1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020 Facebook */
3 #include <test_progs.h>
4 #include "bpf_iter_ipv6_route.skel.h"
5 #include "bpf_iter_netlink.skel.h"
6 #include "bpf_iter_bpf_map.skel.h"
7 #include "bpf_iter_task.skel.h"
8 #include "bpf_iter_task_stack.skel.h"
9 #include "bpf_iter_task_file.skel.h"
10 #include "bpf_iter_tcp4.skel.h"
11 #include "bpf_iter_tcp6.skel.h"
12 #include "bpf_iter_udp4.skel.h"
13 #include "bpf_iter_udp6.skel.h"
14 #include "bpf_iter_test_kern1.skel.h"
15 #include "bpf_iter_test_kern2.skel.h"
16 #include "bpf_iter_test_kern3.skel.h"
17 #include "bpf_iter_test_kern4.skel.h"
18 
19 static int duration;
20 
21 static void test_btf_id_or_null(void)
22 {
23 	struct bpf_iter_test_kern3 *skel;
24 
25 	skel = bpf_iter_test_kern3__open_and_load();
26 	if (CHECK(skel, "bpf_iter_test_kern3__open_and_load",
27 		  "skeleton open_and_load unexpectedly succeeded\n")) {
28 		bpf_iter_test_kern3__destroy(skel);
29 		return;
30 	}
31 }
32 
33 static void do_dummy_read(struct bpf_program *prog)
34 {
35 	struct bpf_link *link;
36 	char buf[16] = {};
37 	int iter_fd, len;
38 
39 	link = bpf_program__attach_iter(prog, NULL);
40 	if (CHECK(IS_ERR(link), "attach_iter", "attach_iter failed\n"))
41 		return;
42 
43 	iter_fd = bpf_iter_create(bpf_link__fd(link));
44 	if (CHECK(iter_fd < 0, "create_iter", "create_iter failed\n"))
45 		goto free_link;
46 
47 	/* not check contents, but ensure read() ends without error */
48 	while ((len = read(iter_fd, buf, sizeof(buf))) > 0)
49 		;
50 	CHECK(len < 0, "read", "read failed: %s\n", strerror(errno));
51 
52 	close(iter_fd);
53 
54 free_link:
55 	bpf_link__destroy(link);
56 }
57 
58 static void test_ipv6_route(void)
59 {
60 	struct bpf_iter_ipv6_route *skel;
61 
62 	skel = bpf_iter_ipv6_route__open_and_load();
63 	if (CHECK(!skel, "bpf_iter_ipv6_route__open_and_load",
64 		  "skeleton open_and_load failed\n"))
65 		return;
66 
67 	do_dummy_read(skel->progs.dump_ipv6_route);
68 
69 	bpf_iter_ipv6_route__destroy(skel);
70 }
71 
72 static void test_netlink(void)
73 {
74 	struct bpf_iter_netlink *skel;
75 
76 	skel = bpf_iter_netlink__open_and_load();
77 	if (CHECK(!skel, "bpf_iter_netlink__open_and_load",
78 		  "skeleton open_and_load failed\n"))
79 		return;
80 
81 	do_dummy_read(skel->progs.dump_netlink);
82 
83 	bpf_iter_netlink__destroy(skel);
84 }
85 
86 static void test_bpf_map(void)
87 {
88 	struct bpf_iter_bpf_map *skel;
89 
90 	skel = bpf_iter_bpf_map__open_and_load();
91 	if (CHECK(!skel, "bpf_iter_bpf_map__open_and_load",
92 		  "skeleton open_and_load failed\n"))
93 		return;
94 
95 	do_dummy_read(skel->progs.dump_bpf_map);
96 
97 	bpf_iter_bpf_map__destroy(skel);
98 }
99 
100 static void test_task(void)
101 {
102 	struct bpf_iter_task *skel;
103 
104 	skel = bpf_iter_task__open_and_load();
105 	if (CHECK(!skel, "bpf_iter_task__open_and_load",
106 		  "skeleton open_and_load failed\n"))
107 		return;
108 
109 	do_dummy_read(skel->progs.dump_task);
110 
111 	bpf_iter_task__destroy(skel);
112 }
113 
114 static void test_task_stack(void)
115 {
116 	struct bpf_iter_task_stack *skel;
117 
118 	skel = bpf_iter_task_stack__open_and_load();
119 	if (CHECK(!skel, "bpf_iter_task_stack__open_and_load",
120 		  "skeleton open_and_load failed\n"))
121 		return;
122 
123 	do_dummy_read(skel->progs.dump_task_stack);
124 
125 	bpf_iter_task_stack__destroy(skel);
126 }
127 
128 static void test_task_file(void)
129 {
130 	struct bpf_iter_task_file *skel;
131 
132 	skel = bpf_iter_task_file__open_and_load();
133 	if (CHECK(!skel, "bpf_iter_task_file__open_and_load",
134 		  "skeleton open_and_load failed\n"))
135 		return;
136 
137 	do_dummy_read(skel->progs.dump_task_file);
138 
139 	bpf_iter_task_file__destroy(skel);
140 }
141 
142 static void test_tcp4(void)
143 {
144 	struct bpf_iter_tcp4 *skel;
145 
146 	skel = bpf_iter_tcp4__open_and_load();
147 	if (CHECK(!skel, "bpf_iter_tcp4__open_and_load",
148 		  "skeleton open_and_load failed\n"))
149 		return;
150 
151 	do_dummy_read(skel->progs.dump_tcp4);
