busybox/coreutils/timeout.c
Denys Vlasenko ec16c030bd libbb: introduce and use sleep1()
function                                             old     new   delta
sleep1                                                 -       9      +9
run_shutdown_and_kill_processes                       97      95      -2
restore_state_and_exit                               116     114      -2
reread_partition_table                                67      65      -2
flush_buffer_cache                                    80      78      -2
chat_main                                           1302    1300      -2
timeout_main                                         310     307      -3
telnet_main                                         1235    1232      -3
stop_handler                                          86      83      -3
process_action                                      1078    1075      -3
nbdclient_main                                      1185    1182      -3
init_main                                            789     786      -3
getty_main                                          1541    1538      -3
do_time                                              410     407      -3
runsv_main                                          1682    1677      -5
pause_and_low_level_reboot                            59      54      -5
inetd_main                                          1917    1911      -6
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/16 up/down: 9/-50)            Total: -41 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2020-11-29 11:37:34 +01:00

133 lines
4.0 KiB
C

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* COPYING NOTES
*
* timeout.c -- a timeout handler for shell commands
*
* Copyright (C) 2005-6, Roberto A. Foglietta <me@roberto.foglietta.name>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
*/
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* REVISION NOTES:
* released 17-11-2005 by Roberto A. Foglietta
* talarm 04-12-2005 by Roberto A. Foglietta
* modified 05-12-2005 by Roberto A. Foglietta
* sizerdct 06-12-2005 by Roberto A. Foglietta
* splitszf 12-05-2006 by Roberto A. Foglietta
* rewrite 14-11-2008 vda
*/
//config:config TIMEOUT
//config: bool "timeout (6 kb)"
//config: default y
//config: help
//config: Runs a program and watches it. If it does not terminate in
//config: specified number of seconds, it is sent a signal.
//applet:IF_TIMEOUT(APPLET(timeout, BB_DIR_USR_BIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_TIMEOUT) += timeout.o
//usage:#define timeout_trivial_usage
//usage: "[-s SIG] SECS PROG ARGS"
//usage:#define timeout_full_usage "\n\n"
//usage: "Runs PROG. Sends SIG to it if it is not gone in SECS seconds.\n"
//usage: "Default SIG: TERM."
#include "libbb.h"
int timeout_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int timeout_main(int argc UNUSED_PARAM, char **argv)
{
int signo;
int status;
int parent = 0;
int timeout;
pid_t pid;
#if !BB_MMU
char *sv1, *sv2;
#endif
const char *opt_s = "TERM";
/* -p option is not documented, it is needed to support NOMMU. */
/* -t SECONDS; -p PARENT_PID */
/* '+': stop at first non-option */
getopt32(argv, "+s:" USE_FOR_NOMMU("p:+"), &opt_s, &parent);
/*argv += optind; - no, wait for bb_daemonize_or_rexec! */
signo = get_signum(opt_s);
if (signo < 0)
bb_error_msg_and_die("unknown signal '%s'", opt_s);
if (!argv[optind])
bb_show_usage();
timeout = parse_duration_str(argv[optind++]);
if (!argv[optind]) /* no PROG? */
bb_show_usage();
/* We want to create a grandchild which will watch
* and kill the grandparent. Other methods:
* making parent watch child disrupts parent<->child link
* (example: "tcpsvd 0.0.0.0 1234 timeout service_prog" -
* it's better if service_prog is a child of tcpsvd!),
* making child watch parent results in programs having
* unexpected children. */
if (parent) /* we were re-execed, already grandchild */
goto grandchild;
#if !BB_MMU
sv1 = argv[optind];
sv2 = argv[optind + 1];
#endif
pid = xvfork();
if (pid == 0) {
/* Child: spawn grandchild and exit */
parent = getppid();
#if !BB_MMU
argv[optind] = xasprintf("-p%u", parent);
argv[optind + 1] = NULL;
#endif
/* NB: exits with nonzero on error: */
bb_daemonize_or_rexec(0, argv);
/* Here we are grandchild. Sleep, then kill grandparent */
grandchild:
/* Just sleep(HUGE_NUM); kill(parent) may kill wrong process! */
while (1) {
sleep1();
if (--timeout <= 0)
break;
if (kill(parent, 0)) {
/* process is gone */
return EXIT_SUCCESS;
}
}
kill(parent, signo);
return EXIT_SUCCESS;
}
/* Parent */
wait(&status); /* wait for child to die */
/* Did intermediate [v]fork or exec fail? */
if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
return EXIT_FAILURE;
/* Ok, exec a program as requested */
argv += optind;
#if !BB_MMU
argv[0] = sv1;
argv[1] = sv2;
#endif
BB_EXECVP_or_die(argv);
}