tests/posix/fs: Add tests for open flags

Add new tests that will utilize open mode flags with the open
function.

A few test functions which assumed O_CREAT behavior are updated
to specify it explicitly.

Signed-off-by: Dominik Ermel <dominik.ermel@nordicsemi.no>

tests/posix/fs/src/main.c

@@ -17,6 +17,7 @@ void test_main(void)
 		ztest_unit_test(test_fs_fd_leak),
 		ztest_unit_test(test_fs_unlink),
 		ztest_unit_test(test_fs_mkdir),
-		ztest_unit_test(test_fs_readdir));
+		ztest_unit_test(test_fs_readdir),
+		ztest_unit_test(test_fs_open_flags));
 	ztest_run_test_suite(posix_fs_test);
 }

tests/posix/fs/src/test_fs.h

@@ -15,6 +15,7 @@ extern const char test_str[];
 
 void test_fs_mount(void);
 void test_fs_open(void);
+void test_fs_open_flags(void);
 void test_fs_write(void);
 void test_fs_read(void);
 void test_fs_close(void);

tests/posix/fs/src/test_fs_dir.c

@@ -27,7 +27,8 @@ static int test_mkdir(void)
 		return res;
 	}
 
-	res = open(TEST_DIR_FILE, O_RDWR);
+	res = open(TEST_DIR_FILE, O_CREAT | O_RDWR);
+
 	if (res < 0) {
 		TC_PRINT("Failed opening file [%d]\n", res);
 		return res;

tests/posix/fs/src/test_fs_file.c

@@ -16,12 +16,13 @@ static int test_file_open(void)
 {
 	int res;
 
-	res = open(TEST_FILE, O_RDWR);
+	res = open(TEST_FILE, O_CREAT | O_RDWR);
+
 	zassert_true(res >= 0, "Failed opening file: %d, errno=%d\n", res, errno);
 
 	file = res;
 
-	return 0;
+	return TC_PASS;
 }
 
 int test_file_write(void)

