xref: /linux/tools/testing/selftests/bpf/testing_helpers.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
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 <bpf/bpf.h>
9 #include <bpf/libbpf.h>
10 #include "disasm.h"
11 #include "test_progs.h"
12 #include "testing_helpers.h"
13 #include <linux/membarrier.h>
14 
15 int parse_num_list(const char *s, bool **num_set, int *num_set_len)
16 {
17 	int i, set_len = 0, new_len, num, start = 0, end = -1;
18 	bool *set = NULL, *tmp, parsing_end = false;
19 	char *next;
20 
21 	while (s[0]) {
22 		errno = 0;
23 		num = strtol(s, &next, 10);
24 		if (errno)
25 			return -errno;
26 
27 		if (parsing_end)
28 			end = num;
29 		else
30 			start = num;
31 
32 		if (!parsing_end && *next == '-') {
33 			s = next + 1;
34 			parsing_end = true;
35 			continue;
36 		} else if (*next == ',') {
37 			parsing_end = false;
38 			s = next + 1;
39 			end = num;
40 		} else if (*next == '\0') {
41 			parsing_end = false;
42 			s = next;
43 			end = num;
44 		} else {
45 			return -EINVAL;
46 		}
47 
48 		if (start > end)
49 			return -EINVAL;
50 
51 		if (end + 1 > set_len) {
52 			new_len = end + 1;
53 			tmp = realloc(set, new_len);
54 			if (!tmp) {
55 				free(set);
56 				return -ENOMEM;
57 			}
58 			for (i = set_len; i < start; i++)
59 				tmp[i] = false;
60 			set = tmp;
61 			set_len = new_len;
62 		}
63 		for (i = start; i <= end; i++)
64 			set[i] = true;
65 	}
66 
67 	if (!set || parsing_end)
68 		return -EINVAL;
69 
70 	*num_set = set;
71 	*num_set_len = set_len;
72 
73 	return 0;
74 }
75 
76 static int do_insert_test(struct test_filter_set *set,
77 			  char *test_str,
78 			  char *subtest_str)
79 {
80 	struct test_filter *tmp, *test;
81 	char **ctmp;
82 	int i;
83 
84 	for (i = 0; i < set->cnt; i++) {
85 		test = &set->tests[i];
86 
87 		if (strcmp(test_str, test->name) == 0) {
88 			free(test_str);
89 			goto subtest;
90 		}
91 	}
92 
93 	tmp = realloc(set->tests, sizeof(*test) * (set->cnt + 1));
94 	if (!tmp)
95 		return -ENOMEM;
96 
97 	set->tests = tmp;
98 	test = &set->tests[set->cnt];
99 
100 	test->name = test_str;
101 	test->subtests = NULL;
102 	test->subtest_cnt = 0;
103 
104 	set->cnt++;
105 
106 subtest:
107 	if (!subtest_str)
108 		return 0;
109 
110 	for (i = 0; i < test->subtest_cnt; i++) {
111 		if (strcmp(subtest_str, test->subtests[i]) == 0) {
112 			free(subtest_str);
113 			return 0;
114 		}
115 	}
116 
117 	ctmp = realloc(test->subtests,
118 		       sizeof(*test->subtests) * (test->subtest_cnt + 1));
119 	if (!ctmp)
120 		return -ENOMEM;
121 
122 	test->subtests = ctmp;
123 	test->subtests[test->subtest_cnt] = subtest_str;
124 
125 	test->subtest_cnt++;
126 
127 	return 0;
128 }
129 
130 static int insert_test(struct test_filter_set *set,
131 		       char *test_spec,
132 		       bool is_glob_pattern)
133 {
134 	char *pattern, *subtest_str, *ext_test_str, *ext_subtest_str = NULL;
135 	int glob_chars = 0;
136 
137 	if (is_glob_pattern) {
138 		pattern = "%s";
139 	} else {
140 		pattern = "*%s*";
141 		glob_chars = 2;
142 	}
143 
