tools/testing/selftests/bpf/prog_tests/bpf_loop.c

   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 }