vendor/rand_os/src/cloudabi.rs

   1 // Copyright 2018 Developers of the Rand project.
   2 //
   3 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   4 // https://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   5 // <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your
   6 // option. This file may not be copied, modified, or distributed
   7 // except according to those terms.
   8
   9 //! Implementation for CloudABI
  10
  11 extern crate cloudabi;
  12
  13 use std::io;
  14 use rand_core::{Error, ErrorKind};
  15 use super::OsRngImpl;
  16
  17 #[derive(Clone, Debug)]
  18 pub struct OsRng;
  19
  20 impl OsRngImpl for OsRng {
  21     fn new() -> Result<OsRng, Error> { Ok(OsRng) }
  22
  23     fn fill_chunk(&mut self, dest: &mut [u8]) -> Result<(), Error> {
  24         let errno = unsafe { cloudabi::random_get(dest) };
  25         if errno == cloudabi::errno::SUCCESS {
  26             Ok(())
  27         } else {
  28             // Cloudlibc provides its own `strerror` implementation so we
  29             // can use `from_raw_os_error` here.
  30             Err(Error::with_cause(
  31                 ErrorKind::Unavailable,
  32                 "random_get() system call failed",
  33                 io::Error::from_raw_os_error(errno as i32),
  34             ))
  35         }
  36     }
  37
  38     fn method_str(&self) -> &'static str { "cloudabi::random_get" }
  39 }