xref: /linux/tools/testing/selftests/bpf/prog_tests/sk_lookup.c (revision 314f14abdeca78de6b16f97d796a9966ce4b90ae)
1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
2 // Copyright (c) 2020 Cloudflare
3 /*
4  * Test BPF attach point for INET socket lookup (BPF_SK_LOOKUP).
5  *
6  * Tests exercise:
7  *  - attaching/detaching/querying programs to BPF_SK_LOOKUP hook,
8  *  - redirecting socket lookup to a socket selected by BPF program,
9  *  - failing a socket lookup on BPF program's request,
10  *  - error scenarios for selecting a socket from BPF program,
11  *  - accessing BPF program context,
12  *  - attaching and running multiple BPF programs.
13  *
14  * Tests run in a dedicated network namespace.
15  */
16 
17 #define _GNU_SOURCE
18 #include <arpa/inet.h>
19 #include <assert.h>
20 #include <errno.h>
21 #include <error.h>
22 #include <fcntl.h>
23 #include <sched.h>
24 #include <stdio.h>
25 #include <sys/types.h>
26 #include <sys/stat.h>
27 #include <unistd.h>
28 
29 #include <bpf/libbpf.h>
30 #include <bpf/bpf.h>
31 
32 #include "test_progs.h"
33 #include "bpf_rlimit.h"
34 #include "bpf_util.h"
35 #include "cgroup_helpers.h"
36 #include "network_helpers.h"
37 #include "testing_helpers.h"
38 #include "test_sk_lookup.skel.h"
39 
40 /* External (address, port) pairs the client sends packets to. */
41 #define EXT_IP4		"127.0.0.1"
42 #define EXT_IP6		"fd00::1"
43 #define EXT_PORT	7007
44 
45 /* Internal (address, port) pairs the server listens/receives at. */
46 #define INT_IP4		"127.0.0.2"
47 #define INT_IP4_V6	"::ffff:127.0.0.2"
48 #define INT_IP6		"fd00::2"
49 #define INT_PORT	8008
50 
51 #define IO_TIMEOUT_SEC	3
52 
53 enum server {
54 	SERVER_A = 0,
55 	SERVER_B = 1,
56 	MAX_SERVERS,
57 };
58 
59 enum {
60 	PROG1 = 0,
61 	PROG2,
62 };
63 
64 struct inet_addr {
65 	const char *ip;
66 	unsigned short port;
67 };
68 
69 struct test {
70 	const char *desc;
71 	struct bpf_program *lookup_prog;
72 	struct bpf_program *reuseport_prog;
73 	struct bpf_map *sock_map;
74 	int sotype;
75 	struct inet_addr connect_to;
76 	struct inet_addr listen_at;
77 	enum server accept_on;
78 	bool reuseport_has_conns; /* Add a connected socket to reuseport group */
79 };
80 
81 static __u32 duration;		/* for CHECK macro */
82 
83 static bool is_ipv6(const char *ip)
84 {
85 	return !!strchr(ip, ':');
86 }
87 
88 static int attach_reuseport(int sock_fd, struct bpf_program *reuseport_prog)
89 {
90 	int err, prog_fd;
91 
92 	prog_fd = bpf_program__fd(reuseport_prog);
93 	if (prog_fd < 0) {
94 		errno = -prog_fd;
95 		return -1;
96 	}
97 
98 	err = setsockopt(sock_fd, SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF,
99 			 &prog_fd, sizeof(prog_fd));
100 	if (err)
101 		return -1;
102 
103 	return 0;
104 }
105 
106 static socklen_t inetaddr_len(const struct sockaddr_storage *addr)
107 {
108 	return (addr->ss_family == AF_INET ? sizeof(struct sockaddr_in) :
109 		addr->ss_family == AF_INET6 ? sizeof(struct sockaddr_in6) : 0);
110 }
111 
112 static int make_socket(int sotype, const char *ip, int port,
113 		       struct sockaddr_storage *addr)
114 {
115 	struct timeval timeo = { .tv_sec = IO_TIMEOUT_SEC };
116 	int err, family, fd;
117 
118 	family = is_ipv6(ip) ? AF_INET6 : AF_INET;
119 	err = make_sockaddr(family, ip, port, addr, NULL);
120 	if (CHECK(err, "make_address", "failed\n"))
121 		return -1;
122 
123 	fd = socket(addr->ss_family, sotype, 0);
124 	if (CHECK(fd < 0, "socket", "failed\n")) {
125 		log_err("failed to make socket");
126 		return -1;
127 	}
128 
129 	err = setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeo, sizeof(timeo));
130 	if (CHECK(err, "setsockopt(SO_SNDTIMEO)", "failed\n")) {
131 		log_err("failed to set SNDTIMEO");
132 		close(fd);
133 		return -1;
134 	}
135 
136 	err = setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &timeo, sizeof(timeo));
137 	if (CHECK(err, "setsockopt(SO_RCVTIMEO)", "failed\n")) {
138 		log_err("failed to set RCVTIMEO");
139 		close(fd);
140 		return -1;
141 	}
142 
143 	return fd;
144 }
145 
146 static int make_server(int sotype, const char *ip, int port,
147 		       struct bpf_program *reuseport_prog)
148 {
149 	struct sockaddr_storage addr = {0};
150 	const int one = 1;
151 	int err, fd = -1;
152 
153 	fd = make_socket(sotype, ip, port, &addr);
154 	if (fd < 0)
155 		return -1;
156 
157 	/* Enabled for UDPv6 sockets for IPv4-mapped IPv6 to work. */
158 	if (sotype == SOCK_DGRAM) {
159 		err = setsockopt(fd, SOL_IP, IP_RECVORIGDSTADDR, &one,
160 				 sizeof(one));
161 		if (CHECK(err, "setsockopt(IP_RECVORIGDSTADDR)", "failed\n")) {
162 			log_err("failed to enable IP_RECVORIGDSTADDR");
163 			goto fail;
164 		}
165 	}
166 
167 	if (sotype == SOCK_DGRAM && addr.ss_family == AF_INET6) {
168 		err = setsockopt(fd, SOL_IPV6, IPV6_RECVORIGDSTADDR, &one,
169 				 sizeof(one));
170 		if (CHECK(err, "setsockopt(IPV6_RECVORIGDSTADDR)", "failed\n")) {
171 			log_err("failed to enable IPV6_RECVORIGDSTADDR");
172 			goto fail;
173 		}
174 	}
175 
176 	if (sotype == SOCK_STREAM) {
177 		err = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one,
178 				 sizeof(one));
179 		if (CHECK(err, "setsockopt(SO_REUSEADDR)", "failed\n")) {
180 			log_err("failed to enable SO_REUSEADDR");
181 			goto fail;
182 		}
183 	}
184 
185 	if (reuseport_prog) {
186 		err = setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &one,
187 				 sizeof(one));
188 		if (CHECK(err, "setsockopt(SO_REUSEPORT)", "failed\n")) {
189 			log_err("failed to enable SO_REUSEPORT");
190 			goto fail;
191 		}
192 	}
193 
194 	err = bind(fd, (void *)&addr, inetaddr_len(&addr));
195 	if (CHECK(err, "bind", "failed\n")) {
196 		log_err("failed to bind listen socket");
197 		goto fail;
198 	}
199 
200 	if (sotype == SOCK_STREAM) {
201 		err = listen(fd, SOMAXCONN);
202 		if (CHECK(err, "make_server", "listen")) {
203 			log_err("failed to listen on port %d", port);