144 	subtest_str = strchr(test_spec, '/');
145 	if (subtest_str) {
146 		*subtest_str = '\0';
147 		subtest_str += 1;
148 	}
149 
150 	ext_test_str = malloc(strlen(test_spec) + glob_chars + 1);
151 	if (!ext_test_str)
152 		goto err;
153 
154 	sprintf(ext_test_str, pattern, test_spec);
155 
156 	if (subtest_str) {
157 		ext_subtest_str = malloc(strlen(subtest_str) + glob_chars + 1);
158 		if (!ext_subtest_str)
159 			goto err;
160 
161 		sprintf(ext_subtest_str, pattern, subtest_str);
162 	}
163 
164 	return do_insert_test(set, ext_test_str, ext_subtest_str);
165 
166 err:
167 	free(ext_test_str);
168 	free(ext_subtest_str);
169 
170 	return -ENOMEM;
171 }
172 
173 int parse_test_list_file(const char *path,
174 			 struct test_filter_set *set,
175 			 bool is_glob_pattern)
176 {
177 	char *buf = NULL, *capture_start, *capture_end, *scan_end;
178 	size_t buflen = 0;
179 	int err = 0;
180 	FILE *f;
181 
182 	f = fopen(path, "r");
183 	if (!f) {
184 		err = -errno;
185 		fprintf(stderr, "Failed to open '%s': %d\n", path, err);
186 		return err;
187 	}
188 
189 	while (getline(&buf, &buflen, f) != -1) {
190 		capture_start = buf;
191 
192 		while (isspace(*capture_start))
193 			++capture_start;
194 
195 		capture_end = capture_start;
196 		scan_end = capture_start;
197 
198 		while (*scan_end && *scan_end != '#') {
199 			if (!isspace(*scan_end))
200 				capture_end = scan_end;
201 
202 			++scan_end;
203 		}
204 
205 		if (capture_end == capture_start)
206 			continue;
207 
208 		*(++capture_end) = '\0';
209 
210 		err = insert_test(set, capture_start, is_glob_pattern);
211 		if (err)
212 			break;
213 	}
214 
215 	fclose(f);
216 	return err;
217 }
218 
219 int parse_test_list(const char *s,
220 		    struct test_filter_set *set,
221 		    bool is_glob_pattern)
222 {
223 	char *input, *state = NULL, *test_spec;
224 	int err = 0, cnt = 0;
225 
226 	input = strdup(s);
227 	if (!input)
228 		return -ENOMEM;
229 
230 	while ((test_spec = strtok_r(cnt++ ? NULL : input, ",", &state))) {
231 		err = insert_test(set, test_spec, is_glob_pattern);
232 		if (err)
233 			break;
234 	}
235 
236 	free(input);
237 	return err;
238 }
239 
240 __u32 link_info_prog_id(const struct bpf_link *link, struct bpf_link_info *info)
241 {
242 	__u32 info_len = sizeof(*info);
243 	int err;
244 
245 	memset(info, 0, sizeof(*info));
246 	err = bpf_link_get_info_by_fd(bpf_link__fd(link), info, &info_len);
247 	if (err) {
248 		printf("failed to get link info: %d\n", -errno);
249 		return 0;
250 	}
251 	return info->prog_id;
252 }
253 
254 int extra_prog_load_log_flags = 0;
255 
256 int testing_prog_flags(void)
257 {
258 	static int cached_flags = -1;
259 	static int prog_flags[] = { BPF_F_TEST_RND_HI32, BPF_F_TEST_REG_INVARIANTS };
260 	static struct bpf_insn insns[] = {
261 		BPF_MOV64_IMM(BPF_REG_0, 0),
262 		BPF_EXIT_INSN(),
263 	};
264 	int insn_cnt = ARRAY_SIZE(insns), i, fd, flags = 0;
265 	LIBBPF_OPTS(bpf_prog_load_opts, opts);
266 
267 	if (cached_flags >= 0)
268 		return cached_flags;
269 
270 	for (i = 0; i < ARRAY_SIZE(prog_flags); i++) {
