xref: /linux/tools/testing/vsock/util.c (revision 1b98f357dadd6ea613a435fbaef1a5dd7b35fd21)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * vsock test utilities
4  *
5  * Copyright (C) 2017 Red Hat, Inc.
6  *
7  * Author: Stefan Hajnoczi <stefanha@redhat.com>
8  */
9 
10 #include <errno.h>
11 #include <stdio.h>
12 #include <stdint.h>
13 #include <stdlib.h>
14 #include <string.h>
15 #include <signal.h>
16 #include <unistd.h>
17 #include <assert.h>
18 #include <sys/epoll.h>
19 #include <sys/mman.h>
20 #include <linux/sockios.h>
21 
22 #include "timeout.h"
23 #include "control.h"
24 #include "util.h"
25 
26 /* Install signal handlers */
27 void init_signals(void)
28 {
29 	struct sigaction act = {
30 		.sa_handler = sigalrm,
31 	};
32 
33 	sigaction(SIGALRM, &act, NULL);
34 	signal(SIGPIPE, SIG_IGN);
35 }
36 
37 static unsigned int parse_uint(const char *str, const char *err_str)
38 {
39 	char *endptr = NULL;
40 	unsigned long n;
41 
42 	errno = 0;
43 	n = strtoul(str, &endptr, 10);
44 	if (errno || *endptr != '\0') {
45 		fprintf(stderr, "malformed %s \"%s\"\n", err_str, str);
46 		exit(EXIT_FAILURE);
47 	}
48 	return n;
49 }
50 
51 /* Parse a CID in string representation */
52 unsigned int parse_cid(const char *str)
53 {
54 	return parse_uint(str, "CID");
55 }
56 
57 /* Parse a port in string representation */
58 unsigned int parse_port(const char *str)
59 {
60 	return parse_uint(str, "port");
61 }
62 
63 /* Wait for the remote to close the connection */
64 void vsock_wait_remote_close(int fd)
65 {
66 	struct epoll_event ev;
67 	int epollfd, nfds;
68 
69 	epollfd = epoll_create1(0);
70 	if (epollfd == -1) {
71 		perror("epoll_create1");
72 		exit(EXIT_FAILURE);
73 	}
74 
75 	ev.events = EPOLLRDHUP | EPOLLHUP;
76 	ev.data.fd = fd;
77 	if (epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev) == -1) {
78 		perror("epoll_ctl");
79 		exit(EXIT_FAILURE);
80 	}
81 
82 	nfds = epoll_wait(epollfd, &ev, 1, TIMEOUT * 1000);
83 	if (nfds == -1) {
84 		perror("epoll_wait");
85 		exit(EXIT_FAILURE);
86 	}
87 
88 	if (nfds == 0) {
89 		fprintf(stderr, "epoll_wait timed out\n");
90 		exit(EXIT_FAILURE);
91 	}
92 
93 	assert(nfds == 1);
94 	assert(ev.events & (EPOLLRDHUP | EPOLLHUP));
95 	assert(ev.data.fd == fd);
96 
97 	close(epollfd);
98 }
99 
100 /* Wait until transport reports no data left to be sent.
101  * Return false if transport does not implement the unsent_bytes() callback.