204 			goto fail;
205 		}
206 	}
207 
208 	/* Late attach reuseport prog so we can have one init path */
209 	if (reuseport_prog) {
210 		err = attach_reuseport(fd, reuseport_prog);
211 		if (CHECK(err, "attach_reuseport", "failed\n")) {
212 			log_err("failed to attach reuseport prog");
213 			goto fail;
214 		}
215 	}
216 
217 	return fd;
218 fail:
219 	close(fd);
220 	return -1;
221 }
222 
223 static int make_client(int sotype, const char *ip, int port)
224 {
225 	struct sockaddr_storage addr = {0};
226 	int err, fd;
227 
228 	fd = make_socket(sotype, ip, port, &addr);
229 	if (fd < 0)
230 		return -1;
231 
232 	err = connect(fd, (void *)&addr, inetaddr_len(&addr));
233 	if (CHECK(err, "make_client", "connect")) {
234 		log_err("failed to connect client socket");
235 		goto fail;
236 	}
237 
238 	return fd;
239 fail:
240 	close(fd);
241 	return -1;
242 }
243 
244 static __u64 socket_cookie(int fd)
245 {
246 	__u64 cookie;
247 	socklen_t cookie_len = sizeof(cookie);
248 
249 	if (CHECK(getsockopt(fd, SOL_SOCKET, SO_COOKIE, &cookie, &cookie_len) < 0,
250 		  "getsockopt(SO_COOKIE)", "%s\n", strerror(errno)))
251 		return 0;
252 	return cookie;
253 }
254 
255 static int fill_sk_lookup_ctx(struct bpf_sk_lookup *ctx, const char *local_ip, __u16 local_port,
256 			      const char *remote_ip, __u16 remote_port)
257 {
258 	void *local, *remote;
259 	int err;
260 
261 	memset(ctx, 0, sizeof(*ctx));
262 	ctx->local_port = local_port;
263 	ctx->remote_port = htons(remote_port);
264 
265 	if (is_ipv6(local_ip)) {
266 		ctx->family = AF_INET6;
267 		local = &ctx->local_ip6[0];
268 		remote = &ctx->remote_ip6[0];
269 	} else {
270 		ctx->family = AF_INET;
271 		local = &ctx->local_ip4;
272 		remote = &ctx->remote_ip4;
273 	}
274 
275 	err = inet_pton(ctx->family, local_ip, local);
276 	if (CHECK(err != 1, "inet_pton", "local_ip failed\n"))
277 		return 1;
278 
279 	err = inet_pton(ctx->family, remote_ip, remote);
280 	if (CHECK(err != 1, "inet_pton", "remote_ip failed\n"))
281 		return 1;
282 
283 	return 0;
284 }
285 
286 static int send_byte(int fd)
287 {
288 	ssize_t n;
289 
290 	errno = 0;
291 	n = send(fd, "a", 1, 0);
292 	if (CHECK(n <= 0, "send_byte", "send")) {
293 		log_err("failed/partial send");
294 		return -1;
295 	}
296 	return 0;
297 }
298 
299 static int recv_byte(int fd)
300 {
301 	char buf[1];
302 	ssize_t n;
303 
304 	n = recv(fd, buf, sizeof(buf), 0);
305 	if (CHECK(n <= 0, "recv_byte", "recv")) {
306 		log_err("failed/partial recv");
307 		return -1;
308 	}
309 	return 0;
310 }
311 
312 static int tcp_recv_send(int server_fd)
313 {
314 	char buf[1];
315 	int ret, fd;
316 	ssize_t n;
317 
318 	fd = accept(server_fd, NULL, NULL);
319 	if (CHECK(fd < 0, "accept", "failed\n")) {
320 		log_err("failed to accept");
321 		return -1;
322 	}
323 
324 	n = recv(fd, buf, sizeof(buf), 0);
325 	if (CHECK(n <= 0, "recv", "failed\n")) {
326 		log_err("failed/partial recv");
327 		ret = -1;
328 		goto close;
329 	}
330 
331 	n = send(fd, buf, n, 0);
332 	if (CHECK(n <= 0, "send", "failed\n")) {
333 		log_err("failed/partial send");
334 		ret = -1;
335 		goto close;
336 	}
337 
338 	ret = 0;
339 close:
340 	close(fd);
341 	return ret;
342 }
343 
344 static void v4_to_v6(struct sockaddr_storage *ss)
345 {
346 	struct sockaddr_in6 *v6 = (struct sockaddr_in6 *)ss;
347 	struct sockaddr_in v4 = *(struct sockaddr_in *)ss;
348 
349 	v6->sin6_family = AF_INET6;
350 	v6->sin6_port = v4.sin_port;
351 	v6->sin6_addr.s6_addr[10] = 0xff;
352 	v6->sin6_addr.s6_addr[11] = 0xff;
353 	memcpy(&v6->sin6_addr.s6_addr[12], &v4.sin_addr.s_addr, 4);
354 	memset(&v6->sin6_addr.s6_addr[0], 0, 10);
355 }
356 
357 static int udp_recv_send(int server_fd)
358 {
359 	char cmsg_buf[CMSG_SPACE(sizeof(struct sockaddr_storage))];
360 	struct sockaddr_storage _src_addr = { 0 };
361 	struct sockaddr_storage *src_addr = &_src_addr;
362 	struct sockaddr_storage *dst_addr = NULL;
363 	struct msghdr msg = { 0 };
364 	struct iovec iov = { 0 };
365 	struct cmsghdr *cm;
366 	char buf[1];
367 	int ret, fd;
368 	ssize_t n;
369 
370 	iov.iov_base = buf;
371 	iov.iov_len = sizeof(buf);
372 
373 	msg.msg_name = src_addr;
374 	msg.msg_namelen = sizeof(*src_addr);
375 	msg.msg_iov = &iov;
376 	msg.msg_iovlen = 1;
377 	msg.msg_control = cmsg_buf;
378 	msg.msg_controllen = sizeof(cmsg_buf);
379 
380 	errno = 0;
381 	n = recvmsg(server_fd, &msg, 0);
382 	if (CHECK(n <= 0, "recvmsg", "failed\n")) {
383 		log_err("failed to receive");
384 		return -1;
385 	}
386 	if (CHECK(msg.msg_flags & MSG_CTRUNC, "recvmsg", "truncated cmsg\n"))
387 		return -1;
388 
389 	for (cm = CMSG_FIRSTHDR(&msg); cm; cm = CMSG_NXTHDR(&msg, cm)) {
390 		if ((cm->cmsg_level == SOL_IP &&
391 		     cm->cmsg_type == IP_ORIGDSTADDR) ||
392 		    (cm->cmsg_level == SOL_IPV6 &&
393 		     cm->cmsg_type == IPV6_ORIGDSTADDR)) {
394 			dst_addr = (struct sockaddr_storage *)CMSG_DATA(cm);
395 			break;
396 		}
397 		log_err("warning: ignored cmsg at level %d type %d",
398 			cm->cmsg_level, cm->cmsg_type);
399 	}
400 	if (CHECK(!dst_addr, "recvmsg", "missing ORIGDSTADDR\n"))
401 		return -1;
402 
403 	/* Server socket bound to IPv4-mapped IPv6 address */
404 	if (src_addr->ss_family == AF_INET6 &&
405 	    dst_addr->ss_family == AF_INET) {
406 		v4_to_v6(dst_addr);
407 	}
408 
409 	/* Reply from original destination address. */
410 	fd = socket(dst_addr->ss_family, SOCK_DGRAM, 0);
411 	if (CHECK(fd < 0, "socket", "failed\n")) {
412 		log_err("failed to create tx socket");
413 		return -1;
414 	}
415 
416 	ret = bind(fd, (struct sockaddr *)dst_addr, sizeof(*dst_addr));
417 	if (CHECK(ret, "bind", "failed\n")) {
418 		log_err("failed to bind tx socket");
419 		goto out;
420 	}
421 
422 	msg.msg_control = NULL;
423 	msg.msg_controllen = 0;
424 	n = sendmsg(fd, &msg, 0);
425 	if (CHECK(n <= 0, "sendmsg", "failed\n")) {
426 		log_err("failed to send echo reply");
