1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Randomized tests for eBPF longest-prefix-match maps
4  *
5  * This program runs randomized tests against the lpm-bpf-map. It implements a
6  * "Trivial Longest Prefix Match" (tlpm) based on simple, linear, singly linked
7  * lists. The implementation should be pretty straightforward.
8  *
9  * Based on tlpm, this inserts randomized data into bpf-lpm-maps and verifies
10  * the trie-based bpf-map implementation behaves the same way as tlpm.
11  */
12 
13 #include <assert.h>
14 #include <errno.h>
15 #include <inttypes.h>
16 #include <linux/bpf.h>
17 #include <pthread.h>
18 #include <stdio.h>
19 #include <stdlib.h>
20 #include <string.h>
21 #include <time.h>
22 #include <unistd.h>
23 #include <arpa/inet.h>
24 #include <sys/time.h>
25 
26 #include <bpf/bpf.h>
27 
28 #include "bpf_util.h"
29 
30 struct tlpm_node {
31 	struct tlpm_node *next;
32 	size_t n_bits;
33 	uint8_t key[];
34 };
35 
36 static struct tlpm_node *tlpm_match(struct tlpm_node *list,
37 				    const uint8_t *key,
38 				    size_t n_bits);
39 
40 static struct tlpm_node *tlpm_add(struct tlpm_node *list,
41 				  const uint8_t *key,
42 				  size_t n_bits)
43 {
44 	struct tlpm_node *node;
45 	size_t n;
46 
47 	n = (n_bits + 7) / 8;
48 
49 	/* 'overwrite' an equivalent entry if one already exists */
50 	node = tlpm_match(list, key, n_bits);
51 	if (node && node->n_bits == n_bits) {
52 		memcpy(node->key, key, n);
53 		return list;
54 	}
55 
56 	/* add new entry with @key/@n_bits to @list and return new head */
57 
58 	node = malloc(sizeof(*node) + n);
59 	assert(node);
60 
61 	node->next = list;
62 	node->n_bits = n_bits;
63 	memcpy(node->key, key, n);
64 
65 	return node;
66 }
67 
68 static void tlpm_clear(struct tlpm_node *list)
69 {
70 	struct tlpm_node *node;
71 
72 	/* free all entries in @list */
73 
74 	while ((node = list)) {
75 		list = list->next;
76 		free(node);
77 	}
78 }
79 
80 static struct tlpm_node *tlpm_match(struct tlpm_node *list,
81 				    const uint8_t *key,
82 				    size_t n_bits)
83 {
84 	struct tlpm_node *best = NULL;
85 	size_t i;
86 
87 	/* Perform longest prefix-match on @key/@n_bits. That is, iterate all
88 	 * entries and match each prefix against @key. Remember the "best"
89 	 * entry we find (i.e., the longest prefix that matches) and return it
90 	 * to the caller when done.
91 	 */
92 
93 	for ( ; list; list = list->next) {
94 		for (i = 0; i < n_bits && i < list->n_bits; ++i) {
95 			if ((key[i / 8] & (1 << (7 - i % 8))) !=
96 			    (list->key[i / 8] & (1 << (7 - i % 8))))
97 				break;
98 		}
99 
100 		if (i >= list->n_bits) {
101 			if (!best || i > best->n_bits)
102 				best = list;
103 		}
104 	}
105 
106 	return best;
107 }
108 
109 static struct tlpm_node *tlpm_delete(struct tlpm_node *list,
110 				     const uint8_t *key,
111 				     size_t n_bits)
112 {
113 	struct tlpm_node *best = tlpm_match(list, key, n_bits);
114 	struct tlpm_node *node;
115 
116 	if (!best || best->n_bits != n_bits)
117 		return list;
118 
119 	if (best == list) {
120 		node = best->next;
121 		free(best);
122 		return node;
123 	}
124 
125 	for (node = list; node; node = node->next) {
126 		if (node->next == best) {
