net: add tos and set_tos methods to TCP and UDP sockets (#4366)

tokio/src/net/tcp/socket.rs

@@ -381,6 +381,61 @@ impl TcpSocket {
         self.inner.linger()
     }
 
+    /// Gets the value of the `IP_TOS` option for this socket.
+    ///
+    /// For more information about this option, see [`set_tos`].
+    ///
+    /// **NOTE:** On Windows, `IP_TOS` is only supported on [Windows 8+ or
+    /// Windows Server 2012+.](https://docs.microsoft.com/en-us/windows/win32/winsock/ipproto-ip-socket-options)
+    ///
+    /// [`set_tos`]: Self::set_tos
+    // https://docs.rs/socket2/0.4.2/src/socket2/socket.rs.html#1178
+    #[cfg(not(any(
+        target_os = "fuchsia",
+        target_os = "redox",
+        target_os = "solaris",
+        target_os = "illumos",
+    )))]
+    #[cfg_attr(
+        docsrs,
+        doc(cfg(not(any(
+            target_os = "fuchsia",
+            target_os = "redox",
+            target_os = "solaris",
+            target_os = "illumos",
+        ))))
+    )]
+    pub fn tos(&self) -> io::Result<u32> {
+        self.inner.tos()
+    }
+
+    /// Sets the value for the `IP_TOS` option on this socket.
+    ///
+    /// This value sets the time-to-live field that is used in every packet sent
+    /// from this socket.
+    ///
+    /// **NOTE:** On Windows, `IP_TOS` is only supported on [Windows 8+ or
+    /// Windows Server 2012+.](https://docs.microsoft.com/en-us/windows/win32/winsock/ipproto-ip-socket-options)
+    // https://docs.rs/socket2/0.4.2/src/socket2/socket.rs.html#1178
+    #[cfg(not(any(
+        target_os = "fuchsia",
+        target_os = "redox",
+        target_os = "solaris",
+        target_os = "illumos",
+    )))]
+    #[cfg_attr(
+        docsrs,
+        doc(cfg(not(any(
+            target_os = "fuchsia",
+            target_os = "redox",
+            target_os = "solaris",
+            target_os = "illumos",
+        ))))
+    )]
+    pub fn set_tos(&self, tos: u32) -> io::Result<()> {
+        self.inner.set_tos(tos)
+    }
+
     /// Gets the local address of this socket.
     ///
     /// Will fail on windows if called before `bind`.

tokio/src/net/udp.rs

@@ -1575,6 +1575,61 @@ impl UdpSocket {
         self.io.set_ttl(ttl)
     }
 
+    /// Gets the value of the `IP_TOS` option for this socket.
+    ///
+    /// For more information about this option, see [`set_tos`].
+    ///
+    /// **NOTE:** On Windows, `IP_TOS` is only supported on [Windows 8+ or
+    /// Windows Server 2012+.](https://docs.microsoft.com/en-us/windows/win32/winsock/ipproto-ip-socket-options)
+    ///
+    /// [`set_tos`]: Self::set_tos
+    // https://docs.rs/socket2/0.4.2/src/socket2/socket.rs.html#1178
+    #[cfg(not(any(
+        target_os = "fuchsia",
+        target_os = "redox",
+        target_os = "solaris",
+        target_os = "illumos",
+    )))]
+    #[cfg_attr(
+        docsrs,
+        doc(cfg(not(any(
+            target_os = "fuchsia",
+            target_os = "redox",
+            target_os = "solaris",
+            target_os = "illumos",
+        ))))
+    )]
+    pub fn tos(&self) -> io::Result<u32> {
+        self.as_socket().tos()
+    }
+
+    /// Sets the value for the `IP_TOS` option on this socket.
+    ///
+    /// This value sets the time-to-live field that is used in every packet sent
+    /// from this socket.
+    ///
+    /// **NOTE:** On Windows, `IP_TOS` is only supported on [Windows 8+ or
+    /// Windows Server 2012+.](https://docs.microsoft.com/en-us/windows/win32/winsock/ipproto-ip-socket-options)
+    // https://docs.rs/socket2/0.4.2/src/socket2/socket.rs.html#1178
+    #[cfg(not(any(
+        target_os = "fuchsia",
+        target_os = "redox",
+        target_os = "solaris",
+        target_os = "illumos",
+    )))]
+    #[cfg_attr(
+        docsrs,
+        doc(cfg(not(any(
+            target_os = "fuchsia",
+            target_os = "redox",
+            target_os = "solaris",
+            target_os = "illumos",
+        ))))
+    )]
+    pub fn set_tos(&self, tos: u32) -> io::Result<()> {
+        self.as_socket().set_tos(tos)
+    }
+
     /// Executes an operation of the `IP_ADD_MEMBERSHIP` type.
     ///
     /// This function specifies a new multicast group for this socket to join.