271 		opts.prog_flags = prog_flags[i];
272 		fd = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, "flag-test", "GPL",
273 				   insns, insn_cnt, &opts);
274 		if (fd >= 0) {
275 			flags |= prog_flags[i];
276 			close(fd);
277 		}
278 	}
279 
280 	cached_flags = flags;
281 	return cached_flags;
282 }
283 
284 int bpf_prog_test_load(const char *file, enum bpf_prog_type type,
285 		       struct bpf_object **pobj, int *prog_fd)
286 {
287 	LIBBPF_OPTS(bpf_object_open_opts, opts,
288 		.kernel_log_level = extra_prog_load_log_flags,
289 	);
290 	struct bpf_object *obj;
291 	struct bpf_program *prog;
292 	__u32 flags;
293 	int err;
294 
295 	obj = bpf_object__open_file(file, &opts);
296 	if (!obj)
297 		return -errno;
298 
299 	prog = bpf_object__next_program(obj, NULL);
300 	if (!prog) {
301 		err = -ENOENT;
302 		goto err_out;
303 	}
304 
305 	if (type != BPF_PROG_TYPE_UNSPEC && bpf_program__type(prog) != type)
306 		bpf_program__set_type(prog, type);
307 
308 	flags = bpf_program__flags(prog) | testing_prog_flags();
309 	bpf_program__set_flags(prog, flags);
310 
311 	err = bpf_object__load(obj);
312 	if (err)
313 		goto err_out;
314 
315 	*pobj = obj;
316 	*prog_fd = bpf_program__fd(prog);
317 
318 	return 0;
319 err_out:
320 	bpf_object__close(obj);
321 	return err;
322 }
323 
324 int bpf_test_load_program(enum bpf_prog_type type, const struct bpf_insn *insns,
325 			  size_t insns_cnt, const char *license,
326 			  __u32 kern_version, char *log_buf,
327 			  size_t log_buf_sz)
328 {
329 	LIBBPF_OPTS(bpf_prog_load_opts, opts,
330 		.kern_version = kern_version,
331 		.prog_flags = testing_prog_flags(),
332 		.log_level = extra_prog_load_log_flags,
333 		.log_buf = log_buf,
334 		.log_size = log_buf_sz,
335 	);
336 
337 	return bpf_prog_load(type, NULL, license, insns, insns_cnt, &opts);
338 }
339 
340 __u64 read_perf_max_sample_freq(void)
341 {
342 	__u64 sample_freq = 5000; /* fallback to 5000 on error */
343 	FILE *f;
344 
345 	f = fopen("/proc/sys/kernel/perf_event_max_sample_rate", "r");
346 	if (f == NULL) {
347 		printf("Failed to open /proc/sys/kernel/perf_event_max_sample_rate: err %d\n"
348 		       "return default value: 5000\n", -errno);
349 		return sample_freq;
350 	}
351 	if (fscanf(f, "%llu", &sample_freq) != 1) {
352 		printf("Failed to parse /proc/sys/kernel/perf_event_max_sample_rate: err %d\n"
353 		       "return default value: 5000\n", -errno);
354 	}
355 
356 	fclose(f);
357 	return sample_freq;
358 }
359 
360 int finit_module(int fd, const char *param_values, int flags)
361 {
362 	return syscall(__NR_finit_module, fd, param_values, flags);
363 }
364 
365 int delete_module(const char *name, int flags)
366 {
367 	return syscall(__NR_delete_module, name, flags);
368 }
369 
370 int unload_module(const char *name, bool verbose)
371 {
372 	int ret, cnt = 0;
373 
374 	if (kern_sync_rcu())
375 		fprintf(stdout, "Failed to trigger kernel-side RCU sync!\n");
376 
377 	for (;;) {
378 		ret = delete_module(name, 0);
379 		if (!ret || errno != EAGAIN)
380 			break;
381 		if (++cnt > 10000) {
