+//! Windows-specific extensions to general I/O primitives.
+//!
+//! Just like raw pointers, raw Windows handles and sockets point to resources
+//! with dynamic lifetimes, and they can dangle if they outlive their resources
+//! or be forged if they're created from invalid values.
+//!
+//! This module provides three types for representing raw handles and sockets
+//! with different ownership properties: raw, borrowed, and owned, which are
+//! analogous to types used for representing pointers:
+//!
+//! | Type                   | Analogous to |
+//! | ---------------------- | ------------ |
+//! | [`RawHandle`]          | `*const _`   |
+//! | [`RawSocket`]          | `*const _`   |
+//! |                        |              |
+//! | [`BorrowedHandle<'a>`] | `&'a _`      |
+//! | [`BorrowedSocket<'a>`] | `&'a _`      |
+//! |                        |              |
+//! | [`OwnedHandle`]        | `Box<_>`     |
+//! | [`OwnedSocket`]        | `Box<_>`     |
+//!
+//! Like raw pointers, `RawHandle` and `RawSocket` values are primitive values.
+//! And in new code, they should be considered unsafe to do I/O on (analogous
+//! to dereferencing them). Rust did not always provide this guidance, so
+//! existing code in the Rust ecosystem often doesn't mark `RawHandle` and
+//! `RawSocket` usage as unsafe. Once the `io_safety` feature is stable,
+//! libraries will be encouraged to migrate, either by adding `unsafe` to APIs
+//! that dereference `RawHandle` and `RawSocket` values, or by using to
+//! `BorrowedHandle`, `BorrowedSocket`, `OwnedHandle`, or `OwnedSocket`.
+//!
+//! Like references, `BorrowedHandle` and `BorrowedSocket` values are tied to a
+//! lifetime, to ensure that they don't outlive the resource they point to.
+//! These are safe to use. `BorrowedHandle` and `BorrowedSocket` values may be
+//! used in APIs which provide safe access to any system call except for
+//! `CloseHandle`, `closesocket`, or any other call that would end the
+//! dynamic lifetime of the resource without ending the lifetime of the
+//! handle or socket.
+//!
+//! `BorrowedHandle` and `BorrowedSocket` values may be used in APIs which
+//! provide safe access to `DuplicateHandle` and `WSADuplicateSocketW` and
+//! related functions, so types implementing `AsHandle`, `AsSocket`,
+//! `From<OwnedHandle>`, or `From<OwnedSocket>` should not assume they always
+//! have exclusive access to the underlying object.
+//!
+//! Like boxes, `OwnedHandle` and `OwnedSocket` values conceptually own the
+//! resource they point to, and free (close) it when they are dropped.
+//!
+//! [`BorrowedHandle<'a>`]: crate::os::windows::io::BorrowedHandle
+//! [`BorrowedSocket<'a>`]: crate::os::windows::io::BorrowedSocket
+
+#![stable(feature = "rust1", since = "1.0.0")]
+
+mod handle;
+mod raw;
+mod socket;
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+pub use handle::*;
+#[stable(feature = "rust1", since = "1.0.0")]
+pub use raw::*;
+#[stable(feature = "io_safety", since = "1.63.0")]
+pub use socket::*;
+
+#[cfg(test)]
+mod tests;
diff --git a/library/std/src/os/windows/io/raw.rs b/library/std/src/os/windows/io/raw.rs
new file mode 100644
index 000000000..49e4f304f
--- /dev/null
+++ b/library/std/src/os/windows/io/raw.rs
@@ -0,0 +1,305 @@
+//! Windows-specific extensions to general I/O primitives.
+
+#![stable(feature = "rust1", since = "1.0.0")]
+
+use crate::fs;
+use crate::io;
+use crate::net;
+#[cfg(doc)]
+use crate::os::windows::io::{AsHandle, AsSocket};
+use crate::os::windows::io::{OwnedHandle, OwnedSocket};
+use crate::os::windows::raw;
+use crate::ptr;
+use crate::sys;
+use crate::sys::c;
+use crate::sys_common::{self, AsInner, FromInner, IntoInner};
+
+/// Raw HANDLEs.
+#[stable(feature = "rust1", since = "1.0.0")]
+pub type RawHandle = raw::HANDLE;
+
+/// Raw SOCKETs.
+#[stable(feature = "rust1", since = "1.0.0")]
+pub type RawSocket = raw::SOCKET;
+
+/// Extracts raw handles.
+#[stable(feature = "rust1", since = "1.0.0")]
+pub trait AsRawHandle {
+    /// Extracts the raw handle.
+    ///
+    /// This function is typically used to **borrow** an owned handle.
+    /// When used in this way, this method does **not** pass ownership of the
+    /// raw handle to the caller, and the handle is only guaranteed
+    /// to be valid while the original object has not yet been destroyed.
+    ///
+    /// This function may return null, such as when called on [`Stdin`],
+    /// [`Stdout`], or [`Stderr`] when the console is detached.
+    ///
+    /// However, borrowing is not strictly required. See [`AsHandle::as_handle`]
+    /// for an API which strictly borrows a handle.
+    ///
+    /// [`Stdin`]: io::Stdin
+    /// [`Stdout`]: io::Stdout
+    /// [`Stderr`]: io::Stderr
+    #[stable(feature = "rust1", since = "1.0.0")]
+    fn as_raw_handle(&self) -> RawHandle;
+}
+
+/// Construct I/O objects from raw handles.
+#[stable(feature = "from_raw_os", since = "1.1.0")]
+pub trait FromRawHandle {
+    /// Constructs a new I/O object from the specified raw handle.
