blob: 9d56593bae4e456964b66266a96039a0e43cbc57
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 | |
31 | //usage:#define timeout_trivial_usage |
32 | //usage: "[-t SECS] [-s SIG] PROG ARGS" |
33 | //usage:#define timeout_full_usage "\n\n" |
34 | //usage: "Runs PROG. Sends SIG to it if it is not gone in SECS seconds.\n" |
35 | //usage: "Defaults: SECS: 10, SIG: TERM." |
36 | |
37 | #include "libbb.h" |
38 | |
39 | int timeout_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
40 | int timeout_main(int argc UNUSED_PARAM, char **argv) |
41 | { |
42 | int signo; |
43 | int status; |
44 | int parent = 0; |
45 | int timeout = 10; |
46 | pid_t pid; |
47 | #if !BB_MMU |
48 | char *sv1, *sv2; |
49 | #endif |
50 | const char *opt_s = "TERM"; |
51 | |
52 | /* -p option is not documented, it is needed to support NOMMU. */ |
53 | |
54 | /* -t SECONDS; -p PARENT_PID */ |
55 | opt_complementary = "t+" USE_FOR_NOMMU(":p+"); |
56 | /* '+': stop at first non-option */ |
57 | getopt32(argv, "+s:t:" USE_FOR_NOMMU("p:"), &opt_s, &timeout, &parent); |
58 | /*argv += optind; - no, wait for bb_daemonize_or_rexec! */ |
59 | signo = get_signum(opt_s); |
60 | if (signo < 0) |
61 | bb_error_msg_and_die("unknown signal '%s'", opt_s); |
62 | |
63 | /* We want to create a grandchild which will watch |
64 | * and kill the grandparent. Other methods: |
65 | * making parent watch child disrupts parent<->child link |
66 | * (example: "tcpsvd 0.0.0.0 1234 timeout service_prog" - |
67 | * it's better if service_prog is a child of tcpsvd!), |
68 | * making child watch parent results in programs having |
69 | * unexpected children. */ |
70 | |
71 | if (parent) /* we were re-execed, already grandchild */ |
72 | goto grandchild; |
73 | if (!argv[optind]) /* no PROG? */ |
74 | bb_show_usage(); |
75 | |
76 | #if !BB_MMU |
77 | sv1 = argv[optind]; |
78 | sv2 = argv[optind + 1]; |
79 | #endif |
80 | pid = xvfork(); |
81 | if (pid == 0) { |
82 | /* Child: spawn grandchild and exit */ |
83 | parent = getppid(); |
84 | #if !BB_MMU |
85 | argv[optind] = xasprintf("-p%u", parent); |
86 | argv[optind + 1] = NULL; |
87 | #endif |
88 | /* NB: exits with nonzero on error: */ |
89 | bb_daemonize_or_rexec(0, argv); |
90 | /* Here we are grandchild. Sleep, then kill grandparent */ |
91 | grandchild: |
92 | /* Just sleep(HUGE_NUM); kill(parent) may kill wrong process! */ |
93 | while (1) { |
94 | sleep(1); |
95 | if (--timeout <= 0) |
96 | break; |
97 | if (kill(parent, 0)) { |
98 | /* process is gone */ |
99 | return EXIT_SUCCESS; |
100 | } |
101 | } |
102 | kill(parent, signo); |
103 | return EXIT_SUCCESS; |
104 | } |
105 | |
106 | /* Parent */ |
107 | wait(&status); /* wait for child to die */ |
108 | /* Did intermediate [v]fork or exec fail? */ |
109 | if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) |
110 | return EXIT_FAILURE; |
111 | /* Ok, exec a program as requested */ |
112 | argv += optind; |
113 | #if !BB_MMU |
114 | argv[0] = sv1; |
115 | argv[1] = sv2; |
116 | #endif |
117 | BB_EXECVP_or_die(argv); |
118 | } |
119 |