xref: /linux/tools/testing/selftests/bpf/prog_tests/select_reuseport.c (revision a7d22ca2a483d6c69c0791954447464297315ffa)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2018 Facebook */
3 
4 #include <stdlib.h>
5 #include <unistd.h>
6 #include <stdbool.h>
7 #include <string.h>
8 #include <errno.h>
9 #include <assert.h>
10 #include <fcntl.h>
11 #include <linux/bpf.h>
12 #include <linux/err.h>
13 #include <linux/types.h>
14 #include <linux/if_ether.h>
15 #include <sys/types.h>
16 #include <sys/epoll.h>
17 #include <sys/socket.h>
18 #include <netinet/in.h>
19 #include <bpf/bpf.h>
20 #include <bpf/libbpf.h>
21 #include "bpf_rlimit.h"
22 #include "bpf_util.h"
23 
24 #include "test_progs.h"
25 #include "test_select_reuseport_common.h"
26 
27 #define MAX_TEST_NAME 80
28 #define MIN_TCPHDR_LEN 20
29 #define UDPHDR_LEN 8
30 
31 #define TCP_SYNCOOKIE_SYSCTL "/proc/sys/net/ipv4/tcp_syncookies"
32 #define TCP_FO_SYSCTL "/proc/sys/net/ipv4/tcp_fastopen"
33 #define REUSEPORT_ARRAY_SIZE 32
34 
35 static int result_map, tmp_index_ovr_map, linum_map, data_check_map;
36 static enum result expected_results[NR_RESULTS];
37 static int sk_fds[REUSEPORT_ARRAY_SIZE];
38 static int reuseport_array = -1, outer_map = -1;
39 static int select_by_skb_data_prog;
40 static int saved_tcp_syncookie = -1;
41 static struct bpf_object *obj;
42 static int saved_tcp_fo = -1;
43 static __u32 index_zero;
44 static int epfd;
45 
46 static union sa46 {
47 	struct sockaddr_in6 v6;
48 	struct sockaddr_in v4;
49 	sa_family_t family;
50 } srv_sa;
51 
52 #define RET_IF(condition, tag, format...) ({				\
53 	if (CHECK_FAIL(condition)) {					\
54 		printf(tag " " format);					\
55 		return;							\
56 	}								\
57 })
58 
59 #define RET_ERR(condition, tag, format...) ({				\
60 	if (CHECK_FAIL(condition)) {					\
61 		printf(tag " " format);					\
62 		return -1;						\
63 	}								\
64 })
65 
66 static int create_maps(void)
67 {
68 	struct bpf_create_map_attr attr = {};
69 
70 	/* Creating reuseport_array */
71 	attr.name = "reuseport_array";
72 	attr.map_type = BPF_MAP_TYPE_REUSEPORT_SOCKARRAY;
73 	attr.key_size = sizeof(__u32);
74 	attr.value_size = sizeof(__u32);
75 	attr.max_entries = REUSEPORT_ARRAY_SIZE;
76 
77 	reuseport_array = bpf_create_map_xattr(&attr);
78 	RET_ERR(reuseport_array == -1, "creating reuseport_array",
79 		"reuseport_array:%d errno:%d\n", reuseport_array, errno);
80 
81 	/* Creating outer_map */
82 	attr.name = "outer_map";
83 	attr.map_type = BPF_MAP_TYPE_ARRAY_OF_MAPS;
84 	attr.key_size = sizeof(__u32);
85 	attr.value_size = sizeof(__u32);
86 	attr.max_entries = 1;
87 	attr.inner_map_fd = reuseport_array;
88 	outer_map = bpf_create_map_xattr(&attr);
89 	RET_ERR(outer_map == -1, "creating outer_map",
90 		"outer_map:%d errno:%d\n", outer_map, errno);
91 
92 	return 0;
93 }
94 
95 static int prepare_bpf_obj(void)
96 {
97 	struct bpf_program *prog;
98 	struct bpf_map *map;
99 	int err;
100 
101 	obj = bpf_object__open("test_select_reuseport_kern.o");
102 	RET_ERR(IS_ERR_OR_NULL(obj), "open test_select_reuseport_kern.o",
103 		"obj:%p PTR_ERR(obj):%ld\n", obj, PTR_ERR(obj));
104 
