Add VxWorks support (#86)

.travis.yml

@@ -139,6 +139,7 @@ matrix:
         - cargo xbuild --target=x86_64-unknown-uefi
         - cargo xbuild --target=x86_64-unknown-hermit
         - cargo xbuild --target=x86_64-unknown-l4re-uclibc
+        - cargo xbuild --target=x86_64-wrs-vxworks
         # also test minimum dependency versions are usable
         - cargo generate-lockfile -Z minimal-versions
         - cargo build --target=x86_64-sun-solaris

Cargo.toml

@@ -22,8 +22,8 @@ cfg-if = "0.1.2"
 compiler_builtins = { version = "0.1", optional = true }
 core = { version = "1.0", optional = true, package = "rustc-std-workspace-core" }
 
-[target.'cfg(any(unix, target_os = "redox"))'.dependencies]
-libc = { version = "0.2.62", default-features = false }
+[target.'cfg(unix)'.dependencies]
+libc = { version = "0.2.64", default-features = false }
 
 [target.'cfg(target_os = "wasi")'.dependencies]
 wasi = "0.7"

src/error.rs

@@ -145,6 +145,7 @@ pub(crate) const BINDGEN_CRYPTO_UNDEF: Error = internal_error!(7);
 pub(crate) const BINDGEN_GRV_UNDEF: Error = internal_error!(8);
 pub(crate) const STDWEB_NO_RNG: Error = internal_error!(9);
 pub(crate) const STDWEB_RNG_FAILED: Error = internal_error!(10);
+pub(crate) const RAND_SECURE_FATAL: Error = internal_error!(11);
 
 fn internal_desc(error: Error) -> Option<&'static str> {
     match error {
@@ -159,6 +160,7 @@ fn internal_desc(error: Error) -> Option<&'static str> {
         BINDGEN_GRV_UNDEF => Some("wasm-bindgen: crypto.getRandomValues is undefined"),
         STDWEB_NO_RNG => Some("stdweb: no randomness source available"),
         STDWEB_RNG_FAILED => Some("stdweb: failed to get randomness"),
+        RAND_SECURE_FATAL => Some("randSecure: random number generator module is not initialized"),
         _ => None,
     }
 }

src/lib.rs

@@ -27,6 +27,7 @@
 //! | Haiku            | `/dev/random` (identical to `/dev/urandom`)
 //! | L4RE, SGX, UEFI  | [RDRAND][18]
 //! | Hermit           | [RDRAND][18] as [`sys_rand`][22] is currently broken.
+//! | VxWorks          | `randABytes` after checking entropy pool initialization with `randSecure`
 //! | Web browsers     | [`Crypto.getRandomValues`][14] (see [Support for WebAssembly and ams.js][14])
 //! | Node.js          | [`crypto.randomBytes`][15] (see [Support for WebAssembly and ams.js][16])
 //! | WASI             | [`__wasi_random_get`][17]
@@ -160,6 +161,10 @@ pub use crate::error::Error;
 #[allow(dead_code)]
 mod util;
 
+#[cfg(target_os = "vxworks")]
+#[allow(dead_code)]
+mod util_libc;
+
 cfg_if! {
     // Unlike the other Unix, Fuchsia and iOS don't use the libc to make any calls.
     if #[cfg(any(target_os = "android", target_os = "dragonfly", target_os = "emscripten",
@@ -221,6 +226,8 @@ cfg_if! {
         #[path = "solaris_illumos.rs"] mod imp;
     } else if #[cfg(target_os = "wasi")] {
         #[path = "wasi.rs"] mod imp;
+    } else if #[cfg(target_os = "vxworks")] {
+        #[path = "vxworks.rs"] mod imp;
     } else if #[cfg(all(windows, getrandom_uwp))] {
         #[path = "windows_uwp.rs"] mod imp;
     } else if #[cfg(windows)] {

src/util_libc.rs

@@ -26,7 +26,10 @@ cfg_if! {
 }
 
 pub fn last_os_error() -> Error {
+    #[cfg(not(target_os = "vxworks"))]
     let errno = unsafe { *errno_location() };
+    #[cfg(target_os = "vxworks")]
+    let errno = unsafe { libc::errnoGet() };
     if errno > 0 {
         Error::from(NonZeroU32::new(errno as u32).unwrap())
     } else {

src/vxworks.rs

@@ -0,0 +1,35 @@
+// Copyright 2018 Developers of the Rand project.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+//! Implementation for VxWorks
+use crate::error::{Error, RAND_SECURE_FATAL};
+use crate::util_libc::last_os_error;
+use core::sync::atomic::{AtomicBool, Ordering::Relaxed};
+
+pub fn getrandom_inner(dest: &mut [u8]) -> Result<(), Error> {
+    static RNG_INIT: AtomicBool = AtomicBool::new(false);
+    while !RNG_INIT.load(Relaxed) {
+        let ret = unsafe { libc::randSecure() };
+        if ret < 0 {
+            return Err(RAND_SECURE_FATAL);
+        } else if ret > 0 {
+            RNG_INIT.store(true, Relaxed);
+            break;
+        }
+        unsafe { libc::usleep(10) };
+    }
+
+    // Prevent overflow of i32
+    for chunk in dest.chunks_mut(i32::max_value() as usize) {
+        let ret = unsafe { libc::randABytes(chunk.as_mut_ptr(), chunk.len() as i32) };
+        if ret != 0 {
+            return Err(last_os_error());
+        }
+    }
+    Ok(())
+}