+    ///
+    /// This function is typically used to **consume ownership** of the handle
+    /// given, passing responsibility for closing the handle to the returned
+    /// object. When used in this way, the returned object
+    /// will take responsibility for closing it when the object goes out of
+    /// scope.
+    ///
+    /// However, consuming ownership is not strictly required. Use a
+    /// `From<OwnedHandle>::from` implementation for an API which strictly
+    /// consumes ownership.
+    ///
+    /// # Safety
+    ///
+    /// The `handle` passed in must:
+    ///   - be a valid an open handle,
+    ///   - be a handle for a resource that may be freed via [`CloseHandle`]
+    ///     (as opposed to `RegCloseKey` or other close functions).
+    ///
+    /// Note that the handle *may* have the value `INVALID_HANDLE_VALUE` (-1),
+    /// which is sometimes a valid handle value. See [here] for the full story.
+    ///
+    /// [`CloseHandle`]: https://docs.microsoft.com/en-us/windows/win32/api/handleapi/nf-handleapi-closehandle
+    /// [here]: https://devblogs.microsoft.com/oldnewthing/20040302-00/?p=40443
+    #[stable(feature = "from_raw_os", since = "1.1.0")]
+    unsafe fn from_raw_handle(handle: RawHandle) -> Self;
+}
+
+/// A trait to express the ability to consume an object and acquire ownership of
+/// its raw `HANDLE`.
+#[stable(feature = "into_raw_os", since = "1.4.0")]
+pub trait IntoRawHandle {
+    /// Consumes this object, returning the raw underlying handle.
+    ///
+    /// This function is typically used to **transfer ownership** of the underlying
+    /// handle to the caller. When used in this way, callers are then the unique
+    /// owners of the handle and must close it once it's no longer needed.
+    ///
+    /// However, transferring ownership is not strictly required. Use a
+    /// `Into<OwnedHandle>::into` implementation for an API which strictly
+    /// transfers ownership.
+    #[stable(feature = "into_raw_os", since = "1.4.0")]
+    fn into_raw_handle(self) -> RawHandle;
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl AsRawHandle for fs::File {
+    #[inline]
+    fn as_raw_handle(&self) -> RawHandle {
+        self.as_inner().as_raw_handle() as RawHandle
+    }
+}
+
+#[stable(feature = "asraw_stdio", since = "1.21.0")]
+impl AsRawHandle for io::Stdin {
+    fn as_raw_handle(&self) -> RawHandle {
+        stdio_handle(unsafe { c::GetStdHandle(c::STD_INPUT_HANDLE) as RawHandle })
+    }
+}
+
+#[stable(feature = "asraw_stdio", since = "1.21.0")]
+impl AsRawHandle for io::Stdout {
+    fn as_raw_handle(&self) -> RawHandle {
+        stdio_handle(unsafe { c::GetStdHandle(c::STD_OUTPUT_HANDLE) as RawHandle })
+    }
+}
+
+#[stable(feature = "asraw_stdio", since = "1.21.0")]
+impl AsRawHandle for io::Stderr {
+    fn as_raw_handle(&self) -> RawHandle {
+        stdio_handle(unsafe { c::GetStdHandle(c::STD_ERROR_HANDLE) as RawHandle })
+    }
+}
+
+#[stable(feature = "asraw_stdio_locks", since = "1.35.0")]
+impl<'a> AsRawHandle for io::StdinLock<'a> {
+    fn as_raw_handle(&self) -> RawHandle {
+        stdio_handle(unsafe { c::GetStdHandle(c::STD_INPUT_HANDLE) as RawHandle })
+    }
+}
+
+#[stable(feature = "asraw_stdio_locks", since = "1.35.0")]
+impl<'a> AsRawHandle for io::StdoutLock<'a> {
+    fn as_raw_handle(&self) -> RawHandle {
+        stdio_handle(unsafe { c::GetStdHandle(c::STD_OUTPUT_HANDLE) as RawHandle })
+    }
+}
+
+#[stable(feature = "asraw_stdio_locks", since = "1.35.0")]
+impl<'a> AsRawHandle for io::StderrLock<'a> {
+    fn as_raw_handle(&self) -> RawHandle {
+        stdio_handle(unsafe { c::GetStdHandle(c::STD_ERROR_HANDLE) as RawHandle })
+    }
+}
+
+// Translate a handle returned from `GetStdHandle` into a handle to return to
+// the user.
+fn stdio_handle(raw: RawHandle) -> RawHandle {
+    // `GetStdHandle` isn't expected to actually fail, so when it returns
+    // `INVALID_HANDLE_VALUE`, it means we were launched from a parent which
+    // didn't provide us with stdio handles, such as a parent with a detached
+    // console. In that case, return null to the user, which is consistent
+    // with what they'd get in the parent, and which avoids the problem that
+    // `INVALID_HANDLE_VALUE` aliases the current process handle.
+    if raw == c::INVALID_HANDLE_VALUE { ptr::null_mut() } else { raw }
+}
+
+#[stable(feature = "from_raw_os", since = "1.1.0")]
+impl FromRawHandle for fs::File {
+    #[inline]
+    unsafe fn from_raw_handle(handle: RawHandle) -> fs::File {
+        let handle = handle as c::HANDLE;
+        fs::File::from_inner(sys::fs::File::from_inner(FromInner::from_inner(
+            OwnedHandle::from_raw_handle(handle),
+        )))
+    }
+}
+
+#[stable(feature = "into_raw_os", since = "1.4.0")]
+impl IntoRawHandle for fs::File {
+    #[inline]
+    fn into_raw_handle(self) -> RawHandle {
+        self.into_inner().into_raw_handle() as *mut _
+    }
+}
+
+/// Extracts raw sockets.
