From: sairoop-elear <sairoop@elear.solutions>
Date: Tue, 7 Apr 2020 20:22:26 +0000 (+0530)
Subject: Add missing atomic test cases to the APIs that affects disk writes
X-Git-Url: https://git.meshlink.io/?a=commitdiff_plain;h=9708fcc1417fc26a4328cfacb39652890cab629d;p=meshlink

Add missing atomic test cases to the APIs that affects disk writes
---

diff --git a/test/blackbox/run_blackbox_tests/test_cases_invite.c b/test/blackbox/run_blackbox_tests/test_cases_invite.c
index 929b002a..f04cb099 100644
--- a/test/blackbox/run_blackbox_tests/test_cases_invite.c
+++ b/test/blackbox/run_blackbox_tests/test_cases_invite.c
@@ -26,16 +26,24 @@
 #include "../common/containers.h"
 #include "../common/test_step.h"
 #include "../common/common_handlers.h"
+#include "../../utils.h"
 #include <assert.h>
 #include <string.h>
 #include <stdlib.h>
 #include <stdarg.h>
 #include <setjmp.h>
 #include <cmocka.h>
+#include <signal.h>
+#include <linux/limits.h>
 
 /* Modify this to change the logging level of Meshlink */
 #define TEST_MESHLINK_LOG_LEVEL MESHLINK_DEBUG
 
+#define NUT                         "nut"
+#define PEER                        "peer"
+#define TEST_MESHLINK_INVITE        "test_invite"
+#define create_path(confbase, node_name, test_case_no)   assert(snprintf(confbase, sizeof(confbase), TEST_MESHLINK_INVITE "_%ld_%s_%02d", (long) getpid(), node_name, test_case_no) > 0)
+
 static void test_case_invite_01(void **state);
 static bool test_invite_01(void);
 static void test_case_invite_02(void **state);
@@ -44,6 +52,8 @@ static void test_case_invite_03(void **state);
 static bool test_invite_03(void);
 static void test_case_invite_04(void **state);
 static bool test_invite_04(void);
+static void test_case_invite_05(void **state);
+static bool test_invite_05(void);
 
 /* State structure for invite API Test Case #1 */
 static black_box_state_t test_case_invite_01_state = {
@@ -65,6 +75,11 @@ static black_box_state_t test_case_invite_04_state = {
 	.test_case_name = "test_case_invite_04",
 };
 
+/* State structure for invite API Test Case #5 */
+static black_box_state_t test_case_invite_05_state = {
+	.test_case_name = "test_case_invite_05",
+};
+
 /* Execute invite Test Case # 1 - valid case*/
 static void test_case_invite_01(void **state) {
 	execute_test(test_invite_01, state);
@@ -78,20 +93,22 @@ static void test_case_invite_01(void **state) {
     Generates an invitation
 */
 static bool test_invite_01(void) {
-	assert(meshlink_destroy("inviteconf"));
-	meshlink_set_log_cb(NULL, TEST_MESHLINK_LOG_LEVEL, meshlink_callback_logger);
+	char nut_confbase[PATH_MAX];
+	char peer_invitation[1000];
+	create_path(nut_confbase, NUT, 1);
 
 	// Create meshlink instance
-	meshlink_handle_t *mesh_handle = meshlink_open("inviteconf", "nut", "node_sim", 1);
-	assert(mesh_handle);
-	meshlink_set_log_cb(mesh_handle, TEST_MESHLINK_LOG_LEVEL, meshlink_callback_logger);
 
-	char *invitation = meshlink_invite(mesh_handle, NULL, "new");
-	assert_int_equal(invitation, NULL);
+	meshlink_set_log_cb(NULL, MESHLINK_DEBUG, log_cb);
+	meshlink_handle_t *mesh = meshlink_open(nut_confbase, NUT, TEST_MESHLINK_INVITE, DEV_CLASS_STATIONARY);
+	assert_non_null(mesh);
+
+	char *invitation = meshlink_invite(mesh, NULL, "new");
+	assert_non_null(invitation);
 
 	free(invitation);
-	meshlink_close(mesh_handle);
-	assert(meshlink_destroy("inviteconf"));
+	meshlink_close(mesh);
+	assert_true(meshlink_destroy(nut_confbase));
 	return true;
 }
 
