diff options
Diffstat (limited to 'third_party/rust/nix/src/sys/sendfile.rs')
| -rw-r--r-- | third_party/rust/nix/src/sys/sendfile.rs | 277 |
1 files changed, 277 insertions, 0 deletions
diff --git a/third_party/rust/nix/src/sys/sendfile.rs b/third_party/rust/nix/src/sys/sendfile.rs new file mode 100644 index 0000000000..fb293a4e74 --- /dev/null +++ b/third_party/rust/nix/src/sys/sendfile.rs @@ -0,0 +1,277 @@ +//! Send data from a file to a socket, bypassing userland. + +use cfg_if::cfg_if; +use std::os::unix::io::RawFd; +use std::ptr; + +use libc::{self, off_t}; + +use crate::errno::Errno; +use crate::Result; + +/// Copy up to `count` bytes to `out_fd` from `in_fd` starting at `offset`. +/// +/// Returns a `Result` with the number of bytes written. +/// +/// If `offset` is `None`, `sendfile` will begin reading at the current offset of `in_fd`and will +/// update the offset of `in_fd`. If `offset` is `Some`, `sendfile` will begin at the specified +/// offset and will not update the offset of `in_fd`. Instead, it will mutate `offset` to point to +/// the byte after the last byte copied. +/// +/// `in_fd` must support `mmap`-like operations and therefore cannot be a socket. +/// +/// For more information, see [the sendfile(2) man page.](https://man7.org/linux/man-pages/man2/sendfile.2.html) +#[cfg(any(target_os = "android", target_os = "linux"))] +#[cfg_attr(docsrs, doc(cfg(all())))] +pub fn sendfile( + out_fd: RawFd, + in_fd: RawFd, + offset: Option<&mut off_t>, + count: usize, +) -> Result<usize> { + let offset = offset + .map(|offset| offset as *mut _) + .unwrap_or(ptr::null_mut()); + let ret = unsafe { libc::sendfile(out_fd, in_fd, offset, count) }; + Errno::result(ret).map(|r| r as usize) +} + +/// Copy up to `count` bytes to `out_fd` from `in_fd` starting at `offset`. +/// +/// Returns a `Result` with the number of bytes written. +/// +/// If `offset` is `None`, `sendfile` will begin reading at the current offset of `in_fd`and will +/// update the offset of `in_fd`. If `offset` is `Some`, `sendfile` will begin at the specified +/// offset and will not update the offset of `in_fd`. Instead, it will mutate `offset` to point to +/// the byte after the last byte copied. +/// +/// `in_fd` must support `mmap`-like operations and therefore cannot be a socket. +/// +/// For more information, see [the sendfile(2) man page.](https://man7.org/linux/man-pages/man2/sendfile.2.html) +#[cfg(target_os = "linux")] +#[cfg_attr(docsrs, doc(cfg(all())))] +pub fn sendfile64( + out_fd: RawFd, + in_fd: RawFd, + offset: Option<&mut libc::off64_t>, + count: usize, +) -> Result<usize> { + let offset = offset + .map(|offset| offset as *mut _) + .unwrap_or(ptr::null_mut()); + let ret = unsafe { libc::sendfile64(out_fd, in_fd, offset, count) }; + Errno::result(ret).map(|r| r as usize) +} + +cfg_if! { + if #[cfg(any(target_os = "dragonfly", + target_os = "freebsd", + target_os = "ios", + target_os = "macos"))] { + use std::io::IoSlice; + + #[derive(Clone, Debug)] + struct SendfileHeaderTrailer<'a>( + libc::sf_hdtr, + Option<Vec<IoSlice<'a>>>, + Option<Vec<IoSlice<'a>>>, + ); + + impl<'a> SendfileHeaderTrailer<'a> { + fn new( + headers: Option<&'a [&'a [u8]]>, + trailers: Option<&'a [&'a [u8]]> + ) -> SendfileHeaderTrailer<'a> { + let header_iovecs: Option<Vec<IoSlice<'_>>> = + headers.map(|s| s.iter().map(|b| IoSlice::new(b)).collect()); + let trailer_iovecs: Option<Vec<IoSlice<'_>>> = + trailers.map(|s| s.iter().map(|b| IoSlice::new(b)).collect()); + SendfileHeaderTrailer( + libc::sf_hdtr { + headers: { + header_iovecs + .as_ref() + .map_or(ptr::null(), |v| v.as_ptr()) as *mut libc::iovec + }, + hdr_cnt: header_iovecs.as_ref().map(|v| v.len()).unwrap_or(0) as i32, + trailers: { + trailer_iovecs + .as_ref() + .map_or(ptr::null(), |v| v.as_ptr()) as *mut libc::iovec + }, + trl_cnt: trailer_iovecs.as_ref().map(|v| v.len()).unwrap_or(0) as i32 + }, + header_iovecs, + trailer_iovecs, + ) + } + } + } +} + +cfg_if! { + if #[cfg(target_os = "freebsd")] { + use libc::c_int; + + libc_bitflags!{ + /// Configuration options for [`sendfile`.](fn.sendfile.html) + pub struct SfFlags: c_int { + /// Causes `sendfile` to return EBUSY instead of blocking when attempting to read a + /// busy page. + SF_NODISKIO; + /// Causes `sendfile` to sleep until the network stack releases its reference to the + /// VM pages read. When `sendfile` returns, the data is not guaranteed to have been + /// sent, but it is safe to modify the file. + SF_SYNC; + /// Causes `sendfile` to cache exactly the number of pages specified in the + /// `readahead` parameter, disabling caching heuristics. + SF_USER_READAHEAD; + /// Causes `sendfile` not to cache the data read. + SF_NOCACHE; + } + } + + /// Read up to `count` bytes from `in_fd` starting at `offset` and write to `out_sock`. + /// + /// Returns a `Result` and a count of bytes written. Bytes written may be non-zero even if + /// an error occurs. + /// + /// `in_fd` must describe a regular file or shared memory object. `out_sock` must describe a + /// stream socket. + /// + /// If `offset` falls past the end of the file, the function returns success and zero bytes + /// written. + /// + /// If `count` is `None` or 0, bytes will be read from `in_fd` until reaching the end of + /// file (EOF). + /// + /// `headers` and `trailers` specify optional slices of byte slices to be sent before and + /// after the data read from `in_fd`, respectively. The length of headers and trailers sent + /// is included in the returned count of bytes written. The values of `offset` and `count` + /// do not apply to headers or trailers. + /// + /// `readahead` specifies the minimum number of pages to cache in memory ahead of the page + /// currently being sent. + /// + /// For more information, see + /// [the sendfile(2) man page.](https://www.freebsd.org/cgi/man.cgi?query=sendfile&sektion=2) + #[allow(clippy::too_many_arguments)] + pub fn sendfile( + in_fd: RawFd, + out_sock: RawFd, + offset: off_t, + count: Option<usize>, + headers: Option<&[&[u8]]>, + trailers: Option<&[&[u8]]>, + flags: SfFlags, + readahead: u16 + ) -> (Result<()>, off_t) { + // Readahead goes in upper 16 bits + // Flags goes in lower 16 bits + // see `man 2 sendfile` + let ra32 = u32::from(readahead); + let flags: u32 = (ra32 << 16) | (flags.bits() as u32); + let mut bytes_sent: off_t = 0; + let hdtr = headers.or(trailers).map(|_| SendfileHeaderTrailer::new(headers, trailers)); + let hdtr_ptr = hdtr.as_ref().map_or(ptr::null(), |s| &s.0 as *const libc::sf_hdtr); + let return_code = unsafe { + libc::sendfile(in_fd, + out_sock, + offset, + count.unwrap_or(0), + hdtr_ptr as *mut libc::sf_hdtr, + &mut bytes_sent as *mut off_t, + flags as c_int) + }; + (Errno::result(return_code).and(Ok(())), bytes_sent) + } + } else if #[cfg(target_os = "dragonfly")] { + /// Read up to `count` bytes from `in_fd` starting at `offset` and write to `out_sock`. + /// + /// Returns