fix(udp): enforce that at most one multicast group is joined

Signed-off-by: Max SCHMELLER <[email protected]>
tier4 · Dec 23, 2024 · 95fb8ea · 95fb8ea
1 parent d962945
commit 95fb8ea
Show file tree

Hide file tree

Showing 2 changed files with 10 additions and 1 deletion.
diff --git a/...w_interfaces/include/nebula_hw_interfaces/nebula_hw_interfaces_common/connections/udp.hpp b/...w_interfaces/include/nebula_hw_interfaces/nebula_hw_interfaces_common/connections/udp.hpp
@@ -214,6 +214,8 @@ class UdpSocket
      */
     Builder && join_multicast_group(const std::string & group_ip)
     {
+      if (config_.multicast_ip)
+        throw UsageError("Only one multicast group can be joined by this socket");
       ip_mreq mreq{parse_ip_or_throw(group_ip), config_.host.ip};
 
       sock_fd_.setsockopt(IPPROTO_IP, IP_ADD_MEMBERSHIP, mreq).value_or_throw();

diff --git a/nebula_hw_interfaces/test/common/test_udp.cpp b/nebula_hw_interfaces/test/common/test_udp.cpp
@@ -27,6 +27,7 @@ static const char localhost_ip[] = "127.0.0.1";
 static const char broadcast_ip[] = "255.255.255.255";
 static const char any_ip[] = "0.0.0.0";
 static const char multicast_group[] = "230.1.2.3";
+static const char multicast_group2[] = "230.4.5.6";
 
 static const char sender_ip[] = "192.168.201";
 static const uint16_t sender_port = 7373;
@@ -94,7 +95,6 @@ TEST(test_udp, test_correct_usage_is_enforced)
   ASSERT_NO_THROW(UdpSocket::Builder(localhost_ip, host_port)
                     .set_polling_interval(20)
                     .set_socket_buffer_size(3000)
-                    .join_multicast_group(multicast_group)
                     .set_mtu(1600)
                     .limit_to_sender(sender_ip, sender_port)
                     .set_polling_interval(20)
@@ -103,6 +103,13 @@ TEST(test_udp, test_correct_usage_is_enforced)
                     .limit_to_sender(sender_ip, sender_port)
                     .bind());
 
+  // Only one multicast group can be joined
+  ASSERT_THROW(
+    UdpSocket::Builder(localhost_ip, host_port)
+      .join_multicast_group(multicast_group)
+      .join_multicast_group(multicast_group2),
+    UsageError);
+
   // Pre-existing subscriptions shall be gracefully unsubscribed when a new subscription is created
   ASSERT_NO_THROW(
     UdpSocket::Builder(localhost_ip, host_port).bind().subscribe(empty_cb()).subscribe(empty_cb()));