diff options
Diffstat (limited to 'library/std/src/sys/pal/unix/fd.rs')
| -rw-r--r-- | library/std/src/sys/pal/unix/fd.rs | 557 |
1 files changed, 557 insertions, 0 deletions
diff --git a/library/std/src/sys/pal/unix/fd.rs b/library/std/src/sys/pal/unix/fd.rs new file mode 100644 index 00000000000..bf1fb3123c4 --- /dev/null +++ b/library/std/src/sys/pal/unix/fd.rs @@ -0,0 +1,557 @@ +#![unstable(reason = "not public", issue = "none", feature = "fd")] + +#[cfg(test)] +mod tests; + +use crate::cmp; +use crate::io::{self, BorrowedCursor, IoSlice, IoSliceMut, Read}; +use crate::os::unix::io::{AsFd, AsRawFd, BorrowedFd, FromRawFd, IntoRawFd, OwnedFd, RawFd}; +use crate::sys::cvt; +use crate::sys_common::{AsInner, FromInner, IntoInner}; + +#[cfg(any( + target_os = "android", + target_os = "linux", + target_os = "emscripten", + target_os = "l4re", + target_os = "hurd", +))] +use libc::off64_t; +#[cfg(not(any( + target_os = "linux", + target_os = "emscripten", + target_os = "l4re", + target_os = "android", + target_os = "hurd", +)))] +use libc::off_t as off64_t; + +#[derive(Debug)] +pub struct FileDesc(OwnedFd); + +// The maximum read limit on most POSIX-like systems is `SSIZE_MAX`, +// with the man 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 = libc::c_int::MAX as usize - 1; +#[cfg(not(target_os = "macos"))] +const READ_LIMIT: usize = libc::ssize_t::MAX as usize; + +#[cfg(any( + target_os = "dragonfly", + target_os = "freebsd", + target_os = "ios", + target_os = "tvos", + target_os = "macos", + target_os = "netbsd", + target_os = "openbsd", + target_os = "watchos", +))] +const fn max_iov() -> usize { + libc::IOV_MAX as usize +} + +#[cfg(any( + target_os = "android", + target_os = "emscripten", + target_os = "linux", + target_os = "nto", +))] +const fn max_iov() -> usize { + libc::UIO_MAXIOV as usize +} + +#[cfg(not(any( + target_os = "android", + target_os = "dragonfly", + target_os = "emscripten", + target_os = "freebsd", + target_os = "ios", + target_os = "tvos", + target_os = "linux", + target_os = "macos", + target_os = "netbsd", + target_os = "nto", + target_os = "openbsd", + target_os = "horizon", + target_os = "vita", + target_os = "watchos", +)))] +const fn max_iov() -> usize { + 16 // The minimum value required by POSIX. +} + +impl FileDesc { + pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> { + let ret = cvt(unsafe { + libc::read( + self.as_raw_fd(), + buf.as_mut_ptr() as *mut libc::c_void, + cmp::min(buf.len(), READ_LIMIT), + ) + })?; + Ok(ret as usize) + } + + #[cfg(not(any(target_os = "espidf", target_os = "horizon", target_os = "vita")))] + pub fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> { + let ret = cvt(unsafe { + libc::readv( + self.as_raw_fd(), + bufs.as_mut_ptr() as *mut libc::iovec as *const libc::iovec, + cmp::min(bufs.len(), max_iov()) as libc::c_int, + ) + })?; + Ok(ret as usize) + } + + #[cfg(any(target_os = "espidf", target_os = "horizon", target_os = "vita"))] + pub fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> { + io::default_read_vectored(|b| self.read(b), bufs) + } + + #[inline] + pub fn is_read_vectored(&self) -> bool { + cfg!