@@ -127,20 +144,22 @@ static void test_case_invite_03(void **state) {
     Reports appropriate error by returning NULL
 */
 static bool test_invite_03(void) {
-	assert(meshlink_destroy("inviteconf"));
-	meshlink_set_log_cb(NULL, TEST_MESHLINK_LOG_LEVEL, meshlink_callback_logger);
+	char nut_confbase[PATH_MAX];
+	char peer_invitation[1000];
+	create_path(nut_confbase, NUT, 3);
 
 	// Create meshlink instance
-	meshlink_handle_t *mesh_handle = meshlink_open("inviteconf", "nut", "node_sim", 1);
-	assert(mesh_handle);
-	meshlink_set_log_cb(mesh_handle, TEST_MESHLINK_LOG_LEVEL, meshlink_callback_logger);
 
-	// Trying to generate INVITATION by passing NULL as mesh link handle
-	char *invitation = meshlink_invite(mesh_handle, NULL, NULL);
+	meshlink_set_log_cb(NULL, MESHLINK_DEBUG, log_cb);
+	meshlink_handle_t *mesh = meshlink_open(nut_confbase, NUT, TEST_MESHLINK_INVITE, DEV_CLASS_STATIONARY);
+	assert_non_null(mesh);
+
+	char *invitation = meshlink_invite(mesh, NULL, NULL);
 	assert_int_equal(invitation, NULL);
 
-	meshlink_close(mesh_handle);
-	assert(meshlink_destroy("inviteconf"));
+	free(invitation);
+	meshlink_close(mesh);
+	assert_true(meshlink_destroy(nut_confbase));
 	return true;
 }
 
@@ -159,30 +178,92 @@ static void test_case_invite_04(void **state) {
     Newly added address should be there in the invitation.
 */
 static bool test_invite_04(void) {
-	assert(meshlink_destroy("inviteconf"));
-	meshlink_set_log_cb(NULL, TEST_MESHLINK_LOG_LEVEL, meshlink_callback_logger);
+	char nut_confbase[PATH_MAX];
+	char peer_invitation[1000];
+	create_path(nut_confbase, NUT, 4);
 
 	// Create meshlink instance
-	meshlink_handle_t *mesh_handle = meshlink_open("inviteconf", "nut", "test", 1);
-	assert(mesh_handle);
-	meshlink_set_log_cb(mesh_handle, TEST_MESHLINK_LOG_LEVEL, meshlink_callback_logger);
 
