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1// SPDX-License-Identifier: GPL-2.0
2
3#include <test_progs.h>
4
5#include <linux/btf.h>
6#include <bpf/bpf.h>
7
8#include "../test_btf.h"
9
10static inline int new_map(void)
11{
12 const char *name = NULL;
13 __u32 max_entries = 1;
14 __u32 value_size = 8;
15 __u32 key_size = 4;
16
17 return bpf_map_create(BPF_MAP_TYPE_ARRAY, name,
18 key_size, value_size,
19 max_entries, NULL);
20}
21
22static int new_btf(void)
23{
24 struct btf_blob {
25 struct btf_header btf_hdr;
26 __u32 types[8];
27 __u32 str;
28 } raw_btf = {
29 .btf_hdr = {
30 .magic = BTF_MAGIC,
31 .version = BTF_VERSION,
32 .hdr_len = sizeof(struct btf_header),
33 .type_len = sizeof(raw_btf.types),
34 .str_off = offsetof(struct btf_blob, str) - offsetof(struct btf_blob, types),
35 .str_len = sizeof(raw_btf.str),
36 },
37 .types = {
38 /* long */
39 BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 64, 8), /* [1] */
40 /* unsigned long */
41 BTF_TYPE_INT_ENC(0, 0, 0, 64, 8), /* [2] */
42 },
43 };
44
45 return bpf_btf_load(&raw_btf, sizeof(raw_btf), NULL);
46}
47
48#define Close(FD) do { \
49 if ((FD) >= 0) { \
50 close(FD); \
51 FD = -1; \
52 } \
53} while(0)
54
55static bool map_exists(__u32 id)
56{
57 int fd;
58
59 fd = bpf_map_get_fd_by_id(id);
60 if (fd >= 0) {
61 close(fd);
62 return true;
63 }
64 return false;
65}
66
67static bool btf_exists(__u32 id)
68{
69 int fd;
70
71 fd = bpf_btf_get_fd_by_id(id);
72 if (fd >= 0) {
73 close(fd);
74 return true;
75 }
76 return false;
77}
78
79static inline int bpf_prog_get_map_ids(int prog_fd, __u32 *nr_map_ids, __u32 *map_ids)
80{
81 __u32 len = sizeof(struct bpf_prog_info);
82 struct bpf_prog_info info;
83 int err;
84
85 memset(&info, 0, len);
86 info.nr_map_ids = *nr_map_ids;
87 info.map_ids = ptr_to_u64(map_ids);
88
89 err = bpf_prog_get_info_by_fd(prog_fd, &info, &len);
90 if (!ASSERT_OK(err, "bpf_prog_get_info_by_fd"))
91 return -1;
92
93 *nr_map_ids = info.nr_map_ids;
94
95 return 0;
96}
97
98static int __load_test_prog(int map_fd, const int *fd_array, int fd_array_cnt)
99{
100 /* A trivial program which uses one map */
101 struct bpf_insn insns[] = {
102 BPF_LD_MAP_FD(BPF_REG_1, map_fd),
103 BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0),
104 BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
105 BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8),
106 BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
107 BPF_MOV64_IMM(BPF_REG_0, 0),
108 BPF_EXIT_INSN(),
109 };
110 LIBBPF_OPTS(bpf_prog_load_opts, opts);
111
112 opts.fd_array = fd_array;
113 opts.fd_array_cnt = fd_array_cnt;
114
115 return bpf_prog_load(BPF_PROG_TYPE_XDP, NULL, "GPL", insns, ARRAY_SIZE(insns), &opts);
116}
117
118static int load_test_prog(const int *fd_array, int fd_array_cnt)
119{
120 int map_fd;
121 int ret;
122
123 map_fd = new_map();
124 if (!ASSERT_GE(map_fd, 0, "new_map"))
125 return map_fd;
126
127 ret = __load_test_prog(map_fd, fd_array, fd_array_cnt);
128 close(map_fd);
129 return ret;
130}
131
132static bool check_expected_map_ids(int prog_fd, int expected, __u32 *map_ids, __u32 *nr_map_ids)
133{
134 int err;
135
136 err = bpf_prog_get_map_ids(prog_fd, nr_map_ids, map_ids);
137 if (!ASSERT_OK(err, "bpf_prog_get_map_ids"))
138 return false;
139 if (!ASSERT_EQ(*nr_map_ids, expected, "unexpected nr_map_ids"))
140 return false;
141
142 return true;
143}
144
145/*
146 * Load a program, which uses one map. No fd_array maps are present.
