tls: prepare for ECDH_anon ciphers
[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 //config:config HALT
10 //config:       bool "halt (3.7 kb)"
11 //config:       default y
12 //config:       help
13 //config:       Stop all processes and halt the system.
14 //config:
15 //config:config POWEROFF
16 //config:       bool "poweroff (3.7 kb)"
17 //config:       default y
18 //config:       help
19 //config:       Stop all processes and power off the system.
20 //config:
21 //config:config REBOOT
22 //config:       bool "reboot (3.7 kb)"
23 //config:       default y
24 //config:       help
25 //config:       Stop all processes and reboot the system.
26 //config:
27 //config:config FEATURE_WAIT_FOR_INIT
28 //config:       bool "Before signaling init, make sure it is ready for it"
29 //config:       default y
30 //config:       depends on HALT || POWEROFF || REBOOT
31 //config:       help
32 //config:       In rare cases, poweroff may be commanded by firmware to OS
33 //config:       even before init process exists. On Linux, this spawns
34 //config:       "/sbin/poweroff" very early. This option adds code
35 //config:       which checks that init is ready to receive poweroff
36 //config:       commands. Code size increase of ~80 bytes.
37 //config:
38 //config:config FEATURE_CALL_TELINIT
39 //config:       bool "Call telinit on shutdown and reboot"
40 //config:       default y
41 //config:       depends on (HALT || POWEROFF || REBOOT) && !INIT
42 //config:       help
43 //config:       Call an external program (normally telinit) to facilitate
44 //config:       a switch to a proper runlevel.
45 //config:
46 //config:       This option is only available if you selected halt and friends,
47 //config:       but did not select init.
48 //config:
49 //config:config TELINIT_PATH
50 //config:       string "Path to telinit executable"
51 //config:       default "/sbin/telinit"
52 //config:       depends on FEATURE_CALL_TELINIT
53 //config:       help
54 //config:       When busybox halt and friends have to call external telinit
55 //config:       to facilitate proper shutdown, this path is to be used when
56 //config:       locating telinit executable.
57
58 //applet:IF_HALT(APPLET(halt, BB_DIR_SBIN, BB_SUID_DROP))
59 //                   APPLET_ODDNAME:name      main  location     suid_type     help
60 //applet:IF_POWEROFF(APPLET_ODDNAME(poweroff, halt, BB_DIR_SBIN, BB_SUID_DROP, poweroff))
61 //applet:IF_REBOOT(  APPLET_ODDNAME(reboot,   halt, BB_DIR_SBIN, BB_SUID_DROP, reboot))
62
63 //kbuild:lib-$(CONFIG_HALT) += halt.o
64 //kbuild:lib-$(CONFIG_POWEROFF) += halt.o
65 //kbuild:lib-$(CONFIG_REBOOT) += halt.o
66
67 //usage:#define halt_trivial_usage
68 //usage:       "[-d DELAY] [-n] [-f]" IF_FEATURE_WTMP(" [-w]")
69 //usage:#define halt_full_usage "\n\n"
70 //usage:       "Halt the system\n"
71 //usage:     "\n        -d SEC  Delay interval"
72 //usage:     "\n        -n      Do not sync"
73 //usage:     "\n        -f      Force (don't go through init)"
74 //usage:        IF_FEATURE_WTMP(
75 //usage:     "\n        -w      Only write a wtmp record"
76 //usage:        )
77 //usage:
78 //usage:#define poweroff_trivial_usage
79 //usage:       "[-d DELAY] [-n] [-f]"
80 //usage:#define poweroff_full_usage "\n\n"
81 //usage:       "Halt and shut off power\n"
82 //usage:     "\n        -d SEC  Delay interval"
83 //usage:     "\n        -n      Do not sync"
84 //usage:     "\n        -f      Force (don't go through init)"
85 //usage:
86 //usage:#define reboot_trivial_usage
87 //usage:       "[-d DELAY] [-n] [-f]"
88 //usage:#define reboot_full_usage "\n\n"
89 //usage:       "Reboot the system\n"
90 //usage:     "\n        -d SEC  Delay interval"
91 //usage:     "\n        -n      Do not sync"
92 //usage:     "\n        -f      Force (don't go through init)"
93
94 #include "libbb.h"
95 #include "reboot.h"
96
97 #if ENABLE_FEATURE_WTMP
98 #include <sys/utsname.h>
99
100 static void write_wtmp(void)
101 {
102         struct utmpx utmp;
103         struct utsname uts;
104         /* "man utmp" says wtmp file should *not* be created automagically */
105         /*if (access(bb_path_wtmp_file, R_OK|W_OK) == -1) {
106                 close(creat(bb_path_wtmp_file, 0664));
107         }*/
108         memset(&utmp, 0, sizeof(utmp));
109         utmp.ut_tv.tv_sec = time(NULL);
110         strcpy(utmp.ut_user, "shutdown"); /* it is wide enough */
111         utmp.ut_type = RUN_LVL;
112         utmp.ut_id[0] = '~'; utmp.ut_id[1] = '~'; /* = strcpy(utmp.ut_id, "~~"); */
113         utmp.ut_line[0] = '~'; utmp.ut_line[1] = '~'; /* = strcpy(utmp.ut_line, "~~"); */
114         uname(&uts);
115         safe_strncpy(utmp.ut_host, uts.release, sizeof(utmp.ut_host));
116         updwtmpx(bb_path_wtmp_file, &utmp);
117 }
118 #else
119 #define write_wtmp() ((void)0)
120 #endif
121
122 #if ENABLE_FEATURE_WAIT_FOR_INIT
123 /* In Linux, "poweroff" may be spawned even before init.