-	char *hostname1 = "127.1.1.1";
-	assert(meshlink_add_address(mesh_handle, hostname1));
-	char *invitation = meshlink_invite(mesh_handle, NULL, "foo");
-	assert_int_not_equal(strstr(invitation, hostname1), NULL);
+	meshlink_set_log_cb(NULL, MESHLINK_DEBUG, log_cb);
+	meshlink_handle_t *mesh = meshlink_open(nut_confbase, NUT, TEST_MESHLINK_INVITE, DEV_CLASS_STATIONARY);
+	assert_non_null(mesh);
+
+	assert_true(meshlink_add_invitation_address(mesh, "11.11.11.11", "2020"));
+	char *invitation = meshlink_invite(mesh, NULL, "foo");
+	assert_non_null(strstr(invitation, "11.11.11.11:2020"));
+	free(invitation);
+
+	assert_true(meshlink_add_invitation_address(mesh, "fe80::1548:d713:3899:f645", "3030"));
+	invitation = meshlink_invite(mesh, NULL, "bar");
+	assert_non_null(strstr(invitation, "11.11.11.11:2020"));
+	assert_non_null(strstr(invitation, "[fe80::1548:d713:3899:f645]:3030"));
+	free(invitation);
+
+	meshlink_close(mesh);
+	assert_true(meshlink_destroy(nut_confbase));
+	return true;
+}
+
+/* Execute invite Test Case # 5 - Synchronization testing */
+static void test_case_invite_05(void **state) {
+	execute_test(test_invite_05, state);
+}
+
+static bool test_invite_05(void) {
+	bool status;
+	pid_t pid;
+	int pid_status;
+	int pipefd[2];
+	char nut_confbase[PATH_MAX];
+	char peer_confbase[PATH_MAX];
+	char peer_invitation[1000];
+	create_path(nut_confbase, NUT, 5);
+	create_path(peer_confbase, PEER, 5);
+
+	assert_int_not_equal(pipe(pipefd), -1);
+
+	// Fork a new process in which NUT opens it's instance and raises SIGINT to terminate.
+
+	pid = fork();
+	assert_int_not_equal(pid, -1);
+
+	if(!pid) {
+		assert(!close(pipefd[0]));
+		meshlink_set_log_cb(NULL, MESHLINK_DEBUG, log_cb);
+		meshlink_handle_t *mesh = meshlink_open(nut_confbase, NUT, TEST_MESHLINK_INVITE, DEV_CLASS_STATIONARY);
+		assert(mesh);
+
+		char *invitation = meshlink_invite(mesh, NULL, PEER);
+		write(pipefd[1], invitation, strlen(invitation) + 1);
+
+		raise(SIGINT);
+	}
+
+	// Wait for child exit and verify which signal terminated it
+
+	assert_int_not_equal(waitpid(pid, &pid_status, 0), -1);
+	assert_int_equal(WIFSIGNALED(pid_status), true);
+	assert_int_equal(WTERMSIG(pid_status), SIGINT);
+
+	assert_int_equal(close(pipefd[1]), 0);
+	assert_int_not_equal(read(pipefd[0], peer_invitation, sizeof(peer_invitation)), -1);
 
-	char *hostname2 = "127.1.2.3";
-	assert(meshlink_add_address(mesh_handle, hostname2));
-	invitation = meshlink_invite(mesh_handle, NULL, "bar");
+	// Reopen the NUT instance in the same test suite
 
-	// Verify we have both the added addresses
-	assert_int_not_equal(strstr(invitation, hostname1), NULL);
-	assert_int_not_equal(strstr(invitation, hostname2), NULL);
+	meshlink_set_log_cb(NULL, MESHLINK_DEBUG, log_cb);
+	meshlink_handle_t *mesh = meshlink_open(nut_confbase, NUT, TEST_MESHLINK_INVITE, DEV_CLASS_STATIONARY);
+	assert_non_null(mesh);
+	meshlink_handle_t *mesh_peer = meshlink_open(peer_confbase, PEER, TEST_MESHLINK_INVITE, DEV_CLASS_STATIONARY);
+	assert_non_null(mesh);
+	assert_true(meshlink_start(mesh));
+	assert_true(meshlink_join(mesh_peer, peer_invitation));
 
-	meshlink_close(mesh_handle);
-	assert(meshlink_destroy("inviteconf"));
+	// Cleanup
 
+	meshlink_close(mesh);
+	meshlink_close(mesh_peer);
+	assert_true(meshlink_destroy(nut_confbase));
+	assert_true(meshlink_destroy(peer_confbase));
 	return true;
 }
 
@@ -195,7 +276,9 @@ int test_meshlink_invite(void) {
 		cmocka_unit_test_prestate_setup_teardown(test_case_invite_03, NULL, NULL,
 		                (void *)&test_case_invite_03_state),
 		cmocka_unit_test_prestate_setup_teardown(test_case_invite_04, NULL, NULL,
-		                (void *)&test_case_invite_04_state)
+		                (void *)&test_case_invite_04_state),
+		cmocka_unit_test_prestate_setup_teardown(test_case_invite_05, NULL, NULL,
+		                (void *)&test_case_invite_05_state)
 	};
 
