1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2021 Facebook */
3 
4 #include <test_progs.h>
5 #include <network_helpers.h>
6 #include "bpf_loop.skel.h"
7 
8 static void check_nr_loops(struct bpf_loop *skel)
9 {
10 	struct bpf_link *link;
11 
12 	link = bpf_program__attach(skel->progs.test_prog);
13 	if (!ASSERT_OK_PTR(link, "link"))
14 		return;
15 
16 	/* test 0 loops */
17 	skel->bss->nr_loops = 0;
18 
19 	usleep(1);
20 
21 	ASSERT_EQ(skel->bss->nr_loops_returned, skel->bss->nr_loops,
22 		  "0 loops");
23 
24 	/* test 500 loops */
25 	skel->bss->nr_loops = 500;
26 
27 	usleep(1);
28 
29 	ASSERT_EQ(skel->bss->nr_loops_returned, skel->bss->nr_loops,
30 		  "500 loops");
31 	ASSERT_EQ(skel->bss->g_output, (500 * 499) / 2, "g_output");
32 
33 	/* test exceeding the max limit */
34 	skel->bss->nr_loops = -1;
35 
36 	usleep(1);
37 
38 	ASSERT_EQ(skel->bss->err, -E2BIG, "over max limit");
39 
40 	bpf_link__destroy(link);
41 }
42 
43 static void check_callback_fn_stop(struct bpf_loop *skel)
44 {
45 	struct bpf_link *link;
46 
47 	link = bpf_program__attach(skel->progs.test_prog);
48 	if (!ASSERT_OK_PTR(link, "link"))
49 		return;
50 
51 	/* testing that loop is stopped when callback_fn returns 1 */
52 	skel->bss->nr_loops = 400;
53 	skel->data->stop_index = 50;
54 
55 	usleep(1);
56 
57 	ASSERT_EQ(skel->bss->nr_loops_returned, skel->data->stop_index + 1,
58 		  "nr_loops_returned");
59 	ASSERT_EQ(skel->bss->g_output, (50 * 49) / 2,
60 		  "g_output");
61 
62 	bpf_link__destroy(link);
63 }
64 
65 static void check_null_callback_ctx(struct bpf_loop *skel)
66 {
67 	struct bpf_link *link;
68 
69 	/* check that user is able to pass in a null callback_ctx */
70 	link = bpf_program__attach(skel->progs.prog_null_ctx);
71 	if (!ASSERT_OK_PTR(link, "link"))
72 		return;
73 
74 	skel->bss->nr_loops = 10;
75 
76 	usleep(1);
77 
78 	ASSERT_EQ(skel->bss->nr_loops_returned, skel->bss->nr_loops,
79 		  "nr_loops_returned");
80 
81 	bpf_link__destroy(link);
82 }
83 
84 static void check_invalid_flags(struct bpf_loop *skel)
85 {
86 	struct bpf_link *link;
87 
88 	/* check that passing in non-zero flags returns -EINVAL */
89 	link = bpf_program__attach(skel->progs.prog_invalid_flags);
90 	if (!ASSERT_OK_PTR(link, "link"))
91 		return;
92 
93 	usleep(1);
94 
95 	ASSERT_EQ(skel->bss->err, -EINVAL, "err");
96 
97 	bpf_link__destroy(link);
98 }
99 
100 static void check_nested_calls(struct bpf_loop *skel)
101 {
102 	__u32 nr_loops = 100, nested_callback_nr_loops = 4;
103 	struct bpf_link *link;
104 
105 	/* check that nested calls are supported */
106 	link = bpf_program__attach(skel->progs.prog_nested_calls);
107 	if (!ASSERT_OK_PTR(link, "link"))
108 		return;
109 
110 	skel->bss->nr_loops = nr_loops;
111 	skel->bss->nested_callback_nr_loops = nested_callback_nr_loops;
112 
113 	usleep(1);
114 
115 	ASSERT_EQ(skel->bss->nr_loops_returned, nr_loops * nested_callback_nr_loops
116 		  * nested_callback_nr_loops, "nr_loops_returned");
117 	ASSERT_EQ(skel->bss->g_output, (4 * 3) / 2 * nested_callback_nr_loops
118 		* nr_loops, "g_output");
119 
120 	bpf_link__destroy(link);
121 }
122 
123 static void check_non_constant_callback(struct bpf_loop *skel)
124 {
125 	struct bpf_link *link =
126 		bpf_program__attach(skel->progs.prog_non_constant_callback);
127 
128 	if (!ASSERT_OK_PTR(link, "link"))
129 		return;
130 
131 	skel->bss->callback_selector = 0x0F;
132 	usleep(1);
133 	ASSERT_EQ(skel->bss->g_output, 0x0F, "g_output #1");
134 
135 	skel->bss->callback_selector = 0xF0;
136 	usleep(1);
137 	ASSERT_EQ(skel->bss->g_output, 0xF0, "g_output #2");
138 
139 	bpf_link__destroy(link);
140 }
141 
142 static void check_stack(struct bpf_loop *skel)
143 {
144 	struct bpf_link *link = bpf_program__attach(skel->progs.stack_check);
145 	const int max_key = 12;
146 	int key;
147 	int map_fd;
148 
149 	if (!ASSERT_OK_PTR(link, "link"))
150 		return;
151 
152 	map_fd = bpf_map__fd(skel->maps.map1);
153 
154 	if (!ASSERT_GE(map_fd, 0, "bpf_map__fd"))
155 		goto out;
156 
157 	for (key = 1; key <= max_key; ++key) {
158 		int val = key;
159 		int err = bpf_map_update_elem(map_fd, &key, &val, BPF_NOEXIST);
160 
161 		if (!ASSERT_OK(err, "bpf_map_update_elem"))
162 			goto out;
163 	}
164 
165 	usleep(1);
166 
167 	for (key = 1; key <= max_key; ++key) {
168 		int val;
169 		int err = bpf_map_lookup_elem(map_fd, &key, &val);
170 
171 		if (!ASSERT_OK(err, "bpf_map_lookup_elem"))
172 			goto out;
173 		if (!ASSERT_EQ(val, key + 1, "bad value in the map"))
174 			goto out;
175 	}
176 
177 out:
178 	bpf_link__destroy(link);
179 }
180 
181 void test_bpf_loop(void)
182 {
183 	struct bpf_loop *skel;
184 
185 	skel = bpf_loop__open_and_load();
186 	if (!ASSERT_OK_PTR(skel, "bpf_loop__open_and_load"))
187 		return;
188 
189 	skel->bss->pid = getpid();
190 
191 	if (test__start_subtest("check_nr_loops"))
192 		check_nr_loops(skel);
193 	if (test__start_subtest("check_callback_fn_stop"))
194 		check_callback_fn_stop(skel);
195 	if (test__start_subtest("check_null_callback_ctx"))
196 		check_null_callback_ctx(skel);
197 	if (test__start_subtest("check_invalid_flags"))
198 		check_invalid_flags(skel);
199 	if (test__start_subtest("check_nested_calls"))
200 		check_nested_calls(skel);
201 	if (test__start_subtest("check_non_constant_callback"))
202 		check_non_constant_callback(skel);
203 	if (test__start_subtest("check_stack"))
204 		check_stack(skel);
205 
206 	bpf_loop__destroy(skel);
207 }
208