tst.fds.c revision 313485 
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27#pragma ident	"%Z%%M%	%I%	%E% SMI"
28
29#include <sys/ioctl.h>
30
31#include <assert.h>
32#include <setjmp.h>
33#include <signal.h>
34#include <unistd.h>
35#include <stdlib.h>
36#include <stdio.h>
37#include <fcntl.h>
38
39static sigjmp_buf env;
40
41static void
42interrupt(int sig)
43{
44	siglongjmp(env, sig);
45}
46
47int
48main(int argc, char *argv[])
49{
50	const char *file = "/dev/null";
51	int i, n, fds[10];
52	struct sigaction act;
53
54	if (argc > 1) {
55		(void) fprintf(stderr, "Usage: %s\n", argv[0]);
56		return (EXIT_FAILURE);
57	}
58
59	act.sa_handler = interrupt;
60	act.sa_flags = 0;
61
62	(void) sigemptyset(&act.sa_mask);
63	(void) sigaction(SIGUSR1, &act, NULL);
64
65	closefrom(0);
66	n = 0;
67
68	/*
69	 * With all of our file descriptors closed, wait here spinning in bogus
70	 * ioctl() calls until DTrace hits us with a SIGUSR1 to start the test.
71	 */
72	if (sigsetjmp(env, 1) == 0) {
73		for (;;)
74			(void) ioctl(-1, 0, NULL);
75	}
76
77	/*
78	 * To test the fds[] array, we open /dev/null (a file with reliable
79	 * pathname and properties) using various flags and seek offsets.
80	 */
81	fds[n++] = open(file, O_RDONLY);
82	fds[n++] = open(file, O_WRONLY);
83	fds[n++] = open(file, O_RDWR);
84
85	fds[n++] = open(file, O_RDWR | O_APPEND | O_CREAT |
86	    O_NOCTTY | O_NONBLOCK | O_NDELAY | O_SYNC | O_TRUNC | 0666);
87
88	fds[n++] = open(file, O_RDWR);
89	(void) lseek(fds[n - 1], 123, SEEK_SET);
90
91	/*
92	 * Once we have all the file descriptors in the state we want to test,
93	 * issue a bogus ioctl() on each fd with cmd 0 and arg NULL to whack
94	 * our DTrace script into recording the content of the fds[] array.
95	 */
96	for (i = 0; i < n; i++)
97		(void) ioctl(fds[i], 0, NULL);
98
99	assert(n <= sizeof (fds) / sizeof (fds[0]));
100	exit(0);
101}
102