inetd: fix order of array index check and array access
[oweals/busybox.git] / init / halt.c
1 /* vi: set sw=4 ts=4: */
2 /*
3  * Poweroff reboot and halt, oh my.
4  *
5  * Copyright 2006 by Rob Landley <rob@landley.net>
6  *
7  * Licensed under GPLv2, see file LICENSE in this source tree.
8  */
9
10 //applet:IF_HALT(APPLET(halt, BB_DIR_SBIN, BB_SUID_DROP))
11 //applet:IF_HALT(APPLET_ODDNAME(poweroff, halt, BB_DIR_SBIN, BB_SUID_DROP, poweroff))
12 //applet:IF_HALT(APPLET_ODDNAME(reboot, halt, BB_DIR_SBIN, BB_SUID_DROP, reboot))
13
14 //kbuild:lib-$(CONFIG_HALT) += halt.o
15
16 //config:config HALT
17 //config:       bool "poweroff, halt, and reboot"
18 //config:       default y
19 //config:       help
20 //config:         Stop all processes and either halt, reboot, or power off the system.
21 //config:
22 //config:config FEATURE_CALL_TELINIT
23 //config:       bool "Call telinit on shutdown and reboot"
24 //config:       default y
25 //config:       depends on HALT && !INIT
26 //config:       help
27 //config:         Call an external program (normally telinit) to facilitate
28 //config:         a switch to a proper runlevel.
29 //config:
30 //config:         This option is only available if you selected halt and friends,
31 //config:         but did not select init.
32 //config:
33 //config:config TELINIT_PATH
34 //config:       string "Path to telinit executable"
35 //config:       default "/sbin/telinit"
36 //config:       depends on FEATURE_CALL_TELINIT
37 //config:       help
38 //config:         When busybox halt and friends have to call external telinit
39 //config:         to facilitate proper shutdown, this path is to be used when
40 //config:         locating telinit executable.
41
42 //usage:#define halt_trivial_usage
43 //usage:       "[-d DELAY] [-n] [-f]" IF_FEATURE_WTMP(" [-w]")
44 //usage:#define halt_full_usage "\n\n"
45 //usage:       "Halt the system\n"
46 //usage:     "\n        -d SEC  Delay interval"
47 //usage:     "\n        -n      Do not sync"
48 //usage:     "\n        -f      Force (don't go through init)"
49 //usage:        IF_FEATURE_WTMP(
50 //usage:     "\n        -w      Only write a wtmp record"
51 //usage:        )
52 //usage:
53 //usage:#define poweroff_trivial_usage
54 //usage:       "[-d DELAY] [-n] [-f]"
55 //usage:#define poweroff_full_usage "\n\n"
56 //usage:       "Halt and shut off power\n"
57 //usage:     "\n        -d SEC  Delay interval"
58 //usage:     "\n        -n      Do not sync"
59 //usage:     "\n        -f      Force (don't go through init)"
60 //usage:
61 //usage:#define reboot_trivial_usage
62 //usage:       "[-d DELAY] [-n] [-f]"
63 //usage:#define reboot_full_usage "\n\n"
64 //usage:       "Reboot the system\n"
65 //usage:     "\n        -d SEC  Delay interval"
66 //usage:     "\n        -n      Do not sync"
67 //usage:     "\n        -f      Force (don't go through init)"
68
69 #include "libbb.h"
70 #include "reboot.h"
71
72 #if ENABLE_FEATURE_WTMP
73 #include <sys/utsname.h>
74
75 static void write_wtmp(void)
76 {
77         struct utmp utmp;
78         struct utsname uts;
79         /* "man utmp" says wtmp file should *not* be created automagically */
80         /*if (access(bb_path_wtmp_file, R_OK|W_OK) == -1) {
81                 close(creat(bb_path_wtmp_file, 0664));
82         }*/
83         memset(&utmp, 0, sizeof(utmp));
84         utmp.ut_tv.tv_sec = time(NULL);
85         strcpy(utmp.ut_user, "shutdown"); /* it is wide enough */
86         utmp.ut_type = RUN_LVL;
87         utmp.ut_id[0] = '~'; utmp.ut_id[1] = '~'; /* = strcpy(utmp.ut_id, "~~"); */
88         utmp.ut_line[0] = '~'; utmp.ut_line[1] = '~'; /* = strcpy(utmp.ut_line, "~~"); */
89         uname(&uts);
90         safe_strncpy(utmp.ut_host, uts.release, sizeof(utmp.ut_host));
91         updwtmp(bb_path_wtmp_file, &utmp);
92 }
93 #else
94 #define write_wtmp() ((void)0)
95 #endif
96
97
98 int halt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
99 int halt_main(int argc UNUSED_PARAM, char **argv)
100 {
101         static const int magic[] = {
102                 RB_HALT_SYSTEM,
103                 RB_POWER_OFF,
104                 RB_AUTOBOOT
105         };
106         static const smallint signals[] = { SIGUSR1, SIGUSR2, SIGTERM };
107
108         int delay = 0;
109         int which, flags, rc;
110
111         /* Figure out which applet we're running */
112         for (which = 0; "hpr"[which] != applet_name[0]; which++)
113                 continue;
114
115         /* Parse and handle arguments */
116         opt_complementary = "d+"; /* -d N */
117         /* We support -w even if !ENABLE_FEATURE_WTMP,
118          * in order to not break scripts.
119          * -i (shut down network interfaces) is ignored.
120          */
121         flags = getopt32(argv, "d:nfwi", &delay);
122
123         sleep(delay);
124
125         write_wtmp();
126
127         if (flags & 8) /* -w */
128                 return EXIT_SUCCESS;
129
130         if (!(flags & 2)) /* no -n */
131                 sync();
132
133         /* Perform action. */
134         rc = 1;
135         if (!(flags & 4)) { /* no -f */
136 //TODO: I tend to think that signalling linuxrc is wrong
137 // pity original author didn't comment on it...
138                 if (ENABLE_FEATURE_INITRD) {
139                         /* talk to linuxrc */
140                         /* bbox init/linuxrc assumed */
141                         pid_t *pidlist = find_pid_by_name("linuxrc");
142                         if (pidlist[0] > 0)
143                                 rc = kill(pidlist[0], signals[which]);
144                         if (ENABLE_FEATURE_CLEAN_UP)
145                                 free(pidlist);
146                 }
147                 if (rc) {
148                         /* talk to init */
149                         if (!ENABLE_FEATURE_CALL_TELINIT) {
150                                 /* bbox init assumed */
151                                 rc = kill(1, signals[which]);
152                         } else {
153                                 /* SysV style init assumed */
154                                 /* runlevels:
155                                  * 0 == shutdown
156                                  * 6 == reboot */
157                                 execlp(CONFIG_TELINIT_PATH,
158                                                 CONFIG_TELINIT_PATH,
159                                                 which == 2 ? "6" : "0",
160                                                 (char *)NULL
161                                 );
162                                 bb_perror_msg_and_die("can't execute '%s'",
163                                                 CONFIG_TELINIT_PATH);
164                         }
165                 }
166         } else {
167                 rc = reboot(magic[which]);
168         }
169
170         if (rc)
171                 bb_perror_nomsg_and_die();
172         return rc;
173 }