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Diffstat (limited to 'src/backend/linux_raw/io/errno.rs')
| -rw-r--r-- | src/backend/linux_raw/io/errno.rs | 553 |
1 files changed, 553 insertions, 0 deletions
diff --git a/src/backend/linux_raw/io/errno.rs b/src/backend/linux_raw/io/errno.rs new file mode 100644 index 0000000..bc40e9a --- /dev/null +++ b/src/backend/linux_raw/io/errno.rs @@ -0,0 +1,553 @@ +//! The `rustix` `Errno` type. +//! +//! This type holds an OS error code, which conceptually corresponds to an +//! `errno` value. +//! +//! # Safety +//! +//! Linux uses error codes in `-4095..0`; we use rustc attributes to describe +//! this restricted range of values. +#![allow(unsafe_code)] +#![cfg_attr(not(rustc_attrs), allow(unused_unsafe))] + +use crate::backend::c; +use crate::backend::fd::RawFd; +use crate::backend::reg::{RetNumber, RetReg}; +use crate::io; +use linux_raw_sys::errno; + +/// `errno`—An error code. +/// +/// The error type for `rustix` APIs. This is similar to [`std::io::Error`], +/// but only holds an OS error code, and no extra error value. +/// +/// # References +/// - [POSIX] +/// - [Linux] +/// - [Winsock] +/// - [FreeBSD] +/// - [NetBSD] +/// - [OpenBSD] +/// - [DragonFly BSD] +/// - [illumos] +/// - [glibc] +/// +/// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/errno.html +/// [Linux]: https://man7.org/linux/man-pages/man3/errno.3.html +/// [Winsock]: https://learn.microsoft.com/en-us/windows/win32/winsock/windows-sockets-error-codes-2 +/// [FreeBSD]: https://man.freebsd.org/cgi/man.cgi?errno +/// [NetBSD]: https://man.netbsd.org/errno.2 +/// [OpenBSD]: https://man.openbsd.org/errno.2 +/// [DragonFly BSD]: https://man.dragonflybsd.org/?command=errno§ion=2 +/// [illumos]: https://illumos.org/man/3C/errno +/// [glibc]: https://www.gnu.org/software/libc/manual/html_node/Error-Codes.html +/// [`std::io::Error`]: Result +#[repr(transparent)] +#[doc(alias = "errno")] +#[derive(Eq, PartialEq, Hash, Copy, Clone)] +// Linux returns negated error codes, and we leave them in negated form, so +// error codes are in `-4095..0`. +#[cfg_attr(rustc_attrs, rustc_layout_scalar_valid_range_start(0xf001))] +#[cfg_attr(rustc_attrs, rustc_layout_scalar_valid_range_end(0xffff))] +pub struct Errno(u16); + +impl Errno { + /// Extract an `Errno` value from a `std::io::Error`. + /// + /// This isn't a `From` conversion because it's expected to be relatively + /// uncommon. + #[cfg(feature = "std")] + #[inline] + pub fn from_io_error(io_err: &std::io::Error) -> Option<Self> { + io_err.raw_os_error().and_then(|raw| { + // `std::io::Error` could theoretically have arbitrary OS error + // values, so check that they're in Linux's range. + if (1..4096).contains(&raw) { + Some(Self::from_errno(raw as u32)) + } else { + None + } + }) + } + + /// Extract the raw OS error number from this error. + #[inline] + pub const fn raw_os_error(self) -> i32 { + (self.0 as i16 as i32).wrapping_neg() + } + + /// Construct an `Errno` from a raw OS error number. + #[inline] + pub const fn from_raw_os_error(raw: i32) -> Self { + Self::from_errno(raw as u32) + } + + /// Convert from a C `errno` value (which is positive) to an `Errno`. + const fn from_errno(raw: u32) -> Self { + // We store error values in negated form, so that we don't have to + // negate them after every syscall. + let encoded = raw.wrapping_neg() as u16; + + // TODO: Use Range::contains, once that's `const`. + assert!