102  */
103 bool vsock_wait_sent(int fd)
104 {
105 	int ret, sock_bytes_unsent;
106 
107 	timeout_begin(TIMEOUT);
108 	do {
109 		ret = ioctl(fd, SIOCOUTQ, &sock_bytes_unsent);
110 		if (ret < 0) {
111 			if (errno == EOPNOTSUPP)
112 				break;
113 
114 			perror("ioctl(SIOCOUTQ)");
115 			exit(EXIT_FAILURE);
116 		}
117 		timeout_check("SIOCOUTQ");
118 	} while (sock_bytes_unsent != 0);
119 	timeout_end();
120 
121 	return !ret;
122 }
123 
124 /* Create socket <type>, bind to <cid, port> and return the file descriptor. */
125 int vsock_bind(unsigned int cid, unsigned int port, int type)
126 {
127 	struct sockaddr_vm sa = {
128 		.svm_family = AF_VSOCK,
129 		.svm_cid = cid,
130 		.svm_port = port,
131 	};
132 	int fd;
133 
134 	fd = socket(AF_VSOCK, type, 0);
135 	if (fd < 0) {
136 		perror("socket");
137 		exit(EXIT_FAILURE);
138 	}
139 
140 	if (bind(fd, (struct sockaddr *)&sa, sizeof(sa))) {
141 		perror("bind");
142 		exit(EXIT_FAILURE);
143 	}
144 
145 	return fd;
146 }
147 
148 int vsock_connect_fd(int fd, unsigned int cid, unsigned int port)
149 {
150 	struct sockaddr_vm sa = {
151 		.svm_family = AF_VSOCK,
152 		.svm_cid = cid,
153 		.svm_port = port,
154 	};
155 	int ret;
156 
157 	timeout_begin(TIMEOUT);
158 	do {
159 		ret = connect(fd, (struct sockaddr *)&sa, sizeof(sa));
160 		timeout_check("connect");
161 	} while (ret < 0 && errno == EINTR);
162 	timeout_end();
163 
164 	return ret;
165 }
166 
167 /* Bind to <bind_port>, connect to <cid, port> and return the file descriptor. */
168 int vsock_bind_connect(unsigned int cid, unsigned int port, unsigned int bind_port, int type)
169 {
170 	int client_fd;
171 
172 	client_fd = vsock_bind(VMADDR_CID_ANY, bind_port, type);
173 
174 	if (vsock_connect_fd(client_fd, cid, port)) {
175 		perror("connect");
176 		exit(EXIT_FAILURE);
177 	}
178 
179 	return client_fd;
180 }
181 
182 /* Connect to <cid, port> and return the file descriptor. */
183 int vsock_connect(unsigned int cid, unsigned int port, int type)
184 {
185 	int fd;
186 
187 	control_expectln("LISTENING");
188 
189 	fd = socket(AF_VSOCK, type, 0);
190 	if (fd < 0) {
191 		perror("socket");
192 		exit(EXIT_FAILURE);
193 	}
194 
195 	if (vsock_connect_fd(fd, cid, port)) {
196 		int old_errno = errno;
197 
198 		close(fd);
199 		fd = -1;
200 		errno = old_errno;
201 	}
202 
203 	return fd;
204 }
205 
206 int vsock_stream_connect(unsigned int cid, unsigned int port)
207 {
208 	return vsock_connect(cid, port, SOCK_STREAM);
209 }
210 
211 int vsock_seqpacket_connect(unsigned int cid, unsigned int port)
212 {
213 	return vsock_connect(cid, port, SOCK_SEQPACKET);
214 }
215 
216 /* Listen on <cid, port> and return the file descriptor. */
217 static int vsock_listen(unsigned int cid, unsigned int port, int type)
218 {
219 	int fd;
220 
221 	fd = vsock_bind(cid, port, type);
222 
223 	if (listen(fd, 1) < 0) {
224 		perror("listen");
225 		exit(EXIT_FAILURE);
226 	}
227 
228 	return fd;
229 }
230 
231 /* Listen on <cid, port> and return the first incoming connection.  The remote
232  * address is stored to clientaddrp.  clientaddrp may be NULL.
