diff --git a/unit/rilmodem-test-engine.c b/unit/rilmodem-test-engine.c
new file mode 100644
index 00000000..c5693607
--- /dev/null
+++ b/unit/rilmodem-test-engine.c
@@ -0,0 +1,280 @@
+/*
+ *
+ *  oFono - Open Source Telephony
+ *
+ *  Copyright (C) 2016 Canonical Ltd.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+#include <ofono/types.h>
+
+#include <gril.h>
+
+#include "rilmodem-test-engine.h"
+
+#define MAX_REQUEST_SIZE 4096
+#define RIL_SERVER_SOCK_PATH "/tmp/unittestril"
+
+static GMainLoop *mainloop;
+
+struct engine_data {
+	int server_sk;
+	int connected_sk;
+	guint connection_watch;
+	rilmodem_test_engine_cb_t connect_func;
+	GIOChannel *server_io;
+	char *sock_name;
+	struct rilmodem_test_data rtd;
+	int step_i;
+	void *user_data;
+};
+
+static void send_parcel(struct engine_data *ed)
+{
+	GIOStatus status;
+	gsize wbytes;
+	const struct rilmodem_test_step *step = &ed->rtd.steps[ed->step_i];
+
+	status = g_io_channel_write_chars(ed->server_io,
+						step->parcel_data,
+						step->parcel_size,
+						&wbytes, NULL);
+
+	g_assert(wbytes == step->parcel_size);
+	g_assert(status == G_IO_STATUS_NORMAL);
+
+	status = g_io_channel_flush(ed->server_io, NULL);
+	g_assert(status == G_IO_STATUS_NORMAL);
+
+	rilmodem_test_engine_next_step(ed);
+}
+
+static gboolean on_rx_data(GIOChannel *chan, GIOCondition cond, gpointer data)
+{
+	struct engine_data *ed = data;
+	GIOStatus status;
+	gsize rbytes;
+	gchar *buf;
+	const struct rilmodem_test_step *step;
+
+	/* We have closed the socket */
+	if (cond == G_IO_NVAL)
+		return FALSE;
+
+	buf = g_malloc0(MAX_REQUEST_SIZE);
+
+	status = g_io_channel_read_chars(ed->server_io, buf, MAX_REQUEST_SIZE,
+								&rbytes, NULL);
+	g_assert(status == G_IO_STATUS_NORMAL);
+
+	/* Check this is the expected step */
+	step = &ed->rtd.steps[ed->step_i];
+	g_assert(step->type == TST_EVENT_RECEIVE);
+
+	g_assert(rbytes == step->parcel_size);
+
+	/* validate received parcel */
+	g_assert(!memcmp(buf, step->parcel_data, rbytes));
+
+	rilmodem_test_engine_next_step(ed);
+
+	return TRUE;
+}
+
+static gboolean on_socket_connected(GIOChannel *chan, GIOCondition cond,
+								gpointer data)
+{
+	struct engine_data *ed = data;
+	struct sockaddr saddr;
+	unsigned int len = sizeof(saddr);
+	GIOStatus status;
+
+	g_assert(cond == G_IO_IN);
+
+	ed->connected_sk = accept(ed->server_sk, &saddr, &len);
+	g_assert(ed->connected_sk != -1);
+
+	ed->server_io = g_io_channel_unix_new(ed->connected_sk);
+	g_assert(ed->server_io != NULL);
+
+	status = g_io_channel_set_encoding(ed->server_io, NULL, NULL);
+	g_assert(status == G_IO_STATUS_NORMAL);
+
+	g_io_channel_set_buffered(ed->server_io, FALSE);
+	g_io_channel_set_close_on_unref(ed->server_io, TRUE);
+
+	if (ed->connect_func)
+		ed->connect_func(ed->user_data);
+
+	ed->connection_watch =
+		g_io_add_watch_full(ed->server_io, G_PRIORITY_DEFAULT,
+				G_IO_IN | G_IO_HUP | G_IO_ERR | G_IO_NVAL,
+				on_rx_data, ed, NULL);
+	g_io_channel_unref(ed->server_io);
+
+	return FALSE;
+}
+
+void rilmodem_test_engine_remove(struct engine_data *ed)
+{
+	if (ed->connection_watch)
+		g_source_remove(ed->connection_watch);
+
+	g_assert(ed->server_sk);
+	close(ed->server_sk);
+	remove(ed->sock_name);
+	g_free(ed->sock_name);
+	g_free(ed);
+}
+
+struct engine_data *rilmodem_test_engine_create(
+				rilmodem_test_engine_cb_t connect,
+				const struct rilmodem_test_data *test_data,
+				void *data)
+{
+	GIOChannel *io;
+	struct sockaddr_un addr;
+	int retval;
+	struct engine_data *ed;
+
+	ed = g_new0(struct engine_data, 1);
+
+	ed->connect_func = connect;
+	ed->user_data = data;
+	ed->rtd = *test_data;
+
+	ed->server_sk = socket(AF_UNIX, SOCK_STREAM, 0);
+	g_assert(ed->server_sk);
+
+	ed->sock_name =
+		g_strdup_printf(RIL_SERVER_SOCK_PATH"%u", (unsigned) getpid());
+
+	memset(&addr, 0, sizeof(addr));
+	addr.sun_family = AF_UNIX;
