add pid to tokio::net::unix::UCred

tokio/src/net/unix/ucred.rs

@@ -1,8 +1,11 @@
-use libc::{gid_t, uid_t};
+use libc::{pid_t, gid_t, uid_t};
 
 /// Credentials of a process
 #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug)]
 pub struct UCred {
+    /// PID (process ID) of the process
+    #[cfg(any(target_os = "linux", target_os = "android"))]
+    pid: pid_t, // TODO: how to get it under macos?
     /// UID (user ID) of the process
     uid: uid_t,
     /// GID (group ID) of the process
@@ -19,6 +22,12 @@ impl UCred {
     pub fn gid(&self) -> gid_t {
         self.gid
     }
+
+    /// Gets PID (process ID) of the process.
+    #[cfg(any(target_os = "linux", target_os = "android"))]
+    pub fn pid(&self) -> pid_t {
+        self.pid
+    }
 }
 
 #[cfg(any(target_os = "linux", target_os = "android"))]
@@ -75,6 +84,7 @@ pub(crate) mod impl_linux {
             );
             if ret == 0 && ucred_size as usize == mem::size_of::<ucred>() {
                 Ok(super::UCred {
+                    pid: ucred.pid,
                     uid: ucred.uid,
                     gid: ucred.gid,
                 })