1/* $NetBSD: timeout.c,v 1.5 2022/12/13 13:25:36 kre Exp $ */
2
3/*-
4 * Copyright (c) 2014 Baptiste Daroussin <bapt@FreeBSD.org>
5 * Copyright (c) 2014 Vsevolod Stakhov <vsevolod@FreeBSD.org>
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer
13 *    in this position and unchanged.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31#if !defined(lint)
32#if 0
33__FBSDID("$FreeBSD: head/usr.bin/timeout/timeout.c 268763 2014-07-16 13:52:05Z bapt $");
34#else
35__RCSID("$NetBSD: timeout.c,v 1.5 2022/12/13 13:25:36 kre Exp $");
36#endif
37#endif /* not lint */
38
39#include <sys/time.h>
40#include <sys/wait.h>
41
42#include <err.h>
43#include <errno.h>
44#include <getopt.h>
45#include <limits.h>
46#include <signal.h>
47#include <stdbool.h>
48#include <stdio.h>
49#include <stdlib.h>
50#include <string.h>
51#include <sysexits.h>
52#include <unistd.h>
53
54#define EXIT_TIMEOUT 124
55
56static sig_atomic_t sig_chld = 0;
57static sig_atomic_t sig_term = 0;
58static sig_atomic_t sig_alrm = 0;
59static sig_atomic_t sig_ign = 0;
60
61static void __dead
62usage(void)
63{
64
65	fprintf(stderr, "Usage: %s [--signal sig | -s sig] [--preserve-status]"
66	    " [--kill-after time | -k time] [--foreground] <duration> <command>"
67	    " <arg ...>\n", getprogname());
68
69	exit(EX_USAGE);
70}
71
72static double
73parse_duration(const char *duration)
74{
75	double ret;
76	char *end;
77
78	ret = strtod(duration, &end);
79	if (ret == 0 && end == duration)
80		errx(EXIT_FAILURE, "invalid duration");
81
82	if (end == NULL || *end == '\0')
83		return (ret);
84
85	if (end != NULL && *(end + 1) != '\0')
86		errx(EX_USAGE, "invalid duration");
87
88	switch (*end) {
89	case 's':
90		break;
91	case 'm':
92		ret *= 60;
93		break;
94	case 'h':
95		ret *= 60 * 60;
96		break;
97	case 'd':
98		ret *= 60 * 60 * 24;
99		break;
100	default:
101		errx(EX_USAGE, "invalid duration");
102	}
103
104	if (ret < 0 || ret >= 100000000UL)
105		errx(EX_USAGE, "invalid duration");
106
107	return (ret);
108}
109
110static int
111parse_signal(const char *str)
112{
113	long sig;
114	int i;
115	char *ep;
116
117	if (strncasecmp(str, "SIG", 3) == 0) {
118		str += 3;
119
120		for (i = 1; i < sys_nsig; i++) {
121			if (strcasecmp(str, sys_signame[i]) == 0)
122				return (i);
123		}
124
125		goto err;
126	}
127
128	errno = 0;
129	sig = strtol(str, &ep, 10);
130
131	if (str[0] == '\0' || *ep != '\0')
132		goto err;
133	if (errno == ERANGE && (sig == LONG_MAX || sig == LONG_MIN))
134		goto err;
135	if (sig >= sys_nsig || sig < 0)
136		goto err;
137
138	return (int)sig;
139
140err:
141	errx(EX_USAGE, "invalid signal");
142}
143
144static void
145sig_handler(int signo)
146{
147	if (sig_ign != 0 && signo == sig_ign) {
148		sig_ign = 0;
149		return;
150	}
151
152	switch(signo) {
153	case 0:
154	case SIGINT:
155	case SIGHUP:
156	case SIGQUIT:
157	case SIGTERM:
158		sig_term = signo;
159		break;
160	case SIGCHLD:
161		sig_chld = 1;
162		break;
163	case SIGALRM:
164		sig_alrm = 1;
165		break;
166	}
167}
168
169static void
170set_interval(double iv)
171{
172	struct itimerval tim;
173
174	memset(&tim, 0, sizeof(tim));
175	tim.it_value.tv_sec = (time_t)iv;
176	iv -= (double)tim.it_value.tv_sec;
177	tim.it_value.tv_usec = (suseconds_t)(iv * 1000000UL);
178
179	if (setitimer(ITIMER_REAL, &tim, NULL) == -1)
180		err(EX_OSERR, "setitimer()");
181}
182
183int
184main(int argc, char **argv)
185{
186	int ch;
187	unsigned long i;
188	int foreground, preserve;
189	int error, pstat, status;
190	int killsig = SIGTERM;
191	pid_t pgid, pid, cpid;
192	double first_kill;
193	double second_kill;
194	bool timedout = false;
195	bool do_second_kill = false;
196	struct sigaction signals;
197	int signums[] = {
198		-1,
199		SIGTERM,
200		SIGINT,