105 	map = bpf_object__find_map_by_name(obj, "outer_map");
106 	RET_ERR(!map, "find outer_map", "!map\n");
107 	err = bpf_map__reuse_fd(map, outer_map);
108 	RET_ERR(err, "reuse outer_map", "err:%d\n", err);
109 
110 	err = bpf_object__load(obj);
111 	RET_ERR(err, "load bpf_object", "err:%d\n", err);
112 
113 	prog = bpf_program__next(NULL, obj);
114 	RET_ERR(!prog, "get first bpf_program", "!prog\n");
115 	select_by_skb_data_prog = bpf_program__fd(prog);
116 	RET_ERR(select_by_skb_data_prog == -1, "get prog fd",
117 		"select_by_skb_data_prog:%d\n", select_by_skb_data_prog);
118 
119 	map = bpf_object__find_map_by_name(obj, "result_map");
120 	RET_ERR(!map, "find result_map", "!map\n");
121 	result_map = bpf_map__fd(map);
122 	RET_ERR(result_map == -1, "get result_map fd",
123 		"result_map:%d\n", result_map);
124 
125 	map = bpf_object__find_map_by_name(obj, "tmp_index_ovr_map");
126 	RET_ERR(!map, "find tmp_index_ovr_map\n", "!map");
127 	tmp_index_ovr_map = bpf_map__fd(map);
128 	RET_ERR(tmp_index_ovr_map == -1, "get tmp_index_ovr_map fd",
129 		"tmp_index_ovr_map:%d\n", tmp_index_ovr_map);
130 
131 	map = bpf_object__find_map_by_name(obj, "linum_map");
132 	RET_ERR(!map, "find linum_map", "!map\n");
133 	linum_map = bpf_map__fd(map);
134 	RET_ERR(linum_map == -1, "get linum_map fd",
135 		"linum_map:%d\n", linum_map);
136 
137 	map = bpf_object__find_map_by_name(obj, "data_check_map");
138 	RET_ERR(!map, "find data_check_map", "!map\n");
139 	data_check_map = bpf_map__fd(map);
140 	RET_ERR(data_check_map == -1, "get data_check_map fd",
141 		"data_check_map:%d\n", data_check_map);
142 
143 	return 0;
144 }
145 
146 static void sa46_init_loopback(union sa46 *sa, sa_family_t family)
147 {
148 	memset(sa, 0, sizeof(*sa));
149 	sa->family = family;
150 	if (sa->family == AF_INET6)
151 		sa->v6.sin6_addr = in6addr_loopback;
152 	else
153 		sa->v4.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
154 }
155 
156 static void sa46_init_inany(union sa46 *sa, sa_family_t family)
157 {
158 	memset(sa, 0, sizeof(*sa));
159 	sa->family = family;
160 	if (sa->family == AF_INET6)
161 		sa->v6.sin6_addr = in6addr_any;
162 	else
163 		sa->v4.sin_addr.s_addr = INADDR_ANY;
164 }
165 
166 static int read_int_sysctl(const char *sysctl)
167 {
168 	char buf[16];
169 	int fd, ret;
170 
171 	fd = open(sysctl, 0);
172 	RET_ERR(fd == -1, "open(sysctl)",
173 		"sysctl:%s fd:%d errno:%d\n", sysctl, fd, errno);
174 
175 	ret = read(fd, buf, sizeof(buf));
176 	RET_ERR(ret <= 0, "read(sysctl)",
177 		"sysctl:%s ret:%d errno:%d\n", sysctl, ret, errno);
178 
179 	close(fd);
180 	return atoi(buf);
181 }
182 
183 static int write_int_sysctl(const char *sysctl, int v)
184 {
185 	int fd, ret, size;
186 	char buf[16];
187 
188 	fd = open(sysctl, O_RDWR);
189 	RET_ERR(fd == -1, "open(sysctl)",
190 		"sysctl:%s fd:%d errno:%d\n", sysctl, fd, errno);
191 
192 	size = snprintf(buf, sizeof(buf), "%d", v);
193 	ret = write(fd, buf, size);
194 	RET_ERR(ret != size, "write(sysctl)",
195 		"sysctl:%s ret:%d size:%d errno:%d\n",
196 		sysctl, ret, size, errno);
197 
198 	close(fd);
199 	return 0;
200 }