147 * On return only one map is expected to be bound to prog.
148 */
149static void check_fd_array_cnt__no_fd_array(void)
150{
151 __u32 map_ids[16];
152 __u32 nr_map_ids;
153 int prog_fd = -1;
154
155 prog_fd = load_test_prog(NULL, 0);
156 if (!ASSERT_GE(prog_fd, 0, "BPF_PROG_LOAD"))
157 return;
158 nr_map_ids = ARRAY_SIZE(map_ids);
159 check_expected_map_ids(prog_fd, 1, map_ids, &nr_map_ids);
160 close(prog_fd);
161}
162
163/*
164 * Load a program, which uses one map, and pass two extra, non-equal, maps in
165 * fd_array with fd_array_cnt=2. On return three maps are expected to be bound
166 * to the program.
167 */
168static void check_fd_array_cnt__fd_array_ok(void)
169{
170 int extra_fds[2] = { -1, -1 };
171 __u32 map_ids[16];
172 __u32 nr_map_ids;
173 int prog_fd = -1;
174
175 extra_fds[0] = new_map();
176 if (!ASSERT_GE(extra_fds[0], 0, "new_map"))
177 goto cleanup;
178 extra_fds[1] = new_map();
179 if (!ASSERT_GE(extra_fds[1], 0, "new_map"))
180 goto cleanup;
181 prog_fd = load_test_prog(extra_fds, 2);
182 if (!ASSERT_GE(prog_fd, 0, "BPF_PROG_LOAD"))
183 goto cleanup;
184 nr_map_ids = ARRAY_SIZE(map_ids);
185 if (!check_expected_map_ids(prog_fd, 3, map_ids, &nr_map_ids))
186 goto cleanup;
187
188 /* maps should still exist when original file descriptors are closed */
189 Close(extra_fds[0]);
190 Close(extra_fds[1]);
191 if (!ASSERT_EQ(map_exists(map_ids[0]), true, "map_ids[0] should exist"))
192 goto cleanup;
193 if (!ASSERT_EQ(map_exists(map_ids[1]), true, "map_ids[1] should exist"))
194 goto cleanup;
195
196 /* some fds might be invalid, so ignore return codes */
197cleanup:
198 Close(extra_fds[1]);
199 Close(extra_fds[0]);
200 Close(prog_fd);
201}
202
203/*
204 * Load a program with a few extra maps duplicated in the fd_array.
205 * After the load maps should only be referenced once.
