1 files changed, 81 insertions, 0 deletions
diff --git a/third_party/rust/audioipc2/src/sys/unix/msg.rs b/third_party/rust/audioipc2/src/sys/unix/msg.rs
new file mode 100644
index 0000000000..a21a893b93
--- /dev/null
+++ b/third_party/rust/audioipc2/src/sys/unix/msg.rs
@@ -0,0 +1,81 @@
+// Copyright © 2017 Mozilla Foundation
+//
+// This program is made available under an ISC-style license.  See the
+// accompanying file LICENSE for details.
+
+use bytes::buf::UninitSlice;
+use iovec::unix;
+use iovec::IoVec;
+use std::os::unix::io::RawFd;
+use std::{cmp, io, mem, ptr};
+
+fn cvt(r: libc::ssize_t) -> io::Result<usize> {
+    if r == -1 {
+        Err(io::Error::last_os_error())
+    } else {
+        Ok(r as usize)
+    }
+}
+
+// Convert return of -1 into error message, handling retry on EINTR
+fn cvt_r<F: FnMut() -> libc::ssize_t>(mut f: F) -> io::Result<usize> {
+    loop {
+        match cvt(f()) {
+            Err(ref e) if e.kind() == io::ErrorKind::Interrupted => {}
+            other => return other,
+        }
+    }
+}
+
+pub(crate) fn recv_msg_with_flags(
+    socket: RawFd,
+    bufs: &mut [&mut IoVec],
+    cmsg: &mut UninitSlice,
+    flags: libc::c_int,
+) -> io::Result<(usize, usize, libc::c_int)> {
+    let slice = unix::as_os_slice_mut(bufs);
+    let len = cmp::min(<libc::c_int>::max_value() as usize, slice.len());
+    let (control, controllen) = if cmsg.len() == 0 {
+        (ptr::null_mut(), 0)
+    } else {
+        (cmsg.as_mut_ptr() as _, cmsg.len())
+    };
+
+    let mut msghdr: libc::msghdr = unsafe { mem::zeroed() };
+    msghdr.msg_name = ptr::null_mut();
+    msghdr.msg_namelen = 0;
+    msghdr.msg_iov = slice.as_mut_ptr();
+    msghdr.msg_iovlen = len as _;
+    msghdr.msg_control = control;
+    msghdr.msg_controllen = controllen as _;
+
+    let n = cvt_r(|| unsafe { libc::recvmsg(socket, &mut msghdr as *mut _, flags) })?;
+
+    let controllen = msghdr.msg_controllen as usize;
+    Ok((n, controllen, msghdr.msg_flags))
+}
+
+pub(crate) fn send_msg_with_flags(
+    socket: RawFd,
+    bufs: &[&IoVec],
+    cmsg: &[u8],
+    flags: libc::c_int,
+) -> io::Result<usize> {
+    let slice = unix::as_os_slice(bufs);
+    let len = cmp::min(<libc::c_int>::max_value() as usize, slice.len());
+    let (control, controllen) = if cmsg.is_empty() {
+        (ptr::null_mut(), 0)
+    } else {
+        (cmsg.as_ptr() as *mut _, cmsg.len())
+    };
+
+    let mut msghdr: libc::msghdr = unsafe { mem::zeroed() };
+    msghdr.msg_name = ptr::null_mut();
+    msghdr.msg_namelen = 0;
+    msghdr.msg_iov = slice.as_ptr() as *mut _;
+    msghdr.msg_iovlen = len as _;
+    msghdr.msg_control = control;
+    msghdr.msg_controllen = controllen as _;
+
+    cvt_r(|| unsafe { libc::sendmsg(socket, &msghdr as *const _, flags) })
+}