127 			node->next = best->next;
128 			free(best);
129 			return list;
130 		}
131 	}
132 	/* should never get here */
133 	assert(0);
134 	return list;
135 }
136 
137 static void test_lpm_basic(void)
138 {
139 	struct tlpm_node *list = NULL, *t1, *t2;
140 
141 	/* very basic, static tests to verify tlpm works as expected */
142 
143 	assert(!tlpm_match(list, (uint8_t[]){ 0xff }, 8));
144 
145 	t1 = list = tlpm_add(list, (uint8_t[]){ 0xff }, 8);
146 	assert(t1 == tlpm_match(list, (uint8_t[]){ 0xff }, 8));
147 	assert(t1 == tlpm_match(list, (uint8_t[]){ 0xff, 0xff }, 16));
148 	assert(t1 == tlpm_match(list, (uint8_t[]){ 0xff, 0x00 }, 16));
149 	assert(!tlpm_match(list, (uint8_t[]){ 0x7f }, 8));
150 	assert(!tlpm_match(list, (uint8_t[]){ 0xfe }, 8));
151 	assert(!tlpm_match(list, (uint8_t[]){ 0xff }, 7));
152 
153 	t2 = list = tlpm_add(list, (uint8_t[]){ 0xff, 0xff }, 16);
154 	assert(t1 == tlpm_match(list, (uint8_t[]){ 0xff }, 8));
155 	assert(t2 == tlpm_match(list, (uint8_t[]){ 0xff, 0xff }, 16));
156 	assert(t1 == tlpm_match(list, (uint8_t[]){ 0xff, 0xff }, 15));
157 	assert(!tlpm_match(list, (uint8_t[]){ 0x7f, 0xff }, 16));
158 
159 	list = tlpm_delete(list, (uint8_t[]){ 0xff, 0xff }, 16);
160 	assert(t1 == tlpm_match(list, (uint8_t[]){ 0xff }, 8));
161 	assert(t1 == tlpm_match(list, (uint8_t[]){ 0xff, 0xff }, 16));
162 
163 	list = tlpm_delete(list, (uint8_t[]){ 0xff }, 8);
164 	assert(!tlpm_match(list, (uint8_t[]){ 0xff }, 8));
165 
166 	tlpm_clear(list);
167 }
168 
169 static void test_lpm_order(void)
170 {
171 	struct tlpm_node *t1, *t2, *l1 = NULL, *l2 = NULL;
172 	size_t i, j;
173 
174 	/* Verify the tlpm implementation works correctly regardless of the
175 	 * order of entries. Insert a random set of entries into @l1, and copy
176 	 * the same data in reverse order into @l2. Then verify a lookup of
177 	 * random keys will yield the same result in both sets.
178 	 */
179 
180 	for (i = 0; i < (1 << 12); ++i)
181 		l1 = tlpm_add(l1, (uint8_t[]){
182 					rand() % 0xff,
183 					rand() % 0xff,
184 				}, rand() % 16 + 1);
185 
186 	for (t1 = l1; t1; t1 = t1->next)
187 		l2 = tlpm_add(l2, t1->key, t1->n_bits);
188 
189 	for (i = 0; i < (1 << 8); ++i) {
190 		uint8_t key[] = { rand() % 0xff, rand() % 0xff };
191 
192 		t1 = tlpm_match(l1, key, 16);
193 		t2 = tlpm_match(l2, key, 16);
194 
195 		assert(!t1 == !t2);
196 		if (t1) {
197 			assert(t1->n_bits == t2->n_bits);
198 			for (j = 0; j < t1->n_bits; ++j)
199 				assert((t1->key[j / 8] & (1 << (7 - j % 8))) ==
200 				       (t2->key[j / 8] & (1 << (7 - j % 8))));
201 		}
202 	}
203 
204 	tlpm_clear(l1);
205 	tlpm_clear(l2);
206 }
207 
208 static void test_lpm_map(int keysize)
209 {
210 	LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_NO_PREALLOC);
211 	volatile size_t n_matches, n_matches_after_delete;
212 	size_t i, j, n_nodes, n_lookups;
213 	struct tlpm_node *t, *list = NULL;
214 	struct bpf_lpm_trie_key_u8 *key;
215 	uint8_t *data, *value;
216 	int r, map;
217 
218 	/* Compare behavior of tlpm vs. bpf-lpm. Create a randomized set of
219 	 * prefixes and insert it into both tlpm and bpf-lpm. Then run some
220 	 * randomized lookups and verify both maps return the same result.
