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author | Valentin Popov <valentin@popov.link> | 2024-01-08 00:21:28 +0300 |
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committer | Valentin Popov <valentin@popov.link> | 2024-01-08 00:21:28 +0300 |
commit | 1b6a04ca5504955c571d1c97504fb45ea0befee4 (patch) | |
tree | 7579f518b23313e8a9748a88ab6173d5e030b227 /vendor/rustix/src/backend/libc/io/syscalls.rs | |
parent | 5ecd8cf2cba827454317368b68571df0d13d7842 (diff) | |
download | fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.tar.xz fparkan-1b6a04ca5504955c571d1c97504fb45ea0befee4.zip |
Initial vendor packages
Signed-off-by: Valentin Popov <valentin@popov.link>
Diffstat (limited to 'vendor/rustix/src/backend/libc/io/syscalls.rs')
-rw-r--r-- | vendor/rustix/src/backend/libc/io/syscalls.rs | 340 |
1 files changed, 340 insertions, 0 deletions
diff --git a/vendor/rustix/src/backend/libc/io/syscalls.rs b/vendor/rustix/src/backend/libc/io/syscalls.rs new file mode 100644 index 0000000..e28e6be --- /dev/null +++ b/vendor/rustix/src/backend/libc/io/syscalls.rs @@ -0,0 +1,340 @@ +//! libc syscalls supporting `rustix::io`. + +use crate::backend::c; +#[cfg(not(target_os = "wasi"))] +use crate::backend::conv::ret_discarded_fd; +use crate::backend::conv::{borrowed_fd, ret, ret_c_int, ret_owned_fd, ret_usize}; +use crate::fd::{AsFd, BorrowedFd, OwnedFd, RawFd}; +#[cfg(not(any( + target_os = "aix", + target_os = "espidf", + target_os = "nto", + target_os = "vita", + target_os = "wasi" +)))] +use crate::io::DupFlags; +#[cfg(linux_kernel)] +use crate::io::ReadWriteFlags; +use crate::io::{self, FdFlags}; +use crate::ioctl::{IoctlOutput, RawOpcode}; +use core::cmp::min; +#[cfg(all(feature = "fs", feature = "net"))] +use libc_errno::errno; +#[cfg(not(target_os = "espidf"))] +use { + crate::backend::MAX_IOV, + crate::io::{IoSlice, IoSliceMut}, +}; + +pub(crate) unsafe fn read(fd: BorrowedFd<'_>, buf: *mut u8, len: usize) -> io::Result<usize> { + ret_usize(c::read(borrowed_fd(fd), buf.cast(), min(len, READ_LIMIT))) +} + +pub(crate) fn write(fd: BorrowedFd<'_>, buf: &[u8]) -> io::Result<usize> { + unsafe { + ret_usize(c::write( + borrowed_fd(fd), + buf.as_ptr().cast(), + min(buf.len(), READ_LIMIT), + )) + } +} + +pub(crate) unsafe fn pread( + fd: BorrowedFd<'_>, + buf: *mut u8, + len: usize, + offset: u64, +) -> io::Result<usize> { + let len = min(len, READ_LIMIT); + + // Silently cast; we'll get `EINVAL` if the value is negative. + let offset = offset as i64; + + // ESP-IDF and Vita don't support 64-bit offsets. + #[cfg(any(target_os = "espidf", target_os = "vita"))] + let offset: i32 = offset.try_into().map_err(|_| io::Errno::OVERFLOW)?; + + ret_usize(c::pread(borrowed_fd(fd), buf.cast(), len, offset)) +} + +pub(crate) fn pwrite(fd: BorrowedFd<'_>, buf: &[u8], offset: u64) -> io::Result<usize> { + let len = min(buf.len(), READ_LIMIT); + + // Silently cast; we'll get `EINVAL` if the value is negative. + let offset = offset as i64; + + // ESP-IDF and Vita don't support 64-bit offsets. + #[cfg(any(target_os = "espidf", target_os = "vita"))] + let offset: i32 = offset.try_into().map_err(|_| io::Errno::OVERFLOW)?; + + unsafe { ret_usize(c::pwrite(borrowed_fd(fd), buf.as_ptr().cast(), len, offset)) } +} + +#[cfg(not(target_os = "espidf"))] +pub(crate) fn readv(fd: BorrowedFd<'_>, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> { + unsafe { + ret_usize(c::readv( + borrowed_fd(fd), + bufs.as_ptr().cast::<c::iovec>(), + min(bufs.len(), MAX_IOV) as c::c_int, + )) + } +} + +#[cfg(not(target_os = "espidf"))] +pub(crate) fn