427 		ret = -1;
428 		goto out;
429 	}
430 
431 	ret = 0;
432 out:
433 	close(fd);
434 	return ret;
435 }
436 
437 static int tcp_echo_test(int client_fd, int server_fd)
438 {
439 	int err;
440 
441 	err = send_byte(client_fd);
442 	if (err)
443 		return -1;
444 	err = tcp_recv_send(server_fd);
445 	if (err)
446 		return -1;
447 	err = recv_byte(client_fd);
448 	if (err)
449 		return -1;
450 
451 	return 0;
452 }
453 
454 static int udp_echo_test(int client_fd, int server_fd)
455 {
456 	int err;
457 
458 	err = send_byte(client_fd);
459 	if (err)
460 		return -1;
461 	err = udp_recv_send(server_fd);
462 	if (err)
463 		return -1;
464 	err = recv_byte(client_fd);
465 	if (err)
466 		return -1;
467 
468 	return 0;
469 }
470 
471 static struct bpf_link *attach_lookup_prog(struct bpf_program *prog)
472 {
473 	struct bpf_link *link;
474 	int net_fd;
475 
476 	net_fd = open("/proc/self/ns/net", O_RDONLY);
477 	if (CHECK(net_fd < 0, "open", "failed\n")) {
478 		log_err("failed to open /proc/self/ns/net");
479 		return NULL;
480 	}
481 
482 	link = bpf_program__attach_netns(prog, net_fd);
483 	if (!ASSERT_OK_PTR(link, "bpf_program__attach_netns")) {
484 		errno = -PTR_ERR(link);
485 		log_err("failed to attach program '%s' to netns",
486 			bpf_program__name(prog));
487 		link = NULL;
488 	}
489 
490 	close(net_fd);
491 	return link;
492 }
493 
494 static int update_lookup_map(struct bpf_map *map, int index, int sock_fd)
495 {
496 	int err, map_fd;
497 	uint64_t value;
498 
499 	map_fd = bpf_map__fd(map);
500 	if (CHECK(map_fd < 0, "bpf_map__fd", "failed\n")) {
501 		errno = -map_fd;
502 		log_err("failed to get map FD");
503 		return -1;
504 	}
505 
506 	value = (uint64_t)sock_fd;
507 	err = bpf_map_update_elem(map_fd, &index, &value, BPF_NOEXIST);
508 	if (CHECK(err, "bpf_map_update_elem", "failed\n")) {
509 		log_err("failed to update redir_map @ %d", index);
510 		return -1;
511 	}
512 
513 	return 0;
514 }
515 
516 static void query_lookup_prog(struct test_sk_lookup *skel)
517 {
518 	struct bpf_link *link[3] = {};
519 	struct bpf_link_info info;
520 	__u32 attach_flags = 0;
521 	__u32 prog_ids[3] = {};
522 	__u32 prog_cnt = 3;
523 	__u32 prog_id;
524 	int net_fd;
525 	int err;
526 
527 	net_fd = open("/proc/self/ns/net", O_RDONLY);
528 	if (CHECK(net_fd < 0, "open", "failed\n")) {
529 		log_err("failed to open /proc/self/ns/net");
530 		return;
531 	}
532 
533 	link[0] = attach_lookup_prog(skel->progs.lookup_pass);
534 	if (!link[0])
535 		goto close;
536 	link[1] = attach_lookup_prog(skel->progs.lookup_pass);
537 	if (!link[1])
538 		goto detach;
539 	link[2] = attach_lookup_prog(skel->progs.lookup_drop);
540 	if (!link[2])
541 		goto detach;
542 
543 	err = bpf_prog_query(net_fd, BPF_SK_LOOKUP, 0 /* query flags */,
544 			     &attach_flags, prog_ids, &prog_cnt);
545 	if (CHECK(err, "bpf_prog_query", "failed\n")) {
546 		log_err("failed to query lookup prog");
547 		goto detach;
548 	}
549 
550 	errno = 0;
551 	if (CHECK(attach_flags != 0, "bpf_prog_query",
552 		  "wrong attach_flags on query: %u", attach_flags))
553 		goto detach;
554 	if (CHECK(prog_cnt != 3, "bpf_prog_query",
555 		  "wrong program count on query: %u", prog_cnt))
556 		goto detach;
557 	prog_id = link_info_prog_id(link[0], &info);
558 	CHECK(prog_ids[0] != prog_id, "bpf_prog_query",
559 	      "invalid program #0 id on query: %u != %u\n",
560 	      prog_ids[0], prog_id);
561 	CHECK(info.netns.netns_ino == 0, "netns_ino",
562 	      "unexpected netns_ino: %u\n", info.netns.netns_ino);
563 	prog_id = link_info_prog_id(link[1], &info);
564 	CHECK(prog_ids[1] != prog_id, "bpf_prog_query",
565 	      "invalid program #1 id on query: %u != %u\n",
566 	      prog_ids[1], prog_id);
567 	CHECK(info.netns.netns_ino == 0, "netns_ino",
568 	      "unexpected netns_ino: %u\n", info.netns.netns_ino);
569 	prog_id = link_info_prog_id(link[2], &info);
570 	CHECK(prog_ids[2] != prog_id, "bpf_prog_query",
571 	      "invalid program #2 id on query: %u != %u\n",
572 	      prog_ids[2], prog_id);
573 	CHECK(info.netns.netns_ino == 0, "netns_ino",
574 	      "unexpected netns_ino: %u\n", info.netns.netns_ino);
575 
576 	err = bpf_link__detach(link[0]);
577 	if (CHECK(err, "link_detach", "failed %d\n", err))
578 		goto detach;
579 
580 	/* prog id is still there, but netns_ino is zeroed out */
581 	prog_id = link_info_prog_id(link[0], &info);
582 	CHECK(prog_ids[0] != prog_id, "bpf_prog_query",
583 	      "invalid program #0 id on query: %u != %u\n",
584 	      prog_ids[0], prog_id);
585 	CHECK(info.netns.netns_ino != 0, "netns_ino",
586 	      "unexpected netns_ino: %u\n", info.netns.netns_ino);
587 
588 detach:
589 	if (link[2])
590 		bpf_link__destroy(link[2]);
591 	if (link[1])
592 		bpf_link__destroy(link[1]);
593 	if (link[0])
594 		bpf_link__destroy(link[0]);
595 close:
596 	close(net_fd);
597 }
598 
599 static void run_lookup_prog(const struct test *t)
600 {
601 	int server_fds[] = { [0 ... MAX_SERVERS - 1] = -1 };
602 	int client_fd, reuse_conn_fd = -1;
603 	struct bpf_link *lookup_link;
604 	int i, err;
605 
606 	lookup_link = attach_lookup_prog(t->lookup_prog);
607 	if (!lookup_link)
608 		return;
609 
610 	for (i = 0; i < ARRAY_SIZE(server_fds); i++) {
611 		server_fds[i] = make_server(t->sotype, t->listen_at.ip,
612 					    t->listen_at.port,
613 					    t->reuseport_prog);
614 		if (server_fds[i] < 0)
615 			goto close;
616 
617 		err = update_lookup_map(t->sock_map, i, server_fds[i]);
618 		if (err)
619 			goto close;
620 
621 		/* want just one server for non-reuseport test */
622 		if (!t->reuseport_prog)
623 			break;
624 	}
625 
626 	/* Regular UDP socket lookup with reuseport behaves
627 	 * differently when reuseport group contains connected
628 	 * sockets. Check that adding a connected UDP socket to the
629 	 * reuseport group does not affect how reuseport works with
630 	 * BPF socket lookup.