201 
202 static void restore_sysctls(void)
203 {
204 	if (saved_tcp_fo != -1)
205 		write_int_sysctl(TCP_FO_SYSCTL, saved_tcp_fo);
206 	if (saved_tcp_syncookie != -1)
207 		write_int_sysctl(TCP_SYNCOOKIE_SYSCTL, saved_tcp_syncookie);
208 }
209 
210 static int enable_fastopen(void)
211 {
212 	int fo;
213 
214 	fo = read_int_sysctl(TCP_FO_SYSCTL);
215 	if (fo < 0)
216 		return -1;
217 
218 	return write_int_sysctl(TCP_FO_SYSCTL, fo | 7);
219 }
220 
221 static int enable_syncookie(void)
222 {
223 	return write_int_sysctl(TCP_SYNCOOKIE_SYSCTL, 2);
224 }
225 
226 static int disable_syncookie(void)
227 {
228 	return write_int_sysctl(TCP_SYNCOOKIE_SYSCTL, 0);
229 }
230 
231 static long get_linum(void)
232 {
233 	__u32 linum;
234 	int err;
235 
236 	err = bpf_map_lookup_elem(linum_map, &index_zero, &linum);
237 	RET_ERR(err == -1, "lookup_elem(linum_map)", "err:%d errno:%d\n",
238 		err, errno);
239 
240 	return linum;
241 }
242 
243 static void check_data(int type, sa_family_t family, const struct cmd *cmd,
244 		       int cli_fd)
245 {
246 	struct data_check expected = {}, result;
247 	union sa46 cli_sa;
248 	socklen_t addrlen;
249 	int err;
250 
251 	addrlen = sizeof(cli_sa);
252 	err = getsockname(cli_fd, (struct sockaddr *)&cli_sa,
253 			  &addrlen);
254 	RET_IF(err == -1, "getsockname(cli_fd)", "err:%d errno:%d\n",
255 	       err, errno);
256 
257 	err = bpf_map_lookup_elem(data_check_map, &index_zero, &result);
258 	RET_IF(err == -1, "lookup_elem(data_check_map)", "err:%d errno:%d\n",
259 	       err, errno);
260 
261 	if (type == SOCK_STREAM) {
262 		expected.len = MIN_TCPHDR_LEN;
263 		expected.ip_protocol = IPPROTO_TCP;
264 	} else {
265 		expected.len = UDPHDR_LEN;
266 		expected.ip_protocol = IPPROTO_UDP;
267 	}
268 
269 	if (family == AF_INET6) {
270 		expected.eth_protocol = htons(ETH_P_IPV6);
271 		expected.bind_inany = !srv_sa.v6.sin6_addr.s6_addr32[3] &&
272 			!srv_sa.v6.sin6_addr.s6_addr32[2] &&
273 			!srv_sa.v6.sin6_addr.s6_addr32[1] &&
274 			!srv_sa.v6.sin6_addr.s6_addr32[0];
275 
276 		memcpy(&expected.skb_addrs[0], cli_sa.v6.sin6_addr.s6_addr32,
277 		       sizeof(cli_sa.v6.sin6_addr));
278 		memcpy(&expected.skb_addrs[4], &in6addr_loopback,
279 		       sizeof(in6addr_loopback));
280 		expected.skb_ports[0] = cli_sa.v6.sin6_port;
281 		expected.skb_ports[1] = srv_sa.v6.sin6_port;
282 	} else {
283 		expected.eth_protocol = htons(ETH_P_IP);
284 		expected.bind_inany = !srv_sa.v4.sin_addr.s_addr;
285 
286 		expected.skb_addrs[0] = cli_sa.v4.sin_addr.s_addr;
287 		expected.skb_addrs[1] = htonl(INADDR_LOOPBACK);
288 		expected.skb_ports[0] = cli_sa.v4.sin_port;
289 		expected.skb_ports[1] = srv_sa.v4.sin_port;
290 	}
291 
292 	if (memcmp(&result, &expected, offsetof(struct data_check,
293 						equal_check_end))) {
294 		printf("unexpected data_check\n");
295 		printf("  result: (0x%x, %u, %u)\n",
296 		       result.eth_protocol, result.ip_protocol,
297 		       result.bind_inany);
298 		printf("expected: (0x%x, %u, %u)\n",
299 		       expected.eth_protocol, expected.ip_protocol,
300 		       expected.bind_inany);
301 		RET_IF(1, "data_check result != expected",
