1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
/*-
* Copyright (c) 2012 David O'Brien
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/types.h>
#include <sys/resource.h>
#include <sys/sysctl.h>
#include <sys/wait.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <err.h>
#include <assert.h>
#ifndef SLEEP
#define SLEEP 20 /* seconds */
#endif
static int verbose;
static void
usage(void)
{
fprintf(stderr, "usage: %s\n", getprogname());
fprintf(stderr, "\t\t-n : length of fork(2) chain\n");
fprintf(stderr, "\t\t-t : limit run-time seconds\n");
exit(1);
/* NOTREACHED */
}
void term(int);
void
term(int signum)
{
if (getpid() == getpgrp() || verbose) {
fprintf(stderr,
"pid %d pgroup %d (ppid %d): Received SIGTERM(%d), exiting...\n",
getpid(), getpgrp(), getppid(), signum);
}
exit(1);
}
void angel_of_mercy(int);
void
angel_of_mercy(int sig __unused)
{
signal(SIGALRM, SIG_IGN); /* ignore this signal */
printf("Master process: alarmed waking up\n");
killpg(0, SIGTERM);
return;
}
int bombing_run(unsigned, int);
int
bombing_run(unsigned chainlen, int stime)
{
struct rusage ru;
pid_t pid, cpid;
int status;
if (chainlen) {
switch (pid = fork()) {
case -1:
errx(1, "%s: can't fork", __func__);
case 0:
/* This is the code the child runs. */
bombing_run(--chainlen, stime);
break;
default:
/* This is the code the parent runs. */
if (getpid() == getpgrp()) {
signal(SIGALRM, angel_of_mercy);
alarm(stime); // time for bombing run...
cpid = wait4(pid, &status, 0, &ru);
alarm(0);
printf(
"Cleanly shutting down - pid %d pgroup %d (ppid %d)\n",
getpid(), getpgrp(), getppid());
} else {
cpid = wait4(pid, &status, 0, &ru);
}
}
}
return 0;
}
int
main(int argc, char *argv[])
{
time_t start /*,tvec*/;
char *endptr, *ctm;
size_t len;
int nflag, tflag;
int ch, k, maxprocperuid;
(void)signal(SIGTERM, term);
nflag = 0;
tflag = SLEEP;
start = time(NULL);
ctm = ctime(&start);
ctm[24] = '\0'; // see: man 3 ctime
fprintf(stderr, "*** fork() generation started on \"%s\" ***\n", ctm);
while ((ch = getopt(argc, argv, "n:t:v")) != -1)
switch (ch) {
case 'n':
nflag = strtol(optarg, &endptr, 10);
if (nflag <= 0 || *endptr != '\0')
errx(1, "illegal number, -n argument -- %s",
optarg);
break;
case 't':
tflag = strtol(optarg, &endptr, 10);
if (tflag <= 0 || *endptr != '\0')
errx(1, "illegal number, -t argument -- %s",
optarg);
break;
case 'v':
++verbose;
break;
default:
usage();
}
argv += optind;
if (!nflag) {
len = sizeof(maxprocperuid);
k = sysctlbyname("kern.maxprocperuid", &maxprocperuid, &len,
NULL, 0);
assert(k != ENOMEM);
/* Try to allow a shell to still be started. */
nflag = maxprocperuid - 10;
}
// Ensure a unique process group to make killing all children easier.
setpgrp(0,0);
printf(" pid %d pgroup %d (ppid %d), %d fork chain over %d sec\n",
getpid(), getpgrp(), getppid(), nflag - 1, tflag);
return bombing_run(nflag, tflag);
}
|