631 	 */
632 	if (t->reuseport_has_conns) {
633 		struct sockaddr_storage addr = {};
634 		socklen_t len = sizeof(addr);
635 
636 		/* Add an extra socket to reuseport group */
637 		reuse_conn_fd = make_server(t->sotype, t->listen_at.ip,
638 					    t->listen_at.port,
639 					    t->reuseport_prog);
640 		if (reuse_conn_fd < 0)
641 			goto close;
642 
643 		/* Connect the extra socket to itself */
644 		err = getsockname(reuse_conn_fd, (void *)&addr, &len);
645 		if (CHECK(err, "getsockname", "errno %d\n", errno))
646 			goto close;
647 		err = connect(reuse_conn_fd, (void *)&addr, len);
648 		if (CHECK(err, "connect", "errno %d\n", errno))
649 			goto close;
650 	}
651 
652 	client_fd = make_client(t->sotype, t->connect_to.ip, t->connect_to.port);
653 	if (client_fd < 0)
654 		goto close;
655 
656 	if (t->sotype == SOCK_STREAM)
657 		tcp_echo_test(client_fd, server_fds[t->accept_on]);
658 	else
659 		udp_echo_test(client_fd, server_fds[t->accept_on]);
660 
661 	close(client_fd);
662 close:
663 	if (reuse_conn_fd != -1)
664 		close(reuse_conn_fd);
665 	for (i = 0; i < ARRAY_SIZE(server_fds); i++) {
666 		if (server_fds[i] != -1)
667 			close(server_fds[i]);
668 	}
669 	bpf_link__destroy(lookup_link);
670 }
671 
672 static void test_redirect_lookup(struct test_sk_lookup *skel)
673 {
674 	const struct test tests[] = {
675 		{
676 			.desc		= "TCP IPv4 redir port",
677 			.lookup_prog	= skel->progs.redir_port,
678 			.sock_map	= skel->maps.redir_map,
679 			.sotype		= SOCK_STREAM,
680 			.connect_to	= { EXT_IP4, EXT_PORT },
681 			.listen_at	= { EXT_IP4, INT_PORT },
682 		},
683 		{
684 			.desc		= "TCP IPv4 redir addr",
685 			.lookup_prog	= skel->progs.redir_ip4,
686 			.sock_map	= skel->maps.redir_map,
687 			.sotype		= SOCK_STREAM,
688 			.connect_to	= { EXT_IP4, EXT_PORT },
689 			.listen_at	= { INT_IP4, EXT_PORT },
690 		},
691 		{
692 			.desc		= "TCP IPv4 redir with reuseport",
693 			.lookup_prog	= skel->progs.select_sock_a,
694 			.reuseport_prog	= skel->progs.select_sock_b,
695 			.sock_map	= skel->maps.redir_map,
696 			.sotype		= SOCK_STREAM,
697 			.connect_to	= { EXT_IP4, EXT_PORT },
698 			.listen_at	= { INT_IP4, INT_PORT },
699 			.accept_on	= SERVER_B,
700 		},
701 		{
702 			.desc		= "TCP IPv4 redir skip reuseport",
703 			.lookup_prog	= skel->progs.select_sock_a_no_reuseport,
704 			.reuseport_prog	= skel->progs.select_sock_b,
705 			.sock_map	= skel->maps.redir_map,
706 			.sotype		= SOCK_STREAM,
707 			.connect_to	= { EXT_IP4, EXT_PORT },
708 			.listen_at	= { INT_IP4, INT_PORT },
709 			.accept_on	= SERVER_A,
710 		},
711 		{
712 			.desc		= "TCP IPv6 redir port",
713 			.lookup_prog	= skel->progs.redir_port,
714 			.sock_map	= skel->maps.redir_map,
715 			.sotype		= SOCK_STREAM,
716 			.connect_to	= { EXT_IP6, EXT_PORT },
717 			.listen_at	= { EXT_IP6, INT_PORT },
718 		},
719 		{
720 			.desc		= "TCP IPv6 redir addr",
721 			.lookup_prog	= skel->progs.redir_ip6,
722 			.sock_map	= skel->maps.redir_map,
723 			.sotype		= SOCK_STREAM,
724 			.connect_to	= { EXT_IP6, EXT_PORT },
725 			.listen_at	= { INT_IP6, EXT_PORT },
726 		},
727 		{
728 			.desc		= "TCP IPv4->IPv6 redir port",
729 			.lookup_prog	= skel->progs.redir_port,
730 			.sock_map	= skel->maps.redir_map,
731 			.sotype		= SOCK_STREAM,
732 			.connect_to	= { EXT_IP4, EXT_PORT },
733 			.listen_at	= { INT_IP4_V6, INT_PORT },
734 		},
735 		{
736 			.desc		= "TCP IPv6 redir with reuseport",
737 			.lookup_prog	= skel->progs.select_sock_a,
738 			.reuseport_prog	= skel->progs.select_sock_b,
739 			.sock_map	= skel->maps.redir_map,
740 			.sotype		= SOCK_STREAM,
741 			.connect_to	= { EXT_IP6, EXT_PORT },
742 			.listen_at	= { INT_IP6, INT_PORT },
743 			.accept_on	= SERVER_B,
744 		},
745 		{
746 			.desc		= "TCP IPv6 redir skip reuseport",
747 			.lookup_prog	= skel->progs.select_sock_a_no_reuseport,
748 			.reuseport_prog	= skel->progs.select_sock_b,
749 			.sock_map	= skel->maps.redir_map,
750 			.sotype		= SOCK_STREAM,
751 			.connect_to	= { EXT_IP6, EXT_PORT },
752 			.listen_at	= { INT_IP6, INT_PORT },
753 			.accept_on	= SERVER_A,
754 		},
755 		{
756 			.desc		= "UDP IPv4 redir port",
757 			.lookup_prog	= skel->progs.redir_port,
758 			.sock_map	= skel->maps.redir_map,
759 			.sotype		= SOCK_DGRAM,
760 			.connect_to	= { EXT_IP4, EXT_PORT },
761 			.listen_at	= { EXT_IP4, INT_PORT },
762 		},
763 		{
764 			.desc		= "UDP IPv4 redir addr",
765 			.lookup_prog	= skel->progs.redir_ip4,
766 			.sock_map	= skel->maps.redir_map,
767 			.sotype		= SOCK_DGRAM,
768 			.connect_to	= { EXT_IP4, EXT_PORT },
769 			.listen_at	= { INT_IP4, EXT_PORT },
770 		},
771 		{
772 			.desc		= "UDP IPv4 redir with reuseport",
773 			.lookup_prog	= skel->progs.select_sock_a,
774 			.reuseport_prog	= skel->progs.select_sock_b,
775 			.sock_map	= skel->maps.redir_map,
776 			.sotype		= SOCK_DGRAM,
777 			.connect_to	= { EXT_IP4, EXT_PORT },
778 			.listen_at	= { INT_IP4, INT_PORT },
779 			.accept_on	= SERVER_B,
780 		},
781 		{
782 			.desc		= "UDP IPv4 redir and reuseport with conns",
