fchownat03: Add error tests for fchownat()

Move the 3 error tests form fchownat01 to here, and add tests for rest
possible errnos per the man page.

Signed-off-by: Shiyang Ruan <[email protected]>
Reviewed-by: Andrea Cervesato <[email protected]>

Author: Shiyang Ruan via ltp

runtest/syscalls

@@ -288,6 +288,7 @@ fchown05_16 fchown05_16
 #fchownat test case
 fchownat01 fchownat01
 fchownat02 fchownat02
+fchownat03 fchownat03
 
 fcntl01 fcntl01
 fcntl01_64 fcntl01_64

testcases/kernel/syscalls/fchownat/.gitignore

@@ -1,2 +1,3 @@
 /fchownat01
 /fchownat02
+/fchownat03

testcases/kernel/syscalls/fchownat/fchownat03.c

@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) International Business Machines  Corp., 2006
+ * Copyright (c) Linux Test Project, 2007-2024
+ */
+
+/*\
+ * [Description]
+ *
+ * Verify that,
+ * - fchownat() returns -1 and sets errno to EACCES if there is no permission
+     to access to the file.
+ * - fchownat() returns -1 and sets errno to EBADF if the file descriptor
+ *   of the specified file is not valid.
+ * - fchownat() returns -1 and sets errno to EFAULT if the filename points
+     outside of accessable address space.
+ * - fchownat() returns -1 and sets errno to EINVAL if the flag is invalid.
+ * - fchownat() returns -1 and sets errno to ELOOP if too many symbolic links
+ *   were encountered in resolving filename.
+ * - fchownat() returns -1 and sets errno to ENAMETOOLONG if the filename is
+     too long.
+ * - fchownat() returns -1 and sets errno to ENOENT if the specified file does
+ *   not exist.
+ * - fchownat() returns -1 and sets errno to ENOTDIR if the file descriptor is
+ *   a file.
+ * - fchownat() returns -1 and sets errno to EPERM if the effective user id
+ *   of process does not match the owner of the file and the process is not
+ *   super user.
+ * - fchownat() returns -1 and sets errno to EROFS if the file is readonly.
+ */
+
+#define _GNU_SOURCE
+#include <pwd.h>
+#include "tst_test.h"
+
+#define TESTFILE		"testfile"
+#define TESTFILE_EACCESS_DIR	"eaccess"
+#define TESTFILE_EACCESS	TESTFILE_EACCESS_DIR"/eaccess"
+#define TESTFILE_ELOOP		"testfile_eloop"
+#define TESTFILE_ENOENT		"/tmp/does/not/exist"
+#define TESTFILE_EPERM		"/dev/null"
+#define TESTFILE_EROFS_MNT	"ro_mntpoint"
+#define TESTFILE_EROFS		TESTFILE_EROFS_MNT"/file"
+
+static int file_fd = -1;
+static int no_fd = -1;
+static int dir_fd = -1;
+
+static char *file_eaccess;
+static char *file_ebadf;
+static char *file_efault;
+static char *file_einval;
+static char *file_eloop;
+static char *file_enametoolong;
+static char *file_enoent;
+static char *file_enotdir;
+static char *file_eperm;
+static char *file_erofs;
+
+static struct tcase {
+	char **filename;
+	char *desc;
+	int *fd;
+	int flag;
+	int exp_errno;
+} tcases[] = {
+	{&file_eaccess,      TESTFILE_EACCESS,  &dir_fd,  0,    EACCES},
+	{&file_ebadf,        TESTFILE,          &no_fd,   0,    EBADF},
+	{&file_efault,       "Invalid address", &dir_fd,  0,    EFAULT},
+	{&file_einval,       TESTFILE,          &dir_fd,  9999, EINVAL},
+	{&file_eloop,        TESTFILE_ELOOP,    &dir_fd,  0,    ELOOP},
+	{&file_enametoolong, "aaaa...",         &dir_fd,  0,    ENAMETOOLONG},
+	{&file_enoent,       TESTFILE_ENOENT,   &dir_fd,  0,    ENOENT},
+	{&file_enotdir,      TESTFILE,          &file_fd, 0,    ENOTDIR},
+	{&file_eperm,        TESTFILE_EPERM,    &dir_fd,  0,    EPERM},
+	{&file_erofs,        TESTFILE_EROFS,    &dir_fd,  0,    EROFS},
+};
+
+static void fchownat_verify(unsigned int n)
+{
+	uid_t euid = geteuid();
+	gid_t egid = getegid();
+
+	TST_EXP_FAIL(fchownat(*tcases[n].fd, *tcases[n].filename, euid, egid, tcases[n].flag),
+		     tcases[n].exp_errno,
+		     "fchownat(%d, %s, %d, %d, %d)",
+		     *tcases[n].fd, tcases[n].desc, euid, egid, tcases[n].flag);
+}
+
+static void setup(void)
+{
+	struct passwd *ltpuser;
+
+	SAFE_TOUCH(TESTFILE, 0600, NULL);
+	dir_fd = SAFE_OPEN("./", O_DIRECTORY);
+
+	/* EACCES setting */
+	SAFE_SETEUID(0);
+	SAFE_MKDIR(TESTFILE_EACCESS_DIR, S_IRWXU);
+	SAFE_TOUCH(TESTFILE_EACCESS, 0666, NULL);
+	ltpuser = SAFE_GETPWNAM("nobody");
+	SAFE_SETEUID(ltpuser->pw_uid);
+
+	/* EFAULT setting */
+	file_efault = tst_get_bad_addr(NULL);
+
+	/* ENOTDIR setting */
+	file_fd = SAFE_OPEN("file_fd", O_CREAT | O_RDWR, 0600);
+
+	/* ELOOP setting */
+	SAFE_SYMLINK(TESTFILE_ELOOP, "test_file_eloop2");
+	SAFE_SYMLINK("test_file_eloop2", TESTFILE_ELOOP);
+
+	/* ENAMETOOLONG setting */
+	memset(file_enametoolong, 'a', PATH_MAX+1);
+	file_enametoolong[PATH_MAX+1] = 0;
+}
+
+static void cleanup(void)
+{
+	if (dir_fd != -1)
+		SAFE_CLOSE(dir_fd);
+	if (file_fd != -1)
+		SAFE_CLOSE(file_fd);
+}
+
+static struct tst_test test = {
+	.needs_tmpdir = 1,
+	.needs_root = 1,
+	.needs_rofs = 1,
+	.mntpoint = TESTFILE_EROFS_MNT,
+	.test = fchownat_verify,
+	.tcnt = ARRAY_SIZE(tcases),
+	.setup = setup,
+	.cleanup = cleanup,
+	.bufs = (struct tst_buffers []) {
+		{&file_eaccess,      .str = TESTFILE_EACCESS},
+		{&file_ebadf,        .str = TESTFILE},
+		{&file_einval,       .str = TESTFILE},
+		{&file_eloop,        .str = TESTFILE_ELOOP},
+		{&file_enametoolong, .size = PATH_MAX+2},
+		{&file_enoent,       .str = TESTFILE_ENOENT},
+		{&file_enotdir,      .str = TESTFILE},
+		{&file_eperm,        .str = TESTFILE_EPERM},
+		{&file_erofs,        .str = TESTFILE_EROFS},
+		{}
+	},
+};