221 	 */
222 
223 	n_matches = 0;
224 	n_matches_after_delete = 0;
225 	n_nodes = 1 << 8;
226 	n_lookups = 1 << 16;
227 
228 	data = alloca(keysize);
229 	memset(data, 0, keysize);
230 
231 	value = alloca(keysize + 1);
232 	memset(value, 0, keysize + 1);
233 
234 	key = alloca(sizeof(*key) + keysize);
235 	memset(key, 0, sizeof(*key) + keysize);
236 
237 	map = bpf_map_create(BPF_MAP_TYPE_LPM_TRIE, NULL,
238 			     sizeof(*key) + keysize,
239 			     keysize + 1,
240 			     4096,
241 			     &opts);
242 	assert(map >= 0);
243 
244 	for (i = 0; i < n_nodes; ++i) {
245 		for (j = 0; j < keysize; ++j)
246 			value[j] = rand() & 0xff;
247 		value[keysize] = rand() % (8 * keysize + 1);
248 
249 		list = tlpm_add(list, value, value[keysize]);
250 
251 		key->prefixlen = value[keysize];
252 		memcpy(key->data, value, keysize);
253 		r = bpf_map_update_elem(map, key, value, 0);
254 		assert(!r);
255 	}
256 
257 	for (i = 0; i < n_lookups; ++i) {
258 		for (j = 0; j < keysize; ++j)
259 			data[j] = rand() & 0xff;
260 
261 		t = tlpm_match(list, data, 8 * keysize);
262 
263 		key->prefixlen = 8 * keysize;
264 		memcpy(key->data, data, keysize);
265 		r = bpf_map_lookup_elem(map, key, value);
266 		assert(!r || errno == ENOENT);
267 		assert(!t == !!r);
268 
269 		if (t) {
270 			++n_matches;
271 			assert(t->n_bits == value[keysize]);
272 			for (j = 0; j < t->n_bits; ++j)
273 				assert((t->key[j / 8] & (1 << (7 - j % 8))) ==
274 				       (value[j / 8] & (1 << (7 - j % 8))));
275 		}
276 	}
277 
278 	/* Remove the first half of the elements in the tlpm and the
279 	 * corresponding nodes from the bpf-lpm.  Then run the same
280 	 * large number of random lookups in both and make sure they match.
281 	 * Note: we need to count the number of nodes actually inserted
282 	 * since there may have been duplicates.
283 	 */
284 	for (i = 0, t = list; t; i++, t = t->next)
285 		;
286 	for (j = 0; j < i / 2; ++j) {
287 		key->prefixlen = list->n_bits;
288 		memcpy(key->data, list->key, keysize);
289 		r = bpf_map_delete_elem(map, key);
290 		assert(!r);
291 		list = tlpm_delete(list, list->key, list->n_bits);
292 		assert(list);
293 	}
294 	for (i = 0; i < n_lookups; ++i) {
295 		for (j = 0; j < keysize; ++j)
296 			data[j] = rand() & 0xff;
297 
298 		t = tlpm_match(list, data, 8 * keysize);
299 
300 		key->prefixlen = 8 * keysize;
301 		memcpy(key->data, data, keysize);
302 		r = bpf_map_lookup_elem(map, key, value);
303 		assert(!r || errno == ENOENT);
304 		assert(!t == !!r);
305 
306 		if (t) {
307 			++n_matches_after_delete;
308 			assert(t->n_bits == value[keysize]);
309 			for (j = 0; j < t->n_bits; ++j)
310 				assert((t->key[j / 8] & (1 << (7 - j % 8))) ==
311 				       (value[j / 8] & (1 << (7 - j % 8))));
312 		}
313 	}
314 
315 	close(map);
316 	tlpm_clear(list);
317 
318 	/* With 255 random nodes in the map, we are pretty likely to match
319 	 * something on every lookup. For statistics, use this:
320 	 *
321 	 *     printf("          nodes: %zu\n"
322 	 *            "        lookups: %zu\n"
323 	 *            "        matches: %zu\n"
324 	 *            "matches(delete): %zu\n",
325 	 *            n_nodes, n_lookups, n_matches, n_matches_after_delete);
326 	 */
327 }
328 
329 /* Test the implementation with some 'real world' examples */
330 
331 static void test_lpm_ipaddr(void)
332 {
333 	LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_NO_PREALLOC);
