xref: /linux/tools/testing/selftests/bpf/testing_helpers.c (revision b85e63cb65f96df373b034cc347b0e18231cb0d5)
1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
2 /* Copyright (C) 2019 Netronome Systems, Inc. */
3 /* Copyright (C) 2020 Facebook, Inc. */
4 #include <ctype.h>
5 #include <stdlib.h>
6 #include <string.h>
7 #include <errno.h>
8 #include <sys/mman.h>
9 #include <alloca.h>
10 #include <bpf/bpf.h>
11 #include <bpf/libbpf.h>
12 #include "disasm.h"
13 #include "test_progs.h"
14 #include "testing_helpers.h"
15 #include <linux/membarrier.h>
16 
17 int parse_num_list(const char *s, bool **num_set, int *num_set_len)
18 {
19 	int i, set_len = 0, new_len, num, start = 0, end = -1;
20 	bool *set = NULL, *tmp, parsing_end = false;
21 	char *next;
22 
23 	while (s[0]) {
24 		errno = 0;
25 		num = strtol(s, &next, 10);
26 		if (errno)
27 			return -errno;
28 
29 		if (parsing_end)
30 			end = num;
31 		else
32 			start = num;
33 
34 		if (!parsing_end && *next == '-') {
35 			s = next + 1;
36 			parsing_end = true;
37 			continue;
38 		} else if (*next == ',') {
39 			parsing_end = false;
40 			s = next + 1;
41 			end = num;
42 		} else if (*next == '\0') {
43 			parsing_end = false;
44 			s = next;
45 			end = num;
46 		} else {
47 			return -EINVAL;
48 		}
49 
50 		if (start > end)
51 			return -EINVAL;
52 
53 		if (end + 1 > set_len) {
54 			new_len = end + 1;
55 			tmp = realloc(set, new_len);
56 			if (!tmp) {
57 				free(set);
58 				return -ENOMEM;
59 			}
60 			for (i = set_len; i < start; i++)
61 				tmp[i] = false;
62 			set = tmp;
63 			set_len = new_len;
64 		}
65 		for (i = start; i <= end; i++)
66 			set[i] = true;
67 	}
68 
69 	if (!set || parsing_end)
70 		return -EINVAL;
71 
72 	*num_set = set;
73 	*num_set_len = set_len;
74 
75 	return 0;
76 }
77 
78 static int do_insert_test(struct test_filter_set *set,
79 			  char *test_str,
80 			  char *subtest_str)
81 {
82 	struct test_filter *tmp, *test;
83 	char **ctmp;
84 	int i;
85 
86 	for (i = 0; i < set->cnt; i++) {
87 		test = &set->tests[i];
88 
89 		if (strcmp(test_str, test->name) == 0) {
90 			free(test_str);
91 			goto subtest;
92 		}
93 	}
94 
95 	tmp = realloc(set->tests, sizeof(*test) * (set->cnt + 1));
96 	if (!tmp)
97 		return -ENOMEM;
98 
99 	set->tests = tmp;
100 	test = &set->tests[set->cnt];
101 
102 	test->name = test_str;
103 	test->subtests = NULL;
104 	test->subtest_cnt = 0;
105 
106 	set->cnt++;
107 
108 subtest:
109 	if (!subtest_str)
110 		return 0;
111 
112 	for (i = 0; i < test->subtest_cnt; i++) {
113 		if (strcmp(subtest_str, test->subtests[i]) == 0) {
114 			free(subtest_str);
115 			return 0;
116 		}
117 	}
118 
119 	ctmp = realloc(test->subtests,
120 		       sizeof(*test->subtests) * (test->subtest_cnt + 1));
121 	if (!ctmp)
122 		return -ENOMEM;
123 
124 	test->subtests = ctmp;
125 	test->subtests[test->subtest_cnt] = subtest_str;
126 
127 	test->subtest_cnt++;
128 
129 	return 0;
130 }
131 
132 static int insert_test(struct test_filter_set *set,
133 		       char *test_spec,
134 		       bool is_glob_pattern)
135 {
136 	char *pattern, *subtest_str, *ext_test_str, *ext_subtest_str = NULL;
137 	int glob_chars = 0;
138 
139 	if (is_glob_pattern) {
140 		pattern = "%s";
141 	} else {
142 		pattern = "*%s*";
143 		glob_chars = 2;
144 	}
145 
146 	subtest_str = strchr(test_spec, '/');