+	strncpy(addr.sun_path, ed->sock_name, sizeof(addr.sun_path) - 1);
+
+	/* Unlink any existing socket for this session */
+	unlink(addr.sun_path);
+
+	retval = bind(ed->server_sk, (struct sockaddr *) &addr, sizeof(addr));
+	g_assert(retval >= 0);
+
+	retval = listen(ed->server_sk, 0);
+	g_assert(retval >= 0);
+
+	io = g_io_channel_unix_new(ed->server_sk);
+	g_assert(io != NULL);
+
+	g_io_channel_set_close_on_unref(io, TRUE);
+	g_io_add_watch_full(io,	G_PRIORITY_DEFAULT,
+				G_IO_IN | G_IO_HUP | G_IO_ERR | G_IO_NVAL,
+				on_socket_connected, ed, NULL);
+
+	g_io_channel_unref(io);
+
+	return ed;
+}
+
+void rilmodem_test_engine_write_socket(struct engine_data *ed,
+						const unsigned char *buf,
+						const size_t buf_len)
+{
+	GIOStatus status;
+	gsize wbytes;
+
+	status = g_io_channel_write_chars(ed->server_io,
+					(const char *) buf,
+					buf_len,
+					&wbytes, NULL);
+
+	g_assert(status == G_IO_STATUS_NORMAL);
+
+	status = g_io_channel_flush(ed->server_io, NULL);
+
+	g_assert(status == G_IO_STATUS_NORMAL);
+}
+
+const char *rilmodem_test_engine_get_socket_name(struct engine_data *ed)
+{
+	return ed->sock_name;
+}
+
+static gboolean action_call(gpointer data)
+{
+	struct engine_data *ed = data;
+	const struct rilmodem_test_step *step;
+
+	step = &ed->rtd.steps[ed->step_i];
+
+	step->call_action(ed->user_data);
+
+	return FALSE;
+}
+
+void rilmodem_test_engine_next_step(struct engine_data *ed)
+{
+	const struct rilmodem_test_step *step;
+
+	ed->step_i++;
+
+	if (ed->step_i >= ed->rtd.num_steps) {
+		/* Finish the test */
+		g_main_loop_quit(mainloop);
+		return;
+	}
+
+	step = &ed->rtd.steps[ed->step_i];
+
+	/* If next step is an action, execute it */
+	switch (step->type) {
+	case TST_ACTION_SEND:
+		send_parcel(ed);
+		break;
+	case TST_ACTION_CALL:
+		g_idle_add(action_call, ed);
+		break;
+	case TST_EVENT_RECEIVE:
+	case TST_EVENT_CALL:
+		break;
+	};
+}
+
+const struct rilmodem_test_step *rilmodem_test_engine_get_current_step(
+							struct engine_data *ed)
+{
+	const struct rilmodem_test_step *step = &ed->rtd.steps[ed->step_i];
+
+	return step;
+}
+
+void rilmodem_test_engine_start(struct engine_data *ed)
+{
+	mainloop = g_main_loop_new(NULL, FALSE);
+
+	g_main_loop_run(mainloop);
+	g_main_loop_unref(mainloop);
+}
diff --git a/unit/rilmodem-test-engine.h b/unit/rilmodem-test-engine.h
new file mode 100644
index 00000000..185d9bce
--- /dev/null
+++ b/unit/rilmodem-test-engine.h
@@ -0,0 +1,74 @@
+/*
+ *
+ *  oFono - Open Source Telephony
+ *
+ *  Copyright (C) 2016 Canonical Ltd.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+struct engine_data;
+
+enum test_step_type {
+	TST_ACTION_SEND,
+	TST_ACTION_CALL,
+	TST_EVENT_RECEIVE,
+	TST_EVENT_CALL,
+};
+
+typedef void (*rilmodem_test_engine_cb_t)(void *data);
+
+struct rilmodem_test_step {
+	enum test_step_type type;
+
+	union {
+		/* For TST_ACTION_CALL */
+		rilmodem_test_engine_cb_t call_action;
+		/* For TST_ACTION_SEND or TST_EVENT_RECEIVE */
+		struct {
+			const char *parcel_data;
+			const size_t parcel_size;
+		};
+		/* For TST_EVENT_CALL */
+		struct {
+			void (*call_func)(void);
+			void (*check_func)(void);
+		};
+	};
+};
+
+struct rilmodem_test_data {
+	const struct rilmodem_test_step *steps;
+	int num_steps;
+};
+
+void rilmodem_test_engine_remove(struct engine_data *ed);
+
+struct engine_data *rilmodem_test_engine_create(
+				rilmodem_test_engine_cb_t connect,
+				const struct rilmodem_test_data *test_data,
+				void *data);
+
+void rilmodem_test_engine_write_socket(struct engine_data *ed,
+						const unsigned char *buf,
+						const size_t buf_len);
+
+const char *rilmodem_test_engine_get_socket_name(struct engine_data *ed);
+
+void rilmodem_test_engine_next_step(struct engine_data *ed);
+const struct rilmodem_test_step *rilmodem_test_engine_get_current_step(
+							struct engine_data *ed);
+
+void rilmodem_test_engine_start(struct engine_data *ed);