233  */
234 int vsock_accept(unsigned int cid, unsigned int port,
235 		 struct sockaddr_vm *clientaddrp, int type)
236 {
237 	union {
238 		struct sockaddr sa;
239 		struct sockaddr_vm svm;
240 	} clientaddr;
241 	socklen_t clientaddr_len = sizeof(clientaddr.svm);
242 	int fd, client_fd, old_errno;
243 
244 	fd = vsock_listen(cid, port, type);
245 
246 	control_writeln("LISTENING");
247 
248 	timeout_begin(TIMEOUT);
249 	do {
250 		client_fd = accept(fd, &clientaddr.sa, &clientaddr_len);
251 		timeout_check("accept");
252 	} while (client_fd < 0 && errno == EINTR);
253 	timeout_end();
254 
255 	old_errno = errno;
256 	close(fd);
257 	errno = old_errno;
258 
259 	if (client_fd < 0)
260 		return client_fd;
261 
262 	if (clientaddr_len != sizeof(clientaddr.svm)) {
263 		fprintf(stderr, "unexpected addrlen from accept(2), %zu\n",
264 			(size_t)clientaddr_len);
265 		exit(EXIT_FAILURE);
266 	}
267 	if (clientaddr.sa.sa_family != AF_VSOCK) {
268 		fprintf(stderr, "expected AF_VSOCK from accept(2), got %d\n",
269 			clientaddr.sa.sa_family);
270 		exit(EXIT_FAILURE);
271 	}
272 
273 	if (clientaddrp)
274 		*clientaddrp = clientaddr.svm;
275 	return client_fd;
276 }
277 
278 int vsock_stream_accept(unsigned int cid, unsigned int port,
279 			struct sockaddr_vm *clientaddrp)
280 {
281 	return vsock_accept(cid, port, clientaddrp, SOCK_STREAM);
282 }
283 
284 int vsock_stream_listen(unsigned int cid, unsigned int port)
285 {
286 	return vsock_listen(cid, port, SOCK_STREAM);
287 }
288 
289 int vsock_seqpacket_accept(unsigned int cid, unsigned int port,
290 			   struct sockaddr_vm *clientaddrp)
291 {
292 	return vsock_accept(cid, port, clientaddrp, SOCK_SEQPACKET);
293 }
294 
295 /* Transmit bytes from a buffer and check the return value.
296  *
297  * expected_ret:
298  *  <0 Negative errno (for testing errors)
299  *   0 End-of-file
300  *  >0 Success (bytes successfully written)
301  */
302 void send_buf(int fd, const void *buf, size_t len, int flags,
303 	      ssize_t expected_ret)
304 {
305 	ssize_t nwritten = 0;
306 	ssize_t ret;
307 
308 	timeout_begin(TIMEOUT);
309 	do {
310 		ret = send(fd, buf + nwritten, len - nwritten, flags);
311 		timeout_check("send");
312 
313 		if (ret == 0 || (ret < 0 && errno != EINTR))
314 			break;
315 
316 		nwritten += ret;
317 	} while (nwritten < len);
318 	timeout_end();
319 
320 	if (expected_ret < 0) {
321 		if (ret != -1) {
322 			fprintf(stderr, "bogus send(2) return value %zd (expected %zd)\n",
323 				ret, expected_ret);
324 			exit(EXIT_FAILURE);
325 		}
326 		if (errno != -expected_ret) {
327 			perror("send");
328 			exit(EXIT_FAILURE);
329 		}
330 		return;
331 	}
332 
333 	if (ret < 0) {
334 		perror("send");
335 		exit(EXIT_FAILURE);
336 	}
337 
338 	if (nwritten != expected_ret) {
339 		if (ret == 0)
340 			fprintf(stderr, "unexpected EOF while sending bytes\n");
341 
342 		fprintf(stderr, "bogus send(2) bytes written %zd (expected %zd)\n",
343 			nwritten, expected_ret);
344 		exit(EXIT_FAILURE);
345 	}
346 }
347 
348 /* Receive bytes in a buffer and check the return value.
