[LTP] [PATCH v2] setreuid04.c: Rewrite using new LTP API

[Avinesh Kumar]

changes in v2:
further cleanup to remove the testcases struct as we are testing
only single scenario.

Signed-off-by: Avinesh Kumar <akumar@suse.de>
---
 .../kernel/syscalls/setreuid/setreuid04.c     | 150 ++++--------------
 1 file changed, 29 insertions(+), 121 deletions(-)

diff --git a/testcases/kernel/syscalls/setreuid/setreuid04.c b/testcases/kernel/syscalls/setreuid/setreuid04.c
index 8eed90df0..d0b9e3f8a 100644
--- a/testcases/kernel/syscalls/setreuid/setreuid04.c
+++ b/testcases/kernel/syscalls/setreuid/setreuid04.c
@@ -1,141 +1,49 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (c) International Business Machines  Corp., 2001
- *
- * This program is free software;  you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * 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 Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
  * Ported by John George
+ * Copyright (c) 2022 SUSE LLC Avinesh Kumar <avinesh.kumar@suse.com>
  */
 
-/*
- * Test that root can change the real and effective uid to an
- * unpriviledged user.
+/*\
+ * [Description]
+ *
+ * Verify that root user can change the real and effective uid to an
+ * unprivileged user.
  */
 
-#include <errno.h>
-#include <stdlib.h>
 #include <pwd.h>
-#include <sys/wait.h>
-
-#include "test.h"
-#include "compat_16.h"
-
-TCID_DEFINE(setreuid04);
-
-static uid_t neg_one = -1;
-
-static struct passwd nobody, root;
-
-/*
- * The following structure contains all test data.  Each structure in the array
- * is used for a separate test.  The tests are executed in the for loop below.
- */
-
-struct test_data_t {
-	uid_t *real_uid;
-	uid_t *eff_uid;
-	struct passwd *exp_real_usr;
-	struct passwd *exp_eff_usr;
-	char *test_msg;
-} test_data[] = {
-	{
-	&neg_one, &neg_one, &root, &root, "After setreuid(-1, nobody),"}, {
-&nobody.pw_uid, &nobody.pw_uid, &nobody, &nobody,
-		    "After setreuid(-1, -1),"},};
-
-int TST_TOTAL = ARRAY_SIZE(test_data);
-
-static void setup(void);
-static void cleanup(void);
-static void uid_verify(struct passwd *, struct passwd *, char *);
-
-int main(int ac, char **av)
-{
-	int lc;
-
-	tst_parse_opts(ac, av, NULL, NULL);
-
-	setup();
-
-	for (lc = 0; TEST_LOOPING(lc); lc++) {
-		int i, pid;
-
-		tst_count = 0;
+#include "tst_test.h"
+#include "compat_tst_16.h"
 
-		if ((pid = FORK_OR_VFORK()) == -1) {
-			tst_brkm(TBROK, cleanup, "fork failed");
-		} else if (pid == 0) {	/* child */
-
-			for (i = 0; i < TST_TOTAL; i++) {
-
-				/* Set the real or effective user id */
-				TEST(SETREUID(cleanup, *test_data[i].real_uid,
-					      *test_data[i].eff_uid));
-
-				if (TEST_RETURN != -1) {
-					tst_resm(TPASS, "setreuid(%d, %d) "
-						 "succeeded as expected.",
-						 *test_data[i].real_uid,
-						 *test_data[i].eff_uid);
-				} else {
-					tst_resm(TFAIL, "setreuid(%d, %d) "
-						 "did not return as expected.",
-						 *test_data[i].real_uid,
-						 *test_data[i].eff_uid);
-				}
-
-				uid_verify(test_data[i].exp_real_usr,
-					   test_data[i].exp_eff_usr,
-					   test_data[i].test_msg);
-			}
-			tst_exit();
-		} else {	/* parent */
-			tst_record_childstatus(cleanup, pid);
-		}
-	}
-	cleanup();
-	tst_exit();
-}
+static uid_t root_uid, nobody_uid;
 
 static void setup(void)
 {
-	tst_require_root();
-
-	tst_sig(FORK, DEF_HANDLER, cleanup);
-
-	if (getpwnam("nobody") == NULL)
-		tst_brkm(TBROK, NULL, "nobody must be a valid user.");
+	struct passwd *nobody;
 
-	root = *(getpwnam("root"));
-	UID16_CHECK(root.pw_uid, setreuid, cleanup);
+	root_uid = getuid();
+	nobody = SAFE_GETPWNAM("nobody");
+	nobody_uid = nobody->pw_uid;
 
-	nobody = *(getpwnam("nobody"));
-	UID16_CHECK(nobody.pw_uid, setreuid, cleanup);
-
-	TEST_PAUSE;
+	UID16_CHECK(nobody_uid, setreuid);
+	UID16_CHECK(root_uid, setreuid);
 }
 
-static void cleanup(void)
+static void run(void)
 {
-}
+	if (!SAFE_FORK()) {
+		TST_EXP_PASS(SETREUID(nobody_uid, nobody_uid));
 
-static void uid_verify(struct passwd *ru, struct passwd *eu, char *when)
-{
-	if ((getuid() != ru->pw_uid) || (geteuid() != eu->pw_uid)) {
-		tst_resm(TFAIL, "ERROR: %s real uid = %d; effective uid = %d",
-			 when, getuid(), geteuid());
-		tst_resm(TINFO, "Expected: real uid = %d; effective uid = %d",
-			 ru->pw_uid, eu->pw_uid);
+		TST_EXP_EQ_LI(getuid(), nobody_uid);
+		TST_EXP_EQ_LI(geteuid(), nobody_uid);
 	}
+	tst_reap_children();
 }
+
+static struct tst_test test = {
+	.setup = setup,
+	.test_all = run,
+	.needs_root = 1,
+	.forks_child = 1
+};
-- 
2.39.0