nix/sys/reboot.rs
1//! Reboot/shutdown
2//!
3//! On Linux, This can also be used to enable/disable Ctrl-Alt-Delete.
4
5use crate::errno::Errno;
6use crate::Result;
7use cfg_if::cfg_if;
8use std::convert::Infallible;
9
10cfg_if! {
11 if #[cfg(target_os = "linux")] {
12 use std::mem::drop;
13
14 libc_enum! {
15 /// How exactly should the system be rebooted.
16 ///
17 /// See [`set_cad_enabled()`](fn.set_cad_enabled.html) for
18 /// enabling/disabling Ctrl-Alt-Delete.
19 #[repr(i32)]
20 #[non_exhaustive]
21 pub enum RebootMode {
22 /// Halt the system.
23 RB_HALT_SYSTEM,
24 /// Execute a kernel that has been loaded earlier with
25 /// [`kexec_load(2)`](https://man7.org/linux/man-pages/man2/kexec_load.2.html).
26 RB_KEXEC,
27 /// Stop the system and switch off power, if possible.
28 RB_POWER_OFF,
29 /// Restart the system.
30 RB_AUTOBOOT,
31 // we do not support Restart2.
32 /// Suspend the system using software suspend.
33 RB_SW_SUSPEND,
34 }
35 }
36
37 /// Reboots or shuts down the system.
38 pub fn reboot(how: RebootMode) -> Result<Infallible> {
39 unsafe { libc::reboot(how as libc::c_int) };
40 Err(Errno::last())
41 }
42
43 /// Enable or disable the reboot keystroke (Ctrl-Alt-Delete).
44 ///
45 /// Corresponds to calling `reboot(RB_ENABLE_CAD)` or `reboot(RB_DISABLE_CAD)` in C.
46 pub fn set_cad_enabled(enable: bool) -> Result<()> {
47 let cmd = if enable {
48 libc::RB_ENABLE_CAD
49 } else {
50 libc::RB_DISABLE_CAD
51 };
52 let res = unsafe { libc::reboot(cmd) };
53 Errno::result(res).map(drop)
54 }
55 } else if #[cfg(netbsdlike)] {
56 use libc::c_int;
57
58 libc_bitflags! {
59 /// How exactly should the system be rebooted.
60 pub struct RebootMode: c_int {
61 /// The default, causing the system to reboot in its usual fashion.
62 RB_AUTOBOOT;
63 /// Interpreted by the bootstrap program itself, causing it to
64 /// prompt on the console as to what file should be booted.
65 /// Normally, the system is booted from the file “xx(0,0)bsd”,
66 /// where xx is the default disk name, without prompting for
67 /// the file name.
68 RB_ASKNAME;
69 /// Dump kernel memory before rebooting; see `savecore(8)` for
70 /// more information.
71 RB_DUMP;
72 /// The processor is simply halted; no reboot takes place.
73 RB_HALT;
74 /// Power off the system if the system hardware supports the
75 /// function, otherwise it has no effect.
76 ///
77 /// Should be used in conjunction with `RB_HALT`.
78 RB_POWERDOWN;
79 /// By default, the system will halt if `reboot()` is called during
80 /// startup (before the system has finished autoconfiguration), even
81 /// if `RB_HALT` is not specified. This is because `panic(9)`s
82 /// during startup will probably just repeat on the next boot.
83 /// Use of this option implies that the user has requested the
84 /// action specified (for example, using the `ddb(4)` boot reboot
85 /// command), so the system will reboot if a halt is not explicitly
86 /// requested.
87 #[cfg(target_os = "openbsd")]
88 RB_USERREQ;
89 /// Load the symbol table and enable a built-in debugger in the
90 /// system. This option will have no useful function if the kernel
91 /// is not configured for debugging. Several other options have
92 /// different meaning if combined with this option, although their
93 /// use may not be possible via the `reboot()` call. See `ddb(4)` for
94 /// more information.
95 RB_KDB;
96 /// Normally, the disks are sync'd (see `sync(8)`) before the
97 /// processor is halted or rebooted. This option may be useful
98 /// if file system changes have been made manually or if the
99 /// processor is on fire.
100 RB_NOSYNC;
101 /// Normally, the reboot procedure involves an automatic disk
102 /// consistency check and then multi-user operations. `RB_SINGLE`
103 /// prevents this, booting the system with a single-user shell on
104 /// the console. `RB_SINGLE` is actually interpreted by the `init(8)`
105 /// program in the newly booted system.
106 ///
107 /// When no options are given (i.e., `RB_AUTOBOOT` is used), the
108 /// system is rebooted from file /bsd in the root file system of
109 /// unit 0 of a disk chosen in a processor specific way. An automatic
110 /// consistency check of the disks is normally performed (see `fsck(8)`).
111 RB_SINGLE;
112 /// Initially invoke the `userconf(4)` facility when the system
113 /// starts up again, if it has been compiled into the kernel
114 /// that is loaded.
115 #[cfg(target_os = "netbsd")]
116 RB_USERCONF;
117 /// Don't update the hardware clock from the system clock, presumably
118 /// because the system clock is suspect.
119 #[cfg(target_os = "openbsd")]
120 RB_TIMEBAD;
121 }
122 }
123
124 /// Reboot system or halt processor
125 ///
126 /// For more information, see the man pages:
127 ///
128 /// * [NetBSD](https://man.netbsd.org/reboot.2)
129 /// * [OpenBSD](https://man.openbsd.org/reboot.2)
130 #[cfg(netbsdlike)]
131 pub fn reboot(how: RebootMode) -> Result<Infallible> {
132 #[cfg(target_os = "openbsd")]
133 unsafe { libc::reboot(how.bits()) };
134 #[cfg(target_os = "netbsd")]
135 unsafe { libc::reboot(how.bits(), std::ptr::null_mut()) };
136
137 Err(Errno::last())
138 }
139 }
140}
141