+#[stable(feature = "rust1", since = "1.0.0")]
+pub trait AsRawSocket {
+    /// Extracts the raw socket.
+    ///
+    /// This function is typically used to **borrow** an owned socket.
+    /// When used in this way, this method does **not** pass ownership of the
+    /// raw socket to the caller, and the socket is only guaranteed
+    /// to be valid while the original object has not yet been destroyed.
+    ///
+    /// However, borrowing is not strictly required. See [`AsSocket::as_socket`]
+    /// for an API which strictly borrows a socket.
+    #[stable(feature = "rust1", since = "1.0.0")]
+    fn as_raw_socket(&self) -> RawSocket;
+}
+
+/// Creates I/O objects from raw sockets.
+#[stable(feature = "from_raw_os", since = "1.1.0")]
+pub trait FromRawSocket {
+    /// Constructs a new I/O object from the specified raw socket.
+    ///
+    /// This function is typically used to **consume ownership** of the socket
+    /// given, passing responsibility for closing the socket to the returned
+    /// object. When used in this way, the returned object
+    /// will take responsibility for closing it when the object goes out of
+    /// scope.
+    ///
+    /// However, consuming ownership is not strictly required. Use a
+    /// `From<OwnedSocket>::from` implementation for an API which strictly
+    /// consumes ownership.
+    ///
+    /// # Safety
+    ///
+    /// The `socket` passed in must:
+    ///   - be a valid an open socket,
+    ///   - be a socket that may be freed via [`closesocket`].
+    ///
+    /// [`closesocket`]: https://docs.microsoft.com/en-us/windows/win32/api/winsock2/nf-winsock2-closesocket
+    #[stable(feature = "from_raw_os", since = "1.1.0")]
+    unsafe fn from_raw_socket(sock: RawSocket) -> Self;
+}
+
+/// A trait to express the ability to consume an object and acquire ownership of
+/// its raw `SOCKET`.
+#[stable(feature = "into_raw_os", since = "1.4.0")]
+pub trait IntoRawSocket {
+    /// Consumes this object, returning the raw underlying socket.
+    ///
+    /// This function is typically used to **transfer ownership** of the underlying
+    /// socket to the caller. When used in this way, callers are then the unique
+    /// owners of the socket and must close it once it's no longer needed.
+    ///
+    /// However, transferring ownership is not strictly required. Use a
+    /// `Into<OwnedSocket>::into` implementation for an API which strictly
+    /// transfers ownership.
+    #[stable(feature = "into_raw_os", since = "1.4.0")]
+    fn into_raw_socket(self) -> RawSocket;
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl AsRawSocket for net::TcpStream {
+    #[inline]
+    fn as_raw_socket(&self) -> RawSocket {
+        self.as_inner().socket().as_raw_socket()
+    }
+}
+#[stable(feature = "rust1", since = "1.0.0")]
+impl AsRawSocket for net::TcpListener {
+    #[inline]
+    fn as_raw_socket(&self) -> RawSocket {
+        self.as_inner().socket().as_raw_socket()
+    }
+}
+#[stable(feature = "rust1", since = "1.0.0")]
+impl AsRawSocket for net::UdpSocket {
+    #[inline]
+    fn as_raw_socket(&self) -> RawSocket {
+        self.as_inner().socket().as_raw_socket()
+    }
+}
+
+#[stable(feature = "from_raw_os", since = "1.1.0")]
+impl FromRawSocket for net::TcpStream {
+    #[inline]
+    unsafe fn from_raw_socket(sock: RawSocket) -> net::TcpStream {
+        let sock = sys::net::Socket::from_inner(OwnedSocket::from_raw_socket(sock));
+        net::TcpStream::from_inner(sys_common::net::TcpStream::from_inner(sock))
+    }
+}
+#[stable(feature = "from_raw_os", since = "1.1.0")]
+impl FromRawSocket for net::TcpListener {
+    #[inline]
+    unsafe fn from_raw_socket(sock: RawSocket) -> net::TcpListener {
+        let sock = sys::net::Socket::from_inner(OwnedSocket::from_raw_socket(sock));
+        net::TcpListener::from_inner(sys_common::net::TcpListener::from_inner(sock))
+    }
+}
+#[stable(feature = "from_raw_os", since = "1.1.0")]
+impl FromRawSocket for net::UdpSocket {
+    #[inline]
+    unsafe fn from_raw_socket(sock: RawSocket) -> net::UdpSocket {
+        let sock = sys::net::Socket::from_inner(OwnedSocket::from_raw_socket(sock));
+        net::UdpSocket::from_inner(sys_common::net::UdpSocket::from_inner(sock))
+    }
+}
+
+#[stable(feature = "into_raw_os", since = "1.4.0")]
+impl IntoRawSocket for net::TcpStream {
+    #[inline]
+    fn into_raw_socket(self) -> RawSocket {
+        self.into_inner().into_socket().into_inner().into_raw_socket()
+    }
+}
+
+#[stable(feature = "into_raw_os", since = "1.4.0")]
+impl IntoRawSocket for net::TcpListener {
+    #[inline]
+    fn into_raw_socket(self) -> RawSocket {
+        self.into_inner().into_socket().into_inner().into_raw_socket()
+    }
+}
+
+#[stable(feature = "into_raw_os", since = "1.4.0")]
+impl IntoRawSocket for net::UdpSocket {
+    #[inline]
+    fn into_raw_socket(self) -> RawSocket {
+        self.into_inner().into_socket().into_inner().into_raw_socket()
+    }
+}
diff --git a/library/std/src/os/windows/io/socket.rs b/library/std/src/os/windows/io/socket.rs
new file mode 100644
index 000000000..72cb3406d
--- /dev/null
+++ b/library/std/src/os/windows/io/socket.rs
@@ -0,0 +1,338 @@
+//! Owned and borrowed OS sockets.