334 	struct bpf_lpm_trie_key_u8 *key_ipv4;
335 	struct bpf_lpm_trie_key_u8 *key_ipv6;
336 	size_t key_size_ipv4;
337 	size_t key_size_ipv6;
338 	int map_fd_ipv4;
339 	int map_fd_ipv6;
340 	__u64 value;
341 
342 	key_size_ipv4 = sizeof(*key_ipv4) + sizeof(__u32);
343 	key_size_ipv6 = sizeof(*key_ipv6) + sizeof(__u32) * 4;
344 	key_ipv4 = alloca(key_size_ipv4);
345 	key_ipv6 = alloca(key_size_ipv6);
346 
347 	map_fd_ipv4 = bpf_map_create(BPF_MAP_TYPE_LPM_TRIE, NULL,
348 				     key_size_ipv4, sizeof(value),
349 				     100, &opts);
350 	assert(map_fd_ipv4 >= 0);
351 
352 	map_fd_ipv6 = bpf_map_create(BPF_MAP_TYPE_LPM_TRIE, NULL,
353 				     key_size_ipv6, sizeof(value),
354 				     100, &opts);
355 	assert(map_fd_ipv6 >= 0);
356 
357 	/* Fill data some IPv4 and IPv6 address ranges */
358 	value = 1;
359 	key_ipv4->prefixlen = 16;
360 	inet_pton(AF_INET, "192.168.0.0", key_ipv4->data);
361 	assert(bpf_map_update_elem(map_fd_ipv4, key_ipv4, &value, 0) == 0);
362 
363 	value = 2;
364 	key_ipv4->prefixlen = 24;
365 	inet_pton(AF_INET, "192.168.0.0", key_ipv4->data);
366 	assert(bpf_map_update_elem(map_fd_ipv4, key_ipv4, &value, 0) == 0);
367 
368 	value = 3;
369 	key_ipv4->prefixlen = 24;
370 	inet_pton(AF_INET, "192.168.128.0", key_ipv4->data);
371 	assert(bpf_map_update_elem(map_fd_ipv4, key_ipv4, &value, 0) == 0);
372 
373 	value = 5;
374 	key_ipv4->prefixlen = 24;
375 	inet_pton(AF_INET, "192.168.1.0", key_ipv4->data);
376 	assert(bpf_map_update_elem(map_fd_ipv4, key_ipv4, &value, 0) == 0);
377 
378 	value = 4;
379 	key_ipv4->prefixlen = 23;
380 	inet_pton(AF_INET, "192.168.0.0", key_ipv4->data);
381 	assert(bpf_map_update_elem(map_fd_ipv4, key_ipv4, &value, 0) == 0);
382 
383 	value = 0xdeadbeef;
384 	key_ipv6->prefixlen = 64;
385 	inet_pton(AF_INET6, "2a00:1450:4001:814::200e", key_ipv6->data);
386 	assert(bpf_map_update_elem(map_fd_ipv6, key_ipv6, &value, 0) == 0);
387 
388 	/* Set tprefixlen to maximum for lookups */
389 	key_ipv4->prefixlen = 32;
390 	key_ipv6->prefixlen = 128;
391 
392 	/* Test some lookups that should come back with a value */
393 	inet_pton(AF_INET, "192.168.128.23", key_ipv4->data);
394 	assert(bpf_map_lookup_elem(map_fd_ipv4, key_ipv4, &value) == 0);
395 	assert(value == 3);
396 
397 	inet_pton(AF_INET, "192.168.0.1", key_ipv4->data);
398 	assert(bpf_map_lookup_elem(map_fd_ipv4, key_ipv4, &value) == 0);
399 	assert(value == 2);
400 
401 	inet_pton(AF_INET6, "2a00:1450:4001:814::", key_ipv6->data);
402 	assert(bpf_map_lookup_elem(map_fd_ipv6, key_ipv6, &value) == 0);
403 	assert(value == 0xdeadbeef);
404 
405 	inet_pton(AF_INET6, "2a00:1450:4001:814::1", key_ipv6->data);
406 	assert(bpf_map_lookup_elem(map_fd_ipv6, key_ipv6, &value) == 0);
407 	assert(value == 0xdeadbeef);
408 
409 	/* Test some lookups that should not match any entry */
410 	inet_pton(AF_INET, "10.0.0.1", key_ipv4->data);
411 	assert(bpf_map_lookup_elem(map_fd_ipv4, key_ipv4, &value) == -ENOENT);
412 
413 	inet_pton(AF_INET, "11.11.11.11", key_ipv4->data);
414 	assert(bpf_map_lookup_elem(map_fd_ipv4, key_ipv4, &value) == -ENOENT);
415 
416 	inet_pton(AF_INET6, "2a00:ffff::", key_ipv6->data);
417 	assert(bpf_map_lookup_elem(map_fd_ipv6, key_ipv6, &value) == -ENOENT);
418 
419 	close(map_fd_ipv4);
420 	close(map_fd_ipv6);
421 }
422 
423 static void test_lpm_delete(void)
424 {
425 	LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_NO_PREALLOC);
426 	struct bpf_lpm_trie_key_u8 *key;
