utils: add join multicast for raw socket

Author: fliqqs

holo-igmp/src/interface.rs

@@ -105,6 +105,14 @@ impl Interface {
             .start_vif(ifindex, ifindex as u16)
             .expect("TODO: panic message");
 
+        #[cfg(not(feature = "testing"))]
+        instance
+            .state
+            .net
+            .socket_rx
+            .get_ref()
+            .join_multicast_ifindex_v4_raw(&network::ALL_ROUTERS, ifindex)
+            .map_err(IoError::SocketError)?;
         // Create raw socket.
         let socket =
             network::socket_tx(&self.name).map_err(IoError::SocketError)?;

holo-utils/src/socket.rs

@@ -413,6 +413,12 @@ pub trait RawSocketExt: SocketExt {
 
     // Tell the kernel to create a vif for this ifindex.
     fn start_vif(&self, ifindex: u32, vifid: u16) -> Result<()>;
+
+    fn join_multicast_ifindex_v4_raw(
+        &self,
+        multiaddr: &Ipv4Addr,
+        ifindex: u32,
+    ) -> Result<()>;
 }
 
 // Extension methods for LinkAddr.
@@ -595,6 +601,30 @@ impl RawSocketExt for Socket {
             std::mem::size_of_val(&vif) as libc::socklen_t,
         )
     }
+
+    fn join_multicast_ifindex_v4_raw(
+        &self,
+        multiaddr: &Ipv4Addr,
+        ifindex: u32,
+    ) -> Result<()> {
+        let multiaddr: u32 = (*multiaddr).into();
+
+        let optval = ip_mreqn {
+            imr_multiaddr: libc::in_addr {
+                s_addr: multiaddr.to_be(),
+            },
+            imr_address: libc::in_addr { s_addr: 0 },
+            imr_ifindex: ifindex as c_int,
+        };
+
+        setsockopt(
+            self,
+            libc::IPPROTO_IP,
+            libc::IP_ADD_MEMBERSHIP,
+            &optval as *const _ as *const c_void,
+            std::mem::size_of::<ip_mreqn>() as libc::socklen_t,
+        )
+    }
 }
 
 // ===== Mock sockets for unit testing =====