1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191
// 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.
use core::{fmt, num::NonZeroU32};
/// A small and `no_std` compatible error type
///
/// The [`Error::raw_os_error()`] will indicate if the error is from the OS, and
/// if so, which error code the OS gave the application. If such an error is
/// encountered, please consult with your system documentation.
///
/// Internally this type is a NonZeroU32, with certain values reserved for
/// certain purposes, see [`Error::INTERNAL_START`] and [`Error::CUSTOM_START`].
///
/// *If this crate's `"std"` Cargo feature is enabled*, then:
/// - [`getrandom::Error`][Error] implements
/// [`std::error::Error`](https://doc.rust-lang.org/std/error/trait.Error.html)
/// - [`std::io::Error`](https://doc.rust-lang.org/std/io/struct.Error.html) implements
/// [`From<getrandom::Error>`](https://doc.rust-lang.org/std/convert/trait.From.html).
#[derive(Copy, Clone, Eq, PartialEq)]
pub struct Error(NonZeroU32);
const fn internal_error(n: u16) -> Error {
// SAFETY: code > 0 as INTERNAL_START > 0 and adding n won't overflow a u32.
let code = Error::INTERNAL_START + (n as u32);
Error(unsafe { NonZeroU32::new_unchecked(code) })
}
impl Error {
/// This target/platform is not supported by `getrandom`.
pub const UNSUPPORTED: Error = internal_error(0);
/// The platform-specific `errno` returned a non-positive value.
pub const ERRNO_NOT_POSITIVE: Error = internal_error(1);
/// Call to iOS [`SecRandomCopyBytes`](https://developer.apple.com/documentation/security/1399291-secrandomcopybytes) failed.
pub const IOS_SEC_RANDOM: Error = internal_error(3);
/// Call to Windows [`RtlGenRandom`](https://docs.microsoft.com/en-us/windows/win32/api/ntsecapi/nf-ntsecapi-rtlgenrandom) failed.
pub const WINDOWS_RTL_GEN_RANDOM: Error = internal_error(4);
/// RDRAND instruction failed due to a hardware issue.
pub const FAILED_RDRAND: Error = internal_error(5);
/// RDRAND instruction unsupported on this target.
pub const NO_RDRAND: Error = internal_error(6);
/// The environment does not support the Web Crypto API.
pub const WEB_CRYPTO: Error = internal_error(7);
/// Calling Web Crypto API `crypto.getRandomValues` failed.
pub const WEB_GET_RANDOM_VALUES: Error = internal_error(8);
/// On VxWorks, call to `randSecure` failed (random number generator is not yet initialized).
pub const VXWORKS_RAND_SECURE: Error = internal_error(11);
/// Node.js does not have the `crypto` CommonJS module.
pub const NODE_CRYPTO: Error = internal_error(12);
/// Calling Node.js function `crypto.randomFillSync` failed.
pub const NODE_RANDOM_FILL_SYNC: Error = internal_error(13);
/// Called from an ES module on Node.js. This is unsupported, see:
/// <https://docs.rs/getrandom#nodejs-es-module-support>.
pub const NODE_ES_MODULE: Error = internal_error(14);
/// Codes below this point represent OS Errors (i.e. positive i32 values).
/// Codes at or above this point, but below [`Error::CUSTOM_START`] are
/// reserved for use by the `rand` and `getrandom` crates.
pub const INTERNAL_START: u32 = 1 << 31;
/// Codes at or above this point can be used by users to define their own
/// custom errors.
pub const CUSTOM_START: u32 = (1 << 31) + (1 << 30);
/// Extract the raw OS error code (if this error came from the OS)
///
/// This method is identical to [`std::io::Error::raw_os_error()`][1], except
/// that it works in `no_std` contexts. If this method returns `None`, the
/// error value can still be formatted via the `Display` implementation.