427 	size_t key_size;
428 	int map_fd;
429 	__u64 value;
430 
431 	key_size = sizeof(*key) + sizeof(__u32);
432 	key = alloca(key_size);
433 
434 	map_fd = bpf_map_create(BPF_MAP_TYPE_LPM_TRIE, NULL,
435 				key_size, sizeof(value),
436 				100, &opts);
437 	assert(map_fd >= 0);
438 
439 	/* Add nodes:
440 	 * 192.168.0.0/16   (1)
441 	 * 192.168.0.0/24   (2)
442 	 * 192.168.128.0/24 (3)
443 	 * 192.168.1.0/24   (4)
444 	 *
445 	 *         (1)
446 	 *        /   \
447          *     (IM)    (3)
448 	 *    /   \
449          *   (2)  (4)
450 	 */
451 	value = 1;
452 	key->prefixlen = 16;
453 	inet_pton(AF_INET, "192.168.0.0", key->data);
454 	assert(bpf_map_update_elem(map_fd, key, &value, 0) == 0);
455 
456 	value = 2;
457 	key->prefixlen = 24;
458 	inet_pton(AF_INET, "192.168.0.0", key->data);
459 	assert(bpf_map_update_elem(map_fd, key, &value, 0) == 0);
460 
461 	value = 3;
462 	key->prefixlen = 24;
463 	inet_pton(AF_INET, "192.168.128.0", key->data);
464 	assert(bpf_map_update_elem(map_fd, key, &value, 0) == 0);
465 
466 	value = 4;
467 	key->prefixlen = 24;
468 	inet_pton(AF_INET, "192.168.1.0", key->data);
469 	assert(bpf_map_update_elem(map_fd, key, &value, 0) == 0);
470 
471 	/* remove non-existent node */
472 	key->prefixlen = 32;
473 	inet_pton(AF_INET, "10.0.0.1", key->data);
474 	assert(bpf_map_lookup_elem(map_fd, key, &value) == -ENOENT);
475 
476 	key->prefixlen = 30; // unused prefix so far
477 	inet_pton(AF_INET, "192.255.0.0", key->data);
478 	assert(bpf_map_delete_elem(map_fd, key) == -ENOENT);
479 
480 	key->prefixlen = 16; // same prefix as the root node
481 	inet_pton(AF_INET, "192.255.0.0", key->data);
482 	assert(bpf_map_delete_elem(map_fd, key) == -ENOENT);
483 
484 	/* assert initial lookup */
485 	key->prefixlen = 32;
486 	inet_pton(AF_INET, "192.168.0.1", key->data);
487 	assert(bpf_map_lookup_elem(map_fd, key, &value) == 0);
488 	assert(value == 2);
489 
490 	/* remove leaf node */
491 	key->prefixlen = 24;
492 	inet_pton(AF_INET, "192.168.0.0", key->data);
493 	assert(bpf_map_delete_elem(map_fd, key) == 0);
494 
495 	key->prefixlen = 32;
496 	inet_pton(AF_INET, "192.168.0.1", key->data);
497 	assert(bpf_map_lookup_elem(map_fd, key, &value) == 0);
498 	assert(value == 1);
499 
500 	/* remove leaf (and intermediary) node */
501 	key->prefixlen = 24;
502 	inet_pton(AF_INET, "192.168.1.0", key->data);
503 	assert(bpf_map_delete_elem(map_fd, key) == 0);
504 
505 	key->prefixlen = 32;
506 	inet_pton(AF_INET, "192.168.1.1", key->data);
507 	assert(bpf_map_lookup_elem(map_fd, key, &value) == 0);
508 	assert(value == 1);
509 
510 	/* remove root node */
511 	key->prefixlen = 16;
512 	inet_pton(AF_INET, "192.168.0.0", key->data);
513 	assert(bpf_map_delete_elem(map_fd, key) == 0);
514 
515 	key->prefixlen = 32;
516 	inet_pton(AF_INET, "192.168.128.1", key->data);
517 	assert(bpf_map_lookup_elem(map_fd, key, &value) == 0);
518 	assert(value == 3);
519 
520 	/* remove last node */
521 	key->prefixlen = 24;
522 	inet_pton(AF_INET, "192.168.128.0", key->data);
523 	assert(bpf_map_delete_elem(map_fd, key) == 0);
524 
525 	key->prefixlen = 32;
526 	inet_pton(AF_INET, "192.168.128.1", key->data);
527 	assert(bpf_map_lookup_elem(map_fd, key, &value) == -ENOENT);
528 
529 	close(map_fd);
530 }
531 
532 static void test_lpm_get_next_key(void)
533 {
534 	LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_NO_PREALLOC);
535 	struct bpf_lpm_trie_key_u8 *key_p, *next_key_p;