tests/posix/fs/src/test_fs_open_flags.c

@@ -0,0 +1,283 @@
+/*
+ * Copyright (c) 2020 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <string.h>
+#include <fcntl.h>
+#include <posix/unistd.h>
+#include "test_fs.h"
+
+#define THE_FILE FATFS_MNTP"/the_file.txt"
+
+static int test_file_open_flags(void)
+{
+	int fd = 0;
+	int data = 0;
+	int ret;
+
+	/* 1 Check opening non-existent without O_CREAT */
+	TC_PRINT("Open of non-existent file, flags = 0\n");
+	fd = open(THE_FILE, 0);
+	if (fd >= 0 || errno != ENOENT) {
+		TC_PRINT("Expected fail; fd = %d, errno = %d\n", fd, errno);
+		return TC_FAIL;
+	}
+
+	TC_PRINT("Open on non-existent file, flags = O_RDONLY\n");
+	fd = open(THE_FILE, O_RDONLY);
+	if (fd >= 0 || errno != ENOENT) {
+		TC_PRINT("Expected fail; fd = %d, errno = %d\n", fd, errno);
+		return TC_FAIL;
+	}
+	TC_PRINT("Open on non-existent file, flags = O_WRONLY\n");
+	fd = open(THE_FILE, O_WRONLY);
+	if (fd >= 0 || errno != ENOENT) {
+		TC_PRINT("Expected fail; fd = %d, errno = %d\n", fd, errno);
+		return TC_FAIL;
+	}
+
+	TC_PRINT("Open on non-existent file, flags = O_RDWR\n");
+	fd = open(THE_FILE, O_RDWR);
+	if (fd >= 0 || errno != ENOENT) {
+		TC_PRINT("Expected fail; fd = %d, errno = %d\n", fd, errno);
+		return TC_FAIL;
+	}
+	/* end 1 */
+
+	/* 2 Create file for read only, attempt to read, attempt to write */
+	TC_PRINT("Open on non-existent file, flags = O_CREAT | O_WRONLY\n");
+	fd = open(THE_FILE, O_CREAT | O_WRONLY);
+	if (fd < 0) {
+		TC_PRINT("Expected success; fd = %d, errno = %d\n", fd, errno);
+		close(fd);
+		return TC_FAIL;
+	}
+
+	TC_PRINT("Attempt read file opened with flags = O_CREAT | O_WRONLY\n");
+	ret = read(fd, &data, sizeof(data));
+	if (ret > 0 || errno != EACCES) {
+		TC_PRINT("Expected fail, ret = %d, errno = %d\n", ret, errno);
+		close(fd);
+		return TC_FAIL;
+	}
+
+	TC_PRINT("Attempt write file opened with flags = O_CREAT | O_WRONLY\n");
+	ret = write(fd, &data, sizeof(data));
+	if (ret <= 0 || errno != EACCES) {
+		TC_PRINT("Expected success, ret = %d, errno = %d\n", ret,
+			 errno);
+		close(fd);
+		return TC_FAIL;
+	}
+
+	close(fd);
+	/* end 2 */
+
+
+	/* 3 Attempt read/write operation on file opened with flags = 0 */
+	TC_PRINT("Attempt open existing with flags = 0\n");
+	fd = open(THE_FILE, 0);
+	if (fd < 0) {
+		TC_PRINT("Expected success, fd = %d, errno = %d\n", fd, errno);
+		return TC_FAIL;
+	}
+
+	TC_PRINT("Attempt read file opened with flags = 0\n");
+	ret = read(fd, &data, sizeof(data));
+	if (ret < 0) {
+		TC_PRINT("Expected success, ret = %d, errno = %d\n", ret,
+			 errno);
+		close(fd);
+		return TC_FAIL;
+	}
+
+	TC_PRINT("Attempt write file opened with flags = 0\n");
+	ret = write(fd, &data, sizeof(data));
+	if (ret >= 0 || errno != EACCES) {
+		TC_PRINT("Expected fail, ret = %d, errno = %d\n", ret, errno);
+		close(fd);
+		return TC_FAIL;
+	}
+
+	close(fd);
+	/* end 3 */
+
+	/* 4 Attempt read/write on file opened with flags O_RDONLY */
+	/* File does have content after previous tests. */
+	TC_PRINT("Attempt open existing with flags = O_RDONLY\n");
+	fd = open(THE_FILE, O_RDONLY);
+	if (fd < 0) {
+		TC_PRINT("Expected success, fd = %d, errno = %d\n", fd, errno);
+		return TC_FAIL;
+	}
+
+	TC_PRINT("Attempt read file opened with flags = O_RDONLY\n");
+	ret = read(fd, &data, sizeof(data));
+	if (ret < 0) {
+		TC_PRINT("Expected success, ret = %d, errno = %d\n", ret,
+			 errno);
+		close(fd);
+		return TC_FAIL;
+	}
+
+	TC_PRINT("Attempt write file opened with flags = O_RDONLY\n");
+	ret = write(fd, &data, sizeof(data));
+	if (ret >= 0 || errno != EACCES) {
+		TC_PRINT("Expected fail, ret = %d, errno = %d\n", ret, errno);
+		close(fd);
+		return TC_FAIL;
+	}
+
+	close(fd);
+	/* end 4 */
+
+	/* 5 Attempt read/write on file opened with flags O_WRONLY */
+	/* File does have content after previous tests. */