349  *
350  * expected_ret:
351  *  <0 Negative errno (for testing errors)
352  *   0 End-of-file
353  *  >0 Success (bytes successfully read)
354  */
355 void recv_buf(int fd, void *buf, size_t len, int flags, ssize_t expected_ret)
356 {
357 	ssize_t nread = 0;
358 	ssize_t ret;
359 
360 	timeout_begin(TIMEOUT);
361 	do {
362 		ret = recv(fd, buf + nread, len - nread, flags);
363 		timeout_check("recv");
364 
365 		if (ret == 0 || (ret < 0 && errno != EINTR))
366 			break;
367 
368 		nread += ret;
369 	} while (nread < len);
370 	timeout_end();
371 
372 	if (expected_ret < 0) {
373 		if (ret != -1) {
374 			fprintf(stderr, "bogus recv(2) return value %zd (expected %zd)\n",
375 				ret, expected_ret);
376 			exit(EXIT_FAILURE);
377 		}
378 		if (errno != -expected_ret) {
379 			perror("recv");
380 			exit(EXIT_FAILURE);
381 		}
382 		return;
383 	}
384 
385 	if (ret < 0) {
386 		perror("recv");
387 		exit(EXIT_FAILURE);
388 	}
389 
390 	if (nread != expected_ret) {
391 		if (ret == 0)
392 			fprintf(stderr, "unexpected EOF while receiving bytes\n");
393 
394 		fprintf(stderr, "bogus recv(2) bytes read %zd (expected %zd)\n",
395 			nread, expected_ret);
396 		exit(EXIT_FAILURE);
397 	}
398 }
399 
400 /* Transmit one byte and check the return value.
401  *
402  * expected_ret:
403  *  <0 Negative errno (for testing errors)
404  *   0 End-of-file
405  *   1 Success
406  */
407 void send_byte(int fd, int expected_ret, int flags)
408 {
409 	static const uint8_t byte = 'A';
410 
411 	send_buf(fd, &byte, sizeof(byte), flags, expected_ret);
412 }
413 
414 /* Receive one byte and check the return value.
415  *
416  * expected_ret:
417  *  <0 Negative errno (for testing errors)
418  *   0 End-of-file
419  *   1 Success
420  */
421 void recv_byte(int fd, int expected_ret, int flags)
422 {
423 	uint8_t byte;
424 
425 	recv_buf(fd, &byte, sizeof(byte), flags, expected_ret);
426 
427 	if (byte != 'A') {
428 		fprintf(stderr, "unexpected byte read 0x%02x\n", byte);
429 		exit(EXIT_FAILURE);
430 	}
431 }
432 
433 /* Run test cases.  The program terminates if a failure occurs. */
434 void run_tests(const struct test_case *test_cases,
435 	       const struct test_opts *opts)
436 {
437 	int i;
438 
439 	for (i = 0; test_cases[i].name; i++) {
440 		void (*run)(const struct test_opts *opts);
441 		char *line;
442 
443 		printf("%d - %s...", i, test_cases[i].name);
444 		fflush(stdout);
445 
446 		/* Full barrier before executing the next test.  This
447 		 * ensures that client and server are executing the
448 		 * same test case.  In particular, it means whoever is
449 		 * faster will not see the peer still executing the
450 		 * last test.  This is important because port numbers
451 		 * can be used by multiple test cases.
452 		 */
453 		if (test_cases[i].skip)
454 			control_writeln("SKIP");
455 		else
456 			control_writeln("NEXT");
457 
458 		line = control_readln();
459 		if (control_cmpln(line, "SKIP", false) || test_cases[i].skip) {
460 
461 			printf("skipped\n");
462 
463 			free(line);
464 			continue;
465 		}
466 
467 		control_cmpln(line, "NEXT", true);
468 		free(line);
469 
470 		if (opts->mode == TEST_MODE_CLIENT)
471 			run = test_cases[i].run_client;
472 		else
473 			run = test_cases[i].run_server;
474 
475 		if (run)
476 			run(opts);
477 
478 		printf("ok\n");
479 	}
480 }
481 
