diff --git a/lib/io.c b/lib/io.c
index 4dedc1873..261edd48c 100644
--- a/lib/io.c
+++ b/lib/io.c
@@ -187,6 +187,8 @@ int io_stream_fd(struct io *io)
 		case IO_MODE_CUSTOM:
 			return -1;
 	}
+	
+	return -1;
 }
 
 
diff --git a/lib/nodes/file.c b/lib/nodes/file.c
index 061f546d4..6ecef27f7 100644
--- a/lib/nodes/file.c
+++ b/lib/nodes/file.c
@@ -339,6 +339,20 @@ int file_write(struct node *n, struct sample *smps[], unsigned cnt)
 	return cnt;
 }
 
+int file_fd(struct node *n)
+{
+	struct file *f = n->_vd;
+	
+	if (f->rate)
+		return task_fd(&f->task);
+	else {
+		if (f->epoch_mode == FILE_EPOCH_ORIGINAL)
+			return io_fd(&f->io);
+		else
+			return -1; /** @todo not supported yet */
+	}
+}
+
 static struct plugin p = {
 	.name		= "file",
 	.description	= "support for file log / replay node type",
@@ -351,7 +365,8 @@ static struct plugin p = {
 		.start		= file_start,
 		.stop		= file_stop,
 		.read		= file_read,
-		.write		= file_write
+		.write		= file_write,
+		.fd		= file_fd
 	}
 };
 
diff --git a/lib/nodes/nanomsg.c b/lib/nodes/nanomsg.c
index 734d84152..3bf0e4b5c 100644
--- a/lib/nodes/nanomsg.c
+++ b/lib/nodes/nanomsg.c
@@ -246,6 +246,21 @@ int nanomsg_write(struct node *n, struct sample *smps[], unsigned cnt)
 	return cnt;
 }
 
+int nanomsg_fd(struct node *n)
+{
+	int ret;
+	struct nanomsg *m = n->_vd;
+	
+	int fd;
+	size_t len = sizeof(fd);
+
+	ret = nn_getsockopt(m->subscriber.socket, NN_SOL_SOCKET, NN_RCVFD, &fd, &len);
+	if (ret)
+		return ret;
+	
+	return fd;
+}
+
 static struct plugin p = {
 	.name		= "nanomsg",
 	.description	= "scalability protocols library (libnanomsg)",
@@ -260,7 +275,8 @@ static struct plugin p = {
 		.stop		= nanomsg_stop,
 		.deinit		= nanomsg_deinit,
 		.read		= nanomsg_read,
-		.write		= nanomsg_write
+		.write		= nanomsg_write,
+		.fd		= nanomsg_fd
 	}
 };
 
diff --git a/lib/nodes/ngsi.c b/lib/nodes/ngsi.c
index 0c2ba042d..84a14b732 100644
--- a/lib/nodes/ngsi.c
+++ b/lib/nodes/ngsi.c
@@ -573,6 +573,13 @@ int ngsi_write(struct node *n, struct sample *smps[], unsigned cnt)
 	return ret ? 0 : cnt;
 }
 
+int ngsi_fd(struct node *n)
+{
+	struct ngsi *i = n->_vd;
+	
+	return task_fd(&i->task);
+}
+
 static struct plugin p = {
 	.name		= "ngsi",
 	.description	= "OMA Next Generation Services Interface 10 (libcurl, libjansson)",
@@ -587,7 +594,8 @@ static struct plugin p = {
 		.read		= ngsi_read,
 		.write		= ngsi_write,
 		.init		= ngsi_init,
-		.deinit		= ngsi_deinit
+		.deinit		= ngsi_deinit,
+		.fd		= ngsi_fd
 	}
 };
 
diff --git a/lib/nodes/signal.c b/lib/nodes/signal.c
index cba5dff57..f718c9beb 100644
--- a/lib/nodes/signal.c
+++ b/lib/nodes/signal.c
@@ -265,7 +265,14 @@ char * signal_print(struct node *n)
 		strcatf(&buf, ", limit=%d", s->limit);
 
 	return buf;
-};
+}
+
+int signal_fd(struct node *n)
+{
+	struct signal *s = n->_vd;
+	
+	return task_fd(&s->task);
+}
 
 static struct plugin p = {
 	.name = "signal",
@@ -280,6 +287,7 @@ static struct plugin p = {
 		.start = signal_open,
 		.stop  = signal_close,
 		.read  = signal_read,
+		.fd    = signal_fd
 	}
 };
 
diff --git a/lib/nodes/socket.c b/lib/nodes/socket.c
index 4035694c4..30f557be6 100644
--- a/lib/nodes/socket.c
+++ b/lib/nodes/socket.c
@@ -703,6 +703,13 @@ int socket_compare_addr(struct sockaddr *x, struct sockaddr *y)
 #undef CMP
 }
 
+int socket_fd(struct node *n)
+{
+	struct socket *s = n->_vd;
+
+	return s->sd;
+}
+
 static struct plugin p = {
 	.name		= "socket",
 	.description	= "BSD network sockets for Ethernet / IP / UDP (libnl3)",
@@ -719,7 +726,8 @@ static struct plugin p = {
 		.read		= socket_read,
 		.write		= socket_write,
 		.init		= socket_init,
-		.deinit		= socket_deinit
+		.deinit		= socket_deinit,
+		.fd		= socket_fd
 	}
 };
 
diff --git a/lib/nodes/test_rtt.c b/lib/nodes/test_rtt.c
index 7a718d46f..6da4b7415 100644
--- a/lib/nodes/test_rtt.c
+++ b/lib/nodes/test_rtt.c
@@ -235,6 +235,13 @@ int test_rtt_write(struct node *n, struct sample *smps[], unsigned cnt)
 	return i;
 }
 
+int test_rtt_fd(struct node *n)
+{
+	struct test_rtt *t = n->_vd;
+	
+	return task_fd(&t->task);
+}
+
 static struct plugin p = {
 	.name		= "test_rtt",
 	.description	= "Test round-trip time with loopback",
@@ -247,7 +254,8 @@ static struct plugin p = {
 		.start		= test_rtt_start,
 		.stop		= test_rtt_stop,
 		.read		= test_rtt_read,
-		.write		= test_rtt_write
+		.write		= test_rtt_write,
+		.fd		= test_rtt_fd
 	}
 };
 
diff --git a/lib/nodes/zeromq.c b/lib/nodes/zeromq.c
index 721a834e4..66819249e 100644
--- a/lib/nodes/zeromq.c
+++ b/lib/nodes/zeromq.c
@@ -488,6 +488,21 @@ fail:
 	return ret;
 }
 
+int zeromq_fd(struct node *n)
+{
+	int ret;
+	struct zeromq *z = n->_vd;
+	
+	int fd;
+	size_t len = sizeof(fd);
+	
+	ret = zmq_getsockopt(z->subscriber.socket, ZMQ_FD, &fd, &len);
+	if (ret)
+		return ret;
+
+	return fd;
+}
+
 static struct plugin p = {
 	.name		= "zeromq",
 	.description	= "ZeroMQ Distributed Messaging (libzmq)",
@@ -503,7 +518,8 @@ static struct plugin p = {
 		.init		= zeromq_init,
 		.deinit		= zeromq_deinit,
 		.read		= zeromq_read,
-		.write		= zeromq_write
+		.write		= zeromq_write,
+		.fd		= zeromq_fd
 	}
 };