From 7d7d9013f1fd4bba8a6993ae09e18c1a56c99373 Mon Sep 17 00:00:00 2001
From: Warner Losh <imp@FreeBSD.org>
Date: Wed, 25 Oct 2017 15:30:35 +0000
Subject: [PATCH] Add power cycle support to reboot/halt as -c.

When -c is specified, the system will be power cycled if the
underlying hardware supports it. Otherwise the system will be halted
or rebooted depending on which command was used.

Sponsored by: Netflix
---
 sbin/reboot/reboot.8 | 19 +++++++++++++++++--
 sbin/reboot/reboot.c | 15 +++++++++++++--
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/sbin/reboot/reboot.8 b/sbin/reboot/reboot.8
index c31f9663a88f..6f2d023e8bb9 100644
--- a/sbin/reboot/reboot.8
+++ b/sbin/reboot/reboot.8
@@ -28,7 +28,7 @@
 .\"	@(#)reboot.8	8.1 (Berkeley) 6/9/93
 .\" $FreeBSD$
 .\"
-.Dd March 19, 2017
+.Dd October 23, 2017
 .Dt REBOOT 8
 .Os
 .Sh NAME
@@ -42,7 +42,7 @@
 .Op Fl lNnpq
 .Op Fl k Ar kernel
 .Nm
-.Op Fl dlNnpqr
+.Op Fl cdlNnpqr
 .Op Fl k Ar kernel
 .Nm fasthalt
 .Op Fl lNnpq
@@ -66,6 +66,20 @@ accounting database.
 .Pp
 The options are as follows:
 .Bl -tag -width indent
+.It Fl c
+The system will turn off the power and then turn it back on if it can.
+If the power down action fails, the system
+will halt or reboot normally, depending on whether
+.Nm halt
+or
+.Nm
+was called.
+At the present time, only the
+.Xr ipmi 4
+driver implements the power cycle functionality and only on hardware
+with a BMC that supports power cycling.
+Unlike power off, the amount of hardware that supports power cycling
+is small.
 .It Fl d
 The system is requested to create a crash dump.
 This option is
@@ -162,6 +176,7 @@ reboot -r
 .Sh SEE ALSO
 .Xr kenv 1 ,
 .Xr getutxent 3 ,
+.Xr ipmi 4 ,
 .Xr boot 8 ,
 .Xr dumpon 8 ,
 .Xr nextboot 8 ,
diff --git a/sbin/reboot/reboot.c b/sbin/reboot/reboot.c
index 8722e27511f5..5bc3328a0b93 100644
--- a/sbin/reboot/reboot.c
+++ b/sbin/reboot/reboot.c
@@ -77,8 +77,11 @@ main(int argc, char *argv[])
 	} else
 		howto = 0;
 	lflag = nflag = qflag = Nflag = 0;
-	while ((ch = getopt(argc, argv, "dk:lNnpqr")) != -1)
+	while ((ch = getopt(argc, argv, "cdk:lNnpqr")) != -1)
 		switch(ch) {
+		case 'c':
+			howto |= RB_POWERCYCLE;
+			break;
 		case 'd':
 			howto |= RB_DUMP;
 			break;
@@ -116,8 +119,10 @@ main(int argc, char *argv[])
 		errx(1, "cannot dump (-d) when halting; must reboot instead");
 	if (Nflag && (howto & RB_NOSYNC) != 0)
 		errx(1, "-N cannot be used with -n");
+	if ((howto & RB_POWEROFF) && (howto & RB_POWERCYCLE))
+		errx(1, "-c and -p cannot be used together");
 	if ((howto & RB_REROOT) != 0 && howto != RB_REROOT)
-		errx(1, "-r cannot be used with -d, -n, or -p");
+		errx(1, "-r cannot be used with -c, -d, -n, or -p");
 	if (geteuid()) {
 		errno = EPERM;
 		err(1, NULL);
@@ -151,6 +156,12 @@ main(int argc, char *argv[])
 		} else if (howto & RB_REROOT) {
 			openlog("reroot", 0, LOG_AUTH | LOG_CONS);
 			syslog(LOG_CRIT, "rerooted by %s", user);
+		} else if (howto & RB_POWEROFF) {
+			openlog("reboot", 0, LOG_AUTH | LOG_CONS);
+			syslog(LOG_CRIT, "powered off by %s", user);
+		} else if (howto & RB_POWERCYCLE) {
+			openlog("reboot", 0, LOG_AUTH | LOG_CONS);
+			syslog(LOG_CRIT, "power cycled by %s", user);
 		} else {
 			openlog("reboot", 0, LOG_AUTH | LOG_CONS);
 			syslog(LOG_CRIT, "rebooted by %s", user);