 	total_tests += sizeof(blackbox_invite_tests) / sizeof(blackbox_invite_tests[0]);
diff --git a/test/blackbox/run_blackbox_tests/test_cases_open.c b/test/blackbox/run_blackbox_tests/test_cases_open.c
index 40bd26c7..a1c1b1ea 100644
--- a/test/blackbox/run_blackbox_tests/test_cases_open.c
+++ b/test/blackbox/run_blackbox_tests/test_cases_open.c
@@ -26,16 +26,24 @@
 #include "../common/containers.h"
 #include "../common/test_step.h"
 #include "../common/common_handlers.h"
+#include "../../utils.h"
 #include <stdlib.h>
 #include <stdarg.h>
 #include <setjmp.h>
 #include <cmocka.h>
 #include <assert.h>
 #include <string.h>
+#include <signal.h>
+#include <linux/limits.h>
 
 /* Modify this to change the logging level of Meshlink */
 #define TEST_MESHLINK_LOG_LEVEL MESHLINK_DEBUG
 
+#define NUT                         "nut"
+#define PEER                        "peer"
+#define TEST_MESHLINK_OPEN          "test_open"
+#define create_path(confbase, node_name, test_case_no)   assert(snprintf(confbase, sizeof(confbase), TEST_MESHLINK_OPEN "_%ld_%s_%02d", (long) getpid(), node_name, test_case_no) > 0)
+
 static void test_case_mesh_open_01(void **state);
 static bool test_steps_mesh_open_01(void);
 static void test_case_mesh_open_02(void **state);
@@ -46,6 +54,10 @@ static void test_case_mesh_open_04(void **state);
 static bool test_steps_mesh_open_04(void);
 static void test_case_mesh_open_05(void **state);
 static bool test_steps_mesh_open_05(void);
+static void test_case_mesh_open_06(void **state);
+static bool test_steps_mesh_open_06(void);
+static void test_case_mesh_open_07(void **state);
+static bool test_steps_mesh_open_07(void);
 
 /* State structure for meshlink_open Test Case #1 */
 static black_box_state_t test_mesh_open_01_state = {
@@ -72,6 +84,16 @@ static black_box_state_t test_mesh_open_05_state = {
 	.test_case_name = "test_case_mesh_open_05",
 };
 
+/* State structure for meshlink_open Test Case #6 */
+static black_box_state_t test_mesh_open_06_state = {
+	.test_case_name = "test_case_mesh_open_06",
+};
+
+/* State structure for meshlink_open Test Case #7 */
+static black_box_state_t test_mesh_open_07_state = {
+	.test_case_name = "test_case_mesh_open_07",
+};
+
 /* Execute meshlink_open Test Case # 1*/
 static void test_case_mesh_open_01(void **state) {
 	execute_test(test_steps_mesh_open_01, state);
@@ -182,6 +204,133 @@ static bool test_steps_mesh_open_05(void) {
 	return true;
 }
 
