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timeout.c revision 1.2 
      1 /* $NetBSD: timeout.c,v 1.2 2014/08/01 14:01:30 christos Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2014 Baptiste Daroussin <bapt (at) FreeBSD.org>
      5  * Copyright (c) 2014 Vsevolod Stakhov <vsevolod (at) 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 1.2 2014/08/01 14:01:30 christos 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 
     56 static sig_atomic_t sig_chld = 0;
     57 static sig_atomic_t sig_term = 0;
     58 static sig_atomic_t sig_alrm = 0;
     59 static sig_atomic_t sig_ign = 0;
     60 
     61 static void __dead
     62 usage(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 
     72 static double
     73 parse_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 
    110 static int
    111 parse_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 == INT_MAX || sig == INT_MIN))
    134 		goto err;
    135 	if (sig >= sys_nsig || sig < 0)
    136 		goto err;
    137 
    138 	return (int)sig;
    139 
    140 err:
    141 	errx(EX_USAGE, "invalid signal");
    142 }
    143 
    144 static void
    145 sig_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 
    169 static void
    170 set_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 
    183 int
    184 main(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,       &preserve,    1 },
    216 		{ "foreground",      no_argument,       &foreground,  1 },
    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 = getopt_long(argc, argv, "+k:s:h", longopts, NULL)) != -1) {
    224 		switch (ch) {
    225 			case 'k':
    226 				do_second_kill = true;
    227 				second_kill = parse_duration(optarg);
    228 				break;
    229 			case 's':
    230 				killsig = parse_signal(optarg);
    231 				break;
    232 			case 0:
    233 				break;
    234 			case 'h':
    235 			default:
    236 				usage();
    237 				break;
    238 		}
    239 	}
    240 
    241 	argc -= optind;
    242 	argv += optind;
    243 
    244 	if (argc < 2)
    245 		usage();
    246 
    247 	first_kill = parse_duration(argv[0]);
    248 	argc--;
    249 	argv++;
    250 
    251 	if (!foreground) {
    252 		pgid = setpgid(0,0);
    253 
    254 		if (pgid == -1)
    255 			err(EX_OSERR, "setpgid()");
    256 	}
    257 
    258 	memset(&signals, 0, sizeof(signals));
    259 	sigemptyset(&signals.sa_mask);
    260 
    261 	if (killsig != SIGKILL && killsig != SIGSTOP)
    262 		signums[0] = killsig;
    263 
    264 	for (i = 0; i < sizeof(signums) / sizeof(signums[0]); i ++)
    265 		sigaddset(&signals.sa_mask, signums[i]);
    266 
    267 	signals.sa_handler = sig_handler;
    268 	signals.sa_flags = SA_RESTART;
    269 
    270 	for (i = 0; i < sizeof(signums) / sizeof(signums[0]); i ++)
    271 		if (signums[i] != -1 && signums[i] != 0 &&
    272 		    sigaction(signums[i], &signals, NULL) == -1)
    273 			err(EX_OSERR, "sigaction()");
    274 
    275 	signal(SIGTTIN, SIG_IGN);
    276 	signal(SIGTTOU, SIG_IGN);
    277 
    278 	pid = fork();
    279 	if (pid == -1)
    280 		err(EX_OSERR, "fork()");
    281 	else if (pid == 0) {
    282 		/* child process */
    283 		signal(SIGTTIN, SIG_DFL);
    284 		signal(SIGTTOU, SIG_DFL);
    285 
    286 		error = execvp(argv[0], argv);
    287 		if (error == -1)
    288 			err(EX_UNAVAILABLE, "exec()");
    289 	}
    290 
    291 	if (sigprocmask(SIG_BLOCK, &signals.sa_mask, NULL) == -1)
    292 		err(EX_OSERR, "sigprocmask()");
    293 
    294 	/* parent continues here */
    295 	set_interval(first_kill);
    296 
    297 	for (;;) {
    298 		sigemptyset(&signals.sa_mask);
    299 		sigsuspend(&signals.sa_mask);
    300 
    301 		if (sig_chld) {
    302 			sig_chld = 0;
    303 			while (((cpid = wait(&status)) < 0) && errno == EINTR)
    304 				continue;
    305 
    306 			if (cpid == pid) {
    307 				pstat = status;
    308 				break;
    309 			}
    310 		} else if (sig_alrm) {
    311 			sig_alrm = 0;
    312 
    313 			timedout = true;
    314 			if (!foreground)
    315 				killpg(pgid, killsig);
    316 			else
    317 				kill(pid, killsig);
    318 
    319 			if (do_second_kill) {
    320 				set_interval(second_kill);
    321 				second_kill = 0;
    322 				sig_ign = killsig;
    323 				killsig = SIGKILL;
    324 			} else
    325 				break;
    326 
    327 		} else if (sig_term) {
    328 			if (!foreground)
    329 				killpg(pgid, killsig);
    330 			else
    331 				kill(pid, sig_term);
    332 
    333 			if (do_second_kill) {
    334 				set_interval(second_kill);
    335 				second_kill = 0;
    336 				sig_ign = killsig;
    337 				killsig = SIGKILL;
    338 			} else
    339 				break;
    340 		}
    341 	}
    342 
    343 	while (cpid != pid  && wait(&pstat) == -1) {
    344 		if (errno != EINTR)
    345 			err(EX_OSERR, "waitpid()");
    346 	}
    347 
    348 	if (WEXITSTATUS(pstat))
    349 		pstat = WEXITSTATUS(pstat);
    350 	else if(WIFSIGNALED(pstat))
    351 		pstat = 128 + WTERMSIG(pstat);
    352 
    353 	if (timedout && !preserve)
    354 		pstat = EXIT_TIMEOUT;
    355 
    356 	return (pstat);
    357 }
    358