(encoded >= 0xf001); + + // SAFETY: Linux syscalls return negated error values in the range + // `-4095..0`, which we just asserted. + unsafe { Self(encoded) } + } +} + +/// Check for an error from the result of a syscall which encodes a +/// `c::c_int` on success. +#[inline] +pub(in crate::backend) fn try_decode_c_int<Num: RetNumber>( + raw: RetReg<Num>, +) -> io::Result<c::c_int> { + if raw.is_in_range(-4095..0) { + // SAFETY: `raw` must be in `-4095..0`, and we just checked that raw is + // in that range. + return Err(unsafe { Errno(raw.decode_error_code()) }); + } + + Ok(raw.decode_c_int()) +} + +/// Check for an error from the result of a syscall which encodes a +/// `c::c_uint` on success. +#[inline] +pub(in crate::backend) fn try_decode_c_uint<Num: RetNumber>( + raw: RetReg<Num>, +) -> io::Result<c::c_uint> { + if raw.is_in_range(-4095..0) { + // SAFETY: `raw` must be in `-4095..0`, and we just checked that raw is + // in that range. + return Err(unsafe { Errno(raw.decode_error_code()) }); + } + + Ok(raw.decode_c_uint()) +} + +/// Check for an error from the result of a syscall which encodes a `usize` on +/// success. +#[inline] +pub(in crate::backend) fn try_decode_usize<Num: RetNumber>(raw: RetReg<Num>) -> io::Result<usize> { + if raw.is_in_range(-4095..0) { + // SAFETY: `raw` must be in `-4095..0`, and we just checked that raw is + // in that range. + return Err(unsafe { Errno(raw.decode_error_code()) }); + } + + Ok(raw.decode_usize()) +} + +/// Check for an error from the result of a syscall which encodes a +/// `*mut c_void` on success. +#[inline] +pub(in crate::backend) fn try_decode_void_star<Num: RetNumber>( + raw: RetReg<Num>, +) -> io::Result<*mut c::c_void> { + if raw.is_in_range(-4095..0) { + // SAFETY: `raw` must be in `-4095..0`, and we just checked that raw is + // in that range. + return Err(unsafe { Errno(raw.decode_error_code()) }); + } + + Ok(raw.decode_void_star()) +} + +/// Check for an error from the result of a syscall which encodes a +/// `u64` on success. +#[cfg(target_pointer_width = "64")] +#[inline] +pub(in crate::backend) fn try_decode_u64<Num: RetNumber>(raw: RetReg<Num>) -> io::Result<u64> { + if raw.is_in_range(-4095..0) { + // SAFETY: `raw` must be in `-4095..0`, and we just checked that raw is + // in that range. + return Err(unsafe { Errno(raw.decode_error_code()) }); + } + + Ok(raw.decode_u64()) +} + +/// Check for an error from the result of a syscall which encodes a file +/// descriptor on success. +/// +/// # Safety +/// +/// This must only be used with syscalls which return file descriptors on +/// success. +#[inline] +pub(in crate::backend) unsafe fn try_decode_raw_fd<Num: RetNumber>( + raw: RetReg<Num>, +) -> io::Result<RawFd> { + // Instead of using `check_result` here, we just check for negative, since + // this function is only used for system calls which return file + // descriptors, and this produces smaller code. + if raw.is_negative() { + debug_assert!