+/* Execute meshlink_open Test Case # 7 - Atomicity testing
+    Validate the meshlink_open behavior opened a new confbase and terminated immediately the open call.
+*/
+static void test_case_mesh_open_06(void **state) {
+	execute_test(test_steps_mesh_open_06, state);
+}
+
+static bool test_steps_mesh_open_06(void) {
+	bool status;
+	pid_t pid;
+	int pid_status;
+	char nut_confbase[PATH_MAX];
+	create_path(nut_confbase, NUT, 6);
+
+	// Fork a new process in which NUT opens it's instance and raises SIGINT to terminate.
+
+	pid = fork();
+	assert_int_not_equal(pid, -1);
+
+	if(!pid) {
+		meshlink_set_log_cb(NULL, MESHLINK_DEBUG, log_cb);
+		meshlink_handle_t *mesh = meshlink_open(nut_confbase, NUT, TEST_MESHLINK_OPEN, DEV_CLASS_STATIONARY);
+		assert(mesh);
+		raise(SIGINT);
+	}
+
+	// Wait for child exit and verify which signal terminated it
+
+	assert_int_not_equal(waitpid(pid, &pid_status, 0), -1);
+	assert_int_equal(WIFSIGNALED(pid_status), true);
+	assert_int_equal(WTERMSIG(pid_status), SIGINT);
+
+	// Reopen the NUT instance in the same test suite
+
+	meshlink_set_log_cb(NULL, MESHLINK_DEBUG, log_cb);
+	meshlink_handle_t *mesh = meshlink_open(nut_confbase, NUT, TEST_MESHLINK_OPEN, DEV_CLASS_STATIONARY);
+	assert_non_null(mesh);
+
+	// Validate parameters that were used to open meshlink instance.
+
+	assert_int_equal(strcmp(mesh->name, NUT), 0);
+	meshlink_node_t *self = meshlink_get_self(mesh);
+	assert_int_equal(strcmp(self->name, NUT), 0);
+	assert_int_equal(meshlink_get_node_dev_class(mesh, self), DEV_CLASS_STATIONARY);
+
+	// Cleanup
+
+	meshlink_close(mesh);
+	assert_true(meshlink_destroy(nut_confbase));
+	return true;
+}
+
+/* Execute meshlink_open Test Case # 7 - Atomicity testing
+    Validate the meshlink_open behavior opened an existing confbase and terminated immediately the open call.
+*/
+static void test_case_mesh_open_07(void **state) {
+	execute_test(test_steps_mesh_open_07, state);
+}
+
+static bool test_steps_mesh_open_07(void) {
+	bool status;
+	pid_t pid;
+	int pid_status;
+	char nut_confbase[PATH_MAX];
+	char peer_confbase[PATH_MAX];
+	create_path(nut_confbase, NUT, 7);
+	create_path(peer_confbase, PEER, 7);
+
+	meshlink_set_log_cb(NULL, MESHLINK_DEBUG, log_cb);
+	meshlink_handle_t *mesh = meshlink_open(nut_confbase, NUT, TEST_MESHLINK_OPEN, DEV_CLASS_BACKBONE);
+	assert_non_null(mesh);
+	meshlink_handle_t *mesh_peer = meshlink_open(peer_confbase, PEER, TEST_MESHLINK_OPEN, DEV_CLASS_STATIONARY);
+	assert_non_null(mesh_peer);
+
+	// Exporting and Importing mutually
+	char *export_data = meshlink_export(mesh);
+	assert_non_null(export_data);
+	assert_true(meshlink_import(mesh_peer, export_data));
+	free(export_data);
+	export_data = meshlink_export(mesh_peer);
+	assert_non_null(export_data);
+	assert_true(meshlink_import(mesh, export_data));
+	free(export_data);
+
+	meshlink_close(mesh);
+	meshlink_close(mesh_peer);
+
+
+	// Fork a new process in which NUT reopens it's instance and raises SIGINT to terminate.
+
+	pid = fork();
+	assert_int_not_equal(pid, -1);
+
+	if(!pid) {
+		meshlink_set_log_cb(NULL, MESHLINK_DEBUG, log_cb);
+		meshlink_handle_t *mesh = meshlink_open(nut_confbase, NUT, TEST_MESHLINK_OPEN, DEV_CLASS_BACKBONE);
+		assert(mesh);
+		raise(SIGINT);
+	}
+
+	// Wait for child exit and verify which signal terminated it
+
+	assert_int_not_equal(waitpid(pid, &pid_status, 0), -1);
+	assert_int_equal(WIFSIGNALED(pid_status), true);
+	assert_int_equal(WTERMSIG(pid_status), SIGINT);
+
+	// Reopen the NUT instance in the same test suite
+
+	meshlink_set_log_cb(NULL, MESHLINK_DEBUG, log_cb);
+	mesh = meshlink_open(nut_confbase, NUT, TEST_MESHLINK_OPEN, DEV_CLASS_STATIONARY);
+	assert_non_null(mesh);
+
+	// Validate parameters that were used to open meshlink instance.
+
+	assert_int_equal(strcmp(mesh->name, NUT), 0);
+	meshlink_node_t *self = meshlink_get_self(mesh);
+	assert_int_equal(strcmp(self->name, NUT), 0);
+	assert_int_equal(meshlink_get_node_dev_class(mesh, self), DEV_CLASS_STATIONARY);
+
+	// Cleanup
+
+	meshlink_close(mesh);
+	assert_true(meshlink_destroy(nut_confbase));
+	assert_true(meshlink_destroy(peer_confbase));
+	return true;
+}
+
 int test_meshlink_open(void) {
 	const struct CMUnitTest blackbox_open_tests[] = {
 		cmocka_unit_test_prestate_setup_teardown(test_case_mesh_open_01, NULL, NULL,
@@ -193,7 +342,11 @@ int test_meshlink_open(void) {
 		cmocka_unit_test_prestate_setup_teardown(test_case_mesh_open_04, NULL, NULL,
 		                (void *)&test_mesh_open_04_state),
 		cmocka_unit_test_prestate_setup_teardown(test_case_mesh_open_05, NULL, NULL,
-		                (void *)&test_mesh_open_05_state)
+		                (void *)&test_mesh_open_05_state),
+		cmocka_unit_test_prestate_setup_teardown(test_case_mesh_open_06, NULL, NULL,
+		                (void *)&test_mesh_open_06_state),
+		cmocka_unit_test_prestate_setup_teardown(test_case_mesh_open_07, NULL, NULL,
+		                (void *)&test_mesh_open_07_state)
 