152 
153 	bpf_iter_tcp4__destroy(skel);
154 }
155 
156 static void test_tcp6(void)
157 {
158 	struct bpf_iter_tcp6 *skel;
159 
160 	skel = bpf_iter_tcp6__open_and_load();
161 	if (CHECK(!skel, "bpf_iter_tcp6__open_and_load",
162 		  "skeleton open_and_load failed\n"))
163 		return;
164 
165 	do_dummy_read(skel->progs.dump_tcp6);
166 
167 	bpf_iter_tcp6__destroy(skel);
168 }
169 
170 static void test_udp4(void)
171 {
172 	struct bpf_iter_udp4 *skel;
173 
174 	skel = bpf_iter_udp4__open_and_load();
175 	if (CHECK(!skel, "bpf_iter_udp4__open_and_load",
176 		  "skeleton open_and_load failed\n"))
177 		return;
178 
179 	do_dummy_read(skel->progs.dump_udp4);
180 
181 	bpf_iter_udp4__destroy(skel);
182 }
183 
184 static void test_udp6(void)
185 {
186 	struct bpf_iter_udp6 *skel;
187 
188 	skel = bpf_iter_udp6__open_and_load();
189 	if (CHECK(!skel, "bpf_iter_udp6__open_and_load",
190 		  "skeleton open_and_load failed\n"))
191 		return;
192 
193 	do_dummy_read(skel->progs.dump_udp6);
194 
195 	bpf_iter_udp6__destroy(skel);
196 }
197 
198 /* The expected string is less than 16 bytes */
199 static int do_read_with_fd(int iter_fd, const char *expected,
200 			   bool read_one_char)
201 {
202 	int err = -1, len, read_buf_len, start;
203 	char buf[16] = {};
204 
205 	read_buf_len = read_one_char ? 1 : 16;
206 	start = 0;
207 	while ((len = read(iter_fd, buf + start, read_buf_len)) > 0) {
208 		start += len;
209 		if (CHECK(start >= 16, "read", "read len %d\n", len))
210 			return -1;
211 		read_buf_len = read_one_char ? 1 : 16 - start;
212 	}
213 	if (CHECK(len < 0, "read", "read failed: %s\n", strerror(errno)))
214 		return -1;
215 
216 	err = strcmp(buf, expected);
217 	if (CHECK(err, "read", "incorrect read result: buf %s, expected %s\n",
218 		  buf, expected))
219 		return -1;
220 
221 	return 0;
222 }
223 
224 static void test_anon_iter(bool read_one_char)
225 {
226 	struct bpf_iter_test_kern1 *skel;
227 	struct bpf_link *link;
228 	int iter_fd, err;
229 
230 	skel = bpf_iter_test_kern1__open_and_load();
231 	if (CHECK(!skel, "bpf_iter_test_kern1__open_and_load",
232 		  "skeleton open_and_load failed\n"))
233 		return;
234 
235 	err = bpf_iter_test_kern1__attach(skel);
236 	if (CHECK(err, "bpf_iter_test_kern1__attach",
237 		  "skeleton attach failed\n")) {
238 		goto out;
239 	}
240 
241 	link = skel->links.dump_task;
242 	iter_fd = bpf_iter_create(bpf_link__fd(link));
243 	if (CHECK(iter_fd < 0, "create_iter", "create_iter failed\n"))
244 		goto out;
245 
246 	do_read_with_fd(iter_fd, "abcd", read_one_char);
247 	close(iter_fd);
248 
249 out:
250 	bpf_iter_test_kern1__destroy(skel);
251 }
252 
253 static int do_read(const char *path, const char *expected)
254 {
255 	int err, iter_fd;
256 
257 	iter_fd = open(path, O_RDONLY);
258 	if (CHECK(iter_fd < 0, "open", "open %s failed: %s\n",
259 		  path, strerror(errno)))
260 		return -1;
261 
262 	err = do_read_with_fd(iter_fd, expected, false);
263 	close(iter_fd);
264 	return err;
265 }
266 
267 static void test_file_iter(void)
268 {
269 	const char *path = "/sys/fs/bpf/bpf_iter_test1";
270 	struct bpf_iter_test_kern1 *skel1;
271 	struct bpf_iter_test_kern2 *skel2;
272 	struct bpf_link *link;
273 	int err;
274 
275 	skel1 = bpf_iter_test_kern1__open_and_load();
276 	if (CHECK(!skel1, "bpf_iter_test_kern1__open_and_load",
277 		  "skeleton open_and_load failed\n"))
278 		return;
279 
280 	link = bpf_program__attach_iter(skel1->progs.dump_task, NULL);
281 	if (CHECK(IS_ERR(link), "attach_iter", "attach_iter failed\n"))
282 		goto out;
283 
284 	/* unlink this path if it exists. */
285 	unlink(path);
286 
287 	err = bpf_link__pin(link, path);
288 	if (CHECK(err, "pin_iter", "pin_iter to %s failed: %d\n", path, err))
289 		goto free_link;
290 
291 	err = do_read(path, "abcd");
292 	if (err)
293 		goto unlink_path;
294 
295 	/* file based iterator seems working fine. Let us a link update
296 	 * of the underlying link and `cat` the iterator again, its content
297 	 * should change.