783 			.lookup_prog	= skel->progs.select_sock_a,
784 			.reuseport_prog	= skel->progs.select_sock_b,
785 			.sock_map	= skel->maps.redir_map,
786 			.sotype		= SOCK_DGRAM,
787 			.connect_to	= { EXT_IP4, EXT_PORT },
788 			.listen_at	= { INT_IP4, INT_PORT },
789 			.accept_on	= SERVER_B,
790 			.reuseport_has_conns = true,
791 		},
792 		{
793 			.desc		= "UDP IPv4 redir skip reuseport",
794 			.lookup_prog	= skel->progs.select_sock_a_no_reuseport,
795 			.reuseport_prog	= skel->progs.select_sock_b,
796 			.sock_map	= skel->maps.redir_map,
797 			.sotype		= SOCK_DGRAM,
798 			.connect_to	= { EXT_IP4, EXT_PORT },
799 			.listen_at	= { INT_IP4, INT_PORT },
800 			.accept_on	= SERVER_A,
801 		},
802 		{
803 			.desc		= "UDP IPv6 redir port",
804 			.lookup_prog	= skel->progs.redir_port,
805 			.sock_map	= skel->maps.redir_map,
806 			.sotype		= SOCK_DGRAM,
807 			.connect_to	= { EXT_IP6, EXT_PORT },
808 			.listen_at	= { EXT_IP6, INT_PORT },
809 		},
810 		{
811 			.desc		= "UDP IPv6 redir addr",
812 			.lookup_prog	= skel->progs.redir_ip6,
813 			.sock_map	= skel->maps.redir_map,
814 			.sotype		= SOCK_DGRAM,
815 			.connect_to	= { EXT_IP6, EXT_PORT },
816 			.listen_at	= { INT_IP6, EXT_PORT },
817 		},
818 		{
819 			.desc		= "UDP IPv4->IPv6 redir port",
820 			.lookup_prog	= skel->progs.redir_port,
821 			.sock_map	= skel->maps.redir_map,
822 			.sotype		= SOCK_DGRAM,
823 			.listen_at	= { INT_IP4_V6, INT_PORT },
824 			.connect_to	= { EXT_IP4, EXT_PORT },
825 		},
826 		{
827 			.desc		= "UDP IPv6 redir and reuseport",
828 			.lookup_prog	= skel->progs.select_sock_a,
829 			.reuseport_prog	= skel->progs.select_sock_b,
830 			.sock_map	= skel->maps.redir_map,
831 			.sotype		= SOCK_DGRAM,
832 			.connect_to	= { EXT_IP6, EXT_PORT },
833 			.listen_at	= { INT_IP6, INT_PORT },
834 			.accept_on	= SERVER_B,
835 		},
836 		{
837 			.desc		= "UDP IPv6 redir and reuseport with conns",
838 			.lookup_prog	= skel->progs.select_sock_a,
839 			.reuseport_prog	= skel->progs.select_sock_b,
840 			.sock_map	= skel->maps.redir_map,
841 			.sotype		= SOCK_DGRAM,
842 			.connect_to	= { EXT_IP6, EXT_PORT },
843 			.listen_at	= { INT_IP6, INT_PORT },
844 			.accept_on	= SERVER_B,
845 			.reuseport_has_conns = true,
846 		},
847 		{
848 			.desc		= "UDP IPv6 redir skip reuseport",
849 			.lookup_prog	= skel->progs.select_sock_a_no_reuseport,
850 			.reuseport_prog	= skel->progs.select_sock_b,
851 			.sock_map	= skel->maps.redir_map,
852 			.sotype		= SOCK_DGRAM,
853 			.connect_to	= { EXT_IP6, EXT_PORT },
854 			.listen_at	= { INT_IP6, INT_PORT },
855 			.accept_on	= SERVER_A,
856 		},
857 	};
858 	const struct test *t;
859 
860 	for (t = tests; t < tests + ARRAY_SIZE(tests); t++) {
861 		if (test__start_subtest(t->desc))
862 			run_lookup_prog(t);
863 	}
864 }
865 
866 static void drop_on_lookup(const struct test *t)
867 {
868 	struct sockaddr_storage dst = {};
869 	int client_fd, server_fd, err;
870 	struct bpf_link *lookup_link;
871 	ssize_t n;
872 
873 	lookup_link = attach_lookup_prog(t->lookup_prog);
874 	if (!lookup_link)
875 		return;
876 
877 	server_fd = make_server(t->sotype, t->listen_at.ip, t->listen_at.port,
878 				t->reuseport_prog);
879 	if (server_fd < 0)
880 		goto detach;
881 
882 	client_fd = make_socket(t->sotype, t->connect_to.ip,
883 				t->connect_to.port, &dst);
884 	if (client_fd < 0)
885 		goto close_srv;
886 
887 	err = connect(client_fd, (void *)&dst, inetaddr_len(&dst));
888 	if (t->sotype == SOCK_DGRAM) {
889 		err = send_byte(client_fd);
890 		if (err)
891 			goto close_all;
892 
893 		/* Read out asynchronous error */
894 		n = recv(client_fd, NULL, 0, 0);
895 		err = n == -1;
896 	}
897 	if (CHECK(!err || errno != ECONNREFUSED, "connect",
898 		  "unexpected success or error\n"))
899 		log_err("expected ECONNREFUSED on connect");
900 
901 close_all:
902 	close(client_fd);
903 close_srv:
904 	close(server_fd);
905 detach:
906 	bpf_link__destroy(lookup_link);
907 }
908 
909 static void test_drop_on_lookup(struct test_sk_lookup *skel)
910 {
911 	const struct test tests[] = {
912 		{
913 			.desc		= "TCP IPv4 drop on lookup",
914 			.lookup_prog	= skel->progs.lookup_drop,
915 			.sotype		= SOCK_STREAM,
916 			.connect_to	= { EXT_IP4, EXT_PORT },
917 			.listen_at	= { EXT_IP4, EXT_PORT },
918 		},
919 		{
920 			.desc		= "TCP IPv6 drop on lookup",
921 			.lookup_prog	= skel->progs.lookup_drop,
922 			.sotype		= SOCK_STREAM,
923 			.connect_to	= { EXT_IP6, EXT_PORT },
924 			.listen_at	= { EXT_IP6, EXT_PORT },
925 		},
926 		{
927 			.desc		= "UDP IPv4 drop on lookup",
928 			.lookup_prog	= skel->progs.lookup_drop,
929 			.sotype		= SOCK_DGRAM,
930 			.connect_to	= { EXT_IP4, EXT_PORT },
931 			.listen_at	= { EXT_IP4, EXT_PORT },
932 		},
933 		{
934 			.desc		= "UDP IPv6 drop on lookup",
935 			.lookup_prog	= skel->progs.lookup_drop,
936 			.sotype		= SOCK_DGRAM,
937 			.connect_to	= { EXT_IP6, EXT_PORT },
938 			.listen_at	= { EXT_IP6, INT_PORT },
939 		},
940 		/* The program will drop on success, meaning that the ifindex
941 		 * was 1.