206 */
207static void check_fd_array_cnt__duplicated_maps(void)
208{
209 int extra_fds[4] = { -1, -1, -1, -1 };
210 __u32 map_ids[16];
211 __u32 nr_map_ids;
212 int prog_fd = -1;
213
214 extra_fds[0] = extra_fds[2] = new_map();
215 if (!ASSERT_GE(extra_fds[0], 0, "new_map"))
216 goto cleanup;
217 extra_fds[1] = extra_fds[3] = new_map();
218 if (!ASSERT_GE(extra_fds[1], 0, "new_map"))
219 goto cleanup;
220 prog_fd = load_test_prog(extra_fds, 4);
221 if (!ASSERT_GE(prog_fd, 0, "BPF_PROG_LOAD"))
222 goto cleanup;
223 nr_map_ids = ARRAY_SIZE(map_ids);
224 if (!check_expected_map_ids(prog_fd, 3, map_ids, &nr_map_ids))
225 goto cleanup;
226
227 /* maps should still exist when original file descriptors are closed */
228 Close(extra_fds[0]);
229 Close(extra_fds[1]);
230 if (!ASSERT_EQ(map_exists(map_ids[0]), true, "map should exist"))
231 goto cleanup;
232 if (!ASSERT_EQ(map_exists(map_ids[1]), true, "map should exist"))
233 goto cleanup;
234
235 /* some fds might be invalid, so ignore return codes */
236cleanup:
237 Close(extra_fds[1]);
238 Close(extra_fds[0]);
239 Close(prog_fd);
240}
241
242/*
243 * Check that if maps which are referenced by a program are
244 * passed in fd_array, then they will be referenced only once
245 */
246static void check_fd_array_cnt__referenced_maps_in_fd_array(void)
247{
248 int extra_fds[1] = { -1 };
249 __u32 map_ids[16];
250 __u32 nr_map_ids;
251 int prog_fd = -1;
252
253 extra_fds[0] = new_map();
254 if (!ASSERT_GE(extra_fds[0], 0, "new_map"))
255 goto cleanup;
256 prog_fd = __load_test_prog(extra_fds[0], extra_fds, 1);
257 if (!ASSERT_GE(prog_fd, 0, "BPF_PROG_LOAD"))
258 goto cleanup;
259 nr_map_ids = ARRAY_SIZE(map_ids);
260 if (!check_expected_map_ids(prog_fd, 1, map_ids, &nr_map_ids))
261 goto cleanup;
262
263 /* map should still exist when original file descriptor is closed */
264 Close(extra_fds[0]);
265 if (!ASSERT_EQ(map_exists(map_ids[0]), true, "map should exist"))
266 goto cleanup;
267
268 /* some fds might be invalid, so ignore return codes */
269cleanup:
270 Close(extra_fds[0]);
271 Close(prog_fd);
272}
273
274static int get_btf_id_by_fd(int btf_fd, __u32 *id)
275{
276 struct bpf_btf_info info;
277 __u32 info_len = sizeof(info);
278 int err;
279
280 memset(&info, 0, info_len);
281 err = bpf_btf_get_info_by_fd(btf_fd, &info, &info_len);
282 if (err)
283 return err;
284 if (id)
285 *id = info.id;
286 return 0;
287}
288
289/*
290 * Check that fd_array operates properly for btfs. Namely, to check that
291 * passing a btf fd in fd_array increases its reference count, do the
292 * following:
293 * 1) Create a new btf, it's referenced only by a file descriptor, so refcnt=1
294 * 2) Load a BPF prog with fd_array[0] = btf_fd; now btf's refcnt=2
295 * 3) Close the btf_fd, now refcnt=1
296 * Wait and check that BTF still exists.
297 */
298static void check_fd_array_cnt__referenced_btfs(void)
299{
300 int extra_fds[1] = { -1 };
301 int prog_fd = -1;
302 __u32 btf_id;
303 int tries;
304 int err;
305
306 extra_fds[0] = new_btf();
307 if (!ASSERT_GE(extra_fds[0], 0, "new_btf"))
308 goto cleanup;
309 prog_fd = load_test_prog(extra_fds, 1);
310 if (!ASSERT_GE(prog_fd, 0, "BPF_PROG_LOAD"))
311 goto cleanup;
312
313 /* btf should still exist when original file descriptor is closed */
314 err = get_btf_id_by_fd(extra_fds[0], &btf_id);
315 if (!ASSERT_EQ(err, 0, "get_btf_id_by_fd"))
316 goto cleanup;
317
318 Close(extra_fds[0]);
319
320 if (!ASSERT_GE(kern_sync_rcu(), 0, "kern_sync_rcu 1"))
321 goto cleanup;
322
323 if (!ASSERT_EQ(btf_exists(btf_id), true, "btf should exist"))
324 goto cleanup;
325
326 Close(prog_fd);
327
328 /* The program is freed by a workqueue, so no reliable
329 * way to sync, so just wait a bit (max ~1 second). */
330 for (tries = 100; tries >= 0; tries--) {
331 usleep(1000);
332
333 if (!btf_exists(btf_id))
334 break;
335
336 if (tries)
337 continue;
338
339 PRINT_FAIL("btf should have been freed");
340 }
341
342 /* some fds might be invalid, so ignore return codes */
343cleanup:
344 Close(extra_fds[0]);
345 Close(prog_fd);
346}
347
348/*
349 * Test that a program with trash in fd_array can't be loaded:
350 * only map and BTF file descriptors should be accepted.
