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 void test_bpf_loop(void)
124 {
125 	struct bpf_loop *skel;
126 
127 	skel = bpf_loop__open_and_load();
128 	if (!ASSERT_OK_PTR(skel, "bpf_loop__open_and_load"))
129 		return;
130 
131 	skel->bss->pid = getpid();
132 
133 	if (test__start_subtest("check_nr_loops"))
134 		check_nr_loops(skel);
135 	if (test__start_subtest("check_callback_fn_stop"))
136 		check_callback_fn_stop(skel);
137 	if (test__start_subtest("check_null_callback_ctx"))
138 		check_null_callback_ctx(skel);
139 	if (test__start_subtest("check_invalid_flags"))
140 		check_invalid_flags(skel);
141 	if (test__start_subtest("check_nested_calls"))
142 		check_nested_calls(skel);
143 
144 	bpf_loop__destroy(skel);
145 }
146