536 	size_t key_size;
537 	__u32 value = 0;
538 	int map_fd;
539 
540 	key_size = sizeof(*key_p) + sizeof(__u32);
541 	key_p = alloca(key_size);
542 	next_key_p = alloca(key_size);
543 
544 	map_fd = bpf_map_create(BPF_MAP_TYPE_LPM_TRIE, NULL, key_size, sizeof(value), 100, &opts);
545 	assert(map_fd >= 0);
546 
547 	/* empty tree. get_next_key should return ENOENT */
548 	assert(bpf_map_get_next_key(map_fd, NULL, key_p) == -ENOENT);
549 
550 	/* get and verify the first key, get the second one should fail. */
551 	key_p->prefixlen = 16;
552 	inet_pton(AF_INET, "192.168.0.0", key_p->data);
553 	assert(bpf_map_update_elem(map_fd, key_p, &value, 0) == 0);
554 
555 	memset(key_p, 0, key_size);
556 	assert(bpf_map_get_next_key(map_fd, NULL, key_p) == 0);
557 	assert(key_p->prefixlen == 16 && key_p->data[0] == 192 &&
558 	       key_p->data[1] == 168);
559 
560 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == -ENOENT);
561 
562 	/* no exact matching key should get the first one in post order. */
563 	key_p->prefixlen = 8;
564 	assert(bpf_map_get_next_key(map_fd, NULL, key_p) == 0);
565 	assert(key_p->prefixlen == 16 && key_p->data[0] == 192 &&
566 	       key_p->data[1] == 168);
567 
568 	/* add one more element (total two) */
569 	key_p->prefixlen = 24;
570 	inet_pton(AF_INET, "192.168.128.0", key_p->data);
571 	assert(bpf_map_update_elem(map_fd, key_p, &value, 0) == 0);
572 
573 	memset(key_p, 0, key_size);
574 	assert(bpf_map_get_next_key(map_fd, NULL, key_p) == 0);
575 	assert(key_p->prefixlen == 24 && key_p->data[0] == 192 &&
576 	       key_p->data[1] == 168 && key_p->data[2] == 128);
577 
578 	memset(next_key_p, 0, key_size);
579 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
580 	assert(next_key_p->prefixlen == 16 && next_key_p->data[0] == 192 &&
581 	       next_key_p->data[1] == 168);
582 
583 	memcpy(key_p, next_key_p, key_size);
584 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == -ENOENT);
585 
586 	/* Add one more element (total three) */
587 	key_p->prefixlen = 24;
588 	inet_pton(AF_INET, "192.168.0.0", key_p->data);
589 	assert(bpf_map_update_elem(map_fd, key_p, &value, 0) == 0);
590 
591 	memset(key_p, 0, key_size);
592 	assert(bpf_map_get_next_key(map_fd, NULL, key_p) == 0);
593 	assert(key_p->prefixlen == 24 && key_p->data[0] == 192 &&
594 	       key_p->data[1] == 168 && key_p->data[2] == 0);
595 
596 	memset(next_key_p, 0, key_size);
597 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
598 	assert(next_key_p->prefixlen == 24 && next_key_p->data[0] == 192 &&
599 	       next_key_p->data[1] == 168 && next_key_p->data[2] == 128);
600 
601 	memcpy(key_p, next_key_p, key_size);
602 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
603 	assert(next_key_p->prefixlen == 16 && next_key_p->data[0] == 192 &&
604 	       next_key_p->data[1] == 168);
605 
606 	memcpy(key_p, next_key_p, key_size);
607 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == -ENOENT);
608 
609 	/* Add one more element (total four) */
610 	key_p->prefixlen = 24;
611 	inet_pton(AF_INET, "192.168.1.0", key_p->data);
612 	assert(bpf_map_update_elem(map_fd, key_p, &value, 0) == 0);
613 
614 	memset(key_p, 0, key_size);
615 	assert(bpf_map_get_next_key(map_fd, NULL, key_p) == 0);
616 	assert(key_p->prefixlen == 24 && key_p->data[0] == 192 &&
617 	       key_p->data[1] == 168 && key_p->data[2] == 0);
618 
619 	memset(next_key_p, 0, key_size);
