Rework namespace functions and types

Cargo.toml

@@ -32,15 +32,15 @@ compiler_builtins = { version = '0.1.49', optional = true }
 [target.'cfg(all(not(rustix_use_libc), not(miri), target_os = "linux", any(target_endian = "little", any(target_arch = "s390x", target_arch = "powerpc")), any(target_arch = "arm", all(target_arch = "aarch64", target_pointer_width = "64"), target_arch = "riscv64", all(rustix_use_experimental_asm, target_arch = "powerpc"), all(rustix_use_experimental_asm, target_arch = "powerpc64"), all(rustix_use_experimental_asm, target_arch = "s390x"), all(rustix_use_experimental_asm, target_arch = "mips"), all(rustix_use_experimental_asm, target_arch = "mips32r6"), all(rustix_use_experimental_asm, target_arch = "mips64"), all(rustix_use_experimental_asm, target_arch = "mips64r6"), target_arch = "x86", all(target_arch = "x86_64", target_pointer_width = "64"))))'.dependencies]
 linux-raw-sys = { version = "0.9.2", default-features = false, features = ["general", "errno", "ioctl", "no_std", "elf"] }
 libc_errno = { package = "errno", version = "0.3.10", default-features = false, optional = true }
-libc = { version = "0.2.171", default-features = false, optional = true }
+libc = { version = "0.2.174", default-features = false, optional = true }
 
 # Dependencies for platforms where only libc is supported:
 #
 # On all other Unix-family platforms, and under Miri, we always use the libc
 # backend, so enable its dependencies unconditionally.
 [target.'cfg(all(not(windows), any(rustix_use_libc, miri, not(all(target_os = "linux", any(target_endian = "little", any(target_arch = "s390x", target_arch = "powerpc")), any(target_arch = "arm", all(target_arch = "aarch64", target_pointer_width = "64"), target_arch = "riscv64", all(rustix_use_experimental_asm, target_arch = "powerpc"), all(rustix_use_experimental_asm, target_arch = "powerpc64"), all(rustix_use_experimental_asm, target_arch = "s390x"), all(rustix_use_experimental_asm, target_arch = "mips"), all(rustix_use_experimental_asm, target_arch = "mips32r6"), all(rustix_use_experimental_asm, target_arch = "mips64"), all(rustix_use_experimental_asm, target_arch = "mips64r6"), target_arch = "x86", all(target_arch = "x86_64", target_pointer_width = "64")))))))'.dependencies]
 libc_errno = { package = "errno", version = "0.3.10", default-features = false }
-libc = { version = "0.2.171", default-features = false }
+libc = { version = "0.2.174", default-features = false }
 
 # Additional dependencies for Linux with the libc backend:
 #
@@ -66,7 +66,7 @@ default-features = false
 
 [dev-dependencies]
 tempfile = "3.5.0"
-libc = "0.2.171"
+libc = "0.2.174"
 libc_errno = { package = "errno", version = "0.3.10", default-features = false }
 serial_test = "2.0.0"
 memoffset = "0.9.0"

src/backend/linux_raw/c.rs

@@ -383,3 +383,12 @@ mod statx_flags {
     )
 ))]
 pub(crate) use statx_flags::*;
+
+#[cfg(feature = "thread")]
+pub(crate) use linux_raw_sys::ioctl::{
+    NS_GET_NSTYPE,
+    NS_GET_OWNER_UID,
+    NS_GET_PARENT,
+    NS_GET_USERNS,
+    // NS_GET_PID_FROM_PIDNS, NS_GET_PID_IN_PIDNS, NS_GET_TGID_FROM_PIDNS, NS_GET_TGID_IN_PIDNS,
+};

src/ioctl/patterns.rs

@@ -39,7 +39,7 @@ unsafe impl<const OPCODE: Opcode> Ioctl for NoArg<OPCODE> {
 
     const IS_MUTATING: bool = false;
 
-    fn opcode(&self) -> self::Opcode {
+    fn opcode(&self) -> Opcode {
         OPCODE
     }
 
@@ -52,6 +52,97 @@ unsafe impl<const OPCODE: Opcode> Ioctl for NoArg<OPCODE> {
     }
 }
 
