fcntl update following up with F_GETPATH but with FreeBSD's F_KINFO flag support instead

Author: devnexen

src/fcntl.rs

@@ -5,6 +5,7 @@ use libc::{self, c_int, c_uint, size_t, ssize_t};
     target_os = "macos",
     target_os = "ios",
     target_os = "dragonfly",
+    target_os = "freebsd",
 ))]
 use std::ffi::CStr;
 use std::ffi::OsString;
@@ -18,6 +19,7 @@ use std::os::unix::io::RawFd;
     target_os = "macos",
     target_os = "ios",
     target_os = "dragonfly",
+    target_os = "freebsd",
 ))]
 use std::path::PathBuf;
 #[cfg(any(
@@ -505,6 +507,8 @@ pub enum FcntlArg<'a> {
     F_SETPIPE_SZ(c_int),
     #[cfg(any(target_os = "netbsd", target_os = "dragonfly", target_os = "macos", target_os = "ios"))]
     F_GETPATH(&'a mut PathBuf),
+    #[cfg(target_os = "freebsd")]
+    F_KINFO(&'a mut PathBuf),
     // TODO: Rest of flags
 }
 
@@ -574,6 +578,18 @@ pub fn fcntl(fd: RawFd, arg: FcntlArg) -> Result<c_int> {
                 *path = PathBuf::from(OsString::from(optr.to_str().unwrap()));
                 return Ok(ok_res)
             },
+            #[cfg(target_os = "freebsd")]
+            F_KINFO(path) => {
+                let mut info: libc::kinfo_file = std::mem::zeroed();
+                info.kf_structsize = std::mem::size_of::<libc::kinfo_file>() as i32;
+                let res = libc::fcntl(fd, libc::F_KINFO, &mut info);
+                let ok_res = Errno::result(res)?;
+                let sl = info.kf_path.to_vec();
+                let vec: &[u8] = &sl.iter().map(|&c| c as u8).collect::<Vec<u8>>()[..];
+                let optr = CStr::from_bytes_until_nul(&vec).unwrap();
+                *path = PathBuf::from(OsString::from(optr.to_str().unwrap()));
+                return Ok(ok_res)
+            },
         }
     };
 

test/test_fcntl.rs

@@ -584,3 +584,17 @@ fn test_f_get_path() {
         tmp.path().canonicalize().unwrap()
     );
 }
+
+#[cfg(target_os = "freebsd")]
+#[test]
+fn test_f_kinfo() {
+    use nix::fcntl::*;
+    use std::{os::unix::io::AsRawFd, path::PathBuf};
+
+    let tmp = NamedTempFile::new().unwrap();
+    let fd = tmp.as_raw_fd();
+    let mut path = PathBuf::new();
+    let res = fcntl(fd, FcntlArg::F_KINFO(&mut path)).expect("get path failed");
+    assert_ne!(res, -1);
+    assert_eq!(path.as_path(), tmp.path());
+}