302 		       "bpf_prog_linum:%ld\n", get_linum());
303 	}
304 
305 	RET_IF(!result.hash, "data_check result.hash empty",
306 	       "result.hash:%u", result.hash);
307 
308 	expected.len += cmd ? sizeof(*cmd) : 0;
309 	if (type == SOCK_STREAM)
310 		RET_IF(expected.len > result.len, "expected.len > result.len",
311 		       "expected.len:%u result.len:%u bpf_prog_linum:%ld\n",
312 		       expected.len, result.len, get_linum());
313 	else
314 		RET_IF(expected.len != result.len, "expected.len != result.len",
315 		       "expected.len:%u result.len:%u bpf_prog_linum:%ld\n",
316 		       expected.len, result.len, get_linum());
317 }
318 
319 static void check_results(void)
320 {
321 	__u32 results[NR_RESULTS];
322 	__u32 i, broken = 0;
323 	int err;
324 
325 	for (i = 0; i < NR_RESULTS; i++) {
326 		err = bpf_map_lookup_elem(result_map, &i, &results[i]);
327 		RET_IF(err == -1, "lookup_elem(result_map)",
328 		       "i:%u err:%d errno:%d\n", i, err, errno);
329 	}
330 
331 	for (i = 0; i < NR_RESULTS; i++) {
332 		if (results[i] != expected_results[i]) {
333 			broken = i;
334 			break;
335 		}
336 	}
337 
338 	if (i == NR_RESULTS)
339 		return;
340 
341 	printf("unexpected result\n");
342 	printf(" result: [");
343 	printf("%u", results[0]);
344 	for (i = 1; i < NR_RESULTS; i++)
345 		printf(", %u", results[i]);
346 	printf("]\n");
347 
348 	printf("expected: [");
349 	printf("%u", expected_results[0]);
350 	for (i = 1; i < NR_RESULTS; i++)
351 		printf(", %u", expected_results[i]);
352 	printf("]\n");
353 
354 	RET_IF(expected_results[broken] != results[broken],
355 	       "unexpected result",
356 	       "expected_results[%u] != results[%u] bpf_prog_linum:%ld\n",
357 	       broken, broken, get_linum());
358 }
359 
360 static int send_data(int type, sa_family_t family, void *data, size_t len,
361 		     enum result expected)
362 {
363 	union sa46 cli_sa;
364 	int fd, err;
365 
366 	fd = socket(family, type, 0);
367 	RET_ERR(fd == -1, "socket()", "fd:%d errno:%d\n", fd, errno);
368 
369 	sa46_init_loopback(&cli_sa, family);
370 	err = bind(fd, (struct sockaddr *)&cli_sa, sizeof(cli_sa));
371 	RET_ERR(fd == -1, "bind(cli_sa)", "err:%d errno:%d\n", err, errno);
372 
373 	err = sendto(fd, data, len, MSG_FASTOPEN, (struct sockaddr *)&srv_sa,
374 		     sizeof(srv_sa));
375 	RET_ERR(err != len && expected >= PASS,
376 		"sendto()", "family:%u err:%d errno:%d expected:%d\n",
377 		family, err, errno, expected);
378 
379 	return fd;
380 }
381 
382 static void do_test(int type, sa_family_t family, struct cmd *cmd,
383 		    enum result expected)
384 {
385 	int nev, srv_fd, cli_fd;
386 	struct epoll_event ev;
387 	struct cmd rcv_cmd;
388 	ssize_t nread;
389 
390 	cli_fd = send_data(type, family, cmd, cmd ? sizeof(*cmd) : 0,
391 			   expected);
392 	if (cli_fd < 0)
393 		return;
394 	nev = epoll_wait(epfd, &ev, 1, expected >= PASS ? 5 : 0);
395 	RET_IF((nev <= 0 && expected >= PASS) ||
396 	       (nev > 0 && expected < PASS),
397 	       "nev <> expected",
398 	       "nev:%d expected:%d type:%d family:%d data:(%d, %d)\n",
399 	       nev, expected, type, family,