147 	if (subtest_str) {
148 		*subtest_str = '\0';
149 		subtest_str += 1;
150 	}
151 
152 	ext_test_str = malloc(strlen(test_spec) + glob_chars + 1);
153 	if (!ext_test_str)
154 		goto err;
155 
156 	sprintf(ext_test_str, pattern, test_spec);
157 
158 	if (subtest_str) {
159 		ext_subtest_str = malloc(strlen(subtest_str) + glob_chars + 1);
160 		if (!ext_subtest_str)
161 			goto err;
162 
163 		sprintf(ext_subtest_str, pattern, subtest_str);
164 	}
165 
166 	return do_insert_test(set, ext_test_str, ext_subtest_str);
167 
168 err:
169 	free(ext_test_str);
170 	free(ext_subtest_str);
171 
172 	return -ENOMEM;
173 }
174 
175 int parse_test_list_file(const char *path,
176 			 struct test_filter_set *set,
177 			 bool is_glob_pattern)
178 {
179 	char *buf = NULL, *capture_start, *capture_end, *scan_end;
180 	size_t buflen = 0;
181 	int err = 0;
182 	FILE *f;
183 
184 	f = fopen(path, "r");
185 	if (!f) {
186 		err = -errno;
187 		fprintf(stderr, "Failed to open '%s': %d\n", path, err);
188 		return err;
189 	}
190 
191 	while (getline(&buf, &buflen, f) != -1) {
192 		capture_start = buf;
193 
194 		while (isspace(*capture_start))
195 			++capture_start;
196 
197 		capture_end = capture_start;
198 		scan_end = capture_start;
199 
200 		while (*scan_end && *scan_end != '#') {
201 			if (!isspace(*scan_end))
202 				capture_end = scan_end;
203 
204 			++scan_end;
205 		}
206 
207 		if (capture_end == capture_start)
208 			continue;
209 
210 		*(++capture_end) = '\0';
211 
212 		err = insert_test(set, capture_start, is_glob_pattern);
213 		if (err)
214 			break;
215 	}
216 
217 	free(buf);
218 	fclose(f);
219 	return err;
220 }
221 
222 int parse_test_list(const char *s,
223 		    struct test_filter_set *set,
224 		    bool is_glob_pattern)
225 {
226 	char *input, *state = NULL, *test_spec;
227 	int err = 0, cnt = 0;
228 
229 	input = strdup(s);
230 	if (!input)
231 		return -ENOMEM;
232 
233 	while ((test_spec = strtok_r(cnt++ ? NULL : input, ",", &state))) {
234 		err = insert_test(set, test_spec, is_glob_pattern);
235 		if (err)
236 			break;
237 	}
238 
239 	free(input);
240 	return err;
241 }
242 
243 __u32 link_info_prog_id(const struct bpf_link *link, struct bpf_link_info *info)
244 {
245 	__u32 info_len = sizeof(*info);
246 	int err;
247 
248 	memset(info, 0, sizeof(*info));
249 	err = bpf_link_get_info_by_fd(bpf_link__fd(link), info, &info_len);
250 	if (err) {
251 		printf("failed to get link info: %d\n", -errno);
252 		return 0;
253 	}
254 	return info->prog_id;
255 }
256 
257 int extra_prog_load_log_flags = 0;
258 
259 int testing_prog_flags(void)
260 {
261 	static int cached_flags = -1;
262 	static int prog_flags[] = { BPF_F_TEST_RND_HI32, BPF_F_TEST_REG_INVARIANTS };
263 	static struct bpf_insn insns[] = {
264 		BPF_MOV64_IMM(BPF_REG_0, 0),
265 		BPF_EXIT_INSN(),
266 	};
267 	int insn_cnt = ARRAY_SIZE(insns), i, fd, flags = 0;
268 	LIBBPF_OPTS(bpf_prog_load_opts, opts);
269 
270 	if (cached_flags >= 0)
271 		return cached_flags;
272 
273 	for (i = 0; i < ARRAY_SIZE(prog_flags); i++) {
274 		opts.prog_flags = prog_flags[i];
275 		fd = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, "flag-test", "GPL",
276 				   insns, insn_cnt, &opts);
277 		if (fd >= 0) {
278 			flags |= prog_flags[i];
279 			close(fd);
280 		}
281 	}
282 
