1/*
2 * Copyright (c) 2015 Dmitry V. Levin <ldv@altlinux.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 *    derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include <assert.h>
29#include <string.h>
30#include <unistd.h>
31#include <sys/socket.h>
32#include <sys/wait.h>
33
34static void
35transpose(char *str, int len)
36{
37	int i;
38
39	for (i = 0; i < len / 2; ++i) {
40		char c = str[i];
41		str[i] = str[len - 1 - i];
42		str[len - 1 - i] = c;
43	}
44}
45
46int
47main(int ac, char **av)
48{
49	assert(ac == 2);
50	const int len = strlen(av[1]);
51	assert(len);
52
53	(void) close(0);
54	(void) close(1);
55
56	int sv[2];
57	assert(socketpair(AF_UNIX, SOCK_STREAM, 0, sv) == 0);
58	assert(sv[0] == 0);
59	assert(sv[1] == 1);
60
61	pid_t pid = fork();
62	assert(pid >= 0);
63
64	if (pid) {
65		assert(close(1) == 0);
66		transpose(av[1], len);
67		assert(sendto(0, av[1], len, MSG_DONTROUTE, NULL, 0) == len);
68		assert(recvfrom(0, av[1], len, MSG_WAITALL, NULL, NULL) == len);
69		assert(close(0) == 0);
70
71                int status;
72		assert(waitpid(pid, &status, 0) == pid);
73		assert(status == 0);
74	} else {
75		assert(close(0) == 0);
76		assert(recvfrom(1, av[1], len, MSG_WAITALL, NULL, NULL) == len);
77		transpose(av[1], len);
78		assert(sendto(1, av[1], len, MSG_DONTROUTE, NULL, 0) == len);
79		assert(recvfrom(1, av[1], len, MSG_WAITALL, NULL, NULL) == 0);
80		assert(close(1) == 0);
81	}
82
83	return 0;
84}
85