+
+#![stable(feature = "io_safety", since = "1.63.0")]
+
+use super::raw::{AsRawSocket, FromRawSocket, IntoRawSocket, RawSocket};
+use crate::fmt;
+use crate::io;
+use crate::marker::PhantomData;
+use crate::mem;
+use crate::mem::forget;
+use crate::sys;
+use crate::sys::c;
+#[cfg(not(target_vendor = "uwp"))]
+use crate::sys::cvt;
+
+/// A borrowed socket.
+///
+/// This has a lifetime parameter to tie it to the lifetime of something that
+/// owns the socket.
+///
+/// This uses `repr(transparent)` and has the representation of a host socket,
+/// so it can be used in FFI in places where a socket is passed as an argument,
+/// it is not captured or consumed, and it never has the value
+/// `INVALID_SOCKET`.
+///
+/// This type's `.to_owned()` implementation returns another `BorrowedSocket`
+/// rather than an `OwnedSocket`. It just makes a trivial copy of the raw
+/// socket, which is then borrowed under the same lifetime.
+#[derive(Copy, Clone)]
+#[repr(transparent)]
+#[rustc_layout_scalar_valid_range_start(0)]
+// This is -2, in two's complement. -1 is `INVALID_SOCKET`.
+#[cfg_attr(target_pointer_width = "32", rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE))]
+#[cfg_attr(
+    target_pointer_width = "64",
+    rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FF_FF_FF_FF_FE)
+)]
+#[rustc_nonnull_optimization_guaranteed]
+#[stable(feature = "io_safety", since = "1.63.0")]
+pub struct BorrowedSocket<'socket> {
+    socket: RawSocket,
+    _phantom: PhantomData<&'socket OwnedSocket>,
+}
+
+/// An owned socket.
+///
+/// This closes the socket on drop.
+///
+/// This uses `repr(transparent)` and has the representation of a host socket,
+/// so it can be used in FFI in places where a socket is passed as a consumed
+/// argument or returned as an owned value, and it never has the value
+/// `INVALID_SOCKET`.
+#[repr(transparent)]
+#[rustc_layout_scalar_valid_range_start(0)]
+// This is -2, in two's complement. -1 is `INVALID_SOCKET`.
+#[cfg_attr(target_pointer_width = "32", rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FE))]
+#[cfg_attr(
+    target_pointer_width = "64",
+    rustc_layout_scalar_valid_range_end(0xFF_FF_FF_FF_FF_FF_FF_FE)
+)]
+#[rustc_nonnull_optimization_guaranteed]
+#[stable(feature = "io_safety", since = "1.63.0")]
+pub struct OwnedSocket {
+    socket: RawSocket,
+}
+
+impl BorrowedSocket<'_> {
+    /// Return a `BorrowedSocket` holding the given raw socket.
+    ///
+    /// # Safety
+    ///
+    /// The resource pointed to by `raw` must remain open for the duration of
+    /// the returned `BorrowedSocket`, and it must not have the value
+    /// `INVALID_SOCKET`.
+    #[inline]
+    #[rustc_const_stable(feature = "io_safety", since = "1.63.0")]
+    #[stable(feature = "io_safety", since = "1.63.0")]
+    pub const unsafe fn borrow_raw(socket: RawSocket) -> Self {
+        assert!(socket != c::INVALID_SOCKET as RawSocket);
+        Self { socket, _phantom: PhantomData }
+    }
+}
+
+impl OwnedSocket {
+    /// Creates a new `OwnedSocket` instance that shares the same underlying
+    /// object as the existing `OwnedSocket` instance.
+    #[stable(feature = "io_safety", since = "1.63.0")]
+    pub fn try_clone(&self) -> io::Result<Self> {
+        self.as_socket().try_clone_to_owned()
+    }
+
+    // FIXME(strict_provenance_magic): we defined RawSocket to be a u64 ;-;
+    #[cfg(not(target_vendor = "uwp"))]
+    pub(crate) fn set_no_inherit(&self) -> io::Result<()> {
+        cvt(unsafe {
+            c::SetHandleInformation(self.as_raw_socket() as c::HANDLE, c::HANDLE_FLAG_INHERIT, 0)
+        })
+        .map(drop)
+    }
+
+    #[cfg(target_vendor = "uwp")]
+    pub(crate) fn set_no_inherit(&self) -> io::Result<()> {
+        Err(io::const_io_error!(io::ErrorKind::Unsupported, "Unavailable on UWP"))
+    }
+}
+
+impl BorrowedSocket<'_> {
+    /// Creates a new `OwnedSocket` instance that shares the same underlying
+    /// object as the existing `BorrowedSocket` instance.