(not(any(target_os = "espidf", target_os = "horizon", target_os = "vita"))) + } + + pub fn read_to_end(&self, buf: &mut Vec<u8>) -> io::Result<usize> { + let mut me = self; + (&mut me).read_to_end(buf) + } + + pub fn read_at(&self, buf: &mut [u8], offset: u64) -> io::Result<usize> { + #[cfg(not(any( + all(target_os = "linux", not(target_env = "musl")), + target_os = "android", + target_os = "hurd" + )))] + use libc::pread as pread64; + #[cfg(any( + all(target_os = "linux", not(target_env = "musl")), + target_os = "android", + target_os = "hurd" + ))] + use libc::pread64; + + unsafe { + cvt(pread64( + self.as_raw_fd(), + buf.as_mut_ptr() as *mut libc::c_void, + cmp::min(buf.len(), READ_LIMIT), + offset as off64_t, + )) + .map(|n| n as usize) + } + } + + pub fn read_buf(&self, mut cursor: BorrowedCursor<'_>) -> io::Result<()> { + let ret = cvt(unsafe { + libc::read( + self.as_raw_fd(), + cursor.as_mut().as_mut_ptr() as *mut libc::c_void, + cmp::min(cursor.capacity(), READ_LIMIT), + ) + })?; + + // Safety: `ret` bytes were written to the initialized portion of the buffer + unsafe { + cursor.advance(ret as usize); + } + Ok(()) + } + + #[cfg(any( + target_os = "emscripten", + target_os = "freebsd", + target_os = "fuchsia", + target_os = "hurd", + target_os = "illumos", + target_os = "linux", + target_os = "netbsd", + ))] + pub fn read_vectored_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize> { + let ret = cvt(unsafe { + libc::preadv( + self.as_raw_fd(), + bufs.as_mut_ptr() as *mut libc::iovec as *const libc::iovec, + cmp::min(bufs.len(), max_iov()) as libc::c_int, + offset as _, + ) + })?; + Ok(ret as usize) + } + + #[cfg(not(any( + target_os = "android", + target_os = "emscripten", + target_os = "freebsd", + target_os = "fuchsia", + target_os = "hurd", + target_os = "illumos", + target_os = "ios", + target_os = "tvos", + target_os = "linux", + target_os = "macos", + target_os = "netbsd", + )))] + pub fn read_vectored_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize> { + io::default_read_vectored(|b| self.read_at(b, offset), bufs) + } + + // We support some old Android versions that do not have `preadv` in libc, + // so we use weak linkage and fallback to a direct syscall if not available. + // + // On 32-bit targets, we don't want to deal with weird ABI issues around + // passing 64-bits parameters to syscalls, so we fallback to the default + // implementation if `preadv` is not available. + #[cfg(all(target_os = "android", target_pointer_width = "64"))] + pub fn read_vectored_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize> { + super::weak::syscall! { + fn preadv( + fd: libc::c_int, + iovec: *const libc::iovec, + n_iovec: libc::c_int, + offset: off64_t + ) -> isize + } + + let ret = cvt(unsafe { + preadv( + self.as_raw_fd(), + bufs.as_mut_ptr() as *mut libc::iovec as *const libc::iovec, + cmp::min(bufs.len(), max_iov()) as libc::c_int, + offset as _, + ) + })?; + Ok(ret as usize) + } + + // We support old MacOS and iOS versions that do not have `preadv`. There is + // no `syscall` possible in these platform. + #[cfg(any( + all(target_os = "android", target_pointer_width = "32"), + target_os = "ios", + target_os = "tvos", + target_os = "macos", + ))] + pub fn read_vectored_at(&self, bufs: &mut [IoSliceMut<'_>], offset: u64) -> io::Result<usize> { + super::weak::weak!(fn preadv64(libc::c_int, *const libc::iovec, libc::c_int, off64_t) -> isize); + + match preadv64.get() { + Some(preadv) => { + let ret = cvt(unsafe { + preadv( + self.as_raw_fd(), + bufs.as_mut_ptr() as *mut libc::iovec as *const libc::iovec, + cmp::min(bufs.len(), max_iov()) as libc::c_int, + offset as _, + ) + })?; + Ok(ret as usize) + } + None => io::default_read_vectored(|b| self.read_at(b, offset), bufs), + } + } + + pub fn write(&self, buf: &[u8]) -> io::Result<usize> { + let ret = cvt(unsafe { + libc::write( + self.as_raw_fd(), + buf.as_ptr() as *const