(raw.is_in_range(-4095..0)); + + // Tell the optimizer that we know the value is in the error range. + // This helps it avoid unnecessary integer conversions. + #[cfg(core_intrinsics)] + { + core::intrinsics::assume(raw.is_in_range(-4095..0)); + } + + return Err(Errno(raw.decode_error_code())); + } + + Ok(raw.decode_raw_fd()) +} + +/// Check for an error from the result of a syscall which encodes no value on +/// success. On success, return the unconsumed `raw` value. +/// +/// # Safety +/// +/// This must only be used with syscalls which return no value on success. +#[inline] +pub(in crate::backend) unsafe fn try_decode_void<Num: RetNumber>( + raw: RetReg<Num>, +) -> io::Result<()> { + // Instead of using `check_result` here, we just check for zero, since this + // function is only used for system calls which have no other return value, + // and this produces smaller code. + if raw.is_nonzero() { + debug_assert!(raw.is_in_range(-4095..0)); + + // Tell the optimizer that we know the value is in the error range. + // This helps it avoid unnecessary integer conversions. + #[cfg(core_intrinsics)] + { + core::intrinsics::assume(raw.is_in_range(-4095..0)); + } + + return Err(Errno(raw.decode_error_code())); + } + + raw.decode_void(); + + Ok(()) +} + +/// Check for an error from the result of a syscall which does not return on +/// success. On success, return the unconsumed `raw` value. +/// +/// # Safety +/// +/// This must only be used with syscalls which do not return on success. +#[cfg(any(feature = "event", feature = "runtime"))] +#[inline] +pub(in crate::backend) unsafe fn try_decode_error<Num: RetNumber>(raw: RetReg<Num>) -> io::Errno { + debug_assert!(raw.is_in_range(-4095..0)); + + // Tell the optimizer that we know the value is in the error range. + // This helps it avoid unnecessary integer conversions. + #[cfg(core_intrinsics)] + { + core::intrinsics::assume(raw.is_in_range(-4095..0)); + } + + Errno(raw.decode_error_code()) +} + +/// Return the contained `usize` value. +#[cfg(not(debug_assertions))] +#[inline] +pub(in crate::backend) fn decode_usize_infallible<Num: RetNumber>(raw: RetReg<Num>) -> usize { + raw.decode_usize() +} + +/// Return the contained `c_int` value. +#[cfg(not(debug_assertions))] +#[inline] +pub(in crate::backend) fn decode_c_int_infallible<Num: RetNumber>(raw: RetReg<Num>) -> c::c_int { + raw.decode_c_int() +} + +/// Return the contained `c_uint` value. +#[cfg(not(debug_assertions))] +#[inline] +pub(in crate::backend) fn decode_c_uint_infallible<Num: RetNumber>(raw: RetReg<Num>) -> c::c_uint { + raw.decode_c_uint() +} + +impl Errno { + /// `EACCES` + #[doc(alias = "ACCES")] + pub const ACCESS: Self = Self::from_errno(errno::EACCES); + /// `EADDRINUSE` + pub const ADDRINUSE: Self = Self::from_errno(errno::EADDRINUSE); + /// `EADDRNOTAVAIL` + pub const ADDRNOTAVAIL: Self = Self::from_errno(errno::EADDRNOTAVAIL); + /// `EADV` + pub const ADV: Self = Self::from_errno(errno::EADV); + /// `EAFNOSUPPORT` + pub const AFNOSUPPORT: Self = Self::from_errno(errno::EAFNOSUPPORT); + /// `EAGAIN` + pub const AGAIN: Self = Self::from_errno(errno::EAGAIN); + /// `EALREADY` + pub const ALREADY: Self = Self::from_errno(errno::EALREADY); + /// `EBADE` + pub const BADE: Self = Self::from_errno(errno::EBADE); + /// `EBADF` + pub const BADF: Self = Self::from_errno(errno::EBADF); + /// `EBADFD` + pub const BADFD: Self = Self::from_errno(errno::EBADFD); + /// `EBADMSG` + pub const BADMSG: Self = Self::from_errno(errno::EBADMSG); + /// `EBADR` + pub