400 	       cmd ? cmd->reuseport_index : -1,
401 	       cmd ? cmd->pass_on_failure : -1);
402 	check_results();
403 	check_data(type, family, cmd, cli_fd);
404 
405 	if (expected < PASS)
406 		return;
407 
408 	RET_IF(expected != PASS_ERR_SK_SELECT_REUSEPORT &&
409 	       cmd->reuseport_index != ev.data.u32,
410 	       "check cmd->reuseport_index",
411 	       "cmd:(%u, %u) ev.data.u32:%u\n",
412 	       cmd->pass_on_failure, cmd->reuseport_index, ev.data.u32);
413 
414 	srv_fd = sk_fds[ev.data.u32];
415 	if (type == SOCK_STREAM) {
416 		int new_fd = accept(srv_fd, NULL, 0);
417 
418 		RET_IF(new_fd == -1, "accept(srv_fd)",
419 		       "ev.data.u32:%u new_fd:%d errno:%d\n",
420 		       ev.data.u32, new_fd, errno);
421 
422 		nread = recv(new_fd, &rcv_cmd, sizeof(rcv_cmd), MSG_DONTWAIT);
423 		RET_IF(nread != sizeof(rcv_cmd),
424 		       "recv(new_fd)",
425 		       "ev.data.u32:%u nread:%zd sizeof(rcv_cmd):%zu errno:%d\n",
426 		       ev.data.u32, nread, sizeof(rcv_cmd), errno);
427 
428 		close(new_fd);
429 	} else {
430 		nread = recv(srv_fd, &rcv_cmd, sizeof(rcv_cmd), MSG_DONTWAIT);
431 		RET_IF(nread != sizeof(rcv_cmd),
432 		       "recv(sk_fds)",
433 		       "ev.data.u32:%u nread:%zd sizeof(rcv_cmd):%zu errno:%d\n",
434 		       ev.data.u32, nread, sizeof(rcv_cmd), errno);
435 	}
436 
437 	close(cli_fd);
438 }
439 
440 static void test_err_inner_map(int type, sa_family_t family)
441 {
442 	struct cmd cmd = {
443 		.reuseport_index = 0,
444 		.pass_on_failure = 0,
445 	};
446 
447 	expected_results[DROP_ERR_INNER_MAP]++;
448 	do_test(type, family, &cmd, DROP_ERR_INNER_MAP);
449 }
450 
451 static void test_err_skb_data(int type, sa_family_t family)
452 {
453 	expected_results[DROP_ERR_SKB_DATA]++;
454 	do_test(type, family, NULL, DROP_ERR_SKB_DATA);
455 }
456 
457 static void test_err_sk_select_port(int type, sa_family_t family)
458 {
459 	struct cmd cmd = {
460 		.reuseport_index = REUSEPORT_ARRAY_SIZE,
461 		.pass_on_failure = 0,
462 	};
463 
464 	expected_results[DROP_ERR_SK_SELECT_REUSEPORT]++;
465 	do_test(type, family, &cmd, DROP_ERR_SK_SELECT_REUSEPORT);
466 }
467 
468 static void test_pass(int type, sa_family_t family)
469 {
470 	struct cmd cmd;
471 	int i;
472 
473 	cmd.pass_on_failure = 0;
474 	for (i = 0; i < REUSEPORT_ARRAY_SIZE; i++) {
475 		expected_results[PASS]++;
476 		cmd.reuseport_index = i;
477 		do_test(type, family, &cmd, PASS);
478 	}
479 }
480 
481 static void test_syncookie(int type, sa_family_t family)
482 {
483 	int err, tmp_index = 1;
484 	struct cmd cmd = {
485 		.reuseport_index = 0,
486 		.pass_on_failure = 0,
487 	};
488 
489 	if (type != SOCK_STREAM)
490 		return;
491 
492 	/*
493 	 * +1 for TCP-SYN and
494 	 * +1 for the TCP-ACK (ack the syncookie)
495 	 */
496 	expected_results[PASS] += 2;
497 	enable_syncookie();
498 	/*
499 	 * Simulate TCP-SYN and TCP-ACK are handled by two different sk:
500 	 * TCP-SYN: select sk_fds[tmp_index = 1] tmp_index is from the
501 	 *          tmp_index_ovr_map
502 	 * TCP-ACK: select sk_fds[reuseport_index = 0] reuseport_index
503 	 *          is from the cmd.reuseport_index