942 		 */
943 		{
944 			.desc		= "TCP IPv4 drop on valid ifindex",
945 			.lookup_prog	= skel->progs.check_ifindex,
946 			.sotype		= SOCK_STREAM,
947 			.connect_to	= { EXT_IP4, EXT_PORT },
948 			.listen_at	= { EXT_IP4, EXT_PORT },
949 		},
950 		{
951 			.desc		= "TCP IPv6 drop on valid ifindex",
952 			.lookup_prog	= skel->progs.check_ifindex,
953 			.sotype		= SOCK_STREAM,
954 			.connect_to	= { EXT_IP6, EXT_PORT },
955 			.listen_at	= { EXT_IP6, EXT_PORT },
956 		},
957 		{
958 			.desc		= "UDP IPv4 drop on valid ifindex",
959 			.lookup_prog	= skel->progs.check_ifindex,
960 			.sotype		= SOCK_DGRAM,
961 			.connect_to	= { EXT_IP4, EXT_PORT },
962 			.listen_at	= { EXT_IP4, EXT_PORT },
963 		},
964 		{
965 			.desc		= "UDP IPv6 drop on valid ifindex",
966 			.lookup_prog	= skel->progs.check_ifindex,
967 			.sotype		= SOCK_DGRAM,
968 			.connect_to	= { EXT_IP6, EXT_PORT },
969 			.listen_at	= { EXT_IP6, EXT_PORT },
970 		},
971 	};
972 	const struct test *t;
973 
974 	for (t = tests; t < tests + ARRAY_SIZE(tests); t++) {
975 		if (test__start_subtest(t->desc))
976 			drop_on_lookup(t);
977 	}
978 }
979 
980 static void drop_on_reuseport(const struct test *t)
981 {
982 	struct sockaddr_storage dst = { 0 };
983 	int client, server1, server2, err;
984 	struct bpf_link *lookup_link;
985 	ssize_t n;
986 
987 	lookup_link = attach_lookup_prog(t->lookup_prog);
988 	if (!lookup_link)
989 		return;
990 
991 	server1 = make_server(t->sotype, t->listen_at.ip, t->listen_at.port,
992 			      t->reuseport_prog);
993 	if (server1 < 0)
994 		goto detach;
995 
996 	err = update_lookup_map(t->sock_map, SERVER_A, server1);
997 	if (err)
998 		goto detach;
999 
1000 	/* second server on destination address we should never reach */
1001 	server2 = make_server(t->sotype, t->connect_to.ip, t->connect_to.port,
1002 			      NULL /* reuseport prog */);
1003 	if (server2 < 0)
1004 		goto close_srv1;
1005 
1006 	client = make_socket(t->sotype, t->connect_to.ip,
1007 			     t->connect_to.port, &dst);
1008 	if (client < 0)
1009 		goto close_srv2;
1010 
1011 	err = connect(client, (void *)&dst, inetaddr_len(&dst));
1012 	if (t->sotype == SOCK_DGRAM) {
1013 		err = send_byte(client);
1014 		if (err)
1015 			goto close_all;
1016 
1017 		/* Read out asynchronous error */
1018 		n = recv(client, NULL, 0, 0);
1019 		err = n == -1;
1020 	}
1021 	if (CHECK(!err || errno != ECONNREFUSED, "connect",
1022 		  "unexpected success or error\n"))
1023 		log_err("expected ECONNREFUSED on connect");
1024 
1025 close_all:
1026 	close(client);
1027 close_srv2:
1028 	close(server2);
1029 close_srv1:
1030 	close(server1);
1031 detach:
1032 	bpf_link__destroy(lookup_link);
1033 }
1034 
1035 static void test_drop_on_reuseport(struct test_sk_lookup *skel)
1036 {
1037 	const struct test tests[] = {
1038 		{
1039 			.desc		= "TCP IPv4 drop on reuseport",
1040 			.lookup_prog	= skel->progs.select_sock_a,
1041 			.reuseport_prog	= skel->progs.reuseport_drop,
1042 			.sock_map	= skel->maps.redir_map,
1043 			.sotype		= SOCK_STREAM,
1044 			.connect_to	= { EXT_IP4, EXT_PORT },
1045 			.listen_at	= { INT_IP4, INT_PORT },
1046 		},
1047 		{
1048 			.desc		= "TCP IPv6 drop on reuseport",
1049 			.lookup_prog	= skel->progs.select_sock_a,
1050 			.reuseport_prog	= skel->progs.reuseport_drop,
1051 			.sock_map	= skel->maps.redir_map,
1052 			.sotype		= SOCK_STREAM,
1053 			.connect_to	= { EXT_IP6, EXT_PORT },
1054 			.listen_at	= { INT_IP6, INT_PORT },
1055 		},
1056 		{
1057 			.desc		= "UDP IPv4 drop on reuseport",
1058 			.lookup_prog	= skel->progs.select_sock_a,
1059 			.reuseport_prog	= skel->progs.reuseport_drop,
1060 			.sock_map	= skel->maps.redir_map,
1061 			.sotype		= SOCK_DGRAM,
1062 			.connect_to	= { EXT_IP4, EXT_PORT },
1063 			.listen_at	= { INT_IP4, INT_PORT },
1064 		},
1065 		{
1066 			.desc		= "TCP IPv6 drop on reuseport",
1067 			.lookup_prog	= skel->progs.select_sock_a,
1068 			.reuseport_prog	= skel->progs.reuseport_drop,
1069 			.sock_map	= skel->maps.redir_map,
1070 			.sotype		= SOCK_STREAM,
1071 			.connect_to	= { EXT_IP6, EXT_PORT },
1072 			.listen_at	= { INT_IP6, INT_PORT },
1073 		},
1074 	};
1075 	const struct test *t;
1076 
1077 	for (t = tests; t < tests + ARRAY_SIZE(tests); t++) {
1078 		if (test__start_subtest(t->desc))
1079 			drop_on_reuseport(t);
1080 	}
1081 }
1082 
1083 static void run_sk_assign(struct test_sk_lookup *skel,
1084 			  struct bpf_program *lookup_prog,
1085 			  const char *remote_ip, const char *local_ip)
1086 {
1087 	int server_fds[] = { [0 ... MAX_SERVERS - 1] = -1 };
1088 	struct bpf_sk_lookup ctx;
1089 	__u64 server_cookie;
1090 	int i, err;
1091 
1092 	DECLARE_LIBBPF_OPTS(bpf_test_run_opts, opts,
1093 		.ctx_in = &ctx,
1094 		.ctx_size_in = sizeof(ctx),
1095 		.ctx_out = &ctx,
1096 		.ctx_size_out = sizeof(ctx),
1097 	);
1098 
1099 	if (fill_sk_lookup_ctx(&ctx, local_ip, EXT_PORT, remote_ip, INT_PORT))
1100 		return;
1101 