+    #[stable(feature = "io_safety", since = "1.63.0")]
+    pub fn try_clone_to_owned(&self) -> io::Result<OwnedSocket> {
+        let mut info = unsafe { mem::zeroed::<c::WSAPROTOCOL_INFO>() };
+        let result = unsafe {
+            c::WSADuplicateSocketW(self.as_raw_socket(), c::GetCurrentProcessId(), &mut info)
+        };
+        sys::net::cvt(result)?;
+        let socket = unsafe {
+            c::WSASocketW(
+                info.iAddressFamily,
+                info.iSocketType,
+                info.iProtocol,
+                &mut info,
+                0,
+                c::WSA_FLAG_OVERLAPPED | c::WSA_FLAG_NO_HANDLE_INHERIT,
+            )
+        };
+
+        if socket != c::INVALID_SOCKET {
+            unsafe { Ok(OwnedSocket::from_raw_socket(socket)) }
+        } else {
+            let error = unsafe { c::WSAGetLastError() };
+
+            if error != c::WSAEPROTOTYPE && error != c::WSAEINVAL {
+                return Err(io::Error::from_raw_os_error(error));
+            }
+
+            let socket = unsafe {
+                c::WSASocketW(
+                    info.iAddressFamily,
+                    info.iSocketType,
+                    info.iProtocol,
+                    &mut info,
+                    0,
+                    c::WSA_FLAG_OVERLAPPED,
+                )
+            };
+
+            if socket == c::INVALID_SOCKET {
+                return Err(last_error());
+            }
+
+            unsafe {
+                let socket = OwnedSocket::from_raw_socket(socket);
+                socket.set_no_inherit()?;
+                Ok(socket)
+            }
+        }
+    }
+}
+
+/// Returns the last error from the Windows socket interface.
+fn last_error() -> io::Error {
+    io::Error::from_raw_os_error(unsafe { c::WSAGetLastError() })
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsRawSocket for BorrowedSocket<'_> {
+    #[inline]
+    fn as_raw_socket(&self) -> RawSocket {
+        self.socket
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsRawSocket for OwnedSocket {
+    #[inline]
+    fn as_raw_socket(&self) -> RawSocket {
+        self.socket
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl IntoRawSocket for OwnedSocket {
+    #[inline]
+    fn into_raw_socket(self) -> RawSocket {
+        let socket = self.socket;
+        forget(self);
+        socket
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl FromRawSocket for OwnedSocket {
+    #[inline]
+    unsafe fn from_raw_socket(socket: RawSocket) -> Self {
+        debug_assert_ne!(socket, c::INVALID_SOCKET as RawSocket);
+        Self { socket }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl Drop for OwnedSocket {
+    #[inline]
+    fn drop(&mut self) {
+        unsafe {
+            let _ = c::closesocket(self.socket);
+        }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl fmt::Debug for BorrowedSocket<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("BorrowedSocket").field("socket", &self.socket).finish()
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl fmt::Debug for OwnedSocket {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("OwnedSocket").field("socket", &self.socket).finish()
+    }
+}
+
+/// A trait to borrow the socket from an underlying object.
+#[stable(feature = "io_safety", since = "1.63.0")]
+pub trait AsSocket {
+    /// Borrows the socket.
+    #[stable(feature = "io_safety", since = "1.63.0")]
+    fn as_socket(&self) -> BorrowedSocket<'_>;
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl<T: AsSocket> AsSocket for &T {
+    #[inline]
+    fn as_socket(&self) -> BorrowedSocket<'_> {
+        T::as_socket(self)
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl<T: AsSocket> AsSocket for &mut T {
+    #[inline]
+    fn as_socket(&self) -> BorrowedSocket<'_> {
+        T::as_socket(self)
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsSocket for BorrowedSocket<'_> {
+    #[inline]
+    fn as_socket(&self) -> BorrowedSocket<'_> {
+        *self
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsSocket for OwnedSocket {
+    #[inline]
+    fn as_socket(&self) -> BorrowedSocket<'_> {
+        // Safety: `OwnedSocket` and `BorrowedSocket` have the same validity
+        // invariants, and the `BorrowdSocket` is bounded by the lifetime
+        // of `&self`.
+        unsafe { BorrowedSocket::borrow_raw(self.as_raw_socket()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsSocket for crate::net::TcpStream {
+    #[inline]
+    fn as_socket(&self) -> BorrowedSocket<'_> {
+        unsafe { BorrowedSocket::borrow_raw(self.as_raw_socket()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<crate::net::TcpStream> for OwnedSocket {
+    #[inline]
+    fn from(tcp_stream: crate::net::TcpStream) -> OwnedSocket {
+        unsafe { OwnedSocket::from_raw_socket(tcp_stream.into_raw_socket()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<OwnedSocket> for crate::net::TcpStream {
+    #[inline]
+    fn from(owned: OwnedSocket) -> Self {
