Add Ipv6MulticastHops as socket option (#2234) (#2234)

Co-authored-by: Simon B. Gasse <sgasse@users.noreply.github.com>

changelog/2234.added.md

@@ -0,0 +1 @@
+Added `Ipv6MulticastHops` as socket option to set and read.

src/sys/socket/sockopt.rs

@@ -355,6 +355,17 @@ sockopt_impl!(
     u8
 );
 #[cfg(feature = "net")]
+sockopt_impl!(
+    #[cfg_attr(docsrs, doc(cfg(feature = "net")))]
+    /// Set or read the hop limit value of outgoing IPv6 multicast packets for
+    /// this socket.
+    Ipv6MulticastHops,
+    Both,
+    libc::IPPROTO_IPV6,
+    libc::IPV6_MULTICAST_HOPS,
+    libc::c_int
+);
+#[cfg(feature = "net")]
 sockopt_impl!(
     #[cfg_attr(docsrs, doc(cfg(feature = "net")))]
     /// Set or read a boolean integer argument that determines whether sent

test/sys/test_sockopt.rs

@@ -325,6 +325,19 @@ fn test_ttl_opts() {
         .expect("setting ipv6ttl on an inet6 socket should succeed");
 }
 
+#[test]
+fn test_ipv6_multicast_hops() {
+    let fd6 = socket(
+        AddressFamily::Inet6,
+        SockType::Datagram,
+        SockFlag::empty(),
+        None,
+    )
+    .unwrap();
+    setsockopt(&fd6, sockopt::Ipv6MulticastHops, &7)
+        .expect("setting ipv6multicasthops on an inet6 socket should succeed");
+}
+
 #[test]
 #[cfg(apple_targets)]
 fn test_dontfrag_opts() {