libc::c_void, + cmp::min(buf.len(), READ_LIMIT), + ) + })?; + Ok(ret as usize) + } + + #[cfg(not(any(target_os = "espidf", target_os = "horizon", target_os = "vita")))] + pub fn write_vectored(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> { + let ret = cvt(unsafe { + libc::writev( + self.as_raw_fd(), + bufs.as_ptr() as *const libc::iovec, + cmp::min(bufs.len(), max_iov()) as libc::c_int, + ) + })?; + Ok(ret as usize) + } + + #[cfg(any(target_os = "espidf", target_os = "horizon", target_os = "vita"))] + pub fn write_vectored(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> { + io::default_write_vectored(|b| self.write(b), bufs) + } + + #[inline] + pub fn is_write_vectored(&self) -> bool { + cfg!(not(any(target_os = "espidf", target_os = "horizon", target_os = "vita"))) + } + + pub fn write_at(&self, buf: &[u8], offset: u64) -> io::Result<usize> { + #[cfg(not(any( + all(target_os = "linux", not(target_env = "musl")), + target_os = "android", + target_os = "hurd" + )))] + use libc::pwrite as pwrite64; + #[cfg(any( + all(target_os = "linux", not(target_env = "musl")), + target_os = "android", + target_os = "hurd" + ))] + use libc::pwrite64; + + unsafe { + cvt(pwrite64( + self.as_raw_fd(), + buf.as_ptr() as *const libc::c_void, + cmp::min(buf.len(), READ_LIMIT), + offset as off64_t, + )) + .map(|n| n as usize) + } + } + + #[cfg(any( + target_os = "emscripten", + target_os = "freebsd", + target_os = "fuchsia", + target_os = "hurd", + target_os = "illumos", + target_os = "linux", + target_os = "netbsd", + ))] + pub fn write_vectored_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize> { + let ret = cvt(unsafe { + libc::pwritev( + self.as_raw_fd(), + bufs.as_ptr() as *const libc::iovec, + cmp::min(bufs.len(), max_iov()) as libc::c_int, + offset as _, + ) + })?; + Ok(ret as usize) + } + + #[cfg(not(any( + target_os = "android", + target_os = "emscripten", + target_os = "freebsd", + target_os = "fuchsia", + target_os = "hurd", + target_os = "illumos", + target_os = "ios", + target_os = "tvos", + target_os = "linux", + target_os = "macos", + target_os = "netbsd", + )))] + pub fn write_vectored_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize> { + io::default_write_vectored(|b| self.write_at(b, offset), bufs) + } + + // We support some old Android versions that do not have `pwritev` in libc, + // so we use weak linkage and fallback to a direct syscall if not available. + // + // On 32-bit targets, we don't want to deal with weird ABI issues around + // passing 64-bits parameters to syscalls, so we fallback to the default + // implementation if `pwritev` is not available. + #[cfg(all(target_os = "android", target_pointer_width = "64"))] + pub fn write_vectored_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize> { + super::weak::syscall! { + fn pwritev( + fd: libc::c_int, + iovec: *const libc::iovec, + n_iovec: libc::c_int, + offset: off64_t + ) -> isize + } + + let ret = cvt(unsafe { + pwritev( + self.as_raw_fd(), + bufs.as_ptr() as *const libc::iovec, + cmp::min(bufs.len(), max_iov()) as libc::c_int, + offset as _, + ) + })?; + Ok(ret as usize) + } + + // We support old MacOS and iOS versions that do not have `pwritev`. There is + // no `syscall` possible in these platform. + #[cfg(any( + all(target_os = "android", target_pointer_width = "32"), + target_os = "ios", + target_os = "tvos", + target_os = "macos", + ))] + pub fn write_vectored_at(&self, bufs: &[IoSlice<'_>], offset: u64) -> io::Result<usize> { + super::weak::weak!