+/// Implements an `ioctl` with no real arguments that returns an integer.
+///
+/// To compute a value for the `OPCODE` argument, see the functions in the
+/// [`opcode`] module.
+///
+/// [`opcode`]: crate::ioctl::opcode
+pub struct NoArgGetter<const OPCODE: Opcode> {}
+impl<const OPCODE: Opcode> fmt::Debug for NoArgGetter<OPCODE> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_tuple("NoArgGetter").field(&OPCODE).finish()
+    }
+}
+impl<const OPCODE: Opcode> NoArgGetter<OPCODE> {
+    /// Create a new no-argument-getter `ioctl` object.
+    ///
+    /// # Safety
+    ///
+    /// - `OPCODE` must provide a valid opcode.
+    #[inline]
+    pub const unsafe fn new() -> Self {
+        Self {}
+    }
+}
+unsafe impl<const OPCODE: Opcode> Ioctl for NoArgGetter<OPCODE> {
+    type Output = IoctlOutput;
+
+    const IS_MUTATING: bool = false;
+
+    fn opcode(&self) -> Opcode {
+        OPCODE
+    }
+
+    fn as_ptr(&mut self) -> *mut c::c_void {
+        core::ptr::null_mut()
+    }
+
+    unsafe fn output_from_ptr(output: IoctlOutput, _: *mut c::c_void) -> Result<Self::Output> {
+        Ok(output)
+    }
+}
+
+/// Implements an `ioctl` with one real argument that returns an integer.
+///
+/// To compute a value for the `OPCODE` argument, see the functions in the
+/// [`opcode`] module.
+///
+/// [`opcode`]: crate::ioctl::opcode
+pub struct ParameterizedReturnGetter<const OPCODE: Opcode> {
+    value: *const c::c_void,
+}
+
+impl<const OPCODE: Opcode> fmt::Debug for ParameterizedReturnGetter<OPCODE> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_tuple("ParameterizedReturnGetter")
+            .field(&OPCODE)
+            .field(&self.value)
+            .finish()
+    }
+}
+
+impl<const OPCODE: Opcode> ParameterizedReturnGetter<OPCODE> {
+    /// Create a new `ioctl` object.
+    ///
+    /// # Safety
+    ///
+    /// - `OPCODE` must provide a valid opcode.
+    #[inline]
+    pub const unsafe fn new(value: usize) -> Self {
+        Self {
+            value: core::ptr::without_provenance(value),
+        }
+    }
+}
+unsafe impl<const OPCODE: Opcode> Ioctl for ParameterizedReturnGetter<OPCODE> {
+    type Output = IoctlOutput;
+
+    const IS_MUTATING: bool = false;
+
+    fn opcode(&self) -> Opcode {
+        OPCODE
+    }
+
+    fn as_ptr(&mut self) -> *mut c::c_void {
+        self.value.cast_mut()
+    }
+
+    unsafe fn output_from_ptr(output: IoctlOutput, _: *mut c::c_void) -> Result<Self::Output> {
+        Ok(output)
+    }
+}
+
 /// Implements the traditional “getter” pattern for `ioctl`s.
 ///
 /// Some `ioctl`s just read data into the userspace. As this is a popular
@@ -93,7 +184,7 @@ unsafe impl<const OPCODE: Opcode, Output> Ioctl for Getter<OPCODE, Output> {
 
     const IS_MUTATING: bool = true;
 
-    fn opcode(&self) -> self::Opcode {
+    fn opcode(&self) -> Opcode {
         OPCODE
     }
 
@@ -148,7 +239,7 @@ unsafe impl<const OPCODE: Opcode, Input> Ioctl for Setter<OPCODE, Input> {
 
     const IS_MUTATING: bool = false;
 
-    fn opcode(&self) -> self::Opcode {
+    fn opcode(&self) -> Opcode {
         OPCODE
     }
 
@@ -175,6 +266,15 @@ pub struct Updater<'a, const OPCODE: Opcode, Value> {
     value: &'a mut Value,
 }
 
+impl<'a, const OPCODE: Opcode, Value: fmt::Debug> fmt::Debug for Updater<'a, OPCODE, Value> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_tuple("Setter")
+            .field(&OPCODE)
+            .field(&self.value)
+            .finish()
+    }
+}
+
 impl<'a, const OPCODE: Opcode, Value> Updater<'a, OPCODE, Value> {
     /// Create a new pointer updater-style `ioctl` object.
     ///
@@ -194,7 +294,7 @@ unsafe impl<'a, const OPCODE: Opcode, T> Ioctl for Updater<'a, OPCODE, T> {
 
     const IS_MUTATING: bool = true;
 
-    fn opcode(&self) -> self::Opcode {
+    fn opcode(&self) -> Opcode {
         OPCODE
     }
 
@@ -220,6 +320,15 @@ pub struct IntegerSetter<const OPCODE: Opcode> {
     value: *mut c::c_void,
 }
 
+impl<const OPCODE: Opcode> fmt::Debug for IntegerSetter<OPCODE> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_tuple("IntegerSetter")
+            .field(&OPCODE)
+            .field(&self.value)
+            .finish()
+    }
+}
+
 impl<const OPCODE: Opcode> IntegerSetter<OPCODE> {
     /// Create a new integer `Ioctl` helper containing a `usize`.
     ///
@@ -251,7 +360,7 @@ unsafe impl<const OPCODE: Opcode> Ioctl for IntegerSetter<OPCODE> {
 
     const IS_MUTATING: bool = false;
 
-    fn opcode(&self) -> self::Opcode {
+    fn opcode(&self) -> Opcode {
         OPCODE
     }
 

src/thread/mod.rs

@@ -11,12 +11,12 @@ mod libcap;
 #[cfg(linux_kernel)]
 mod membarrier;
 #[cfg(linux_kernel)]
+mod ns;
+#[cfg(linux_kernel)]
 mod prctl;
 #[cfg(any(freebsdlike, linux_kernel, target_os = "fuchsia"))]
 mod sched;
 mod sched_yield;
-#[cfg(linux_kernel)]
-mod setns;
 
 #[cfg(not(target_os = "redox"))]
 pub use clock::*;
@@ -29,9 +29,9 @@ pub use libcap::{capabilities, set_capabilities, CapabilityFlags, CapabilitySet,
 #[cfg(linux_kernel)]
 pub use membarrier::*;
 #[cfg(linux_kernel)]
+pub use ns::*;
+#[cfg(linux_kernel)]
 pub use prctl::*;
 #[cfg(any(freebsdlike, linux_kernel, target_os = "fuchsia"))]
 pub use sched::*;
 pub use sched_yield::sched_yield;
-#[cfg(linux_kernel)]
-pub use setns::*;