482 void list_tests(const struct test_case *test_cases)
483 {
484 	int i;
485 
486 	printf("ID\tTest name\n");
487 
488 	for (i = 0; test_cases[i].name; i++)
489 		printf("%d\t%s\n", i, test_cases[i].name);
490 
491 	exit(EXIT_FAILURE);
492 }
493 
494 static unsigned long parse_test_id(const char *test_id_str, size_t test_cases_len)
495 {
496 	unsigned long test_id;
497 	char *endptr = NULL;
498 
499 	errno = 0;
500 	test_id = strtoul(test_id_str, &endptr, 10);
501 	if (errno || *endptr != '\0') {
502 		fprintf(stderr, "malformed test ID \"%s\"\n", test_id_str);
503 		exit(EXIT_FAILURE);
504 	}
505 
506 	if (test_id >= test_cases_len) {
507 		fprintf(stderr, "test ID (%lu) larger than the max allowed (%lu)\n",
508 			test_id, test_cases_len - 1);
509 		exit(EXIT_FAILURE);
510 	}
511 
512 	return test_id;
513 }
514 
515 void skip_test(struct test_case *test_cases, size_t test_cases_len,
516 	       const char *test_id_str)
517 {
518 	unsigned long test_id = parse_test_id(test_id_str, test_cases_len);
519 	test_cases[test_id].skip = true;
520 }
521 
522 void pick_test(struct test_case *test_cases, size_t test_cases_len,
523 	       const char *test_id_str)
524 {
525 	static bool skip_all = true;
526 	unsigned long test_id;
527 
528 	if (skip_all) {
529 		unsigned long i;
530 
531 		for (i = 0; i < test_cases_len; ++i)
532 			test_cases[i].skip = true;
533 
534 		skip_all = false;
535 	}
536 
537 	test_id = parse_test_id(test_id_str, test_cases_len);
538 	test_cases[test_id].skip = false;
539 }
540 
541 unsigned long hash_djb2(const void *data, size_t len)
542 {
543 	unsigned long hash = 5381;
544 	int i = 0;
545 
546 	while (i < len) {
547 		hash = ((hash << 5) + hash) + ((unsigned char *)data)[i];
548 		i++;
549 	}
550 
551 	return hash;
552 }
553 
554 size_t iovec_bytes(const struct iovec *iov, size_t iovnum)
555 {
556 	size_t bytes;
557 	int i;
558 
559 	for (bytes = 0, i = 0; i < iovnum; i++)
560 		bytes += iov[i].iov_len;
561 
562 	return bytes;
563 }
564 
565 unsigned long iovec_hash_djb2(const struct iovec *iov, size_t iovnum)
566 {
567 	unsigned long hash;
568 	size_t iov_bytes;
569 	size_t offs;
570 	void *tmp;
571 	int i;
572 
573 	iov_bytes = iovec_bytes(iov, iovnum);
574 
575 	tmp = malloc(iov_bytes);
576 	if (!tmp) {
577 		perror("malloc");
578 		exit(EXIT_FAILURE);
579 	}
580 
581 	for (offs = 0, i = 0; i < iovnum; i++) {
582 		memcpy(tmp + offs, iov[i].iov_base, iov[i].iov_len);
583 		offs += iov[i].iov_len;
584 	}
585 
586 	hash = hash_djb2(tmp, iov_bytes);
587 	free(tmp);
588 
589 	return hash;
590 }
591 
592 /* Allocates and returns new 'struct iovec *' according pattern
593  * in the 'test_iovec'. For each element in the 'test_iovec' it
594  * allocates new element in the resulting 'iovec'. 'iov_len'
595  * of the new element is copied from 'test_iovec'. 'iov_base' is
596  * allocated depending on the 'iov_base' of 'test_iovec':
597  *
598  * 'iov_base' == NULL -> valid buf: mmap('iov_len').
599  *
600  * 'iov_base' == MAP_FAILED -> invalid buf:
601  *               mmap('iov_len'), then munmap('iov_len').
602  *               'iov_base' still contains result of
603  *               mmap().
604  *
605  * 'iov_base' == number -> unaligned valid buf:
606  *               mmap('iov_len') + number.
607  *
608  * 'iovnum' is number of elements in 'test_iovec'.
609  *
610  * Returns new 'iovec' or calls 'exit()' on error.