1102 	ctx.protocol = IPPROTO_TCP;
1103 
1104 	for (i = 0; i < ARRAY_SIZE(server_fds); i++) {
1105 		server_fds[i] = make_server(SOCK_STREAM, local_ip, 0, NULL);
1106 		if (server_fds[i] < 0)
1107 			goto close_servers;
1108 
1109 		err = update_lookup_map(skel->maps.redir_map, i,
1110 					server_fds[i]);
1111 		if (err)
1112 			goto close_servers;
1113 	}
1114 
1115 	server_cookie = socket_cookie(server_fds[SERVER_B]);
1116 	if (!server_cookie)
1117 		return;
1118 
1119 	err = bpf_prog_test_run_opts(bpf_program__fd(lookup_prog), &opts);
1120 	if (CHECK(err, "test_run", "failed with error %d\n", errno))
1121 		goto close_servers;
1122 
1123 	if (CHECK(ctx.cookie == 0, "ctx.cookie", "no socket selected\n"))
1124 		goto close_servers;
1125 
1126 	CHECK(ctx.cookie != server_cookie, "ctx.cookie",
1127 	      "selected sk %llu instead of %llu\n", ctx.cookie, server_cookie);
1128 
1129 close_servers:
1130 	for (i = 0; i < ARRAY_SIZE(server_fds); i++) {
1131 		if (server_fds[i] != -1)
1132 			close(server_fds[i]);
1133 	}
1134 }
1135 
1136 static void run_sk_assign_v4(struct test_sk_lookup *skel,
1137 			     struct bpf_program *lookup_prog)
1138 {
1139 	run_sk_assign(skel, lookup_prog, INT_IP4, EXT_IP4);
1140 }
1141 
1142 static void run_sk_assign_v6(struct test_sk_lookup *skel,
1143 			     struct bpf_program *lookup_prog)
1144 {
1145 	run_sk_assign(skel, lookup_prog, INT_IP6, EXT_IP6);
1146 }
1147 
1148 static void run_sk_assign_connected(struct test_sk_lookup *skel,
1149 				    int sotype)
1150 {
1151 	int err, client_fd, connected_fd, server_fd;
1152 	struct bpf_link *lookup_link;
1153 
1154 	server_fd = make_server(sotype, EXT_IP4, EXT_PORT, NULL);
1155 	if (server_fd < 0)
1156 		return;
1157 
1158 	connected_fd = make_client(sotype, EXT_IP4, EXT_PORT);
1159 	if (connected_fd < 0)
1160 		goto out_close_server;
1161 
1162 	/* Put a connected socket in redirect map */
1163 	err = update_lookup_map(skel->maps.redir_map, SERVER_A, connected_fd);
1164 	if (err)
1165 		goto out_close_connected;
1166 
1167 	lookup_link = attach_lookup_prog(skel->progs.sk_assign_esocknosupport);
1168 	if (!lookup_link)
1169 		goto out_close_connected;
1170 
1171 	/* Try to redirect TCP SYN / UDP packet to a connected socket */
1172 	client_fd = make_client(sotype, EXT_IP4, EXT_PORT);
1173 	if (client_fd < 0)
1174 		goto out_unlink_prog;
1175 	if (sotype == SOCK_DGRAM) {
1176 		send_byte(client_fd);
1177 		recv_byte(server_fd);
1178 	}
1179 
1180 	close(client_fd);
1181 out_unlink_prog:
1182 	bpf_link__destroy(lookup_link);
1183 out_close_connected:
1184 	close(connected_fd);
1185 out_close_server:
1186 	close(server_fd);
1187 }
1188 
1189 static void test_sk_assign_helper(struct test_sk_lookup *skel)
1190 {
1191 	if (test__start_subtest("sk_assign returns EEXIST"))
1192 		run_sk_assign_v4(skel, skel->progs.sk_assign_eexist);
1193 	if (test__start_subtest("sk_assign honors F_REPLACE"))
1194 		run_sk_assign_v4(skel, skel->progs.sk_assign_replace_flag);
1195 	if (test__start_subtest("sk_assign accepts NULL socket"))
1196 		run_sk_assign_v4(skel, skel->progs.sk_assign_null);
1197 	if (test__start_subtest("access ctx->sk"))
1198 		run_sk_assign_v4(skel, skel->progs.access_ctx_sk);
1199 	if (test__start_subtest("narrow access to ctx v4"))
1200 		run_sk_assign_v4(skel, skel->progs.ctx_narrow_access);
1201 	if (test__start_subtest("narrow access to ctx v6"))
1202 		run_sk_assign_v6(skel, skel->progs.ctx_narrow_access);
1203 	if (test__start_subtest("sk_assign rejects TCP established"))
1204 		run_sk_assign_connected(skel, SOCK_STREAM);
1205 	if (test__start_subtest("sk_assign rejects UDP connected"))
1206 		run_sk_assign_connected(skel, SOCK_DGRAM);
1207 }
1208 
1209 struct test_multi_prog {
1210 	const char *desc;
1211 	struct bpf_program *prog1;
1212 	struct bpf_program *prog2;
1213 	struct bpf_map *redir_map;
1214 	struct bpf_map *run_map;
1215 	int expect_errno;
1216 	struct inet_addr listen_at;
1217 };
1218 
1219 static void run_multi_prog_lookup(const struct test_multi_prog *t)
1220 {
1221 	struct sockaddr_storage dst = {};
1222 	int map_fd, server_fd, client_fd;
1223 	struct bpf_link *link1, *link2;
1224 	int prog_idx, done, err;
1225 
1226 	map_fd = bpf_map__fd(t->run_map);
1227 
1228 	done = 0;
1229 	prog_idx = PROG1;
1230 	err = bpf_map_update_elem(map_fd, &prog_idx, &done, BPF_ANY);
1231 	if (CHECK(err, "bpf_map_update_elem", "failed\n"))
1232 		return;
1233 	prog_idx = PROG2;
1234 	err = bpf_map_update_elem(map_fd, &prog_idx, &done, BPF_ANY);
1235 	if (CHECK(err, "bpf_map_update_elem", "failed\n"))
1236 		return;
1237 
1238 	link1 = attach_lookup_prog(t->prog1);
1239 	if (!link1)
1240 		return;
1241 	link2 = attach_lookup_prog(t->prog2);
1242 	if (!link2)
1243 		goto out_unlink1;
1244 
1245 	server_fd = make_server(SOCK_STREAM, t->listen_at.ip,
1246 				t->listen_at.port, NULL);
1247 	if (server_fd < 0)
1248 		goto out_unlink2;
1249 
1250 	err = update_lookup_map(t->redir_map, SERVER_A, server_fd);