const BADR: Self = Self::from_errno(errno::EBADR); + /// `EBADRQC` + pub const BADRQC: Self = Self::from_errno(errno::EBADRQC); + /// `EBADSLT` + pub const BADSLT: Self = Self::from_errno(errno::EBADSLT); + /// `EBFONT` + pub const BFONT: Self = Self::from_errno(errno::EBFONT); + /// `EBUSY` + pub const BUSY: Self = Self::from_errno(errno::EBUSY); + /// `ECANCELED` + pub const CANCELED: Self = Self::from_errno(errno::ECANCELED); + /// `ECHILD` + pub const CHILD: Self = Self::from_errno(errno::ECHILD); + /// `ECHRNG` + pub const CHRNG: Self = Self::from_errno(errno::ECHRNG); + /// `ECOMM` + pub const COMM: Self = Self::from_errno(errno::ECOMM); + /// `ECONNABORTED` + pub const CONNABORTED: Self = Self::from_errno(errno::ECONNABORTED); + /// `ECONNREFUSED` + pub const CONNREFUSED: Self = Self::from_errno(errno::ECONNREFUSED); + /// `ECONNRESET` + pub const CONNRESET: Self = Self::from_errno(errno::ECONNRESET); + /// `EDEADLK` + pub const DEADLK: Self = Self::from_errno(errno::EDEADLK); + /// `EDEADLOCK` + pub const DEADLOCK: Self = Self::from_errno(errno::EDEADLOCK); + /// `EDESTADDRREQ` + pub const DESTADDRREQ: Self = Self::from_errno(errno::EDESTADDRREQ); + /// `EDOM` + pub const DOM: Self = Self::from_errno(errno::EDOM); + /// `EDOTDOT` + pub const DOTDOT: Self = Self::from_errno(errno::EDOTDOT); + /// `EDQUOT` + pub const DQUOT: Self = Self::from_errno(errno::EDQUOT); + /// `EEXIST` + pub const EXIST: Self = Self::from_errno(errno::EEXIST); + /// `EFAULT` + pub const FAULT: Self = Self::from_errno(errno::EFAULT); + /// `EFBIG` + pub const FBIG: Self = Self::from_errno(errno::EFBIG); + /// `EHOSTDOWN` + pub const HOSTDOWN: Self = Self::from_errno(errno::EHOSTDOWN); + /// `EHOSTUNREACH` + pub const HOSTUNREACH: Self = Self::from_errno(errno::EHOSTUNREACH); + /// `EHWPOISON` + pub const HWPOISON: Self = Self::from_errno(errno::EHWPOISON); + /// `EIDRM` + pub const IDRM: Self = Self::from_errno(errno::EIDRM); + /// `EILSEQ` + pub const ILSEQ: Self = Self::from_errno(errno::EILSEQ); + /// `EINPROGRESS` + pub const INPROGRESS: Self = Self::from_errno(errno::EINPROGRESS); + /// `EINTR`. + /// + /// For a convenient way to retry system calls that exit with `INTR`, use + /// [`retry_on_intr`]. + /// + /// [`retry_on_intr`]: io::retry_on_intr + pub const INTR: Self = Self::from_errno(errno::EINTR); + /// `EINVAL` + pub const INVAL: Self = Self::from_errno(errno::EINVAL); + /// `EIO` + pub const IO: Self = Self::from_errno(errno::EIO); + /// `EISCONN` + pub const ISCONN: Self = Self::from_errno(errno::EISCONN); + /// `EISDIR` + pub const ISDIR: Self = Self::from_errno(errno::EISDIR); + /// `EISNAM` + pub const ISNAM: Self = Self::from_errno(errno::EISNAM); + /// `EKEYEXPIRED` + pub const KEYEXPIRED: Self = Self::from_errno(errno::EKEYEXPIRED); + /// `EKEYREJECTED` + pub const KEYREJECTED: Self = Self::from_errno(errno::EKEYREJECTED); + /// `EKEYREVOKED` + pub const KEYREVOKED: Self = Self::from_errno(errno::EKEYREVOKED); + /// `EL2HLT` + pub const L2HLT: Self = Self::from_errno(errno::EL2HLT); + /// `EL2NSYNC` + pub const L2NSYNC: Self = Self::from_errno(errno::EL2NSYNC); + /// `EL3HLT` + pub const L3HLT: Self = Self::from_errno(errno::EL3HLT); + /// `EL3RST` + pub const L3RST: Self = Self::from_errno(errno::EL3RST); + /// `ELIBACC` + pub const LIBACC: