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#ifdef HAVE_CONFIG_H
29# include "config.h"
30#endif
31
32#include <stdio.h>
33#include <string.h>
34#include <unistd.h>
35#include <sys/wait.h>
36
37static int
38logit(const char *const str)
39{
40	return pwrite(-1, str, strlen(str), 0) >= 0;
41}
42
43int main(int ac, char **av, char **ep)
44{
45	if (ac < 1)
46		return 1;
47	if (ac > 1)
48		return logit(av[1]);
49
50	logit("start");
51
52	int fds[2];
53	(void) close(0);
54	if (pipe(fds)) {
55		perror("pipe");
56		return 77;
57	}
58
59	pid_t pid = fork();
60
61	if (pid < 0) {
62		perror("fork");
63		return 77;
64	}
65
66	if (!pid) {
67		close(fds[1]);
68
69		if (read(0, fds, sizeof(int)))
70			_exit(2);
71
72		char *const args[] = { av[0], (char *) "exec", NULL };
73		if (logit("child") || execve(args[0], args, args + 1))
74			_exit(2);
75	}
76
77	close(0);
78
79	logit("parent");
80	close(fds[1]);
81
82	int status;
83	if (wait(&status) != pid) {
84		perror("wait");
85		return 77;
86	}
87	if (status) {
88		fprintf(stderr, "status = %d\n", status);
89		return 77;
90	}
91
92	logit("finish");
93
94	pid_t ppid = getpid();
95	close(-1);
96	printf("%-5d pwrite64(-1, \"start\", 5, 0) = -1 EBADF (%m)\n"
97	       "%-5d pwrite64(-1, \"parent\", 6, 0) = -1 EBADF (%m)\n"
98	       "%-5d pwrite64(-1, \"child\", 5, 0) = -1 EBADF (%m)\n"
99	       "%-5d pwrite64(-1, \"exec\", 4, 0) = -1 EBADF (%m)\n"
100	       "%-5d pwrite64(-1, \"finish\", 6, 0) = -1 EBADF (%m)\n",
101	       ppid, ppid, pid, pid, ppid);
102	return 0;
103}
104