 	};
 	total_tests += sizeof(blackbox_open_tests) / sizeof(blackbox_open_tests[0]);
diff --git a/test/blackbox/run_blackbox_tests/test_cases_set_port.c b/test/blackbox/run_blackbox_tests/test_cases_set_port.c
index e514e57f..c2153999 100644
--- a/test/blackbox/run_blackbox_tests/test_cases_set_port.c
+++ b/test/blackbox/run_blackbox_tests/test_cases_set_port.c
@@ -26,6 +26,7 @@
 #include "../common/containers.h"
 #include "../common/test_step.h"
 #include "../common/common_handlers.h"
+#include "../../utils.h"
 #include "test_cases_set_port.h"
 #include <assert.h>
 #include <string.h>
@@ -33,17 +34,26 @@
 #include <stdarg.h>
 #include <setjmp.h>
 #include <cmocka.h>
-
+#include <signal.h>
+#include <wait.h>
+#include <linux/limits.h>
 
 /* Modify this to change the logging level of Meshlink */
 #define TEST_MESHLINK_LOG_LEVEL MESHLINK_DEBUG
 
+#define NUT                         "nut"
+#define PEER                        "peer"
+#define TEST_MESHLINK_SET_PORT      "test_set_port"
+#define create_path(confbase, node_name, test_case_no)   assert(snprintf(confbase, sizeof(confbase), TEST_MESHLINK_SET_PORT "_%ld_%s_%02d", (long) getpid(), node_name, test_case_no) > 0)
+
 static void test_case_set_port_01(void **state);
 static bool test_set_port_01(void);
 static void test_case_set_port_02(void **state);
 static bool test_set_port_02(void);
 static void test_case_set_port_03(void **state);
 static bool test_set_port_03(void);
+static void test_case_set_port_04(void **state);
+static bool test_set_port_04(void);
 