writev(fd: BorrowedFd<'_>, bufs: &[IoSlice<'_>]) -> io::Result<usize> { + unsafe { + ret_usize(c::writev( + borrowed_fd(fd), + bufs.as_ptr().cast::<c::iovec>(), + min(bufs.len(), MAX_IOV) as c::c_int, + )) + } +} + +#[cfg(not(any( + target_os = "espidf", + target_os = "haiku", + target_os = "nto", + target_os = "redox", + target_os = "solaris", + target_os = "vita" +)))] +pub(crate) fn preadv( + fd: BorrowedFd<'_>, + bufs: &mut [IoSliceMut<'_>], + offset: u64, +) -> io::Result<usize> { + // Silently cast; we'll get `EINVAL` if the value is negative. + let offset = offset as i64; + unsafe { + ret_usize(c::preadv( + borrowed_fd(fd), + bufs.as_ptr().cast::<c::iovec>(), + min(bufs.len(), MAX_IOV) as c::c_int, + offset, + )) + } +} + +#[cfg(not(any( + target_os = "espidf", + target_os = "haiku", + target_os = "nto", + target_os = "redox", + target_os = "solaris", + target_os = "vita" +)))] +pub(crate) fn pwritev(fd: BorrowedFd<'_>, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize> { + // Silently cast; we'll get `EINVAL` if the value is negative. + let offset = offset as i64; + unsafe { + ret_usize(c::pwritev( + borrowed_fd(fd), + bufs.as_ptr().cast::<c::iovec>(), + min(bufs.len(), MAX_IOV) as c::c_int, + offset, + )) + } +} + +#[cfg(linux_kernel)] +pub(crate) fn preadv2( + fd: BorrowedFd<'_>, + bufs: &mut [IoSliceMut<'_>], + offset: u64, + flags: ReadWriteFlags, +) -> io::Result<usize> { + // Silently cast; we'll get `EINVAL` if the value is negative. + let offset = offset as i64; + unsafe { + ret_usize(c::preadv2( + borrowed_fd(fd), + bufs.as_ptr().cast::<c::iovec>(), + min(bufs.len(), MAX_IOV) as c::c_int, + offset, + bitflags_bits!(flags), + )) + } +} + +#[cfg(linux_kernel)] +pub(crate) fn pwritev2( + fd: BorrowedFd<'_>, + bufs: &[IoSlice<'_>], + offset: u64, + flags: ReadWriteFlags, +) -> io::Result<usize> { + // Silently cast; we'll get `EINVAL` if the value is negative. + let offset = offset as i64; + unsafe { + ret_usize(c::pwritev2( + borrowed_fd(fd), + bufs.as_ptr().cast::<c::iovec>(), + min(bufs.len(), MAX_IOV) as c::c_int, + offset, + bitflags_bits!(flags), + )) + } +} + +// These functions are derived from Rust's library/std/src/sys/unix/fd.rs at +// revision 326ef470a8b379a180d6dc4bbef08990698a737a. + +// The maximum read limit on most POSIX-like systems is `SSIZE_MAX`, with the +// manual page quoting that if the count of bytes to read is greater than +// `SSIZE_MAX` the result is “unspecified”. +// +// On macOS, however, apparently the 64-bit libc is either buggy or +// intentionally showing odd behavior by rejecting any read with a size larger +// than or equal to `INT_MAX`. To handle both of these the read size is capped +// on both platforms. +#[cfg(target_os = "macos")] +const READ_LIMIT: usize = c::c_int::MAX as usize - 1; +#[cfg(not(target_os = "macos"))] +const READ_LIMIT: usize = c::ssize_t::MAX as usize; + +pub(crate) unsafe fn close(raw_fd: RawFd) { + let _ = c::close(raw_fd as c::c_int); +} + +#[inline] +pub(crate) unsafe fn ioctl( + fd: BorrowedFd<'_>, + request: RawOpcode, + arg: *mut c::c_void, +) -> io::Result<IoctlOutput> { + ret_c_int(c::ioctl(borrowed_fd(fd), request, arg)) +} + +#[inline] +pub(crate) unsafe fn ioctl_readonly( + fd: BorrowedFd<'_>, + request: RawOpcode, + arg: *mut c::c_void, +) -> io::Result<IoctlOutput> { + ioctl(fd, request, arg) +} + +#[cfg(not(any(target_os = "redox", target_os = "wasi")))] +#[cfg(all(feature = "fs", feature = "net"))] +pub(crate) fn is_read_write(fd: BorrowedFd<'_>) -> io::Result<(bool, bool)> { + use core::mem::MaybeUninit; + + let (mut