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/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* 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
*/
#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 = 10;
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 */
opt_complementary = "t+" USE_FOR_NOMMU(":p+");
/* '+': stop at first non-option */
getopt32(argv, "+s:t:" USE_FOR_NOMMU("p:"), &opt_s, &timeout, &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);
/* 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 (!argv[optind]) /* no PROG? */
bb_show_usage();
#if !BB_MMU
sv1 = argv[optind];
sv2 = argv[optind + 1];
#endif
pid = vfork();
if (pid < 0)
bb_perror_msg_and_die("vfork");
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(NUGE_NUM); kill(parent) may kill wrong process! */
while (1) {
sleep(1);
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(argv[0], argv);
bb_perror_msg_and_die("can't execute '%s'", argv[0]);
}
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