Vendor dependencies for 0.3.0 release

vendor/rustix/src/rand/getrandom.rs

@@ -0,0 +1,33 @@
+//! Wrappers for `getrandom`.
+
+#![allow(unsafe_code)]
+
+use crate::buffer::Buffer;
+use crate::{backend, io};
+
+pub use backend::rand::types::GetRandomFlags;
+
+/// `getrandom(buf, flags)`—Reads a sequence of random bytes.
+///
+/// This is a very low-level API which may be difficult to use correctly. Most
+/// users should prefer to use [`getrandom`] or [`rand`] APIs instead.
+///
+/// This function is implemented using a system call, and not the
+/// [vDSO mechanism] introduced in Linux 6.11. See [#1185] for details.
+///
+/// [`getrandom`]: https://crates.io/crates/getrandom
+/// [`rand`]: https://crates.io/crates/rand
+/// [vDSO mechanism]: https://lwn.net/Articles/983186/
+/// [#1185]: https://github.com/bytecodealliance/rustix/issues/1185
+///
+/// # References
+///  - [Linux]
+///
+/// [Linux]: https://man7.org/linux/man-pages/man2/getrandom.2.html
+#[inline]
+pub fn getrandom<Buf: Buffer<u8>>(mut buf: Buf, flags: GetRandomFlags) -> io::Result<Buf::Output> {
+    // SAFETY: `getrandom` behaves.
+    let len = unsafe { backend::rand::syscalls::getrandom(buf.parts_mut(), flags)? };
+    // SAFETY: `getrandom` behaves.
+    unsafe { Ok(buf.assume_init(len)) }
+}