+        unsafe { Self::from_raw_socket(owned.into_raw_socket()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsSocket for crate::net::TcpListener {
+    #[inline]
+    fn as_socket(&self) -> BorrowedSocket<'_> {
+        unsafe { BorrowedSocket::borrow_raw(self.as_raw_socket()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<crate::net::TcpListener> for OwnedSocket {
+    #[inline]
+    fn from(tcp_listener: crate::net::TcpListener) -> OwnedSocket {
+        unsafe { OwnedSocket::from_raw_socket(tcp_listener.into_raw_socket()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<OwnedSocket> for crate::net::TcpListener {
+    #[inline]
+    fn from(owned: OwnedSocket) -> Self {
+        unsafe { Self::from_raw_socket(owned.into_raw_socket()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsSocket for crate::net::UdpSocket {
+    #[inline]
+    fn as_socket(&self) -> BorrowedSocket<'_> {
+        unsafe { BorrowedSocket::borrow_raw(self.as_raw_socket()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<crate::net::UdpSocket> for OwnedSocket {
+    #[inline]
+    fn from(udp_socket: crate::net::UdpSocket) -> OwnedSocket {
+        unsafe { OwnedSocket::from_raw_socket(udp_socket.into_raw_socket()) }
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<OwnedSocket> for crate::net::UdpSocket {
+    #[inline]
+    fn from(owned: OwnedSocket) -> Self {
+        unsafe { Self::from_raw_socket(owned.into_raw_socket()) }
+    }
+}
diff --git a/library/std/src/os/windows/io/tests.rs b/library/std/src/os/windows/io/tests.rs
new file mode 100644
index 000000000..41734e52e
--- /dev/null
+++ b/library/std/src/os/windows/io/tests.rs
@@ -0,0 +1,21 @@
+#[test]
+fn test_niche_optimizations_socket() {
+    use crate::mem::size_of;
+    use crate::os::windows::io::{
+        BorrowedSocket, FromRawSocket, IntoRawSocket, OwnedSocket, RawSocket,
+    };
+
+    assert_eq!(size_of::<Option<OwnedSocket>>(), size_of::<RawSocket>());
+    assert_eq!(size_of::<Option<BorrowedSocket<'static>>>(), size_of::<RawSocket>(),);
+    unsafe {
+        #[cfg(target_pointer_width = "32")]
+        let (min, max) = (i32::MIN as u32, i32::MAX as u32);
+        #[cfg(target_pointer_width = "64")]
+        let (min, max) = (i64::MIN as u64, i64::MAX as u64);
+
+        assert_eq!(OwnedSocket::from_raw_socket(min).into_raw_socket(), min);
+        assert_eq!(OwnedSocket::from_raw_socket(max).into_raw_socket(), max);
+        assert_eq!(Some(OwnedSocket::from_raw_socket(min)).unwrap().into_raw_socket(), min);
+        assert_eq!(Some(OwnedSocket::from_raw_socket(max)).unwrap().into_raw_socket(), max);
+    }
+}
diff --git a/library/std/src/os/windows/mod.rs b/library/std/src/os/windows/mod.rs
new file mode 100644
index 000000000..52eb3b7c0
--- /dev/null
+++ b/library/std/src/os/windows/mod.rs
@@ -0,0 +1,58 @@
+//! Platform-specific extensions to `std` for Windows.
+//!
+//! Provides access to platform-level information for Windows, and exposes
+//! Windows-specific idioms that would otherwise be inappropriate as part
+//! the core `std` library. These extensions allow developers to use
+//! `std` types and idioms with Windows in a way that the normal
+//! platform-agnostic idioms would not normally support.
+//!
+//! # Examples
+//!
+//! ```no_run
+//! use std::fs::File;
+//! use std::os::windows::prelude::*;
+//!
+//! fn main() -> std::io::Result<()> {
+//!     let f = File::create("foo.txt")?;
+//!     let handle = f.as_raw_handle();
+//!
+//!     // use handle with native windows bindings
+//!
+//!     Ok(())
+//! }
+//! ```
+
+#![stable(feature = "rust1", since = "1.0.0")]
+#![doc(cfg(windows))]
+
+pub mod ffi;
+pub mod fs;
+pub mod io;
+pub mod process;
+pub mod raw;
+pub mod thread;
+
+/// A prelude for conveniently writing platform-specific code.
+///
+/// Includes all extension traits, and some important type definitions.
+#[stable(feature = "rust1", since = "1.0.0")]
+pub mod prelude {
+    #[doc(no_inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::ffi::{OsStrExt, OsStringExt};
+    #[doc(no_inline)]
+    #[stable(feature = "file_offset", since = "1.15.0")]
+    pub use super::fs::FileExt;
+    #[doc(no_inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::fs::{MetadataExt, OpenOptionsExt};
+    #[doc(no_inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::io::{
+        AsHandle, AsSocket, BorrowedHandle, BorrowedSocket, FromRawHandle, FromRawSocket,
+        HandleOrInvalid, IntoRawHandle, IntoRawSocket, OwnedHandle, OwnedSocket,
+    };
+    #[doc(no_inline)]
+    #[stable(feature = "rust1", since = "1.0.0")]
+    pub use super::io::{AsRawHandle, AsRawSocket, RawHandle, RawSocket};
+}
diff --git a/library/std/src/os/windows/process.rs b/library/std/src/os/windows/process.rs
new file mode 100644
index 000000000..073168cf2
--- /dev/null
+++ b/library/std/src/os/windows/process.rs
@@ -0,0 +1,259 @@
+//! Windows-specific extensions to primitives in the [`std::process`] module.
+//!