351 */
352static void check_fd_array_cnt__fd_array_with_trash(void)
353{
354 int extra_fds[3] = { -1, -1, -1 };
355 int prog_fd = -1;
356
357 extra_fds[0] = new_map();
358 if (!ASSERT_GE(extra_fds[0], 0, "new_map"))
359 goto cleanup;
360 extra_fds[1] = new_btf();
361 if (!ASSERT_GE(extra_fds[1], 0, "new_btf"))
362 goto cleanup;
363
364 /* trash 1: not a file descriptor */
365 extra_fds[2] = 0xbeef;
366 prog_fd = load_test_prog(extra_fds, 3);
367 if (!ASSERT_EQ(prog_fd, -EBADF, "prog should have been rejected with -EBADF"))
368 goto cleanup;
369
370 /* trash 2: not a map or btf */
371 extra_fds[2] = socket(AF_INET, SOCK_STREAM, 0);
372 if (!ASSERT_GE(extra_fds[2], 0, "socket"))
373 goto cleanup;
374
375 prog_fd = load_test_prog(extra_fds, 3);
376 if (!ASSERT_EQ(prog_fd, -EINVAL, "prog should have been rejected with -EINVAL"))
377 goto cleanup;
378
379 /* Validate that the prog is ok if trash is removed */
380 Close(extra_fds[2]);
381 extra_fds[2] = new_btf();
382 if (!ASSERT_GE(extra_fds[2], 0, "new_btf"))
383 goto cleanup;
384
385 prog_fd = load_test_prog(extra_fds, 3);
386 if (!ASSERT_GE(prog_fd, 0, "prog should have been loaded"))
387 goto cleanup;
388
389 /* some fds might be invalid, so ignore return codes */
390cleanup:
391 Close(extra_fds[2]);
392 Close(extra_fds[1]);
393 Close(extra_fds[0]);
394}
395
396/*
397 * Test that a program with too big fd_array can't be loaded.
398 */
399static void check_fd_array_cnt__fd_array_too_big(void)
400{
401 int extra_fds[65];
402 int prog_fd = -1;
403 int i;
404
405 for (i = 0; i < 65; i++) {
406 extra_fds[i] = new_map();
407 if (!ASSERT_GE(extra_fds[i], 0, "new_map"))
408 goto cleanup_fds;
409 }
410
411 prog_fd = load_test_prog(extra_fds, 65);
412 ASSERT_EQ(prog_fd, -E2BIG, "prog should have been rejected with -E2BIG");
413
414cleanup_fds:
415 while (i-- > 0)
416 Close(extra_fds[i]);
417}
418
419void test_fd_array_cnt(void)
420{
421 if (test__start_subtest("no-fd-array"))
422 check_fd_array_cnt__no_fd_array();
423
424 if (test__start_subtest("fd-array-ok"))
425 check_fd_array_cnt__fd_array_ok();
426
427 if (test__start_subtest("fd-array-dup-input"))
428 check_fd_array_cnt__duplicated_maps();
429
430 if (test__start_subtest("fd-array-ref-maps-in-array"))
431 check_fd_array_cnt__referenced_maps_in_fd_array();
432
433 if (test__start_subtest("fd-array-ref-btfs"))
434 check_fd_array_cnt__referenced_btfs();
435
436 if (test__start_subtest("fd-array-trash-input"))
437 check_fd_array_cnt__fd_array_with_trash();
438
439 if (test__start_subtest("fd-array-2big"))
440 check_fd_array_cnt__fd_array_too_big();
441}