620 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
621 	assert(next_key_p->prefixlen == 24 && next_key_p->data[0] == 192 &&
622 	       next_key_p->data[1] == 168 && next_key_p->data[2] == 1);
623 
624 	memcpy(key_p, next_key_p, key_size);
625 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
626 	assert(next_key_p->prefixlen == 24 && next_key_p->data[0] == 192 &&
627 	       next_key_p->data[1] == 168 && next_key_p->data[2] == 128);
628 
629 	memcpy(key_p, next_key_p, key_size);
630 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
631 	assert(next_key_p->prefixlen == 16 && next_key_p->data[0] == 192 &&
632 	       next_key_p->data[1] == 168);
633 
634 	memcpy(key_p, next_key_p, key_size);
635 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == -ENOENT);
636 
637 	/* Add one more element (total five) */
638 	key_p->prefixlen = 28;
639 	inet_pton(AF_INET, "192.168.1.128", key_p->data);
640 	assert(bpf_map_update_elem(map_fd, key_p, &value, 0) == 0);
641 
642 	memset(key_p, 0, key_size);
643 	assert(bpf_map_get_next_key(map_fd, NULL, key_p) == 0);
644 	assert(key_p->prefixlen == 24 && key_p->data[0] == 192 &&
645 	       key_p->data[1] == 168 && key_p->data[2] == 0);
646 
647 	memset(next_key_p, 0, key_size);
648 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
649 	assert(next_key_p->prefixlen == 28 && next_key_p->data[0] == 192 &&
650 	       next_key_p->data[1] == 168 && next_key_p->data[2] == 1 &&
651 	       next_key_p->data[3] == 128);
652 
653 	memcpy(key_p, next_key_p, key_size);
654 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
655 	assert(next_key_p->prefixlen == 24 && next_key_p->data[0] == 192 &&
656 	       next_key_p->data[1] == 168 && next_key_p->data[2] == 1);
657 
658 	memcpy(key_p, next_key_p, key_size);
659 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
660 	assert(next_key_p->prefixlen == 24 && next_key_p->data[0] == 192 &&
661 	       next_key_p->data[1] == 168 && next_key_p->data[2] == 128);
662 
663 	memcpy(key_p, next_key_p, key_size);
664 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
665 	assert(next_key_p->prefixlen == 16 && next_key_p->data[0] == 192 &&
666 	       next_key_p->data[1] == 168);
667 
668 	memcpy(key_p, next_key_p, key_size);
669 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == -ENOENT);
670 
671 	/* no exact matching key should return the first one in post order */
672 	key_p->prefixlen = 22;
673 	inet_pton(AF_INET, "192.168.1.0", key_p->data);
674 	assert(bpf_map_get_next_key(map_fd, key_p, next_key_p) == 0);
675 	assert(next_key_p->prefixlen == 24 && next_key_p->data[0] == 192 &&
676 	       next_key_p->data[1] == 168 && next_key_p->data[2] == 0);
677 
678 	close(map_fd);
679 }
680 
681 #define MAX_TEST_KEYS	4
682 struct lpm_mt_test_info {
683 	int cmd; /* 0: update, 1: delete, 2: lookup, 3: get_next_key */
684 	int iter;
685 	int map_fd;
686 	struct {
687 		__u32 prefixlen;
688 		__u32 data;
689 	} key[MAX_TEST_KEYS];
690 };
691 
692 static void *lpm_test_command(void *arg)
693 {
694 	int i, j, ret, iter, key_size;
695 	struct lpm_mt_test_info *info = arg;
696 	struct bpf_lpm_trie_key_u8 *key_p;
697 
698 	key_size = sizeof(*key_p) + sizeof(__u32);
699 	key_p = alloca(key_size);
700 	for (iter = 0; iter < info->iter; iter++)
701 		for (i = 0; i < MAX_TEST_KEYS; i++) {
702 			/* first half of iterations in forward order,
703 			 * and second half in backward order.
