blob: f29dc8a9ced4da02addaa8d1fc90fcf8e9294d9c
| 1 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * |
| 2 | * COPYING NOTES |
| 3 | * |
| 4 | * timeout.c -- a timeout handler for shell commands |
| 5 | * |
| 6 | * Copyright (C) 2005-6, Roberto A. Foglietta <me@roberto.foglietta.name> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; version 2 of the License. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA. |
| 20 | */ |
| 21 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * |
| 22 | * REVISION NOTES: |
| 23 | * released 17-11-2005 by Roberto A. Foglietta |
| 24 | * talarm 04-12-2005 by Roberto A. Foglietta |
| 25 | * modified 05-12-2005 by Roberto A. Foglietta |
| 26 | * sizerdct 06-12-2005 by Roberto A. Foglietta |
| 27 | * splitszf 12-05-2006 by Roberto A. Foglietta |
| 28 | * rewrite 14-11-2008 vda |
| 29 | */ |
| 30 | //config:config TIMEOUT |
| 31 | //config: bool "timeout" |
| 32 | //config: default y |
| 33 | //config: help |
| 34 | //config: Runs a program and watches it. If it does not terminate in |
| 35 | //config: specified number of seconds, it is sent a signal. |
| 36 | |
| 37 | //applet:IF_TIMEOUT(APPLET(timeout, BB_DIR_USR_BIN, BB_SUID_DROP)) |
| 38 | |
| 39 | //kbuild:lib-$(CONFIG_TIMEOUT) += timeout.o |
| 40 | |
| 41 | //usage:#define timeout_trivial_usage |
| 42 | //usage: "[-t SECS] [-s SIG] PROG ARGS" |
| 43 | //usage:#define timeout_full_usage "\n\n" |
| 44 | //usage: "Runs PROG. Sends SIG to it if it is not gone in SECS seconds.\n" |
| 45 | //usage: "Defaults: SECS: 10, SIG: TERM." |
| 46 | |
| 47 | #include "libbb.h" |
| 48 | |
| 49 | int timeout_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
| 50 | int timeout_main(int argc UNUSED_PARAM, char **argv) |
| 51 | { |
| 52 | int signo; |
| 53 | int status; |
| 54 | int parent = 0; |
| 55 | int timeout = 10; |
| 56 | pid_t pid; |
| 57 | #if !BB_MMU |
| 58 | char *sv1, *sv2; |
| 59 | #endif |
| 60 | const char *opt_s = "TERM"; |
| 61 | |
| 62 | /* -p option is not documented, it is needed to support NOMMU. */ |
| 63 | |
| 64 | /* -t SECONDS; -p PARENT_PID */ |
| 65 | /* '+': stop at first non-option */ |
| 66 | getopt32(argv, "+s:t:+" USE_FOR_NOMMU("p:+"), &opt_s, &timeout, &parent); |
| 67 | /*argv += optind; - no, wait for bb_daemonize_or_rexec! */ |
| 68 | signo = get_signum(opt_s); |
| 69 | if (signo < 0) |
| 70 | bb_error_msg_and_die("unknown signal '%s'", opt_s); |
| 71 | |
| 72 | /* We want to create a grandchild which will watch |
| 73 | * and kill the grandparent. Other methods: |
| 74 | * making parent watch child disrupts parent<->child link |
| 75 | * (example: "tcpsvd 0.0.0.0 1234 timeout service_prog" - |
| 76 | * it's better if service_prog is a child of tcpsvd!), |
| 77 | * making child watch parent results in programs having |
| 78 | * unexpected children. */ |
| 79 | |
| 80 | if (parent) /* we were re-execed, already grandchild */ |
| 81 | goto grandchild; |
| 82 | if (!argv[optind]) /* no PROG? */ |
| 83 | bb_show_usage(); |
| 84 | |
| 85 | #if !BB_MMU |
| 86 | sv1 = argv[optind]; |
| 87 | sv2 = argv[optind + 1]; |
| 88 | #endif |
| 89 | pid = xvfork(); |
| 90 | if (pid == 0) { |
| 91 | /* Child: spawn grandchild and exit */ |
| 92 | parent = getppid(); |
| 93 | #if !BB_MMU |
| 94 | argv[optind] = xasprintf("-p%u", parent); |
| 95 | argv[optind + 1] = NULL; |
| 96 | #endif |
| 97 | /* NB: exits with nonzero on error: */ |
| 98 | bb_daemonize_or_rexec(0, argv); |
| 99 | /* Here we are grandchild. Sleep, then kill grandparent */ |
| 100 | grandchild: |
| 101 | /* Just sleep(HUGE_NUM); kill(parent) may kill wrong process! */ |
| 102 | while (1) { |
| 103 | sleep(1); |
| 104 | if (--timeout <= 0) |
| 105 | break; |
| 106 | if (kill(parent, 0)) { |
| 107 | /* process is gone */ |
| 108 | return EXIT_SUCCESS; |
| 109 | } |
| 110 | } |
| 111 | kill(parent, signo); |
| 112 | return EXIT_SUCCESS; |
| 113 | } |
| 114 | |
| 115 | /* Parent */ |
| 116 | wait(&status); /* wait for child to die */ |
| 117 | /* Did intermediate [v]fork or exec fail? */ |
| 118 | if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) |
| 119 | return EXIT_FAILURE; |
| 120 | /* Ok, exec a program as requested */ |
| 121 | argv += optind; |
| 122 | #if !BB_MMU |
| 123 | argv[0] = sv1; |
| 124 | argv[1] = sv2; |
| 125 | #endif |
| 126 | BB_EXECVP_or_die(argv); |
| 127 | } |
| 128 |