Add multicast SSM join and leave for IPv4 (IGMP)

Cargo.toml

@@ -33,7 +33,7 @@ rustdoc-args = ["--cfg", "docsrs"]
 features = ["all"]
 
 [target."cfg(unix)".dependencies]
-libc = "0.2.114"
+libc = "0.2.124"
 
 [target."cfg(windows)".dependencies]
 winapi = { version = "0.3.9", features = ["handleapi", "ws2ipdef", "ws2tcpip"] }

src/socket.rs

@@ -1184,6 +1184,62 @@ impl Socket {
         }
     }
 
+    /// Join a multicast SSM channel using `IP_ADD_SOURCE_MEMBERSHIP` option on this socket.
+    ///
+    /// This function specifies a new multicast channel for this socket to join.
+    /// The g must be a valid SSM group address, the s must be the address of the sender
+    /// and `interface` is the address of the local interface with which the system should join the
+    /// multicast group. If it's [`Ipv4Addr::UNSPECIFIED`] (`INADDR_ANY`) then
+    /// an appropriate interface is chosen by the system.
+    #[cfg(not(any(
+        target_os = "haiku",
+        target_os = "netbsd",
+        target_os = "redox",
+        target_os = "fuchsia",
+    )))]
+    pub fn join_ssm_v4(&self, s: &Ipv4Addr, g: &Ipv4Addr, interface: &Ipv4Addr) -> io::Result<()> {
+        let mreqs = sys::IpMreqSource {
+            imr_multiaddr: sys::to_in_addr(g),
+            imr_interface: sys::to_in_addr(interface),
+            imr_sourceaddr: sys::to_in_addr(s),
+        };
+        unsafe {
+            setsockopt(
+                self.as_raw(),
+                sys::IPPROTO_IP,
+                sys::IP_ADD_SOURCE_MEMBERSHIP,
+                mreqs,
+            )
+        }
+    }
+
+    /// Leave a multicast group using `IP_DROP_SOURCE_MEMBERSHIP` option on this socket.
+    ///
+    /// For more information about this option, see [`join_ssm_v4`].
+    ///
+    /// [`join_ssm_v4`]: Socket::join_ssm_v4
+    #[cfg(not(any(
+        target_os = "haiku",
+        target_os = "netbsd",
+        target_os = "redox",
+        target_os = "fuchsia",
+    )))]
+    pub fn leave_ssm_v4(&self, s: &Ipv4Addr, g: &Ipv4Addr, interface: &Ipv4Addr) -> io::Result<()> {
+        let mreqs = sys::IpMreqSource {
+            imr_multiaddr: sys::to_in_addr(g),
+            imr_interface: sys::to_in_addr(interface),
+            imr_sourceaddr: sys::to_in_addr(s),
+        };
+        unsafe {
+            setsockopt(
+                self.as_raw(),
+                sys::IPPROTO_IP,
+                sys::IP_DROP_SOURCE_MEMBERSHIP,
+                mreqs,
+            )
+        }
+    }
+
     /// Get the value of the `IP_MULTICAST_IF` option for this socket.
     ///
     /// For more information about this option, see [`set_multicast_if_v4`].

src/sys/unix.rs

@@ -95,6 +95,15 @@ pub(crate) use libc::{
     IP_TTL, MSG_OOB, MSG_PEEK, SOL_SOCKET, SO_BROADCAST, SO_ERROR, SO_KEEPALIVE, SO_RCVBUF,
     SO_RCVTIMEO, SO_REUSEADDR, SO_SNDBUF, SO_SNDTIMEO, SO_TYPE, TCP_NODELAY,
 };
+#[cfg(not(any(
+    target_os = "haiku",
+    target_os = "netbsd",
+    target_os = "redox",
+    target_os = "fuchsia",
+)))]
+pub(crate) use libc::{
+    ip_mreq_source as IpMreqSource, IP_ADD_SOURCE_MEMBERSHIP, IP_DROP_SOURCE_MEMBERSHIP,
+};
 #[cfg(not(any(
     target_os = "dragonfly",
     target_os = "freebsd",

src/sys/windows.rs

@@ -71,8 +71,9 @@ pub(crate) use winapi::shared::ws2ipdef::IP_HDRINCL;
 pub(crate) use winapi::shared::ws2ipdef::{
     IPV6_ADD_MEMBERSHIP, IPV6_DROP_MEMBERSHIP, IPV6_MREQ as Ipv6Mreq, IPV6_MULTICAST_HOPS,
     IPV6_MULTICAST_IF, IPV6_MULTICAST_LOOP, IPV6_UNICAST_HOPS, IPV6_V6ONLY, IP_ADD_MEMBERSHIP,
-    IP_DROP_MEMBERSHIP, IP_MREQ as IpMreq, IP_MULTICAST_IF, IP_MULTICAST_LOOP, IP_MULTICAST_TTL,
-    IP_TOS, IP_TTL,
+    IP_ADD_SOURCE_MEMBERSHIP, IP_DROP_MEMBERSHIP, IP_DROP_SOURCE_MEMBERSHIP, IP_MREQ as IpMreq,
+    IP_MREQ_SOURCE as IpMreqSource, IP_MULTICAST_IF, IP_MULTICAST_LOOP, IP_MULTICAST_TTL, IP_TOS,
+    IP_TTL,
 };
 pub(crate) use winapi::um::winsock2::{linger, MSG_OOB, MSG_PEEK};
 pub(crate) const IPPROTO_IPV6: c_int = winapi::shared::ws2def::IPPROTO_IPV6 as c_int;

tests/socket.rs

@@ -1219,6 +1219,22 @@ fn join_leave_multicast_v4_n() {
         .expect("leave multicast group");
 }
 
+#[test]
+#[cfg(not(any(
+    target_os = "haiku",
+    target_os = "netbsd",
+    target_os = "redox",
+    target_os = "fuchsia",
+)))]
+fn join_leave_ssm_v4() {
+    let socket = Socket::new(Domain::IPV4, Type::DGRAM, None).unwrap();
+    let g = Ipv4Addr::new(232, 123, 52, 36);
+    let s = Ipv4Addr::new(62, 40, 109, 31);
+    let interface = Ipv4Addr::new(0, 0, 0, 0);
+    let () = socket.join_ssm_v4(&s, &g, &interface).expect("Joined SSM");
+    let () = socket.leave_ssm_v4(&s, &g, &interface).expect("Left SSM");
+}
+
 #[test]
 #[cfg(all(feature = "all", not(target_os = "redox")))]
 fn header_included() {