+//! [`std::process`]: crate::process
+
+#![stable(feature = "process_extensions", since = "1.2.0")]
+
+use crate::ffi::OsStr;
+use crate::os::windows::io::{
+    AsHandle, AsRawHandle, BorrowedHandle, FromRawHandle, IntoRawHandle, OwnedHandle, RawHandle,
+};
+use crate::process;
+use crate::sealed::Sealed;
+use crate::sys;
+use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
+
+#[stable(feature = "process_extensions", since = "1.2.0")]
+impl FromRawHandle for process::Stdio {
+    unsafe fn from_raw_handle(handle: RawHandle) -> process::Stdio {
+        let handle = sys::handle::Handle::from_raw_handle(handle as *mut _);
+        let io = sys::process::Stdio::Handle(handle);
+        process::Stdio::from_inner(io)
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<OwnedHandle> for process::Stdio {
+    fn from(handle: OwnedHandle) -> process::Stdio {
+        let handle = sys::handle::Handle::from_inner(handle);
+        let io = sys::process::Stdio::Handle(handle);
+        process::Stdio::from_inner(io)
+    }
+}
+
+#[stable(feature = "process_extensions", since = "1.2.0")]
+impl AsRawHandle for process::Child {
+    #[inline]
+    fn as_raw_handle(&self) -> RawHandle {
+        self.as_inner().handle().as_raw_handle() as *mut _
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl AsHandle for process::Child {
+    #[inline]
+    fn as_handle(&self) -> BorrowedHandle<'_> {
+        self.as_inner().handle().as_handle()
+    }
+}
+
+#[stable(feature = "into_raw_os", since = "1.4.0")]
+impl IntoRawHandle for process::Child {
+    fn into_raw_handle(self) -> RawHandle {
+        self.into_inner().into_handle().into_raw_handle() as *mut _
+    }
+}
+
+#[stable(feature = "io_safety", since = "1.63.0")]
+impl From<process::Child> for OwnedHandle {
+    fn from(child: process::Child) -> OwnedHandle {
+        child.into_inner().into_handle().into_inner()
+    }
+}
+
+#[stable(feature = "process_extensions", since = "1.2.0")]
+impl AsRawHandle for process::ChildStdin {
+    #[inline]
+    fn as_raw_handle(&self) -> RawHandle {
+        self.as_inner().handle().as_raw_handle() as *mut _
+    }
+}
+
+#[stable(feature = "process_extensions", since = "1.2.0")]
+impl AsRawHandle for process::ChildStdout {
+    #[inline]
+    fn as_raw_handle(&self) -> RawHandle {
+        self.as_inner().handle().as_raw_handle() as *mut _
+    }
+}
+
+#[stable(feature = "process_extensions", since = "1.2.0")]
+impl AsRawHandle for process::ChildStderr {
+    #[inline]
+    fn as_raw_handle(&self) -> RawHandle {
+        self.as_inner().handle().as_raw_handle() as *mut _
+    }
+}
+
+#[stable(feature = "into_raw_os", since = "1.4.0")]
+impl IntoRawHandle for process::ChildStdin {
+    fn into_raw_handle(self) -> RawHandle {
+        self.into_inner().into_handle().into_raw_handle() as *mut _
+    }
+}
+
+#[stable(feature = "into_raw_os", since = "1.4.0")]
+impl IntoRawHandle for process::ChildStdout {
+    fn into_raw_handle(self) -> RawHandle {
+        self.into_inner().into_handle().into_raw_handle() as *mut _
+    }
+}
+
+#[stable(feature = "into_raw_os", since = "1.4.0")]
+impl IntoRawHandle for process::ChildStderr {
+    fn into_raw_handle(self) -> RawHandle {
+        self.into_inner().into_handle().into_raw_handle() as *mut _
+    }
+}
+
+/// Windows-specific extensions to [`process::ExitStatus`].
+///
+/// This trait is sealed: it cannot be implemented outside the standard library.
+/// This is so that future additional methods are not breaking changes.
+#[stable(feature = "exit_status_from", since = "1.12.0")]
+pub trait ExitStatusExt: Sealed {
+    /// Creates a new `ExitStatus` from the raw underlying `u32` return value of
+    /// a process.
+    #[stable(feature = "exit_status_from", since = "1.12.0")]
+    fn from_raw(raw: u32) -> Self;
+}
+
+#[stable(feature = "exit_status_from", since = "1.12.0")]
+impl ExitStatusExt for process::ExitStatus {
+    fn from_raw(raw: u32) -> Self {
+        process::ExitStatus::from_inner(From::from(raw))
+    }
+}
+
+/// Windows-specific extensions to the [`process::Command`] builder.
+///
+/// This trait is sealed: it cannot be implemented outside the standard library.
+/// This is so that future additional methods are not breaking changes.
+#[stable(feature = "windows_process_extensions", since = "1.16.0")]
+pub trait CommandExt: Sealed {
+    /// Sets the [process creation flags][1] to be passed to `CreateProcess`.
+    ///
+    /// These will always be ORed with `CREATE_UNICODE_ENVIRONMENT`.
+    ///
+    /// [1]: https://docs.microsoft.com/en-us/windows/win32/procthread/process-creation-flags
+    #[stable(feature = "windows_process_extensions", since = "1.16.0")]
+    fn creation_flags(&mut self, flags: u32) -> &mut process::Command;
+
+    /// Forces all arguments to be wrapped in quote (`"`) characters.
+    ///
+    /// This is useful for passing arguments to [MSYS2/Cygwin][1] based
+    /// executables: these programs will expand unquoted arguments containing
+    /// wildcard characters (`?` and `*`) by searching for any file paths
+    /// matching the wildcard pattern.
+    ///
+    /// Adding quotes has no effect when passing arguments to programs
+    /// that use [msvcrt][2]. This includes programs built with both
+    /// MinGW and MSVC.
+    ///
+    /// [1]: <https://github.com/msys2/MSYS2-packages/issues/2176>
+    /// [2]: <https://msdn.microsoft.com/en-us/library/17w5ykft.aspx>
+    #[unstable(feature = "windows_process_extensions_force_quotes", issue = "82227")]
+    fn force_quotes(&mut self, enabled: bool) -> &mut process::Command;
+
+    /// Append literal text to the command line without any quoting or escaping.
+    ///
+    /// This is useful for passing arguments to `cmd.exe /c`, which doesn't follow
+    /// `CommandLineToArgvW` escaping rules.
+    #[stable(feature = "windows_process_extensions_raw_arg", since = "1.62.0")]
+    fn raw_arg<S: AsRef<OsStr>>(&mut self, text_to_append_as_is: S) -> &mut process::Command;
+
+    /// When [`process::Command`] creates pipes, request that our side is always async.
+    ///
+    /// By default [`process::Command`] may choose to use pipes where both ends
+    /// are opened for synchronous read or write operations. By using
+    /// `async_pipes(true)`, this behavior is overridden so that our side is
+    /// always async.