283 	cached_flags = flags;
284 	return cached_flags;
285 }
286 
287 int bpf_prog_test_load(const char *file, enum bpf_prog_type type,
288 		       struct bpf_object **pobj, int *prog_fd)
289 {
290 	LIBBPF_OPTS(bpf_object_open_opts, opts,
291 		.kernel_log_level = extra_prog_load_log_flags,
292 	);
293 	struct bpf_object *obj;
294 	struct bpf_program *prog;
295 	__u32 flags;
296 	int err;
297 
298 	obj = bpf_object__open_file(file, &opts);
299 	if (!obj)
300 		return -errno;
301 
302 	prog = bpf_object__next_program(obj, NULL);
303 	if (!prog) {
304 		err = -ENOENT;
305 		goto err_out;
306 	}
307 
308 	if (type != BPF_PROG_TYPE_UNSPEC && bpf_program__type(prog) != type)
309 		bpf_program__set_type(prog, type);
310 
311 	flags = bpf_program__flags(prog) | testing_prog_flags();
312 	bpf_program__set_flags(prog, flags);
313 
314 	err = bpf_object__load(obj);
315 	if (err)
316 		goto err_out;
317 
318 	*pobj = obj;
319 	*prog_fd = bpf_program__fd(prog);
320 
321 	return 0;
322 err_out:
323 	bpf_object__close(obj);
324 	return err;
325 }
326 
327 int bpf_test_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
328 			  size_t insns_cnt, const char *license,
329 			  __u32 kern_version, char *log_buf,
330 			  size_t log_buf_sz)
331 {
332 	LIBBPF_OPTS(bpf_prog_load_opts, opts,
333 		.kern_version = kern_version,
334 		.prog_flags = testing_prog_flags(),
335 		.log_level = extra_prog_load_log_flags,
336 		.log_buf = log_buf,
337 		.log_size = log_buf_sz,
338 	);
339 
340 	return bpf_prog_load(type, NULL, license, insns, insns_cnt, &opts);
341 }
342 
343 __u64 read_perf_max_sample_freq(void)
344 {
345 	__u64 sample_freq = 5000; /* fallback to 5000 on error */
346 	FILE *f;
347 
348 	f = fopen("/proc/sys/kernel/perf_event_max_sample_rate", "r");
349 	if (f == NULL) {
350 		printf("Failed to open /proc/sys/kernel/perf_event_max_sample_rate: err %d\n"
351 		       "return default value: 5000\n", -errno);
352 		return sample_freq;
353 	}
354 	if (fscanf(f, "%llu", &sample_freq) != 1) {
355 		printf("Failed to parse /proc/sys/kernel/perf_event_max_sample_rate: err %d\n"
356 		       "return default value: 5000\n", -errno);
357 	}
358 
359 	fclose(f);
360 	return sample_freq;
361 }
362 
363 int finit_module(int fd, const char *param_values, int flags)
364 {
365 	return syscall(__NR_finit_module, fd, param_values, flags);
366 }
367 
368 int delete_module(const char *name, int flags)
369 {
370 	return syscall(__NR_delete_module, name, flags);
371 }
372 
373 int try_unload_module(const char *name, int retries, bool verbose)
374 {
375 	int ret, cnt = 0;
376 
377 	if (kern_sync_rcu())
378 		fprintf(stdout, "Failed to trigger kernel-side RCU sync!\n");
379 
380 	for (;;) {
381 		ret = delete_module(name, 0);
382 		if (!ret || errno != EAGAIN)
383 			break;
384 		if (++cnt > retries) {
385 			fprintf(stdout, "Unload of %s timed out\n", name);
386 			break;
387 		}
388 		usleep(100);
389 	}
390 
391 	if (ret) {
392 		if (errno == ENOENT) {
393 			if (verbose)
394 				fprintf(stdout, "%s.ko is already unloaded.\n", name);
395 			return -1;
396 		}
397 		fprintf(stdout, "Failed to unload %s.ko from kernel: %d\n", name, -errno);
398 		return -1;
399 	}
400 	if (verbose)
401 		fprintf(stdout, "Successfully unloaded %s.ko.\n", name);
402 	return 0;
403 }
404 
405 int unload_module(const char *name, bool verbose)