Self = Self::from_errno(errno::ELIBACC); + /// `ELIBBAD` + pub const LIBBAD: Self = Self::from_errno(errno::ELIBBAD); + /// `ELIBEXEC` + pub const LIBEXEC: Self = Self::from_errno(errno::ELIBEXEC); + /// `ELIBMAX` + pub const LIBMAX: Self = Self::from_errno(errno::ELIBMAX); + /// `ELIBSCN` + pub const LIBSCN: Self = Self::from_errno(errno::ELIBSCN); + /// `ELNRNG` + pub const LNRNG: Self = Self::from_errno(errno::ELNRNG); + /// `ELOOP` + pub const LOOP: Self = Self::from_errno(errno::ELOOP); + /// `EMEDIUMTYPE` + pub const MEDIUMTYPE: Self = Self::from_errno(errno::EMEDIUMTYPE); + /// `EMFILE` + pub const MFILE: Self = Self::from_errno(errno::EMFILE); + /// `EMLINK` + pub const MLINK: Self = Self::from_errno(errno::EMLINK); + /// `EMSGSIZE` + pub const MSGSIZE: Self = Self::from_errno(errno::EMSGSIZE); + /// `EMULTIHOP` + pub const MULTIHOP: Self = Self::from_errno(errno::EMULTIHOP); + /// `ENAMETOOLONG` + pub const NAMETOOLONG: Self = Self::from_errno(errno::ENAMETOOLONG); + /// `ENAVAIL` + pub const NAVAIL: Self = Self::from_errno(errno::ENAVAIL); + /// `ENETDOWN` + pub const NETDOWN: Self = Self::from_errno(errno::ENETDOWN); + /// `ENETRESET` + pub const NETRESET: Self = Self::from_errno(errno::ENETRESET); + /// `ENETUNREACH` + pub const NETUNREACH: Self = Self::from_errno(errno::ENETUNREACH); + /// `ENFILE` + pub const NFILE: Self = Self::from_errno(errno::ENFILE); + /// `ENOANO` + pub const NOANO: Self = Self::from_errno(errno::ENOANO); + /// `ENOBUFS` + pub const NOBUFS: Self = Self::from_errno(errno::ENOBUFS); + /// `ENOCSI` + pub const NOCSI: Self = Self::from_errno(errno::ENOCSI); + /// `ENODATA` + #[doc(alias = "NOATTR")] + pub const NODATA: Self = Self::from_errno(errno::ENODATA); + /// `ENODEV` + pub const NODEV: Self = Self::from_errno(errno::ENODEV); + /// `ENOENT` + pub const NOENT: Self = Self::from_errno(errno::ENOENT); + /// `ENOEXEC` + pub const NOEXEC: Self = Self::from_errno(errno::ENOEXEC); + /// `ENOKEY` + pub const NOKEY: Self = Self::from_errno(errno::ENOKEY); + /// `ENOLCK` + pub const NOLCK: Self = Self::from_errno(errno::ENOLCK); + /// `ENOLINK` + pub const NOLINK: Self = Self::from_errno(errno::ENOLINK); + /// `ENOMEDIUM` + pub const NOMEDIUM: Self = Self::from_errno(errno::ENOMEDIUM); + /// `ENOMEM` + pub const NOMEM: Self = Self::from_errno(errno::ENOMEM); + /// `ENOMSG` + pub const NOMSG: Self = Self::from_errno(errno::ENOMSG); + /// `ENONET` + pub const NONET: Self = Self::from_errno(errno::ENONET); + /// `ENOPKG` + pub const NOPKG: Self = Self::from_errno(errno::ENOPKG); + /// `ENOPROTOOPT` + pub const NOPROTOOPT: Self = Self::from_errno(errno::ENOPROTOOPT); + /// `ENOSPC` + pub const NOSPC: Self = Self::from_errno(errno::ENOSPC); + /// `ENOSR` + pub const NOSR: Self = Self::from_errno(errno::ENOSR); + /// `ENOSTR` + pub const NOSTR: Self = Self::from_errno(errno::ENOSTR); + /// `ENOSYS` + pub const NOSYS: Self = Self::from_errno(errno::ENOSYS); + /// `ENOTBLK` + pub const NOTBLK: Self = Self::from_errno(errno::ENOTBLK); + /// `ENOTCONN` + pub const NOTCONN: Self = Self::from_errno(errno::ENOTCONN); + /// `ENOTDIR` + pub const NOTDIR: Self = Self::from_errno(errno::ENOTDIR); + /// `ENOTEMPTY` + pub const NOTEMPTY: Self = Self::from_errno(errno::ENOTEMPTY); + /// `ENOTNAM` + pub const NOTNAM: Self = Self::from_errno(errno::ENOTNAM); + /// `ENOTRECOVERABLE` + pub const NOTRECOVERABLE: Self = Self::from_errno(errno::ENOTRECOVERABLE); + /// `ENOTSOCK` + pub const NOTSOCK: Self = Self::from_errno(errno::ENOTSOCK); + /// `ENOTSUP` + // On Linux, `ENOTSUP` has the same value as `EOPNOTSUPP`. + pub const NOTSUP: Self = Self::from_errno(errno::EOPNOTSUPP); + /// `ENOTTY` + pub const NOTTY: Self = Self::from_errno(errno::ENOTTY); + /// `ENOTUNIQ` + pub const NOTUNIQ: Self = Self::from_errno(errno::ENOTUNIQ); + /// `ENXIO` + pub const NXIO: Self = Self::from_errno(errno::ENXIO); + /// `EOPNOTSUPP` + pub const OPNOTSUPP: Self = Self::from_errno(errno::EOPNOTSUPP); + /// `EOVERFLOW` + pub const OVERFLOW: Self = Self::from_errno(errno::EOVERFLOW); + /// `EOWNERDEAD` + pub const OWNERDEAD: Self = Self::from_errno(errno::EOWNERDEAD); + /// `EPERM` + pub const PERM: Self = Self::from_errno(errno::EPERM); + /// `EPFNOSUPPORT` + pub const PFNOSUPPORT: Self = Self::from_errno(errno::EPFNOSUPPORT); + /// `EPIPE` + pub const PIPE: Self = Self::from_errno(errno::EPIPE); + /// `EPROTO` + pub const PROTO: Self = Self::from_errno(errno::EPROTO); + /// `EPROTONOSUPPORT` + pub const PROTONOSUPPORT: Self = Self::from_errno(errno::EPROTONOSUPPORT); + /// `EPROTOTYPE` + pub const PROTOTYPE: Self = Self::from_errno(errno::EPROTOTYPE); + /// `ERANGE` + pub const RANGE: Self = Self::from_errno(errno::ERANGE); + /// `EREMCHG` + pub const REMCHG: Self = Self::from_errno(errno::EREMCHG); + /// `EREMOTE` + pub const REMOTE: Self = Self::from_errno(errno::EREMOTE); + /// `EREMOTEIO` + pub const REMOTEIO: Self = Self::from_errno(errno::EREMOTEIO); + /// `ERESTART` + pub const RESTART: Self = Self::from_errno(errno::ERESTART); + /// `ERFKILL` + pub const RFKILL: Self = Self::from_errno(errno::ERFKILL); + /// `EROFS` + pub const ROFS: Self = Self::from_errno(errno::EROFS); + /// `ESHUTDOWN` + pub const SHUTDOWN: Self = Self::from_errno(errno::ESHUTDOWN); + /// `ESOCKTNOSUPPORT` + pub const SOCKTNOSUPPORT: Self = Self::from_errno(errno::ESOCKTNOSUPPORT); + /// `ESPIPE` + pub const SPIPE: Self = Self::from_errno(errno::ESPIPE); + /// `ESRCH` + pub const SRCH: Self = Self::from_errno(errno::ESRCH); + /// `ESRMNT` + pub const SRMNT: Self = Self::from_errno(errno::ESRMNT); + /// `ESTALE` + pub const STALE: Self = Self::from_errno(errno::ESTALE); + /// `ESTRPIPE` + pub const STRPIPE: Self = Self::from_errno(errno::ESTRPIPE); + /// `ETIME` + pub const TIME: Self = Self::from_errno(errno::ETIME); + /// `ETIMEDOUT` + pub const TIMEDOUT: Self = Self::from_errno(errno::ETIMEDOUT); + /// `E2BIG` + #[doc(alias = "2BIG")] + pub const TOOBIG: Self = Self::from_errno(errno::E2BIG); + /// `ETOOMANYREFS` + pub const TOOMANYREFS: Self = Self::from_errno(errno::ETOOMANYREFS); + /// `ETXTBSY` + pub const TXTBSY: Self = Self::from_errno(errno::ETXTBSY); + /// `EUCLEAN` + pub const UCLEAN: Self = Self::from_errno(errno::EUCLEAN); + /// `EUNATCH` + pub const UNATCH: Self = Self::from_errno(errno::EUNATCH); + /// `EUSERS` + pub const USERS: Self = Self::from_errno(errno::EUSERS); + /// `EWOULDBLOCK` + pub const WOULDBLOCK: Self = Self::from_errno(errno::EWOULDBLOCK); + /// `EXDEV` + pub const XDEV: Self = Self::from_errno(errno::EXDEV); + /// `EXFULL` + pub const XFULL: Self = Self::from_errno(errno::EXFULL); +} |