a `Result` and a count of bytes written. Bytes written may be non-zero even if + /// an error occurs. + /// + /// `in_fd` must describe a regular file. `out_sock` must describe a stream socket. + /// + /// If `offset` falls past the end of the file, the function returns success and zero bytes + /// written. + /// + /// If `count` is `None` or 0, bytes will be read from `in_fd` until reaching the end of + /// file (EOF). + /// + /// `headers` and `trailers` specify optional slices of byte slices to be sent before and + /// after the data read from `in_fd`, respectively. The length of headers and trailers sent + /// is included in the returned count of bytes written. The values of `offset` and `count` + /// do not apply to headers or trailers. + /// + /// For more information, see + /// [the sendfile(2) man page.](https://leaf.dragonflybsd.org/cgi/web-man?command=sendfile§ion=2) + pub fn sendfile( + in_fd: RawFd, + out_sock: RawFd, + offset: off_t, + count: Option<usize>, + headers: Option<&[&[u8]]>, + trailers: Option<&[&[u8]]>, + ) -> (Result<()>, off_t) { + let mut bytes_sent: off_t = 0; + let hdtr = headers.or(trailers).map(|_| SendfileHeaderTrailer::new(headers, trailers)); + let hdtr_ptr = hdtr.as_ref().map_or(ptr::null(), |s| &s.0 as *const libc::sf_hdtr); + let return_code = unsafe { + libc::sendfile(in_fd, + out_sock, + offset, + count.unwrap_or(0), + hdtr_ptr as *mut libc::sf_hdtr, + &mut bytes_sent as *mut off_t, + 0) + }; + (Errno::result(return_code).and(Ok(())), bytes_sent) + } + } else if #[cfg(any(target_os = "ios", target_os = "macos"))] { + /// Read bytes from `in_fd` starting at `offset` and write up to `count` bytes to + /// `out_sock`. + /// + /// Returns a `Result` and a count of bytes written. Bytes written may be non-zero even if + /// an error occurs. + /// + /// `in_fd` must describe a regular file. `out_sock` must describe a stream socket. + /// + /// If `offset` falls past the end of the file, the function returns success and zero bytes + /// written. + /// + /// If `count` is `None` or 0, bytes will be read from `in_fd` until reaching the end of + /// file (EOF). + /// + /// `hdtr` specifies an optional list of headers and trailers to be sent before and after + /// the data read from `in_fd`, respectively. The length of headers and trailers sent is + /// included in the returned count of bytes written. If any headers are specified and + /// `count` is non-zero, the length of the headers will be counted in the limit of total + /// bytes sent. Trailers do not count toward the limit of bytes sent and will always be sent + /// regardless. The value of `offset` does not affect headers or trailers. + /// + /// For more information, see + /// [the sendfile(2) man page.](https://developer.apple.com/legacy/library/documentation/Darwin/Reference/ManPages/man2/sendfile.2.html) + pub fn sendfile( + in_fd: RawFd, + out_sock: RawFd, + offset: off_t, + count: Option<off_t>, + headers: Option<&[&[u8]]>, + trailers: Option<&[&[u8]]> + ) -> (Result<()>, off_t) { + let mut len = count.unwrap_or(0); + let hdtr = headers.or(trailers).map(|_| SendfileHeaderTrailer::new(headers, trailers)); + let hdtr_ptr = hdtr.as_ref().map_or(ptr::null(), |s| &s.0 as *const libc::sf_hdtr); + let return_code = unsafe { + libc::sendfile(in_fd, + out_sock, + offset, + &mut len as *mut off_t, + hdtr_ptr as *mut libc::sf_hdtr, + 0) + }; + (Errno::result(return_code).and(Ok(())), len) + } + } +} |