704 			 */
705 			j = (iter < (info->iter / 2)) ? i : MAX_TEST_KEYS - i - 1;
706 			key_p->prefixlen = info->key[j].prefixlen;
707 			memcpy(key_p->data, &info->key[j].data, sizeof(__u32));
708 			if (info->cmd == 0) {
709 				__u32 value = j;
710 				/* update must succeed */
711 				assert(bpf_map_update_elem(info->map_fd, key_p, &value, 0) == 0);
712 			} else if (info->cmd == 1) {
713 				ret = bpf_map_delete_elem(info->map_fd, key_p);
714 				assert(ret == 0 || errno == ENOENT);
715 			} else if (info->cmd == 2) {
716 				__u32 value;
717 				ret = bpf_map_lookup_elem(info->map_fd, key_p, &value);
718 				assert(ret == 0 || errno == ENOENT);
719 			} else {
720 				struct bpf_lpm_trie_key_u8 *next_key_p = alloca(key_size);
721 				ret = bpf_map_get_next_key(info->map_fd, key_p, next_key_p);
722 				assert(ret == 0 || errno == ENOENT || errno == ENOMEM);
723 			}
724 		}
725 
726 	// Pass successful exit info back to the main thread
727 	pthread_exit((void *)info);
728 }
729 
730 static void setup_lpm_mt_test_info(struct lpm_mt_test_info *info, int map_fd)
731 {
732 	info->iter = 2000;
733 	info->map_fd = map_fd;
734 	info->key[0].prefixlen = 16;
735 	inet_pton(AF_INET, "192.168.0.0", &info->key[0].data);
736 	info->key[1].prefixlen = 24;
737 	inet_pton(AF_INET, "192.168.0.0", &info->key[1].data);
738 	info->key[2].prefixlen = 24;
739 	inet_pton(AF_INET, "192.168.128.0", &info->key[2].data);
740 	info->key[3].prefixlen = 24;
741 	inet_pton(AF_INET, "192.168.1.0", &info->key[3].data);
742 }
743 
744 static void test_lpm_multi_thread(void)
745 {
746 	LIBBPF_OPTS(bpf_map_create_opts, opts, .map_flags = BPF_F_NO_PREALLOC);
747 	struct lpm_mt_test_info info[4];
748 	size_t key_size, value_size;
749 	pthread_t thread_id[4];
750 	int i, map_fd;
751 	void *ret;
752 
753 	/* create a trie */
754 	value_size = sizeof(__u32);
755 	key_size = sizeof(struct bpf_lpm_trie_key_hdr) + value_size;
756 	map_fd = bpf_map_create(BPF_MAP_TYPE_LPM_TRIE, NULL, key_size, value_size, 100, &opts);
757 
758 	/* create 4 threads to test update, delete, lookup and get_next_key */
759 	setup_lpm_mt_test_info(&info[0], map_fd);
760 	for (i = 0; i < 4; i++) {
761 		if (i != 0)
762 			memcpy(&info[i], &info[0], sizeof(info[i]));
763 		info[i].cmd = i;
764 		assert(pthread_create(&thread_id[i], NULL, &lpm_test_command, &info[i]) == 0);
765 	}
766 
767 	for (i = 0; i < 4; i++)
768 		assert(pthread_join(thread_id[i], &ret) == 0 && ret == (void *)&info[i]);
769 
770 	close(map_fd);
771 }
772 
773 int main(void)
774 {
775 	int i;
776 
777 	/* we want predictable, pseudo random tests */
778 	srand(0xf00ba1);
779 
780 	/* Use libbpf 1.0 API mode */
781 	libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
782 
783 	test_lpm_basic();
784 	test_lpm_order();
785 
786 	/* Test with 8, 16, 24, 32, ... 128 bit prefix length */
787 	for (i = 1; i <= 16; ++i)
788 		test_lpm_map(i);
789 
790 	test_lpm_ipaddr();
791 	test_lpm_delete();
792 	test_lpm_get_next_key();
793 	test_lpm_multi_thread();
794 
795 	printf("test_lpm: OK\n");
796 	return 0;
797 }
798