504 	 */
505 	err = bpf_map_update_elem(tmp_index_ovr_map, &index_zero,
506 				  &tmp_index, BPF_ANY);
507 	RET_IF(err == -1, "update_elem(tmp_index_ovr_map, 0, 1)",
508 	       "err:%d errno:%d\n", err, errno);
509 	do_test(type, family, &cmd, PASS);
510 	err = bpf_map_lookup_elem(tmp_index_ovr_map, &index_zero,
511 				  &tmp_index);
512 	RET_IF(err == -1 || tmp_index != -1,
513 	       "lookup_elem(tmp_index_ovr_map)",
514 	       "err:%d errno:%d tmp_index:%d\n",
515 	       err, errno, tmp_index);
516 	disable_syncookie();
517 }
518 
519 static void test_pass_on_err(int type, sa_family_t family)
520 {
521 	struct cmd cmd = {
522 		.reuseport_index = REUSEPORT_ARRAY_SIZE,
523 		.pass_on_failure = 1,
524 	};
525 
526 	expected_results[PASS_ERR_SK_SELECT_REUSEPORT] += 1;
527 	do_test(type, family, &cmd, PASS_ERR_SK_SELECT_REUSEPORT);
528 }
529 
530 static void test_detach_bpf(int type, sa_family_t family)
531 {
532 #ifdef SO_DETACH_REUSEPORT_BPF
533 	__u32 nr_run_before = 0, nr_run_after = 0, tmp, i;
534 	struct epoll_event ev;
535 	int cli_fd, err, nev;
536 	struct cmd cmd = {};
537 	int optvalue = 0;
538 
539 	err = setsockopt(sk_fds[0], SOL_SOCKET, SO_DETACH_REUSEPORT_BPF,
540 			 &optvalue, sizeof(optvalue));
541 	RET_IF(err == -1, "setsockopt(SO_DETACH_REUSEPORT_BPF)",
542 	       "err:%d errno:%d\n", err, errno);
543 
544 	err = setsockopt(sk_fds[1], SOL_SOCKET, SO_DETACH_REUSEPORT_BPF,
545 			 &optvalue, sizeof(optvalue));
546 	RET_IF(err == 0 || errno != ENOENT,
547 	       "setsockopt(SO_DETACH_REUSEPORT_BPF)",
548 	       "err:%d errno:%d\n", err, errno);
549 
550 	for (i = 0; i < NR_RESULTS; i++) {
551 		err = bpf_map_lookup_elem(result_map, &i, &tmp);
552 		RET_IF(err == -1, "lookup_elem(result_map)",
553 		       "i:%u err:%d errno:%d\n", i, err, errno);
554 		nr_run_before += tmp;
555 	}
556 
557 	cli_fd = send_data(type, family, &cmd, sizeof(cmd), PASS);
558 	if (cli_fd < 0)
559 		return;
560 	nev = epoll_wait(epfd, &ev, 1, 5);
561 	RET_IF(nev <= 0, "nev <= 0",
562 	       "nev:%d expected:1 type:%d family:%d data:(0, 0)\n",
563 	       nev,  type, family);
564 
565 	for (i = 0; i < NR_RESULTS; i++) {
566 		err = bpf_map_lookup_elem(result_map, &i, &tmp);
567 		RET_IF(err == -1, "lookup_elem(result_map)",
568 		       "i:%u err:%d errno:%d\n", i, err, errno);
569 		nr_run_after += tmp;
570 	}
571 
572 	RET_IF(nr_run_before != nr_run_after,
573 	       "nr_run_before != nr_run_after",
574 	       "nr_run_before:%u nr_run_after:%u\n",
575 	       nr_run_before, nr_run_after);
576 
577 	close(cli_fd);
578 #else
579 	test__skip();
580 #endif
581 }
582 
583 static void prepare_sk_fds(int type, sa_family_t family, bool inany)
584 {
585 	const int first = REUSEPORT_ARRAY_SIZE - 1;
586 	int i, err, optval = 1;
587 	struct epoll_event ev;
588 	socklen_t addrlen;
589 
590 	if (inany)
591 		sa46_init_inany(&srv_sa, family);
592 	else
593 		sa46_init_loopback(&srv_sa, family);
594 	addrlen = sizeof(srv_sa);
595 
596 	/*
597 	 * The sk_fds[] is filled from the back such that the order
598 	 * is exactly opposite to the (struct sock_reuseport *)reuse->socks[].
