1 files changed, 154 insertions, 0 deletions
diff --git a/tokio/src/net/unix/ucred.rs b/tokio/src/net/unix/ucred.rs
new file mode 100644
index 00000000..c785e68e
--- /dev/null
+++ b/tokio/src/net/unix/ucred.rs
@@ -0,0 +1,154 @@
+use libc::{gid_t, uid_t};
+
+/// Credentials of a process
+#[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
+pub struct UCred {
+    /// UID (user ID) of the process
+    pub uid: uid_t,
+    /// GID (group ID) of the process
+    pub gid: gid_t,
+}
+
+#[cfg(any(target_os = "linux", target_os = "android"))]
+pub(crate) use self::impl_linux::get_peer_cred;
+
+#[cfg(any(
+    target_os = "dragonfly",
+    target_os = "macos",
+    target_os = "ios",
+    target_os = "freebsd",
+    target_os = "netbsd",
+    target_os = "openbsd"
+))]
+pub(crate) use self::impl_macos::get_peer_cred;
+
+#[cfg(any(target_os = "solaris"))]
+pub(crate) use self::impl_solaris::get_peer_cred;
+
+#[cfg(any(target_os = "linux", target_os = "android"))]
+pub(crate) mod impl_linux {
+    use crate::net::unix::UnixStream;
+
+    use libc::{c_void, getsockopt, socklen_t, SOL_SOCKET, SO_PEERCRED};
+    use std::{io, mem};
+
+    use libc::ucred;
+
+    pub(crate) fn get_peer_cred(sock: &UnixStream) -> io::Result<super::UCred> {
+        use std::os::unix::io::AsRawFd;
+
+        unsafe {
+            let raw_fd = sock.as_raw_fd();
+
+            let mut ucred = ucred {
+                pid: 0,
+                uid: 0,
+                gid: 0,
+            };
+
+            let ucred_size = mem::size_of::<ucred>();
+
+            // These paranoid checks should be optimized-out
+            assert!(mem::size_of::<u32>() <= mem::size_of::<usize>());
+            assert!(ucred_size <= u32::max_value() as usize);
+
+            let mut ucred_size = ucred_size as socklen_t;
+
+            let ret = getsockopt(
+                raw_fd,
+                SOL_SOCKET,
+                SO_PEERCRED,
+                &mut ucred as *mut ucred as *mut c_void,
+                &mut ucred_size,
+            );
+            if ret == 0 && ucred_size as usize == mem::size_of::<ucred>() {
+                Ok(super::UCred {
+                    uid: ucred.uid,
+                    gid: ucred.gid,
+                })
+            } else {
+                Err(io::Error::last_os_error())
+            }
+        }
+    }
+}
+
+#[cfg(any(
+    target_os = "dragonfly",
+    target_os = "macos",
+    target_os = "ios",
+    target_os = "freebsd",
+    target_os = "netbsd",
+    target_os = "openbsd"
+))]
+pub(crate) mod impl_macos {
+    use crate::net::unix::UnixStream;
+
+    use libc::getpeereid;
+    use std::io;
+    use std::mem::MaybeUninit;
+    use std::os::unix::io::AsRawFd;
+
+    pub(crate) fn get_peer_cred(sock: &UnixStream) -> io::Result<super::UCred> {
+        unsafe {
+            let raw_fd = sock.as_raw_fd();
+
+            let mut uid = MaybeUninit::uninit();
+            let mut gid = MaybeUninit::uninit();
+
+            let ret = getpeereid(raw_fd, uid.as_mut_ptr(), gid.as_mut_ptr());
+
+            if ret == 0 {
+                Ok(super::UCred {
+                    uid: uid.assume_init(),
+                    gid: gid.assume_init(),
+                })
+            } else {
+                Err(io::Error::last_os_error())
+            }
+        }
+    }
+}
+
+#[cfg(any(target_os = "solaris"))]
+pub(crate) mod impl_solaris {
+    use std::io;
+    use std::os::unix::io::AsRawFd;
+    use std::ptr;
+    use UnixStream;
+
+    #[allow(non_camel_case_types)]
+    enum ucred_t {}
+
+    extern "C" {
+        fn ucred_free(cred: *mut ucred_t);
+        fn ucred_geteuid(cred: *const ucred_t) -> super::uid_t;
+        fn ucred_getegid(cred: *const ucred_t) -> super::gid_t;
+
+        fn getpeerucred(
+            fd: ::std::os::raw::c_int,
+            cred: *mut *mut ucred_t,
+        ) -> ::std::os::raw::c_int;
+    }
+
+    pub(crate) fn get_peer_cred(sock: &UnixStream) -> io::Result<super::UCred> {
+        unsafe {
+            let raw_fd = sock.as_raw_fd();
+
+            let mut cred = ptr::null_mut::<*mut ucred_t>() as *mut ucred_t;
+
+            let ret = getpeerucred(raw_fd, &mut cred);
+
+            if ret == 0 {
+                let uid = ucred_geteuid(cred);
+                let gid = ucred_getegid(cred);
+
+                ucred_free(cred);
+
+                Ok(super::UCred { uid, gid })
+            } else {
+                Err(io::Error::last_os_error())
+            }
+        }
+    }
+}