Connection: close on EPOLLHUP, eliminate last recvmsg() call

Author: MaxKellermann

debian/changelog

@@ -2,6 +2,7 @@ cm4all-spawn (0.23) unstable; urgency=low
 
   * accessory: rename the PID namespace init process to "init"
   * accessory: support user namespaces
+  * accessory: eliminate last recvmsg() system call on closed connection
 
  --   
 

src/accessory/Connection.cxx

@@ -157,6 +157,13 @@ try {
 	return false;
 }
 
+bool
+SpawnConnection::OnUdpHangup()
+{
+	delete this;
+	return false;
+}
+
 void
 SpawnConnection::OnUdpError(std::exception_ptr ep) noexcept
 {

src/accessory/Connection.hxx

@@ -38,5 +38,6 @@ private:
 	bool OnUdpDatagram(std::span<const std::byte> payload,
 			   std::span<UniqueFileDescriptor> fds,
 			   SocketAddress address, int uid) override;
+	bool OnUdpHangup() override;
 	void OnUdpError(std::exception_ptr ep) noexcept override;
 };