599 	 */
600 	for (i = first; i >= 0; i--) {
601 		sk_fds[i] = socket(family, type, 0);
602 		RET_IF(sk_fds[i] == -1, "socket()", "sk_fds[%d]:%d errno:%d\n",
603 		       i, sk_fds[i], errno);
604 		err = setsockopt(sk_fds[i], SOL_SOCKET, SO_REUSEPORT,
605 				 &optval, sizeof(optval));
606 		RET_IF(err == -1, "setsockopt(SO_REUSEPORT)",
607 		       "sk_fds[%d] err:%d errno:%d\n",
608 		       i, err, errno);
609 
610 		if (i == first) {
611 			err = setsockopt(sk_fds[i], SOL_SOCKET,
612 					 SO_ATTACH_REUSEPORT_EBPF,
613 					 &select_by_skb_data_prog,
614 					 sizeof(select_by_skb_data_prog));
615 			RET_IF(err == -1, "setsockopt(SO_ATTACH_REUEPORT_EBPF)",
616 			       "err:%d errno:%d\n", err, errno);
617 		}
618 
619 		err = bind(sk_fds[i], (struct sockaddr *)&srv_sa, addrlen);
620 		RET_IF(err == -1, "bind()", "sk_fds[%d] err:%d errno:%d\n",
621 		       i, err, errno);
622 
623 		if (type == SOCK_STREAM) {
624 			err = listen(sk_fds[i], 10);
625 			RET_IF(err == -1, "listen()",
626 			       "sk_fds[%d] err:%d errno:%d\n",
627 			       i, err, errno);
628 		}
629 
630 		err = bpf_map_update_elem(reuseport_array, &i, &sk_fds[i],
631 					  BPF_NOEXIST);
632 		RET_IF(err == -1, "update_elem(reuseport_array)",
633 		       "sk_fds[%d] err:%d errno:%d\n", i, err, errno);
634 
635 		if (i == first) {
636 			socklen_t addrlen = sizeof(srv_sa);
637 
638 			err = getsockname(sk_fds[i], (struct sockaddr *)&srv_sa,
639 					  &addrlen);
640 			RET_IF(err == -1, "getsockname()",
641 			       "sk_fds[%d] err:%d errno:%d\n", i, err, errno);
642 		}
643 	}
644 
645 	epfd = epoll_create(1);
646 	RET_IF(epfd == -1, "epoll_create(1)",
647 	       "epfd:%d errno:%d\n", epfd, errno);
648 
649 	ev.events = EPOLLIN;
650 	for (i = 0; i < REUSEPORT_ARRAY_SIZE; i++) {
651 		ev.data.u32 = i;
652 		err = epoll_ctl(epfd, EPOLL_CTL_ADD, sk_fds[i], &ev);
653 		RET_IF(err, "epoll_ctl(EPOLL_CTL_ADD)", "sk_fds[%d]\n", i);
654 	}
655 }
656 
657 static void setup_per_test(int type, sa_family_t family, bool inany,
658 			   bool no_inner_map)
659 {
660 	int ovr = -1, err;
661 
662 	prepare_sk_fds(type, family, inany);
663 	err = bpf_map_update_elem(tmp_index_ovr_map, &index_zero, &ovr,
664 				  BPF_ANY);
665 	RET_IF(err == -1, "update_elem(tmp_index_ovr_map, 0, -1)",
666 	       "err:%d errno:%d\n", err, errno);
667 
668 	/* Install reuseport_array to outer_map? */
669 	if (no_inner_map)
670 		return;
671 
672 	err = bpf_map_update_elem(outer_map, &index_zero, &reuseport_array,
673 				  BPF_ANY);
674 	RET_IF(err == -1, "update_elem(outer_map, 0, reuseport_array)",
675 	       "err:%d errno:%d\n", err, errno);
676 }
677 
678 static void cleanup_per_test(bool no_inner_map)
679 {
680 	int i, err;
681 
682 	for (i = 0; i < REUSEPORT_ARRAY_SIZE; i++)
683 		close(sk_fds[i]);
684 	close(epfd);
685 
686 	/* Delete reuseport_array from outer_map? */
687 	if (no_inner_map)
688 		return;
