feat: I/O safety for 'sys/sendfile'

Author: SteveLauC

src/sys/sendfile.rs

@@ -1,7 +1,7 @@
 //! Send data from a file to a socket, bypassing userland.
 
 use cfg_if::cfg_if;
-use std::os::unix::io::RawFd;
+use std::os::unix::io::{AsFd, AsRawFd};
 use std::ptr;
 
 use libc::{self, off_t};
@@ -23,16 +23,23 @@ use crate::Result;
 /// 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,
+pub fn sendfile<F1: AsFd, F2: AsFd>(
+    out_fd: F1,
+    in_fd: F2,
     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) };
+    let ret = unsafe {
+        libc::sendfile(
+            out_fd.as_fd().as_raw_fd(),
+            in_fd.as_fd().as_raw_fd(),
+            offset,
+            count,
+        )
+    };
     Errno::result(ret).map(|r| r as usize)
 }
 
@@ -50,16 +57,23 @@ pub fn sendfile(
 /// 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,
+pub fn sendfile64<F1: AsFd, F2: AsFd>(
+    out_fd: F1,
+    in_fd: F2,
     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) };
+    let ret = unsafe {
+        libc::sendfile64(
+            out_fd.as_fd().as_raw_fd(),
+            in_fd.as_fd().as_raw_fd(),
+            offset,
+            count,
+        )
+    };
     Errno::result(ret).map(|r| r as usize)
 }
 
@@ -156,9 +170,9 @@ cfg_if! {
         /// 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,
+        pub fn sendfile<F1: AsFd, F2: AsFd>(
+            in_fd: F1,
+            out_sock: F2,
             offset: off_t,
             count: Option<usize>,
             headers: Option<&[&[u8]]>,
@@ -175,8 +189,8 @@ cfg_if! {
             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,
+                libc::sendfile(in_fd.as_fd().as_raw_fd(),
+                               out_sock.as_fd().as_raw_fd(),
                                offset,
                                count.unwrap_or(0),
                                hdtr_ptr as *mut libc::sf_hdtr,
@@ -206,9 +220,9 @@ cfg_if! {
         ///
         /// For more information, see
         /// [the sendfile(2) man page.](https://leaf.dragonflybsd.org/cgi/web-man?command=sendfile&section=2)
-        pub fn sendfile(
-            in_fd: RawFd,
-            out_sock: RawFd,
+        pub fn sendfile<F1: AsFd, F2: AsFd>(
+            in_fd: F1,
+            out_sock: F2,
             offset: off_t,
             count: Option<usize>,
             headers: Option<&[&[u8]]>,
@@ -218,8 +232,8 @@ cfg_if! {
             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,
+                libc::sendfile(in_fd.as_fd().as_raw_fd(),
+                               out_sock.as_fd().as_raw_fd(),
                                offset,
                                count.unwrap_or(0),
                                hdtr_ptr as *mut libc::sf_hdtr,
@@ -252,9 +266,9 @@ cfg_if! {
         ///
         /// 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,
+        pub fn sendfile<F1: AsFd, F2: AsFd>(
+            in_fd: F1,
+            out_sock: F2,
             offset: off_t,
             count: Option<off_t>,
             headers: Option<&[&[u8]]>,
@@ -264,8 +278,8 @@ cfg_if! {
             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,
+                libc::sendfile(in_fd.as_fd().as_raw_fd(),
+                               out_sock.as_fd().as_raw_fd(),
                                offset,
                                &mut len as *mut off_t,
                                hdtr_ptr as *mut libc::sf_hdtr,

test/test_sendfile.rs

@@ -1,5 +1,6 @@
 use std::io::prelude::*;
-use std::os::unix::prelude::*;
+#[cfg(any(target_os = "android", target_os = "linux"))]
+use std::os::unix::io::{FromRawFd, OwnedFd};
 
 use libc::off_t;
 use nix::sys::sendfile::*;
@@ -23,7 +24,12 @@ fn test_sendfile_linux() {
 
     let (rd, wr) = pipe().unwrap();
     let mut offset: off_t = 5;
-    let res = sendfile(wr, tmp.as_raw_fd(), Some(&mut offset), 2).unwrap();
+    // The construct of this `OwnedFd` is a temporary workaround, when `pipe(2)`
+    // becomes I/O-safe:
+    // pub fn pipe() -> std::result::Result<(OwnedFd, OwnedFd), Error>
+    // then it is no longer needed.
+    let wr = unsafe { OwnedFd::from_raw_fd(wr) };
+    let res = sendfile(&wr, &tmp, Some(&mut offset), 2).unwrap();
 
     assert_eq!(2, res);
 
@@ -33,7 +39,6 @@ fn test_sendfile_linux() {
     assert_eq!(7, offset);
 
     close(rd).unwrap();
-    close(wr).unwrap();
 }
 
 #[cfg(target_os = "linux")]
@@ -45,7 +50,12 @@ fn test_sendfile64_linux() {
 
     let (rd, wr) = pipe().unwrap();
     let mut offset: libc::off64_t = 5;
-    let res = sendfile64(wr, tmp.as_raw_fd(), Some(&mut offset), 2).unwrap();
+    // The construct of this `OwnedFd` is a temporary workaround, when `pipe(2)`
+    // becomes I/O-safe:
+    // pub fn pipe() -> std::result::Result<(OwnedFd, OwnedFd), Error>
+    // then it is no longer needed.
+    let wr = unsafe { OwnedFd::from_raw_fd(wr) };
+    let res = sendfile64(&wr, &tmp, Some(&mut offset), 2).unwrap();
 
     assert_eq!(2, res);
 
@@ -55,7 +65,6 @@ fn test_sendfile64_linux() {
     assert_eq!(7, offset);
 
     close(rd).unwrap();
-    close(wr).unwrap();
 }
 
 #[cfg(target_os = "freebsd")]
@@ -83,8 +92,8 @@ fn test_sendfile_freebsd() {
 
     // Call the test method
     let (res, bytes_written) = sendfile(
-        tmp.as_raw_fd(),
-        wr.as_raw_fd(),
+        &tmp,
+        &wr,
         body_offset as off_t,
         None,
         Some(headers.as_slice()),
@@ -134,8 +143,8 @@ fn test_sendfile_dragonfly() {
 
     // Call the test method
     let (res, bytes_written) = sendfile(
-        tmp.as_raw_fd(),
-        wr.as_raw_fd(),
+        &tmp,
+        &wr,
         body_offset as off_t,
         None,
         Some(headers.as_slice()),
@@ -183,8 +192,8 @@ fn test_sendfile_darwin() {
 
     // Call the test method
     let (res, bytes_written) = sendfile(
-        tmp.as_raw_fd(),
-        wr.as_raw_fd(),
+        &tmp,
+        &wr,
         body_offset as off_t,
         None,
         Some(headers.as_slice()),