298 	 */
299 	skel2 = bpf_iter_test_kern2__open_and_load();
300 	if (CHECK(!skel2, "bpf_iter_test_kern2__open_and_load",
301 		  "skeleton open_and_load failed\n"))
302 		goto unlink_path;
303 
304 	err = bpf_link__update_program(link, skel2->progs.dump_task);
305 	if (CHECK(err, "update_prog", "update_prog failed\n"))
306 		goto destroy_skel2;
307 
308 	do_read(path, "ABCD");
309 
310 destroy_skel2:
311 	bpf_iter_test_kern2__destroy(skel2);
312 unlink_path:
313 	unlink(path);
314 free_link:
315 	bpf_link__destroy(link);
316 out:
317 	bpf_iter_test_kern1__destroy(skel1);
318 }
319 
320 static void test_overflow(bool test_e2big_overflow, bool ret1)
321 {
322 	__u32 map_info_len, total_read_len, expected_read_len;
323 	int err, iter_fd, map1_fd, map2_fd, len;
324 	struct bpf_map_info map_info = {};
325 	struct bpf_iter_test_kern4 *skel;
326 	struct bpf_link *link;
327 	__u32 page_size;
328 	char *buf;
329 
330 	skel = bpf_iter_test_kern4__open();
331 	if (CHECK(!skel, "bpf_iter_test_kern4__open",
332 		  "skeleton open failed\n"))
333 		return;
334 
335 	/* create two maps: bpf program will only do bpf_seq_write
336 	 * for these two maps. The goal is one map output almost
337 	 * fills seq_file buffer and then the other will trigger
338 	 * overflow and needs restart.
339 	 */
340 	map1_fd = bpf_create_map(BPF_MAP_TYPE_ARRAY, 4, 8, 1, 0);
341 	if (CHECK(map1_fd < 0, "bpf_create_map",
342 		  "map_creation failed: %s\n", strerror(errno)))
343 		goto out;
344 	map2_fd = bpf_create_map(BPF_MAP_TYPE_ARRAY, 4, 8, 1, 0);
345 	if (CHECK(map2_fd < 0, "bpf_create_map",
346 		  "map_creation failed: %s\n", strerror(errno)))
347 		goto free_map1;
348 
349 	/* bpf_seq_printf kernel buffer is one page, so one map
350 	 * bpf_seq_write will mostly fill it, and the other map
351 	 * will partially fill and then trigger overflow and need
352 	 * bpf_seq_read restart.