611  */
612 struct iovec *alloc_test_iovec(const struct iovec *test_iovec, int iovnum)
613 {
614 	struct iovec *iovec;
615 	int i;
616 
617 	iovec = malloc(sizeof(*iovec) * iovnum);
618 	if (!iovec) {
619 		perror("malloc");
620 		exit(EXIT_FAILURE);
621 	}
622 
623 	for (i = 0; i < iovnum; i++) {
624 		iovec[i].iov_len = test_iovec[i].iov_len;
625 
626 		iovec[i].iov_base = mmap(NULL, iovec[i].iov_len,
627 					 PROT_READ | PROT_WRITE,
628 					 MAP_PRIVATE | MAP_ANONYMOUS | MAP_POPULATE,
629 					 -1, 0);
630 		if (iovec[i].iov_base == MAP_FAILED) {
631 			perror("mmap");
632 			exit(EXIT_FAILURE);
633 		}
634 
635 		if (test_iovec[i].iov_base != MAP_FAILED)
636 			iovec[i].iov_base += (uintptr_t)test_iovec[i].iov_base;
637 	}
638 
639 	/* Unmap "invalid" elements. */
640 	for (i = 0; i < iovnum; i++) {
641 		if (test_iovec[i].iov_base == MAP_FAILED) {
642 			if (munmap(iovec[i].iov_base, iovec[i].iov_len)) {
643 				perror("munmap");
644 				exit(EXIT_FAILURE);
645 			}
646 		}
647 	}
648 
649 	for (i = 0; i < iovnum; i++) {
650 		int j;
651 
652 		if (test_iovec[i].iov_base == MAP_FAILED)
653 			continue;
654 
655 		for (j = 0; j < iovec[i].iov_len; j++)
656 			((uint8_t *)iovec[i].iov_base)[j] = rand() & 0xff;
657 	}
658 
659 	return iovec;
660 }
661 
662 /* Frees 'iovec *', previously allocated by 'alloc_test_iovec()'.
663  * On error calls 'exit()'.
664  */
665 void free_test_iovec(const struct iovec *test_iovec,
666 		     struct iovec *iovec, int iovnum)
667 {
668 	int i;
669 
670 	for (i = 0; i < iovnum; i++) {
671 		if (test_iovec[i].iov_base != MAP_FAILED) {
672 			if (test_iovec[i].iov_base)
673 				iovec[i].iov_base -= (uintptr_t)test_iovec[i].iov_base;
674 
675 			if (munmap(iovec[i].iov_base, iovec[i].iov_len)) {
676 				perror("munmap");
677 				exit(EXIT_FAILURE);
678 			}
679 		}
680 	}
681 
682 	free(iovec);
683 }
684 
685 /* Set "unsigned long long" socket option and check that it's indeed set */
686 void setsockopt_ull_check(int fd, int level, int optname,
687 			  unsigned long long val, char const *errmsg)
688 {
689 	unsigned long long chkval;
690 	socklen_t chklen;
691 	int err;
692 
693 	err = setsockopt(fd, level, optname, &val, sizeof(val));
694 	if (err) {
695 		fprintf(stderr, "setsockopt err: %s (%d)\n",
696 			strerror(errno), errno);
697 		goto fail;
698 	}
699 
700 	chkval = ~val; /* just make storage != val */
701 	chklen = sizeof(chkval);
702 
703 	err = getsockopt(fd, level, optname, &chkval, &chklen);
704 	if (err) {
705 		fprintf(stderr, "getsockopt err: %s (%d)\n",
706 			strerror(errno), errno);
707 		goto fail;
708 	}
709 
710 	if (chklen != sizeof(chkval)) {
711 		fprintf(stderr, "size mismatch: set %zu got %d\n", sizeof(val),
712 			chklen);
713 		goto fail;
714 	}
715 
716 	if (chkval != val) {
717 		fprintf(stderr, "value mismatch: set %llu got %llu\n", val,
718 			chkval);
719 		goto fail;
720 	}
721 	return;
722 fail:
723 	fprintf(stderr, "%s  val %llu\n", errmsg, val);
724 	exit(EXIT_FAILURE);
