Adds IP_TOS, IPV6_TCLASS and SO_PRIORITY sockopt wrappers

Author: mzachar

CHANGELOG.md

@@ -30,7 +30,9 @@ This project adheres to [Semantic Versioning](https://semver.org/).
   ([#1841](https://github.com/nix-rust/nix/pull/1841))
 - Added `eaccess()` on FreeBSD, DragonFly and Linux (glibc and musl).
   ([#1842](https://github.com/nix-rust/nix/pull/1842))
-  
+- Added `IP_TOS` `SO_PRIORITY` and `IPV6_TCLASS` sockopts for Linux
+  ([#1853](https://github.com/nix-rust/nix/pull/1853))
+
 ### Changed
 
 - The MSRV is now 1.56.1

src/sys/socket/sockopt.rs

@@ -371,6 +371,41 @@ sockopt_impl!(
     libc::IP_MULTICAST_LOOP,
     bool
 );
+#[cfg(target_os = "linux")]
+#[cfg(feature = "net")]
+sockopt_impl!(
+    #[cfg_attr(docsrs, doc(cfg(feature = "net")))]
+    /// Set the protocol-defined priority for all packets to be
+    /// sent on this socket
+    Priority,
+    Both,
+    libc::SOL_SOCKET,
+    libc::SO_PRIORITY,
+    libc::c_int
+);
+#[cfg(target_os = "linux")]
+#[cfg(feature = "net")]
+sockopt_impl!(
+    #[cfg_attr(docsrs, doc(cfg(feature = "net")))]
+    /// Set or receive the Type-Of-Service (TOS) field that is
+    /// sent with every IP packet originating from this socket
+    IpTos,
+    Both,
+    libc::IPPROTO_IP,
+    libc::IP_TOS,
+    libc::c_int
+);
+#[cfg(target_os = "linux")]
+#[cfg(feature = "net")]
+sockopt_impl!(
+    #[cfg_attr(docsrs, doc(cfg(feature = "net")))]
+    /// Traffic class associated with outgoing packets
+    Ipv6TClass,
+    Both,
+    libc::IPPROTO_IPV6,
+    libc::IPV6_TCLASS,
+    libc::c_int
+);
 #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
 #[cfg(feature = "net")]
 sockopt_impl!(

test/sys/test_sockopt.rs

@@ -327,3 +327,51 @@ fn test_v6dontfrag_opts() {
         "unsetting IPV6_DONTFRAG on an inet6 datagram socket should succeed",
     );
 }
+
+#[test]
+#[cfg(target_os = "linux")]
+fn test_so_priority() {
+    let fd = socket(
+        AddressFamily::Inet,
+        SockType::Stream,
+        SockFlag::empty(),
+        SockProtocol::Tcp,
+    )
+    .unwrap();
+    let priority = 3;
+    setsockopt(fd, sockopt::Priority, &priority).unwrap();
+    assert_eq!(getsockopt(fd, sockopt::Priority).unwrap(), priority);
+}
+
+#[test]
+#[cfg(target_os = "linux")]
+fn test_ip_tos() {
+    let fd = socket(
+        AddressFamily::Inet,
+        SockType::Stream,
+        SockFlag::empty(),
+        SockProtocol::Tcp,
+    )
+    .unwrap();
+    let tos = 0x80; // CS4
+    setsockopt(fd, sockopt::IpTos, &tos).unwrap();
+    assert_eq!(getsockopt(fd, sockopt::IpTos).unwrap(), tos);
+}
+
+#[test]
+#[cfg(target_os = "linux")]
+// Disable the test under emulation because it fails in Cirrus-CI.  Lack
+// of QEMU support is suspected.
+#[cfg_attr(qemu, ignore)]
+fn test_ipv6_tclass() {
+    let fd = socket(
+        AddressFamily::Inet6,
+        SockType::Stream,
+        SockFlag::empty(),
+        SockProtocol::Tcp,
+    )
+    .unwrap();
+    let class = 0x80; // CS4
+    setsockopt(fd, sockopt::Ipv6TClass, &class).unwrap();
+    assert_eq!(getsockopt(fd, sockopt::Ipv6TClass).unwrap(), class);
+}