124  * For example, with ACPI:
125  * linux/drivers/acpi/bus.c:
126  *  static void sb_notify_work(struct work_struct *dummy)
127  *      orderly_poweroff(true);
128  * linux/kernel/reboot.c:
129  *  static int run_cmd(const char *cmd)
130  *      ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
131  *  poweroff_cmd[] = "/sbin/poweroff";
132  *  static int __orderly_poweroff(bool force)
133  *      ret = run_cmd(poweroff_cmd);
134  *
135  * We want to make sure init exists and listens to signals.
136  */
137 static int init_was_not_there(void)
138 {
139         enum { initial = 5 }; /* 5 seconds should be plenty for timeout */
140         int cnt = initial - 1;
141
142         /* Just existence of PID 1 does not mean it installed
143          * the handlers already.
144          */
145 #if 0
146         while (kill(1, 0) != 0 && --cnt >= 0)
147                 sleep(1);
148 #endif
149         /* ... so let's wait for some evidence a usual startup event,
150          * mounting of /proc, happened. By that time init should be ready
151          * for signals.
152          */
153         while (access("/proc/meminfo", F_OK) != 0 && --cnt >= 0)
154                 sleep(1);
155
156         /* Does it look like init wasn't there? */
157         return (cnt != initial - 1);
158 }
159 #else
160   /* Assume it's always there */
161 # define init_was_not_there() 0
162 #endif
163
164 int halt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
165 int halt_main(int argc UNUSED_PARAM, char **argv)
166 {
167         static const int magic[] = {
168                 RB_HALT_SYSTEM,
169                 RB_POWER_OFF,
170                 RB_AUTOBOOT
171         };
172         static const smallint signals[] = { SIGUSR1, SIGUSR2, SIGTERM };
173
174         int delay = 0;
175         int which, flags, rc;
176
177         /* Figure out which applet we're running */
178         if (ENABLE_HALT && !ENABLE_POWEROFF && !ENABLE_REBOOT)
179                 which = 0;
180         else
181         if (!ENABLE_HALT && ENABLE_POWEROFF && !ENABLE_REBOOT)
182                 which = 1;
183         else
184         if (!ENABLE_HALT && !ENABLE_POWEROFF && ENABLE_REBOOT)
185                 which = 2;
186         else
187         for (which = 0; "hpr"[which] != applet_name[0]; which++)
188                 continue;
189
190         /* Parse and handle arguments */
191         /* We support -w even if !ENABLE_FEATURE_WTMP,
192          * in order to not break scripts.
193          * -i (shut down network interfaces) is ignored.
194          */
195         flags = getopt32(argv, "d:+nfwi", &delay);
196
197         sleep(delay);
198
199         write_wtmp();
200
201         if (flags & 8) /* -w */
202                 return EXIT_SUCCESS;
203
204         if (!(flags & 2)) /* no -n */
205                 sync();
206
207         /* Perform action. */
208         rc = 1;
209         if (!(flags & 4)) { /* no -f */
210 //TODO: I tend to think that signalling linuxrc is wrong
211 // pity original author didn't comment on it...
212                 if (ENABLE_LINUXRC) {
213                         /* talk to linuxrc */
214                         /* bbox init/linuxrc assumed */
215                         pid_t *pidlist = find_pid_by_name("linuxrc");
216                         if (pidlist[0] > 0)
217                                 rc = kill(pidlist[0], signals[which]);
218                         if (ENABLE_FEATURE_CLEAN_UP)
219                                 free(pidlist);
220                 }
221                 if (rc) {
222                         /* talk to init */
223                         if (!ENABLE_FEATURE_CALL_TELINIT) {
224                                 /* bbox init assumed */
225                                 rc = kill(1, signals[which]);
226                                 if (init_was_not_there())
227                                         rc = kill(1, signals[which]);
228                         } else {
229                                 /* SysV style init assumed */
230                                 /* runlevels:
231                                  * 0 == shutdown
232                                  * 6 == reboot */
233                                 execlp(CONFIG_TELINIT_PATH,
234                                                 CONFIG_TELINIT_PATH,
235                                                 which == 2 ? "6" : "0",
236                                                 (char *)NULL
237                                 );
238                                 bb_perror_msg_and_die("can't execute '%s'",
239                                                 CONFIG_TELINIT_PATH);
240                         }
241                 }
242         } else {
243                 rc = reboot(magic[which]);
244         }
245
246         if (rc)
247                 bb_perror_nomsg_and_die();
248         return rc;
249 }