xref: /aosp_15_r20/external/ltp/testcases/kernel/syscalls/unlink/unlink08.c (revision 49cdfc7efb34551c7342be41a7384b9c40d7cab7)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) Linux Test Project, 2002-2022
4  * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
5  */
6 
7 /*\
8  * [Description]
9  *
10  * Verify that unlink(2) fails with
11  *
12  * - EACCES when no write access to the directory containing pathname
13  * - EACCES when one of the directories in pathname did not allow search
14  * - EISDIR when deleting directory as root user
15  * - EISDIR when deleting directory as non-root user
16  */
17 
18 #include <errno.h>
19 #include <pwd.h>
20 #include <stdlib.h>
21 #include <unistd.h>
22 #include "tst_test.h"
23 
24 static struct passwd *pw;
25 
26 static struct test_case_t {
27 	char *name;
28 	char *desc;
29 	int exp_errno;
30 	int exp_user;
31 } tcases[] = {
32 	{"unwrite_dir/file", "unwritable directory", EACCES, 1},
33 	{"unsearch_dir/file", "unsearchable directory", EACCES, 1},
34 	{"regdir", "directory", EISDIR, 0},
35 	{"regdir", "directory", EISDIR, 1},
36 };
37 
verify_unlink(struct test_case_t * tc)38 static void verify_unlink(struct test_case_t *tc)
39 {
40 	TST_EXP_FAIL(unlink(tc->name), tc->exp_errno, "%s", tc->desc);
41 }
42 
do_unlink(unsigned int n)43 static void do_unlink(unsigned int n)
44 {
45 	struct test_case_t *cases = &tcases[n];
46 	pid_t pid;
47 
48 	if (cases->exp_user) {
49 		pid = SAFE_FORK();
50 		if (!pid) {
51 			SAFE_SETUID(pw->pw_uid);
52 			verify_unlink(cases);
53 			exit(0);
54 		}
55 		SAFE_WAITPID(pid, NULL, 0);
56 	} else {
57 		verify_unlink(cases);
58 	}
59 }
60 
setup(void)61 static void setup(void)
62 {
63 	SAFE_MKDIR("unwrite_dir", 0777);
64 	SAFE_TOUCH("unwrite_dir/file", 0777, NULL);
65 	SAFE_CHMOD("unwrite_dir", 0555);
66 
67 	SAFE_MKDIR("unsearch_dir", 0777);
68 	SAFE_TOUCH("unsearch_dir/file", 0777, NULL);
69 	SAFE_CHMOD("unsearch_dir", 0666);
70 
71 	SAFE_MKDIR("regdir", 0777);
72 
73 	pw = SAFE_GETPWNAM("nobody");
74 }
75 
76 static struct tst_test test = {
77 	.needs_root = 1,
78 	.forks_child = 1,
79 	.needs_tmpdir = 1,
80 	.setup = setup,
81 	.tcnt = ARRAY_SIZE(tcases),
82 	.test = do_unlink,
83 };
84