///
/// [1]: https://doc.rust-lang.org/std/io/struct.Error.html#method.raw_os_error
#[inline]
pub fn raw_os_error(self) -> Option<i32> {
if self.0.get() < Self::INTERNAL_START {
match () {
#[cfg(target_os = "solid_asp3")]
// On SOLID, negate the error code again to obtain the original
// error code.
() => Some(-(self.0.get() as i32)),
#[cfg(not(target_os = "solid_asp3"))]
() => Some(self.0.get() as i32),
}
} else {
None
}
}
/// Extract the bare error code.
///
/// This code can either come from the underlying OS, or be a custom error.
/// Use [`Error::raw_os_error()`] to disambiguate.
#[inline]
pub const fn code(self) -> NonZeroU32 {
self.0
}
}
cfg_if! {
if #[cfg(unix)] {
fn os_err(errno: i32, buf: &mut [u8]) -> Option<&str> {
let buf_ptr = buf.as_mut_ptr() as *mut libc::c_char;
if unsafe { libc::strerror_r(errno, buf_ptr, buf.len()) } != 0 {
return None;
}
// Take up to trailing null byte
let n = buf.len();
let idx = buf.iter().position(|&b| b == 0).unwrap_or(n);
core::str::from_utf8(&buf[..idx]).ok()
}
} else {
fn os_err(_errno: i32, _buf: &mut [u8]) -> Option<&str> {
None
}
}
}
impl fmt::Debug for Error {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let mut dbg = f.debug_struct("Error");
if let Some(errno) = self.raw_os_error() {
dbg.field("os_error", &errno);
let mut buf = [0u8; 128];
if let Some(err) = os_err(errno, &mut buf) {
dbg.field("description", &err);
}
} else if let Some(desc) = internal_desc(*self) {
dbg.field("internal_code", &self.0.get());
dbg.field("description", &desc);
} else {
dbg.field("unknown_code", &self.0.get());
}
dbg.finish()
}
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
if let Some(errno) = self.raw_os_error() {
let mut buf = [0u8; 128];
match os_err(errno, &mut buf) {
Some(err) => err.fmt(f),
None => write!(f, "OS Error: {}", errno),
}
} else if let Some(desc) = internal_desc(*self) {
f.write_str(desc)
} else {
write!(f, "Unknown Error: {}", self.0.get())
}
}
}
impl From<NonZeroU32> for Error {
fn from(code: NonZeroU32) -> Self {
Self(code)
}
}
fn internal_desc(error: Error) -> Option<&'static str> {
match error {
Error::UNSUPPORTED => Some("getrandom: this target is not supported"),
Error::ERRNO_NOT_POSITIVE => Some("errno: did not return a positive value"),
Error::IOS_SEC_RANDOM => Some("SecRandomCopyBytes: iOS Security framework failure"),
Error::WINDOWS_RTL_GEN_RANDOM => Some("RtlGenRandom: Windows system function failure"),
Error::FAILED_RDRAND => Some("RDRAND: failed multiple times: CPU issue likely"),
Error::NO_RDRAND => Some("RDRAND: instruction not supported"),
Error::WEB_CRYPTO => Some("Web Crypto API is unavailable"),
Error::WEB_GET_RANDOM_VALUES => Some("Calling Web API crypto.getRandomValues failed"),
Error::VXWORKS_RAND_SECURE => Some("randSecure: VxWorks RNG module is not initialized"),
Error::NODE_CRYPTO => Some("Node.js crypto CommonJS module is unavailable"),
Error::NODE_RANDOM_FILL_SYNC => Some("Calling Node.js API crypto.randomFillSync failed"),
Error::NODE_ES_MODULE => Some("Node.js ES modules are not directly supported, see https://docs.rs/getrandom#nodejs-es-module-support"),
_ => None,
}
}
#[cfg(test)]
mod tests {
use super::Error;
use core::mem::size_of;
#[test]
fn test_size() {
assert_eq!(size_of::<Error>(), 4);
assert_eq!(size_of::<Result<(), Error>>(), 4);
}
}