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Diffstat (limited to 'third_party/rust/getrandom/src/error.rs')
| -rw-r--r-- | third_party/rust/getrandom/src/error.rs | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/third_party/rust/getrandom/src/error.rs b/third_party/rust/getrandom/src/error.rs new file mode 100644 index 0000000000..ab39a3c33a --- /dev/null +++ b/third_party/rust/getrandom/src/error.rs @@ -0,0 +1,191 @@ +// 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); + } +} |