use cfg_if::cfg_if;
use std::os::unix::io::RawFd;
use std::ptr;
use libc::{self, off_t};
use crate::Result;
use crate::errno::Errno;
/// 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.](http://man7.org/linux/man-pages/man2/sendfile.2.html)
#[cfg(any(target_os = "android", target_os = "linux"))]
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)
}
cfg_if! {
if #[cfg(any(target_os = "freebsd",
target_os = "ios",
target_os = "macos"))] {
use crate::sys::uio::IoVec;
#[derive(Clone, Debug, Eq, Hash, PartialEq)]
struct SendfileHeaderTrailer<'a>(
libc::sf_hdtr,
Option<Vec<IoVec<&'a [u8]>>>,
Option<Vec<IoVec<&'a [u8]>>>,
);
impl<'a> SendfileHeaderTrailer<'a> {
fn new(
headers: Option<&'a [&'a [u8]]>,
trailers: Option<&'a [&'a [u8]]>
) -> SendfileHeaderTrailer<'a> {
let header_iovecs: Option<Vec<IoVec<&[u8]>>> =
headers.map(|s| s.iter().map(|b| IoVec::from_slice(b)).collect());
let trailer_iovecs: Option<Vec<IoVec<&[u8]>>> =
trailers.map(|s| s.iter().map(|b| IoVec::from_slice(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(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)
}
}
}