+	TC_PRINT("Attempt open existing with flags = O_WRONLY\n");
+	fd = open(THE_FILE, O_WRONLY);
+	if (fd < 0) {
+		TC_PRINT("Expected success, fd = %d, errno = %d\n", fd, errno);
+		return TC_FAIL;
+	}
+
+	TC_PRINT("Attempt read file opened with flags = O_WRONLY\n");
+	ret = read(fd, &data, sizeof(data));
+	if (ret >= 0 || errno != EACCES) {
+		TC_PRINT("Expected fail, ret = %d, errno = %d\n", ret, errno);
+		close(fd);
+		return TC_FAIL;
+	}
+
+	TC_PRINT("Attempt write file opened with flags = O_WRONLY\n");
+	ret = write(fd, &data, sizeof(data));
+	if (ret < 0) {
+		TC_PRINT("Expected success, ret = %d, errno = %d\n", ret,
+			 errno);
+		close(fd);
+		return TC_FAIL;
+	}
+
+	close(fd);
+	/* end 5 */
+
+	/* 6 Attempt read/write on file opened with flags O_APPEND | O_WRONLY */
+	TC_PRINT("Attempt open existing with flags = O_APPEND | O_WRONLY\n");
+	fd = open(THE_FILE, O_APPEND | O_WRONLY);
+	if (fd < 0) {
+		TC_PRINT("Expected success, fd = %d, errno = %d\n", fd, errno);
+		return TC_FAIL;
+	}
+
+	TC_PRINT("Attempt read file opened with flags = O_APPEND | O_WRONLY\n");
+	ret = read(fd, &data, sizeof(data));
+	if (ret >= 0 || errno != EACCES) {
+		TC_PRINT("Expected fail, ret = %d, errno = %d\n", ret, errno);
+		close(fd);
+		return TC_FAIL;
+	}
+
+	TC_PRINT("Attempt write to opened with flags = O_APPEND | O_WRONLY\n");
+	ret = write(fd, &data, sizeof(data));
+	if (ret < 0) {
+		TC_PRINT("Expected success, ret = %d, errno = %d\n", ret,
+			 errno);
+		close(fd);
+		return TC_FAIL;
+	}
+
+	close(fd);
+	/* end 6 */
+
+	/* 7 Attempt read/write on file opened with flags O_APPEND | O_RDWR */
+	TC_PRINT("Attempt open existing with flags = O_APPEND | O_RDWR\n");
+	fd = open(THE_FILE, O_APPEND | O_RDWR);
+	if (fd < 0) {
+		TC_PRINT("Expected success, fd = %d, errno = %d\n", fd, errno);
+		return TC_FAIL;
+	}
+
+
+	TC_PRINT("Attempt read file opened with flags = O_APPEND | O_RDWR\n");
+	lseek(fd, 0, SEEK_SET);
+	ret = read(fd, &data, sizeof(data));
+	if (ret < 0) {
+		TC_PRINT("Expected success, ret = %d, errno = %d\n", ret,
+			 errno);
+		close(fd);
+		return TC_FAIL;
+	}
+
+	TC_PRINT("Attempt write file opened with flags = O_APPEND | O_RDWR\n");
+	ret = write(fd, &data, sizeof(data));
+	if (ret < 0) {
+		TC_PRINT("Expected success, ret = %d, errno = %d\n", ret,
+			 errno);
+		close(fd);
+		return TC_FAIL;
+	}
+
+	close(fd);
+	/* end 7 */
+
+	/* 8 Check if appended file is always written at the end */
+	TC_PRINT("Attempt write to file opened with O_APPEND | O_RDWR\n");
+	/* Clean start */
+	unlink(THE_FILE);
+	fd = open(THE_FILE, O_CREAT | O_WRONLY);
+	if (fd < 0) {
+		TC_PRINT("Expected success, fd = %d, errno = %d\n", fd, errno);
+		return TC_FAIL;
+	}
+
+	ret = write(fd, &data, sizeof(data));
+	if (ret < 0) {
+		TC_PRINT("Expected success, ret = %d, errno = %d\n", ret,
+			 errno);
+		close(fd);
+		return TC_FAIL;
+	}
+
+	close(fd);
+
+	fd = open(THE_FILE, O_APPEND | O_RDWR);
+	if (fd < 0) {
+		TC_PRINT("Expected success, fd = %d, errno = %d\n", fd, errno);
+		return TC_FAIL;
+	}
+
+	lseek(fd, 0, SEEK_SET);
+	ret = write(fd, &data, sizeof(data));
+	if (ret < 0) {
+		TC_PRINT("Expected success, ret = %d, errno = %d\n", ret,
+			 errno);
+		close(fd);
+		return TC_FAIL;
+	}
+
+	ret = lseek(fd, 0, SEEK_END);
+
+	if (ret != (sizeof(data) * 2)) {
+		TC_PRINT("Expected file size %zu, ret = %d, errno = %d\n",
+			 sizeof(data) * 2, ret, errno);
+		close(fd);
+		return TC_FAIL;
+	}
+
+	close(fd);
+	/* end 8 */
+
+	return TC_PASS;
+}
+
+/**
+ * @brief Test for POSIX open flags
+ *
+ * @details Test attempts to open file with different combinations of open
+ * flags and checks if operations on files are permitted according to flags.
+ */
+void test_fs_open_flags(void)
+{
+	zassert_true(test_file_open_flags() == TC_PASS, NULL);
+}