 /* State structure for set port API Test Case #1 */
 static black_box_state_t test_case_set_port_01_state = {
@@ -57,6 +67,75 @@ static black_box_state_t test_case_set_port_02_state = {
 static black_box_state_t test_case_set_port_03_state = {
 	.test_case_name = "test_case_set_port_03",
 };
+/* State structure for set port API Test Case #4 */
+static black_box_state_t test_case_set_port_04_state = {
+	.test_case_name = "test_case_set_port_04",
+};
+
+static bool try_bind(int portno) {
+	int socket_fd = socket(AF_INET, SOCK_STREAM, 0);
+	assert_int_not_equal(socket_fd, -1);
+
+	struct sockaddr_in sin;
+	socklen_t len = sizeof(sin);
+	bzero(&sin, len);
+
+	assert_int_not_equal(getsockname(socket_fd, (struct sockaddr *)&sin, &len), -1);
+	sin.sin_addr.s_addr = INADDR_ANY;
+	sin.sin_port = htons(portno);
+
+	errno = 0;
+	int bind_status = bind(socket_fd, (struct sockaddr *)&sin, len);
+
+	// Exempt EADDRINUSE error only
+
+	if(bind_status) {
+		assert_int_equal(errno, EADDRINUSE);
+	}
+
+	assert_int_not_equal(close(socket_fd), -1);
+
+	return !bind_status;
+}
+
+static void wait_for_socket_free(int portno) {
+
+	// Wait upto 20 seconds and poll every second whether the port is freed or not
+
+	for(int i = 0; i < 20; i++) {
+		if(try_bind(portno)) {
+			return;
+		} else {
+			sleep(1);
+		}
+	}
+
+	fail();
+}
+
+static int get_free_port(void) {
+
+	// Get a free port
+
+	int socket_fd = socket(AF_INET, SOCK_STREAM, 0);
+	assert_int_not_equal(socket_fd, -1);
+
+	struct sockaddr_in sin;
+	socklen_t len = sizeof(sin);
+	bzero(&sin, len);
+
+	assert_int_not_equal(getsockname(socket_fd, (struct sockaddr *)&sin, &len), -1);
+	sin.sin_addr.s_addr = INADDR_ANY;
+	sin.sin_port = 0;
+
+	assert_int_not_equal(bind(socket_fd, (struct sockaddr *)&sin, len), -1);
+
+	assert_int_not_equal(getsockname(socket_fd, (struct sockaddr *)&sin, &len), -1);
+
+	assert_int_not_equal(close(socket_fd), -1);
+
+	return (int) sin.sin_port;
+}
 
 
 /* Execute meshlink_set_port Test Case # 1 - valid case*/
@@ -99,63 +178,116 @@ static bool test_set_port_01(void) {
 	return true;
 }
 
-/* Execute meshlink_set_port Test Case # 2 - Invalid case*/
+
+/* Execute meshlink_set_port Test Case # 2 - Invalid arguments */
 static void test_case_set_port_02(void **state) {
 	execute_test(test_set_port_02, state);
 }
 
-/* Test Steps for meshlink_set_port Test Case # 2 - Invalid case
+/* Test Steps for meshlink_set_port Test Case # 2 - functionality test
 
     Test Steps:
-    1. Pass NULL as mesh handle argument for meshlink_set_port
+    1. Open and start NUT and then pass invalid arguments to the set port API
 
     Expected Result:
-    Report false indicating error.
+    Meshlink set port API should fail and error out when invalid arguments are passed
 */
 static bool test_set_port_02(void) {
+	char nut_confbase[PATH_MAX];
+	create_path(nut_confbase, NUT, 2);
+
+	// Create meshlink instance
+
+	meshlink_set_log_cb(NULL, TEST_MESHLINK_LOG_LEVEL, log_cb);
+	meshlink_handle_t *mesh = meshlink_open(nut_confbase, NUT, TEST_MESHLINK_SET_PORT, DEV_CLASS_STATIONARY);
+	meshlink_set_log_cb(mesh, TEST_MESHLINK_LOG_LEVEL, log_cb);
+
 	// meshlink_set_port called using NULL as mesh handle
 
-	bool ret = meshlink_set_port(NULL, 8000);
-	assert_int_equal(meshlink_errno, 0);
-	assert_int_equal(ret, false);
+	meshlink_errno = MESHLINK_OK;
+	assert_false(meshlink_set_port(NULL, 8000));
+	assert_int_equal(meshlink_errno, MESHLINK_EINVAL);
 