201		SIGHUP,
202		SIGCHLD,
203		SIGALRM,
204		SIGQUIT,
205	};
206
207	setprogname(argv[0]);
208
209	foreground = preserve = 0;
210	second_kill = 0;
211	cpid = -1;
212	pgid = -1;
213
214	const struct option longopts[] = {
215		{ "preserve-status", no_argument,       NULL,        'p'},
216		{ "foreground",      no_argument,       NULL,        'f'},
217		{ "kill-after",      required_argument, NULL,        'k'},
218		{ "signal",          required_argument, NULL,        's'},
219		{ "help",            no_argument,       NULL,        'h'},
220		{ NULL,              0,                 NULL,         0 }
221	};
222
223	while ((ch =
224	    getopt_long(argc, argv, "+fk:ps:h", longopts, NULL)) != -1) {
225		switch (ch) {
226			case 'f':
227				foreground = 1;
228				break;
229			case 'k':
230				do_second_kill = true;
231				second_kill = parse_duration(optarg);
232				break;
233			case 'p':
234				preserve = 1;
235				break;
236			case 's':
237				killsig = parse_signal(optarg);
238				break;
239			case 0:
240				break;
241			case 'h':
242			default:
243				usage();
244				break;
245		}
246	}
247
248	argc -= optind;
249	argv += optind;
250
251	if (argc < 2)
252		usage();
253
254	first_kill = parse_duration(argv[0]);
255	argc--;
256	argv++;
257
258	if (!foreground) {
259		pgid = setpgid(0,0);
260
261		if (pgid == -1)
262			err(EX_OSERR, "setpgid()");
263	}
264
265	memset(&signals, 0, sizeof(signals));
266	sigemptyset(&signals.sa_mask);
267
268	if (killsig != SIGKILL && killsig != SIGSTOP)
269		signums[0] = killsig;
270
271	for (i = 0; i < sizeof(signums) / sizeof(signums[0]); i ++)
272		sigaddset(&signals.sa_mask, signums[i]);
273
274	signals.sa_handler = sig_handler;
275	signals.sa_flags = SA_RESTART;
276
277	for (i = 0; i < sizeof(signums) / sizeof(signums[0]); i ++)
278		if (signums[i] != -1 && signums[i] != 0 &&
279		    sigaction(signums[i], &signals, NULL) == -1)
280			err(EX_OSERR, "sigaction()");
281
282	signal(SIGTTIN, SIG_IGN);
283	signal(SIGTTOU, SIG_IGN);
284
285	pid = fork();
286	if (pid == -1)
287		err(EX_OSERR, "fork()");
288	else if (pid == 0) {
289		/* child process */
290		signal(SIGTTIN, SIG_DFL);
291		signal(SIGTTOU, SIG_DFL);
292
293		error = execvp(argv[0], argv);
294		if (error == -1)
295			err(EX_UNAVAILABLE, "exec()");
296	}
297
298	if (sigprocmask(SIG_BLOCK, &signals.sa_mask, NULL) == -1)
299		err(EX_OSERR, "sigprocmask()");
300
301	/* parent continues here */
302	set_interval(first_kill);
303
304	for (;;) {
305		sigemptyset(&signals.sa_mask);
306		sigsuspend(&signals.sa_mask);
307
308		if (sig_chld) {
309			sig_chld = 0;
310			while (((cpid = wait(&status)) < 0) && errno == EINTR)
311				continue;
312
313			if (cpid == pid) {
314				pstat = status;
315				break;
316			}
317		} else if (sig_alrm) {
318			sig_alrm = 0;
319
320			timedout = true;
321			if (!foreground)
322				killpg(pgid, killsig);
323			else
324				kill(pid, killsig);
325
326			if (do_second_kill) {
327				set_interval(second_kill);
328				second_kill = 0;
329				sig_ign = killsig;
330				killsig = SIGKILL;
331			} else
332				break;
333
334		} else if (sig_term) {
335			if (!foreground)
336				killpg(pgid, killsig);
337			else
338				kill(pid, (int)sig_term);
339
340			if (do_second_kill) {
341				set_interval(second_kill);
342				second_kill = 0;
343				sig_ign = killsig;
344				killsig = SIGKILL;
345			} else
346				break;
347		}
348	}
349
350	while (cpid != pid  && wait(&pstat) == -1) {
351		if (errno != EINTR)
352			err(EX_OSERR, "waitpid()");
353	}
354
355	if (WEXITSTATUS(pstat))
356		pstat = WEXITSTATUS(pstat);
357	else if(WIFSIGNALED(pstat))
358		pstat = 128 + WTERMSIG(pstat);
359
360	if (timedout && !preserve)
361		pstat = EXIT_TIMEOUT;
362
363	return (pstat);
364}
365