+    ///
+    /// This is important because if doing async I/O a pipe or a file has to be
+    /// opened for async access.
+    ///
+    /// The end of the pipe sent to the child process will always be synchronous
+    /// regardless of this option.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// #![feature(windows_process_extensions_async_pipes)]
+    /// use std::os::windows::process::CommandExt;
+    /// use std::process::{Command, Stdio};
+    ///
+    /// # let program = "";
+    ///
+    /// Command::new(program)
+    ///     .async_pipes(true)
+    ///     .stdin(Stdio::piped())
+    ///     .stdout(Stdio::piped())
+    ///     .stderr(Stdio::piped());
+    /// ```
+    #[unstable(feature = "windows_process_extensions_async_pipes", issue = "98289")]
+    fn async_pipes(&mut self, always_async: bool) -> &mut process::Command;
+}
+
+#[stable(feature = "windows_process_extensions", since = "1.16.0")]
+impl CommandExt for process::Command {
+    fn creation_flags(&mut self, flags: u32) -> &mut process::Command {
+        self.as_inner_mut().creation_flags(flags);
+        self
+    }
+
+    fn force_quotes(&mut self, enabled: bool) -> &mut process::Command {
+        self.as_inner_mut().force_quotes(enabled);
+        self
+    }
+
+    fn raw_arg<S: AsRef<OsStr>>(&mut self, raw_text: S) -> &mut process::Command {
+        self.as_inner_mut().raw_arg(raw_text.as_ref());
+        self
+    }
+
+    fn async_pipes(&mut self, always_async: bool) -> &mut process::Command {
+        // FIXME: This currently has an intentional no-op implementation.
+        // For the time being our side of the pipes will always be async.
+        // Once the ecosystem has adjusted, we may then be able to start making
+        // use of synchronous pipes within the standard library.
+        let _ = always_async;
+        self
+    }
+}
+
+#[unstable(feature = "windows_process_extensions_main_thread_handle", issue = "96723")]
+pub trait ChildExt: Sealed {
+    /// Extracts the main thread raw handle, without taking ownership
+    #[unstable(feature = "windows_process_extensions_main_thread_handle", issue = "96723")]
+    fn main_thread_handle(&self) -> BorrowedHandle<'_>;
+}
+
+#[unstable(feature = "windows_process_extensions_main_thread_handle", issue = "96723")]
+impl ChildExt for process::Child {
+    fn main_thread_handle(&self) -> BorrowedHandle<'_> {
+        self.handle.main_thread_handle()
+    }
+}
+
+/// Windows-specific extensions to [`process::ExitCode`].
+///
+/// This trait is sealed: it cannot be implemented outside the standard library.
+/// This is so that future additional methods are not breaking changes.
+#[unstable(feature = "windows_process_exit_code_from", issue = "none")]
+pub trait ExitCodeExt: Sealed {
+    /// Creates a new `ExitCode` from the raw underlying `u32` return value of
+    /// a process.
+    ///
+    /// The exit code should not be 259, as this conflicts with the `STILL_ACTIVE`
+    /// macro returned from the `GetExitCodeProcess` function to signal that the
+    /// process has yet to run to completion.
+    #[unstable(feature = "windows_process_exit_code_from", issue = "none")]
+    fn from_raw(raw: u32) -> Self;
+}
+
+#[unstable(feature = "windows_process_exit_code_from", issue = "none")]
+impl ExitCodeExt for process::ExitCode {
+    fn from_raw(raw: u32) -> Self {
+        process::ExitCode::from_inner(From::from(raw))
+    }
+}
diff --git a/library/std/src/os/windows/raw.rs b/library/std/src/os/windows/raw.rs
new file mode 100644
index 000000000..0ef3adade
--- /dev/null
+++ b/library/std/src/os/windows/raw.rs
@@ -0,0 +1,16 @@
+//! Windows-specific primitives.
+
+#![stable(feature = "raw_ext", since = "1.1.0")]
+
+use crate::os::raw::c_void;
+
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type HANDLE = *mut c_void;
+#[cfg(target_pointer_width = "32")]
+#[doc(cfg(all()))]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type SOCKET = u32;
+#[cfg(target_pointer_width = "64")]
+#[doc(cfg(all()))]
+#[stable(feature = "raw_ext", since = "1.1.0")]
+pub type SOCKET = u64;
diff --git a/library/std/src/os/windows/thread.rs b/library/std/src/os/windows/thread.rs
new file mode 100644
index 000000000..d81d6d0ac
--- /dev/null
+++ b/library/std/src/os/windows/thread.rs
@@ -0,0 +1,25 @@
+//! Windows-specific extensions to primitives in the [`std::thread`] module.
+//!
+//! [`std::thread`]: crate::thread
+
+#![stable(feature = "thread_extensions", since = "1.9.0")]
+
+use crate::os::windows::io::{AsRawHandle, IntoRawHandle, RawHandle};
+use crate::sys_common::{AsInner, IntoInner};
+use crate::thread;
+
+#[stable(feature = "thread_extensions", since = "1.9.0")]
+impl<T> AsRawHandle for thread::JoinHandle<T> {
+    #[inline]
+    fn as_raw_handle(&self) -> RawHandle {
+        self.as_inner().handle().as_raw_handle() as *mut _
+    }
+}
+
+#[stable(feature = "thread_extensions", since = "1.9.0")]
+impl<T> IntoRawHandle for thread::JoinHandle<T> {
+    #[inline]
+    fn into_raw_handle(self) -> RawHandle {
+        self.into_inner().into_handle().into_raw_handle() as *mut _
+    }
+}