353 	 */
354 	page_size = sysconf(_SC_PAGE_SIZE);
355 
356 	if (test_e2big_overflow) {
357 		skel->rodata->print_len = (page_size + 8) / 8;
358 		expected_read_len = 2 * (page_size + 8);
359 	} else if (!ret1) {
360 		skel->rodata->print_len = (page_size - 8) / 8;
361 		expected_read_len = 2 * (page_size - 8);
362 	} else {
363 		skel->rodata->print_len = 1;
364 		expected_read_len = 2 * 8;
365 	}
366 	skel->rodata->ret1 = ret1;
367 
368 	if (CHECK(bpf_iter_test_kern4__load(skel),
369 		  "bpf_iter_test_kern4__load", "skeleton load failed\n"))
370 		goto free_map2;
371 
372 	/* setup filtering map_id in bpf program */
373 	map_info_len = sizeof(map_info);
374 	err = bpf_obj_get_info_by_fd(map1_fd, &map_info, &map_info_len);
375 	if (CHECK(err, "get_map_info", "get map info failed: %s\n",
376 		  strerror(errno)))
377 		goto free_map2;
378 	skel->bss->map1_id = map_info.id;
379 
380 	err = bpf_obj_get_info_by_fd(map2_fd, &map_info, &map_info_len);
381 	if (CHECK(err, "get_map_info", "get map info failed: %s\n",
382 		  strerror(errno)))
383 		goto free_map2;
384 	skel->bss->map2_id = map_info.id;
385 
386 	link = bpf_program__attach_iter(skel->progs.dump_bpf_map, NULL);
387 	if (CHECK(IS_ERR(link), "attach_iter", "attach_iter failed\n"))
388 		goto free_map2;
389 
390 	iter_fd = bpf_iter_create(bpf_link__fd(link));
391 	if (CHECK(iter_fd < 0, "create_iter", "create_iter failed\n"))
392 		goto free_link;
393 
394 	buf = malloc(expected_read_len);
395 	if (!buf)
396 		goto close_iter;
397 
398 	/* do read */
399 	total_read_len = 0;
400 	if (test_e2big_overflow) {
401 		while ((len = read(iter_fd, buf, expected_read_len)) > 0)
402 			total_read_len += len;
403 
404 		CHECK(len != -1 || errno != E2BIG, "read",
405 		      "expected ret -1, errno E2BIG, but get ret %d, error %s\n",
406 			  len, strerror(errno));
407 		goto free_buf;
408 	} else if (!ret1) {
409 		while ((len = read(iter_fd, buf, expected_read_len)) > 0)
410 			total_read_len += len;
411 
412 		if (CHECK(len < 0, "read", "read failed: %s\n",
413 			  strerror(errno)))
414 			goto free_buf;
415 	} else {
416 		do {
417 			len = read(iter_fd, buf, expected_read_len);
418 			if (len > 0)
419 				total_read_len += len;
420 		} while (len > 0 || len == -EAGAIN);
421 
422 		if (CHECK(len < 0, "read", "read failed: %s\n",
423 			  strerror(errno)))
424 			goto free_buf;
425 	}
426 
427 	if (CHECK(total_read_len != expected_read_len, "read",
428 		  "total len %u, expected len %u\n", total_read_len,
429 		  expected_read_len))
430 		goto free_buf;
431 
432 	if (CHECK(skel->bss->map1_accessed != 1, "map1_accessed",
433 		  "expected 1 actual %d\n", skel->bss->map1_accessed))
434 		goto free_buf;
435 
436 	if (CHECK(skel->bss->map2_accessed != 2, "map2_accessed",
437 		  "expected 2 actual %d\n", skel->bss->map2_accessed))
438 		goto free_buf;
439 
440 	CHECK(skel->bss->map2_seqnum1 != skel->bss->map2_seqnum2,
441 	      "map2_seqnum", "two different seqnum %lld %lld\n",
442 	      skel->bss->map2_seqnum1, skel->bss->map2_seqnum2);
443 
444 free_buf:
445 	free(buf);
446 close_iter:
447 	close(iter_fd);
448 free_link:
449 	bpf_link__destroy(link);
450 free_map2:
451 	close(map2_fd);
452 free_map1:
453 	close(map1_fd);
454 out:
455 	bpf_iter_test_kern4__destroy(skel);
456 }
457 
458 void test_bpf_iter(void)
459 {
460 	if (test__start_subtest("btf_id_or_null"))
461 		test_btf_id_or_null();
462 	if (test__start_subtest("ipv6_route"))
463 		test_ipv6_route();
464 	if (test__start_subtest("netlink"))
465 		test_netlink();
466 	if (test__start_subtest("bpf_map"))
467 		test_bpf_map();
468 	if (test__start_subtest("task"))
469 		test_task();
470 	if (test__start_subtest("task_stack"))
471 		test_task_stack();
472 	if (test__start_subtest("task_file"))
473 		test_task_file();
474 	if (test__start_subtest("tcp4"))
475 		test_tcp4();
476 	if (test__start_subtest("tcp6"))
477 		test_tcp6();
478 	if (test__start_subtest("udp4"))
479 		test_udp4();
480 	if (test__start_subtest("udp6"))
481 		test_udp6();
482 	if (test__start_subtest("anon"))
483 		test_anon_iter(false);
484 	if (test__start_subtest("anon-read-one-char"))
485 		test_anon_iter(true);
486 	if (test__start_subtest("file"))
487 		test_file_iter();
488 	if (test__start_subtest("overflow"))
489 		test_overflow(false, false);
490 	if (test__start_subtest("overflow-e2big"))
491 		test_overflow(true, false);
492 	if (test__start_subtest("prog-ret-1"))
493 		test_overflow(false, true);
494 }
495