406 {
407 	return try_unload_module(name, 10000, verbose);
408 }
409 
410 static int __load_module(const char *path, const char *param_values, bool verbose)
411 {
412 	int fd;
413 
414 	if (verbose)
415 		fprintf(stdout, "Loading %s...\n", path);
416 
417 	fd = open(path, O_RDONLY);
418 	if (fd < 0) {
419 		fprintf(stdout, "Can't find %s kernel module: %d\n", path, -errno);
420 		return -ENOENT;
421 	}
422 	if (finit_module(fd, param_values, 0)) {
423 		fprintf(stdout, "Failed to load %s into the kernel: %d\n", path, -errno);
424 		close(fd);
425 		return -EINVAL;
426 	}
427 	close(fd);
428 
429 	if (verbose)
430 		fprintf(stdout, "Successfully loaded %s.\n", path);
431 	return 0;
432 }
433 
434 int load_module_params(const char *path, const char *param_values, bool verbose)
435 {
436 	return __load_module(path, param_values, verbose);
437 }
438 
439 int load_module(const char *path, bool verbose)
440 {
441 	return __load_module(path, "", verbose);
442 }
443 
444 int unload_bpf_testmod(bool verbose)
445 {
446 	return unload_module("bpf_testmod", verbose);
447 }
448 
449 int load_bpf_testmod(bool verbose)
450 {
451 	return load_module("bpf_testmod.ko", verbose);
452 }
453 
454 /*
455  * Trigger synchronize_rcu() in kernel.
456  */
457 int kern_sync_rcu(void)
458 {
459 	return syscall(__NR_membarrier, MEMBARRIER_CMD_SHARED, 0, 0);
460 }
461 
462 int get_xlated_program(int fd_prog, struct bpf_insn **buf, __u32 *cnt)
463 {
464 	__u32 buf_element_size = sizeof(struct bpf_insn);
465 	struct bpf_prog_info info = {};
466 	__u32 info_len = sizeof(info);
467 	__u32 xlated_prog_len;
468 
469 	if (bpf_prog_get_info_by_fd(fd_prog, &info, &info_len)) {
470 		perror("bpf_prog_get_info_by_fd failed");
471 		return -1;
472 	}
473 
474 	xlated_prog_len = info.xlated_prog_len;
475 	if (xlated_prog_len % buf_element_size) {
476 		printf("Program length %u is not multiple of %u\n",
477 		       xlated_prog_len, buf_element_size);
478 		return -1;
479 	}
480 
481 	*cnt = xlated_prog_len / buf_element_size;
482 	*buf = calloc(*cnt, buf_element_size);
483 	if (!*buf) {
484 		perror("can't allocate xlated program buffer");
485 		return -ENOMEM;
486 	}
487 
488 	bzero(&info, sizeof(info));
489 	info.xlated_prog_len = xlated_prog_len;
490 	info.xlated_prog_insns = (__u64)(unsigned long)*buf;
491 	if (bpf_prog_get_info_by_fd(fd_prog, &info, &info_len)) {
492 		perror("second bpf_prog_get_info_by_fd failed");
493 		goto out_free_buf;
494 	}
495 
496 	return 0;
497 
498 out_free_buf:
499 	free(*buf);
500 	*buf = NULL;
501 	return -1;
502 }
503 
504 bool is_jit_enabled(void)
505 {
506 	const char *jit_sysctl = "/proc/sys/net/core/bpf_jit_enable";
507 	bool enabled = false;
508 	int sysctl_fd;
509 
510 	sysctl_fd = open(jit_sysctl, O_RDONLY);
511 	if (sysctl_fd != -1) {
512 		char tmpc;
513 
514 		if (read(sysctl_fd, &tmpc, sizeof(tmpc)) == 1)
515 			enabled = (tmpc != '0');
516 		close(sysctl_fd);
517 	}
518 
519 	return enabled;
520 }
521 
522 int stack_mprotect(void)
523 {
524 	void *buf;
525 	long sz;
526 	int ret;
527 
528 	sz = sysconf(_SC_PAGESIZE);
529 	if (sz < 0)
530 		return sz;
531 
532 	buf = alloca(sz * 3);
533 	ret = mprotect((void *)(((unsigned long)(buf + sz)) & ~(sz - 1)), sz,
534 		       PROT_READ | PROT_WRITE | PROT_EXEC);
535 	return ret;
536 }
537