382 			fprintf(stdout, "Unload of %s timed out\n", name);
383 			break;
384 		}
385 		usleep(100);
386 	}
387 
388 	if (ret) {
389 		if (errno == ENOENT) {
390 			if (verbose)
391 				fprintf(stdout, "%s.ko is already unloaded.\n", name);
392 			return -1;
393 		}
394 		fprintf(stdout, "Failed to unload %s.ko from kernel: %d\n", name, -errno);
395 		return -1;
396 	}
397 	if (verbose)
398 		fprintf(stdout, "Successfully unloaded %s.ko.\n", name);
399 	return 0;
400 }
401 
402 int load_module(const char *path, bool verbose)
403 {
404 	int fd;
405 
406 	if (verbose)
407 		fprintf(stdout, "Loading %s...\n", path);
408 
409 	fd = open(path, O_RDONLY);
410 	if (fd < 0) {
411 		fprintf(stdout, "Can't find %s kernel module: %d\n", path, -errno);
412 		return -ENOENT;
413 	}
414 	if (finit_module(fd, "", 0)) {
415 		fprintf(stdout, "Failed to load %s into the kernel: %d\n", path, -errno);
416 		close(fd);
417 		return -EINVAL;
418 	}
419 	close(fd);
420 
421 	if (verbose)
422 		fprintf(stdout, "Successfully loaded %s.\n", path);
423 	return 0;
424 }
425 
426 int unload_bpf_testmod(bool verbose)
427 {
428 	return unload_module("bpf_testmod", verbose);
429 }
430 
431 int load_bpf_testmod(bool verbose)
432 {
433 	return load_module("bpf_testmod.ko", verbose);
434 }
435 
436 /*
437  * Trigger synchronize_rcu() in kernel.
438  */
439 int kern_sync_rcu(void)
440 {
441 	return syscall(__NR_membarrier, MEMBARRIER_CMD_SHARED, 0, 0);
442 }
443 
444 int get_xlated_program(int fd_prog, struct bpf_insn **buf, __u32 *cnt)
445 {
446 	__u32 buf_element_size = sizeof(struct bpf_insn);
447 	struct bpf_prog_info info = {};
448 	__u32 info_len = sizeof(info);
449 	__u32 xlated_prog_len;
450 
451 	if (bpf_prog_get_info_by_fd(fd_prog, &info, &info_len)) {
452 		perror("bpf_prog_get_info_by_fd failed");
453 		return -1;
454 	}
455 
456 	xlated_prog_len = info.xlated_prog_len;
457 	if (xlated_prog_len % buf_element_size) {
458 		printf("Program length %u is not multiple of %u\n",
459 		       xlated_prog_len, buf_element_size);
460 		return -1;
461 	}
462 
463 	*cnt = xlated_prog_len / buf_element_size;
464 	*buf = calloc(*cnt, buf_element_size);
465 	if (!*buf) {
466 		perror("can't allocate xlated program buffer");
467 		return -ENOMEM;
468 	}
469 
470 	bzero(&info, sizeof(info));
471 	info.xlated_prog_len = xlated_prog_len;
472 	info.xlated_prog_insns = (__u64)(unsigned long)*buf;
473 	if (bpf_prog_get_info_by_fd(fd_prog, &info, &info_len)) {
474 		perror("second bpf_prog_get_info_by_fd failed");
475 		goto out_free_buf;
476 	}
477 
478 	return 0;
479 
480 out_free_buf:
481 	free(*buf);
482 	*buf = NULL;
483 	return -1;
484 }
485 
486 bool is_jit_enabled(void)
487 {
488 	const char *jit_sysctl = "/proc/sys/net/core/bpf_jit_enable";
489 	bool enabled = false;
490 	int sysctl_fd;
491 
492 	sysctl_fd = open(jit_sysctl, O_RDONLY);
493 	if (sysctl_fd != -1) {
494 		char tmpc;
495 
496 		if (read(sysctl_fd, &tmpc, sizeof(tmpc)) == 1)
497 			enabled = (tmpc != '0');
498 		close(sysctl_fd);
499 	}
500 
501 	return enabled;
502 }
503