-	return false;
-}
+	// Setting port after starting NUT
+	meshlink_errno = MESHLINK_OK;
+	assert_false(meshlink_set_port(mesh, -1));
+	assert_int_equal(meshlink_errno, MESHLINK_EINVAL);
+
+	meshlink_errno = MESHLINK_OK;
+	assert_false(meshlink_set_port(mesh, 70000));
+	assert_int_equal(meshlink_errno, MESHLINK_EINVAL);
+
+	assert_true(meshlink_start(mesh));
+	meshlink_errno = MESHLINK_OK;
+	assert_false(meshlink_set_port(mesh, 8000));
+	assert_int_equal(meshlink_errno, MESHLINK_EINVAL);
 
+	// Clean up
+
+	meshlink_close(mesh);
+	assert_true(meshlink_destroy(nut_confbase));
+	return true;
+}
 
-/* Execute meshlink_set_port Test Case # 3 - Setting port after starting mesh*/
+/* Execute meshlink_set_port Test Case # 3 - Synchronization testing */
 static void test_case_set_port_03(void **state) {
 	execute_test(test_set_port_03, state);
 }
 
-/* Test Steps for meshlink_set_port Test Case # 2 - functionality test
+static bool test_set_port_03(void) {
+	pid_t pid;
+	int pid_status;
+	char nut_confbase[PATH_MAX];
+	create_path(nut_confbase, NUT, 3);
 
-    Test Steps:
-    1. Open and start NUT and then try to set new port number
+	int new_port = get_free_port();
 
-    Expected Result:
-    New port number cannot be set while mesh is running.
-*/
-static bool test_set_port_03(void) {
-	meshlink_set_log_cb(NULL, TEST_MESHLINK_LOG_LEVEL, meshlink_callback_logger);
+	// Fork a new process in which NUT opens it's instance, set's the new port and raises SIGINT to terminate.
 
-	// Create meshlink instance
+	pid = fork();
+	assert_int_not_equal(pid, -1);
 
-	mesh_handle = meshlink_open("getportconf", "nut", "test", 1);
-	assert(mesh_handle);
-	meshlink_set_log_cb(mesh_handle, TEST_MESHLINK_LOG_LEVEL, meshlink_callback_logger);
+	if(!pid) {
+		meshlink_set_log_cb(NULL, MESHLINK_DEBUG, log_cb);
+		meshlink_handle_t *mesh = meshlink_open(nut_confbase, NUT, TEST_MESHLINK_SET_PORT, DEV_CLASS_STATIONARY);
+		assert(mesh);
 
-	// Setting port after starting NUT
-	bool ret = meshlink_set_port(mesh_handle, 50000);
-	assert_int_equal(meshlink_errno, 0);
-	assert_int_equal(ret, false);
+		assert(meshlink_set_port(mesh, new_port));
+		raise(SIGINT);
+	}
 
-	// Clean up
+	// Wait for child exit and verify which signal terminated it
 
-	meshlink_close(mesh_handle);
-	assert(meshlink_destroy("getportconf"));
+	assert_int_not_equal(waitpid(pid, &pid_status, 0), -1);
+	assert_int_equal(WIFSIGNALED(pid_status), true);
+	assert_int_equal(WTERMSIG(pid_status), SIGINT);
+
+	// Wait for the NUT's listening socket to be freed. (i.e, preventing meshlink from binding to a new port
+	// when NUT instance is reopened and the actual port is not freed due EADDRINUSE)
+
+	wait_for_socket_free(new_port);
+
+	// Reopen the NUT instance in the same test suite
 
-	return false;
+	meshlink_set_log_cb(NULL, MESHLINK_DEBUG, log_cb);
+	meshlink_handle_t *mesh = meshlink_open(nut_confbase, NUT, TEST_MESHLINK_SET_PORT, DEV_CLASS_STATIONARY);
+	assert_non_null(mesh);
+
+	assert_false(try_bind(new_port));
+
+	// Validate the new port that's being set in the previous instance persists.
+
+	int get_port = meshlink_get_port(mesh);
+	assert_int_equal(get_port, new_port);
+
+	// Close the mesh instance and verify that the listening port is closed or not
+
+	meshlink_close(mesh);
+
+	wait_for_socket_free(new_port);
+
+	assert_true(meshlink_destroy(nut_confbase));
+	return true;
 }