1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (C) 2021. Huawei Technologies Co., Ltd */
3#include <test_progs.h>
4#include "strncmp_test.skel.h"
5
6static int trigger_strncmp(const struct strncmp_test *skel)
7{
8	int cmp;
9
10	usleep(1);
11
12	cmp = skel->bss->cmp_ret;
13	if (cmp > 0)
14		return 1;
15	if (cmp < 0)
16		return -1;
17	return 0;
18}
19
20/*
21 * Compare str and target after making str[i] != target[i].
22 * When exp is -1, make str[i] < target[i] and delta = -1.
23 */
24static void strncmp_full_str_cmp(struct strncmp_test *skel, const char *name,
25				 int exp)
26{
27	size_t nr = sizeof(skel->bss->str);
28	char *str = skel->bss->str;
29	int delta = exp;
30	int got;
31	size_t i;
32
33	memcpy(str, skel->rodata->target, nr);
34	for (i = 0; i < nr - 1; i++) {
35		str[i] += delta;
36
37		got = trigger_strncmp(skel);
38		ASSERT_EQ(got, exp, name);
39
40		str[i] -= delta;
41	}
42}
43
44static void test_strncmp_ret(void)
45{
46	struct strncmp_test *skel;
47	int err, got;
48
49	skel = strncmp_test__open();
50	if (!ASSERT_OK_PTR(skel, "strncmp_test open"))
51		return;
52
53	bpf_program__set_autoload(skel->progs.do_strncmp, true);
54
55	err = strncmp_test__load(skel);
56	if (!ASSERT_EQ(err, 0, "strncmp_test load"))
57		goto out;
58
59	err = strncmp_test__attach(skel);
60	if (!ASSERT_EQ(err, 0, "strncmp_test attach"))
61		goto out;
62
63	skel->bss->target_pid = getpid();
64
65	/* Empty str */
66	skel->bss->str[0] = '\0';
67	got = trigger_strncmp(skel);
68	ASSERT_EQ(got, -1, "strncmp: empty str");
69
70	/* Same string */
71	memcpy(skel->bss->str, skel->rodata->target, sizeof(skel->bss->str));
72	got = trigger_strncmp(skel);
73	ASSERT_EQ(got, 0, "strncmp: same str");
74
75	/* Not-null-termainted string  */
76	memcpy(skel->bss->str, skel->rodata->target, sizeof(skel->bss->str));
77	skel->bss->str[sizeof(skel->bss->str) - 1] = 'A';
78	got = trigger_strncmp(skel);
79	ASSERT_EQ(got, 1, "strncmp: not-null-term str");
80
81	strncmp_full_str_cmp(skel, "strncmp: less than", -1);
82	strncmp_full_str_cmp(skel, "strncmp: greater than", 1);
83out:
84	strncmp_test__destroy(skel);
85}
86
87static void test_strncmp_bad_not_const_str_size(void)
88{
89	struct strncmp_test *skel;
90	int err;
91
92	skel = strncmp_test__open();
93	if (!ASSERT_OK_PTR(skel, "strncmp_test open"))
94		return;
95
96	bpf_program__set_autoload(skel->progs.strncmp_bad_not_const_str_size, true);
97
98	err = strncmp_test__load(skel);
99	ASSERT_ERR(err, "strncmp_test load bad_not_const_str_size");
100
101	strncmp_test__destroy(skel);
102}
103
104static void test_strncmp_bad_writable_target(void)
105{
106	struct strncmp_test *skel;
107	int err;
108
109	skel = strncmp_test__open();
110	if (!ASSERT_OK_PTR(skel, "strncmp_test open"))
111		return;
112
113	bpf_program__set_autoload(skel->progs.strncmp_bad_writable_target, true);
114
115	err = strncmp_test__load(skel);
116	ASSERT_ERR(err, "strncmp_test load bad_writable_target");
117
118	strncmp_test__destroy(skel);
119}
120
121static void test_strncmp_bad_not_null_term_target(void)
122{
123	struct strncmp_test *skel;
124	int err;
125
126	skel = strncmp_test__open();
127	if (!ASSERT_OK_PTR(skel, "strncmp_test open"))
128		return;
129
130	bpf_program__set_autoload(skel->progs.strncmp_bad_not_null_term_target, true);
131
132	err = strncmp_test__load(skel);
133	ASSERT_ERR(err, "strncmp_test load bad_not_null_term_target");
134
135	strncmp_test__destroy(skel);
136}
137
138void test_test_strncmp(void)
139{
140	if (test__start_subtest("strncmp_ret"))
141		test_strncmp_ret();
142	if (test__start_subtest("strncmp_bad_not_const_str_size"))
143		test_strncmp_bad_not_const_str_size();
144	if (test__start_subtest("strncmp_bad_writable_target"))
145		test_strncmp_bad_writable_target();
146	if (test__start_subtest("strncmp_bad_not_null_term_target"))
147		test_strncmp_bad_not_null_term_target();
148}
149