(fn pwritev64(libc::c_int, *const libc::iovec, libc::c_int, off64_t) -> isize); + + match pwritev64.get() { + Some(pwritev) => { + let ret = cvt(unsafe { + pwritev( + self.as_raw_fd(), + bufs.as_ptr() as *const libc::iovec, + cmp::min(bufs.len(), max_iov()) as libc::c_int, + offset as _, + ) + })?; + Ok(ret as usize) + } + None => io::default_write_vectored(|b| self.write_at(b, offset), bufs), + } + } + + #[cfg(not(any( + target_env = "newlib", + target_os = "solaris", + target_os = "illumos", + target_os = "emscripten", + target_os = "fuchsia", + target_os = "l4re", + target_os = "linux", + target_os = "haiku", + target_os = "redox", + target_os = "vxworks", + target_os = "nto", + )))] + pub fn set_cloexec(&self) -> io::Result<()> { + unsafe { + cvt(libc::ioctl(self.as_raw_fd(), libc::FIOCLEX))?; + Ok(()) + } + } + #[cfg(any( + all( + target_env = "newlib", + not(any(target_os = "espidf", target_os = "horizon", target_os = "vita")) + ), + target_os = "solaris", + target_os = "illumos", + target_os = "emscripten", + target_os = "fuchsia", + target_os = "l4re", + target_os = "linux", + target_os = "haiku", + target_os = "redox", + target_os = "vxworks", + target_os = "nto", + ))] + pub fn set_cloexec(&self) -> io::Result<()> { + unsafe { + let previous = cvt(libc::fcntl(self.as_raw_fd(), libc::F_GETFD))?; + let new = previous | libc::FD_CLOEXEC; + if new != previous { + cvt(libc::fcntl(self.as_raw_fd(), libc::F_SETFD, new))?; + } + Ok(()) + } + } + #[cfg(any(target_os = "espidf", target_os = "horizon", target_os = "vita"))] + pub fn set_cloexec(&self) -> io::Result<()> { + // FD_CLOEXEC is not supported in ESP-IDF, Horizon OS and Vita but there's no need to, + // because none of them supports spawning processes. + Ok(()) + } + + #[cfg(target_os = "linux")] + pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> { + unsafe { + let v = nonblocking as libc::c_int; + cvt(libc::ioctl(self.as_raw_fd(), libc::FIONBIO, &v))?; + Ok(()) + } + } + + #[cfg(not(target_os = "linux"))] + pub fn set_nonblocking(&self, nonblocking: bool) -> io::Result<()> { + unsafe { + let previous = cvt(libc::fcntl(self.as_raw_fd(), libc::F_GETFL))?; + let new = if nonblocking { + previous | libc::O_NONBLOCK + } else { + previous & !libc::O_NONBLOCK + }; + if new != previous { + cvt(libc::fcntl(self.as_raw_fd(), libc::F_SETFL, new))?; + } + Ok(()) + } + } + + #[inline] + pub fn duplicate(&self) -> io::Result<FileDesc> { + Ok(Self(self.0.try_clone()?)) + } +} + +impl<'a> Read for &'a FileDesc { + fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> { + (**self).read(buf) + } + + fn read_buf(&mut self, cursor: BorrowedCursor<'_>) -> io::Result<()> { + (**self).read_buf(cursor) + } + + fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> { + (**self).read_vectored(bufs) + } + + #[inline] + fn is_read_vectored(&self) -> bool { + (**self).is_read_vectored() + } +} + +impl AsInner<OwnedFd> for FileDesc { + #[inline] + fn as_inner(&self) -> &OwnedFd { + &self.0 + } +} + +impl IntoInner<OwnedFd> for FileDesc { + fn into_inner(self) -> OwnedFd { + self.0 + } +} + +impl FromInner<OwnedFd> for FileDesc { + fn from_inner(owned_fd: OwnedFd) -> Self { + Self(owned_fd) + } +} + +impl AsFd for FileDesc { + fn as_fd(&self) -> BorrowedFd<'_> { + self.0.as_fd() + } +} + +impl AsRawFd for FileDesc { + #[inline] + fn as_raw_fd(&self) -> RawFd { + self.0.as_raw_fd() + } +} + +impl IntoRawFd for FileDesc { + fn into_raw_fd(self) -> RawFd { + self.0.into_raw_fd() + } +} + +impl FromRawFd for FileDesc { + unsafe fn from_raw_fd(raw_fd: RawFd) -> Self { + Self(FromRawFd::from_raw_fd(raw_fd)) + } +} |