725 ;
726 }
727 
728 /* Set "int" socket option and check that it's indeed set */
729 void setsockopt_int_check(int fd, int level, int optname, int val,
730 			  char const *errmsg)
731 {
732 	int chkval;
733 	socklen_t chklen;
734 	int err;
735 
736 	err = setsockopt(fd, level, optname, &val, sizeof(val));
737 	if (err) {
738 		fprintf(stderr, "setsockopt err: %s (%d)\n",
739 			strerror(errno), errno);
740 		goto fail;
741 	}
742 
743 	chkval = ~val; /* just make storage != val */
744 	chklen = sizeof(chkval);
745 
746 	err = getsockopt(fd, level, optname, &chkval, &chklen);
747 	if (err) {
748 		fprintf(stderr, "getsockopt err: %s (%d)\n",
749 			strerror(errno), errno);
750 		goto fail;
751 	}
752 
753 	if (chklen != sizeof(chkval)) {
754 		fprintf(stderr, "size mismatch: set %zu got %d\n", sizeof(val),
755 			chklen);
756 		goto fail;
757 	}
758 
759 	if (chkval != val) {
760 		fprintf(stderr, "value mismatch: set %d got %d\n", val, chkval);
761 		goto fail;
762 	}
763 	return;
764 fail:
765 	fprintf(stderr, "%s val %d\n", errmsg, val);
766 	exit(EXIT_FAILURE);
767 }
768 
769 static void mem_invert(unsigned char *mem, size_t size)
770 {
771 	size_t i;
772 
773 	for (i = 0; i < size; i++)
774 		mem[i] = ~mem[i];
775 }
776 
777 /* Set "timeval" socket option and check that it's indeed set */
778 void setsockopt_timeval_check(int fd, int level, int optname,
779 			      struct timeval val, char const *errmsg)
780 {
781 	struct timeval chkval;
782 	socklen_t chklen;
783 	int err;
784 
785 	err = setsockopt(fd, level, optname, &val, sizeof(val));
786 	if (err) {
787 		fprintf(stderr, "setsockopt err: %s (%d)\n",
788 			strerror(errno), errno);
789 		goto fail;
790 	}
791 
792 	 /* just make storage != val */
793 	chkval = val;
794 	mem_invert((unsigned char *)&chkval, sizeof(chkval));
795 	chklen = sizeof(chkval);
796 
797 	err = getsockopt(fd, level, optname, &chkval, &chklen);
798 	if (err) {
799 		fprintf(stderr, "getsockopt err: %s (%d)\n",
800 			strerror(errno), errno);
801 		goto fail;
802 	}
803 
804 	if (chklen != sizeof(chkval)) {
805 		fprintf(stderr, "size mismatch: set %zu got %d\n", sizeof(val),
806 			chklen);
807 		goto fail;
808 	}
809 
810 	if (memcmp(&chkval, &val, sizeof(val)) != 0) {
811 		fprintf(stderr, "value mismatch: set %ld:%ld got %ld:%ld\n",
812 			val.tv_sec, val.tv_usec, chkval.tv_sec, chkval.tv_usec);
813 		goto fail;
814 	}
815 	return;
816 fail:
817 	fprintf(stderr, "%s val %ld:%ld\n", errmsg, val.tv_sec, val.tv_usec);
818 	exit(EXIT_FAILURE);
819 }
820 
821 void enable_so_zerocopy_check(int fd)
822 {
823 	setsockopt_int_check(fd, SOL_SOCKET, SO_ZEROCOPY, 1,
824 			     "setsockopt SO_ZEROCOPY");
825 }
826 
827 void enable_so_linger(int fd, int timeout)
828 {
829 	struct linger optval = {
830 		.l_onoff = 1,
831 		.l_linger = timeout
832 	};
833 
834 	if (setsockopt(fd, SOL_SOCKET, SO_LINGER, &optval, sizeof(optval))) {
835 		perror("setsockopt(SO_LINGER)");
836 		exit(EXIT_FAILURE);
837 	}
838 }
839