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 2007 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/stat.h>
30#include <stdio.h>
31#include <stdlib.h>
32#include <fcntl.h>
33#include <sys/varargs.h>
34#include <errno.h>
35#include <sys/mman.h>
36#include <sys/wait.h>
37#include <unistd.h>
38
39#define	DTRACEIOC	(('d' << 24) | ('t' << 16) | ('r' << 8))
40#define	DTRACEIOC_MAX	17
41
42void
43fatal(char *fmt, ...)
44{
45	va_list ap;
46
47	va_start(ap, fmt);
48
49	fprintf(stderr, "%s: ", "badioctl");
50	vfprintf(stderr, fmt, ap);
51
52	if (fmt[strlen(fmt) - 1] != '\n')
53		fprintf(stderr, ": %s\n", strerror(errno));
54
55	exit(1);
56}
57
58void
59badioctl(pid_t parent)
60{
61	int fd = -1, random, ps = sysconf(_SC_PAGESIZE);
62	int i = 0, seconds;
63	caddr_t addr;
64	hrtime_t now, last = 0, end;
65
66	if ((random = open("/dev/random", O_RDONLY)) == -1)
67		fatal("couldn't open /dev/random");
68
69	if ((addr = mmap(0, ps, PROT_READ | PROT_WRITE,
70	    MAP_ANON | MAP_PRIVATE, -1, 0)) == (caddr_t)-1)
71		fatal("mmap");
72
73	for (;;) {
74		unsigned int ioc;
75
76		if ((now = gethrtime()) - last > NANOSEC) {
77			if (kill(parent, 0) == -1 && errno == ESRCH) {
78				/*
79				 * Our parent died.  We will kill ourselves in
80				 * sympathy.
81				 */
82				exit(0);
83			}
84
85			/*
86			 * Once a second, we'll reopen the device.
87			 */
88			if (fd != -1)
89				close(fd);
90
91			fd = open("/devices/pseudo/dtrace@0:dtrace", O_RDONLY);
92
93			if (fd == -1)
94				fatal("couldn't open DTrace pseudo device");
95
96			last = now;
97		}
98
99
100		if ((i++ % 1000) == 0) {
101			/*
102			 * Every thousand iterations, change our random gunk.
103			 */
104			read(random, addr, ps);
105		}
106
107		read(random, &ioc, sizeof (ioc));
108		ioc %= DTRACEIOC_MAX;
109		ioc++;
110		ioctl(fd, DTRACEIOC | ioc, addr);
111	}
112}
113
114int
115main()
116{
117	pid_t child, parent = getpid();
118	int status;
119
120	for (;;) {
121		if ((child = fork()) == 0)
122			badioctl(parent);
123
124		while (waitpid(child, &status, WEXITED) != child)
125			continue;
126
127		if (WIFEXITED(status)) {
128			/*
129			 * Our child exited by design -- we'll exit with
130			 * the same status code.
131			 */
132			exit(WEXITSTATUS(status));
133		}
134
135		/*
136		 * Our child died on a signal.  Respawn it.
137		 */
138		printf("badioctl: child died on signal %d; respawning.\n",
139		    WTERMSIG(status));
140		fflush(stdout);
141	}
142
143	/* NOTREACHED */
144	return (0);
145}
146