689 
690 	err = bpf_map_delete_elem(outer_map, &index_zero);
691 	RET_IF(err == -1, "delete_elem(outer_map)",
692 	       "err:%d errno:%d\n", err, errno);
693 }
694 
695 static void cleanup(void)
696 {
697 	if (outer_map != -1)
698 		close(outer_map);
699 	if (reuseport_array != -1)
700 		close(reuseport_array);
701 	if (obj)
702 		bpf_object__close(obj);
703 }
704 
705 static const char *family_str(sa_family_t family)
706 {
707 	switch (family) {
708 	case AF_INET:
709 		return "IPv4";
710 	case AF_INET6:
711 		return "IPv6";
712 	default:
713 		return "unknown";
714 	}
715 }
716 
717 static const char *sotype_str(int sotype)
718 {
719 	switch (sotype) {
720 	case SOCK_STREAM:
721 		return "TCP";
722 	case SOCK_DGRAM:
723 		return "UDP";
724 	default:
725 		return "unknown";
726 	}
727 }
728 
729 #define TEST_INIT(fn, ...) { fn, #fn, __VA_ARGS__ }
730 
731 static void test_config(int sotype, sa_family_t family, bool inany)
732 {
733 	const struct test {
734 		void (*fn)(int sotype, sa_family_t family);
735 		const char *name;
736 		bool no_inner_map;
737 	} tests[] = {
738 		TEST_INIT(test_err_inner_map, true /* no_inner_map */),
739 		TEST_INIT(test_err_skb_data),
740 		TEST_INIT(test_err_sk_select_port),
741 		TEST_INIT(test_pass),
742 		TEST_INIT(test_syncookie),
743 		TEST_INIT(test_pass_on_err),
744 		TEST_INIT(test_detach_bpf),
745 	};
746 	char s[MAX_TEST_NAME];
747 	const struct test *t;
748 
749 	for (t = tests; t < tests + ARRAY_SIZE(tests); t++) {
750 		snprintf(s, sizeof(s), "%s/%s %s %s",
751 			 family_str(family), sotype_str(sotype),
752 			 inany ? "INANY" : "LOOPBACK", t->name);
753 
754 		if (!test__start_subtest(s))
755 			continue;
756 
757 		setup_per_test(sotype, family, inany, t->no_inner_map);
758 		t->fn(sotype, family);
759 		cleanup_per_test(t->no_inner_map);
760 	}
761 }
762 
763 #define BIND_INANY true
764 
765 static void test_all(void)
766 {
767 	const struct config {
768 		int sotype;
769 		sa_family_t family;
770 		bool inany;
771 	} configs[] = {
772 		{ SOCK_STREAM, AF_INET },
773 		{ SOCK_STREAM, AF_INET, BIND_INANY },
774 		{ SOCK_STREAM, AF_INET6 },
775 		{ SOCK_STREAM, AF_INET6, BIND_INANY },
776 		{ SOCK_DGRAM, AF_INET },
777 		{ SOCK_DGRAM, AF_INET6 },
778 	};
779 	const struct config *c;
780 
781 	for (c = configs; c < configs + ARRAY_SIZE(configs); c++)
782 		test_config(c->sotype, c->family, c->inany);
783 }
784 
785 void test_select_reuseport(void)
786 {
787 	if (create_maps())
788 		goto out;
789 	if (prepare_bpf_obj())
790 		goto out;
791 
792 	saved_tcp_fo = read_int_sysctl(TCP_FO_SYSCTL);
793 	saved_tcp_syncookie = read_int_sysctl(TCP_SYNCOOKIE_SYSCTL);
794 	if (saved_tcp_syncookie < 0 || saved_tcp_syncookie < 0)
795 		goto out;
796 
797 	if (enable_fastopen())
798 		goto out;
799 	if (disable_syncookie())
800 		goto out;
801 
802 	test_all();
803 out:
804 	cleanup();
805 	restore_sysctls();
806 }
807