read, mut write) = crate::fs::fd::_is_file_read_write(fd)?; + let mut not_socket = false; + if read { + // Do a `recv` with `PEEK` and `DONTWAIT` for 1 byte. A 0 indicates + // the read side is shut down; an `EWOULDBLOCK` indicates the read + // side is still open. + match unsafe { + c::recv( + borrowed_fd(fd), + MaybeUninit::<[u8; 1]>::uninit() + .as_mut_ptr() + .cast::<c::c_void>(), + 1, + c::MSG_PEEK | c::MSG_DONTWAIT, + ) + } { + 0 => read = false, + -1 => { + #[allow(unreachable_patterns)] // `EAGAIN` may equal `EWOULDBLOCK` + match errno().0 { + c::EAGAIN | c::EWOULDBLOCK => (), + c::ENOTSOCK => not_socket = true, + err => return Err(io::Errno(err)), + } + } + _ => (), + } + } + if write && !not_socket { + // Do a `send` with `DONTWAIT` for 0 bytes. An `EPIPE` indicates + // the write side is shut down. + if unsafe { c::send(borrowed_fd(fd), [].as_ptr(), 0, c::MSG_DONTWAIT) } == -1 { + #[allow(unreachable_patterns)] // `EAGAIN` may equal `EWOULDBLOCK` + match errno().0 { + c::EAGAIN | c::EWOULDBLOCK | c::ENOTSOCK => (), + c::EPIPE => write = false, + err => return Err(io::Errno(err)), + } + } + } + Ok((read, write)) +} + +#[cfg(target_os = "wasi")] +#[cfg(all(feature = "fs", feature = "net"))] +pub(crate) fn is_read_write(_fd: BorrowedFd<'_>) -> io::Result<(bool, bool)> { + todo!("Implement is_read_write for WASI in terms of fd_fdstat_get"); +} + +pub(crate) fn fcntl_getfd(fd: BorrowedFd<'_>) -> io::Result<FdFlags> { + let flags = unsafe { ret_c_int(c::fcntl(borrowed_fd(fd), c::F_GETFD))? }; + Ok(FdFlags::from_bits_retain(bitcast!(flags))) +} + +pub(crate) fn fcntl_setfd(fd: BorrowedFd<'_>, flags: FdFlags) -> io::Result<()> { + unsafe { ret(c::fcntl(borrowed_fd(fd), c::F_SETFD, flags.bits())) } +} + +#[cfg(not(any(target_os = "espidf", target_os = "wasi")))] +pub(crate) fn fcntl_dupfd_cloexec(fd: BorrowedFd<'_>, min: RawFd) -> io::Result<OwnedFd> { + unsafe { ret_owned_fd(c::fcntl(borrowed_fd(fd), c::F_DUPFD_CLOEXEC, min)) } +} + +#[cfg(target_os = "espidf")] +pub(crate) fn fcntl_dupfd(fd: BorrowedFd<'_>, min: RawFd) -> io::Result<OwnedFd> { + unsafe { ret_owned_fd(c::fcntl(borrowed_fd(fd), c::F_DUPFD, min)) } +} + +#[cfg(not(target_os = "wasi"))] +pub(crate) fn dup(fd: BorrowedFd<'_>) -> io::Result<OwnedFd> { + unsafe { ret_owned_fd(c::dup(borrowed_fd(fd))) } +} + +#[allow(clippy::needless_pass_by_ref_mut)] +#[cfg(not(target_os = "wasi"))] +pub(crate) fn dup2(fd: BorrowedFd<'_>, new: &mut OwnedFd) -> io::Result<()> { + unsafe { ret_discarded_fd(c::dup2(borrowed_fd(fd), borrowed_fd(new.as_fd()))) } +} + +#[allow(clippy::needless_pass_by_ref_mut)] +#[cfg(not(any( + apple, + target_os = "aix", + target_os = "android", + target_os = "dragonfly", + target_os = "espidf", + target_os = "haiku", + target_os = "nto", + target_os = "redox", + target_os = "vita", + target_os = "wasi", +)))] +pub(crate) fn dup3(fd: BorrowedFd<'_>, new: &mut OwnedFd, flags: DupFlags) -> io::Result<()> { + unsafe { + ret_discarded_fd(c::dup3( + borrowed_fd(fd), + borrowed_fd(new.as_fd()), + bitflags_bits!(flags), + )) + } +} + +#[cfg(any( + apple, + target_os = "android", + target_os = "dragonfly", + target_os = "haiku", + target_os = "redox", +))] +pub(crate) fn dup3(fd: BorrowedFd<'_>, new: &mut OwnedFd, _flags: DupFlags) -> io::Result<()> { + // Android 5.0 has `dup3`, but libc doesn't have bindings. Emulate it + // using `dup2`. We don't need to worry about the difference between + // `dup2` and `dup3` when the file descriptors are equal because we + // have an `&mut OwnedFd` which means `fd` doesn't alias it. + dup2(fd, new) +} |