Add support for the SO_TXTIME sockopt and SCM_TXTIME control message

2 files changed, 27 insertions, 0 deletions

diff --git a/src/sys/socket/mod.rs b/src/sys/socket/mod.rs
index 9df5ed4a..f6d37c99 100644
--- a/src/sys/socket/mod.rs
+++ b/src/sys/socket/mod.rs
@@ -1056,6 +1056,14 @@ pub enum ControlMessage<'a> {
     #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
     #[cfg_attr(docsrs, doc(cfg(all())))]
     RxqOvfl(&'a u32),
+
+    /// Configure the transmission time of packets.
+    ///
+    /// For further information, please refer to the
+    /// [`tc-etf(8)`](https://man7.org/linux/man-pages/man8/tc-etf.8.html) man
+    /// page.
+    #[cfg(target_os = "linux")]
+    TxTime(&'a u64),
 }
 
 // An opaque structure used to prevent cmsghdr from being a public type
@@ -1153,6 +1161,10 @@ impl<'a> ControlMessage<'a> {
             ControlMessage::RxqOvfl(drop_count) => {
                 drop_count as *const _ as *const u8
             },
+            #[cfg(target_os = "linux")]
+            ControlMessage::TxTime(tx_time) => {
+                tx_time as *const _ as *const u8
+            },
         };
         unsafe {
             ptr::copy_nonoverlapping(
@@ -1208,6 +1220,10 @@ impl<'a> ControlMessage<'a> {
             ControlMessage::RxqOvfl(drop_count) => {
                 mem::size_of_val(drop_count)
             },
+            #[cfg(target_os = "linux")]
+            ControlMessage::TxTime(tx_time) => {
+                mem::size_of_val(tx_time)
+            },
         }
     }
 
@@ -1237,6 +1253,8 @@ impl<'a> ControlMessage<'a> {
             ControlMessage::Ipv6PacketInfo(_) => libc::IPPROTO_IPV6,
             #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
             ControlMessage::RxqOvfl(_) => libc::SOL_SOCKET,
+            #[cfg(target_os = "linux")]
+            ControlMessage::TxTime(_) => libc::SOL_SOCKET,
         }
     }
 
@@ -1279,6 +1297,10 @@ impl<'a> ControlMessage<'a> {
             ControlMessage::RxqOvfl(_) => {
                 libc::SO_RXQ_OVFL
             },
+            #[cfg(target_os = "linux")]
+            ControlMessage::TxTime(_) => {
+                libc::SCM_TXTIME
+            },
         }
     }
 
diff --git a/src/sys/socket/sockopt.rs b/src/sys/socket/sockopt.rs
index 056ded42..c600391c 100644
--- a/src/sys/socket/sockopt.rs
+++ b/src/sys/socket/sockopt.rs
@@ -582,6 +582,11 @@ sockopt_impl!(
     #[allow(missing_docs)]
     // Not documented by Linux!
     UdpGroSegment, Both, libc::IPPROTO_UDP, libc::UDP_GRO, bool);
+#[cfg(target_os = "linux")]
+sockopt_impl!(
+    /// Configures the behavior of time-based transmission of packets, for use
+    /// with the `TxTime` control message.
+    TxTime, Both, libc::SOL_SOCKET, libc::SO_TXTIME, libc::sock_txtime);
 #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
 sockopt_impl!(
     /// Indicates that an unsigned 32-bit value ancillary message (cmsg) should