1251 	if (err)
1252 		goto out_close_server;
1253 
1254 	client_fd = make_socket(SOCK_STREAM, EXT_IP4, EXT_PORT, &dst);
1255 	if (client_fd < 0)
1256 		goto out_close_server;
1257 
1258 	err = connect(client_fd, (void *)&dst, inetaddr_len(&dst));
1259 	if (CHECK(err && !t->expect_errno, "connect",
1260 		  "unexpected error %d\n", errno))
1261 		goto out_close_client;
1262 	if (CHECK(err && t->expect_errno && errno != t->expect_errno,
1263 		  "connect", "unexpected error %d\n", errno))
1264 		goto out_close_client;
1265 
1266 	done = 0;
1267 	prog_idx = PROG1;
1268 	err = bpf_map_lookup_elem(map_fd, &prog_idx, &done);
1269 	CHECK(err, "bpf_map_lookup_elem", "failed\n");
1270 	CHECK(!done, "bpf_map_lookup_elem", "PROG1 !done\n");
1271 
1272 	done = 0;
1273 	prog_idx = PROG2;
1274 	err = bpf_map_lookup_elem(map_fd, &prog_idx, &done);
1275 	CHECK(err, "bpf_map_lookup_elem", "failed\n");
1276 	CHECK(!done, "bpf_map_lookup_elem", "PROG2 !done\n");
1277 
1278 out_close_client:
1279 	close(client_fd);
1280 out_close_server:
1281 	close(server_fd);
1282 out_unlink2:
1283 	bpf_link__destroy(link2);
1284 out_unlink1:
1285 	bpf_link__destroy(link1);
1286 }
1287 
1288 static void test_multi_prog_lookup(struct test_sk_lookup *skel)
1289 {
1290 	struct test_multi_prog tests[] = {
1291 		{
1292 			.desc		= "multi prog - pass, pass",
1293 			.prog1		= skel->progs.multi_prog_pass1,
1294 			.prog2		= skel->progs.multi_prog_pass2,
1295 			.listen_at	= { EXT_IP4, EXT_PORT },
1296 		},
1297 		{
1298 			.desc		= "multi prog - drop, drop",
1299 			.prog1		= skel->progs.multi_prog_drop1,
1300 			.prog2		= skel->progs.multi_prog_drop2,
1301 			.listen_at	= { EXT_IP4, EXT_PORT },
1302 			.expect_errno	= ECONNREFUSED,
1303 		},
1304 		{
1305 			.desc		= "multi prog - pass, drop",
1306 			.prog1		= skel->progs.multi_prog_pass1,
1307 			.prog2		= skel->progs.multi_prog_drop2,
1308 			.listen_at	= { EXT_IP4, EXT_PORT },
1309 			.expect_errno	= ECONNREFUSED,
1310 		},
1311 		{
1312 			.desc		= "multi prog - drop, pass",
1313 			.prog1		= skel->progs.multi_prog_drop1,
1314 			.prog2		= skel->progs.multi_prog_pass2,
1315 			.listen_at	= { EXT_IP4, EXT_PORT },
1316 			.expect_errno	= ECONNREFUSED,
1317 		},
1318 		{
1319 			.desc		= "multi prog - pass, redir",
1320 			.prog1		= skel->progs.multi_prog_pass1,
1321 			.prog2		= skel->progs.multi_prog_redir2,
1322 			.listen_at	= { INT_IP4, INT_PORT },
1323 		},
1324 		{
1325 			.desc		= "multi prog - redir, pass",
1326 			.prog1		= skel->progs.multi_prog_redir1,
1327 			.prog2		= skel->progs.multi_prog_pass2,
1328 			.listen_at	= { INT_IP4, INT_PORT },
1329 		},
1330 		{
1331 			.desc		= "multi prog - drop, redir",
1332 			.prog1		= skel->progs.multi_prog_drop1,
1333 			.prog2		= skel->progs.multi_prog_redir2,
1334 			.listen_at	= { INT_IP4, INT_PORT },
1335 		},
1336 		{
1337 			.desc		= "multi prog - redir, drop",
1338 			.prog1		= skel->progs.multi_prog_redir1,
1339 			.prog2		= skel->progs.multi_prog_drop2,
1340 			.listen_at	= { INT_IP4, INT_PORT },
1341 		},
1342 		{
1343 			.desc		= "multi prog - redir, redir",
1344 			.prog1		= skel->progs.multi_prog_redir1,
1345 			.prog2		= skel->progs.multi_prog_redir2,
1346 			.listen_at	= { INT_IP4, INT_PORT },
1347 		},
1348 	};
1349 	struct test_multi_prog *t;
1350 
1351 	for (t = tests; t < tests + ARRAY_SIZE(tests); t++) {
1352 		t->redir_map = skel->maps.redir_map;
1353 		t->run_map = skel->maps.run_map;
1354 		if (test__start_subtest(t->desc))
1355 			run_multi_prog_lookup(t);
1356 	}
1357 }
1358 
1359 static void run_tests(struct test_sk_lookup *skel)
1360 {
1361 	if (test__start_subtest("query lookup prog"))
1362 		query_lookup_prog(skel);
1363 	test_redirect_lookup(skel);
1364 	test_drop_on_lookup(skel);
1365 	test_drop_on_reuseport(skel);
1366 	test_sk_assign_helper(skel);
1367 	test_multi_prog_lookup(skel);
1368 }
1369 
1370 static int switch_netns(void)
1371 {
1372 	static const char * const setup_script[] = {
1373 		"ip -6 addr add dev lo " EXT_IP6 "/128",
1374 		"ip -6 addr add dev lo " INT_IP6 "/128",
1375 		"ip link set dev lo up",
1376 		NULL,
1377 	};
1378 	const char * const *cmd;
1379 	int err;
1380 
1381 	err = unshare(CLONE_NEWNET);
1382 	if (CHECK(err, "unshare", "failed\n")) {
1383 		log_err("unshare(CLONE_NEWNET)");
1384 		return -1;
1385 	}
1386 
1387 	for (cmd = setup_script; *cmd; cmd++) {
1388 		err = system(*cmd);
1389 		if (CHECK(err, "system", "failed\n")) {
1390 			log_err("system(%s)", *cmd);
1391 			return -1;
1392 		}
1393 	}
1394 
1395 	return 0;
1396 }
1397 
1398 void test_sk_lookup(void)
1399 {
1400 	struct test_sk_lookup *skel;
1401 	int err;
1402 
1403 	err = switch_netns();
1404 	if (err)
1405 		return;
1406 
1407 	skel = test_sk_lookup__open_and_load();
1408 	if (CHECK(!skel, "skel open_and_load", "failed\n"))
1409 		return;
1410 
1411 	run_tests(skel);
1412 
1413 	test_sk_lookup__destroy(skel);
1414 }
1415