From addb8c4019038815538c602de7921400e98959a3 Mon Sep 17 00:00:00 2001
From: Joachim Wiberg <troglobit@gmail.com>
Date: Mon, 25 Apr 2022 21:18:59 +0200
Subject: [PATCH] Fix #247: fall back to `reboot -f` in sulogin mode

When logged in from sulogin we cannot send IPC to Finit, not even
signals, to delegate reboot.  For usability, attempt to tell reboot that
it's in sulogin mode -- provided the bundled sulogin is used -- to let
reboot trigger over to forced reboot.

We cannot do much about initctl, just document this as a limitation.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
---
 doc/build.md   | 3 +++
 doc/cmdline.md | 5 ++++-
 doc/config.md  | 3 +++
 src/reboot.c   | 5 +++++
 src/sulogin.c  | 3 +++
 5 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/doc/build.md b/doc/build.md
index 996a08be..21aa9878 100644
--- a/doc/build.md
+++ b/doc/build.md
@@ -153,6 +153,9 @@ enabled.  The default Finit rescue mode configuration is installed into
 
 By default the a root shell, without login, is started.
 
+> **Note:** in this mode `initctl` will not work.  Use the `-f` flag to
+> force `reboot`, `shutdown`, or `poweroff`.
+
 
 Debugging
 ---------
diff --git a/doc/cmdline.md b/doc/cmdline.md
index c0dab112..30b029be 100644
--- a/doc/cmdline.md
+++ b/doc/cmdline.md
@@ -63,7 +63,10 @@ The `bool` setting is one of `on, off, true false, 1, 0`.
     you will be given a root login to a maintenance shell.  However, if
     `sulogin` is missing, the file `/lib/finit/rescue.conf` is read and
     the system booted in a limited fallback mode.  See [config.md][]
-	for more information.
+    for more information.
+
+    **Note:** in this mode `initctl` will not work.  Correct the problem
+    and use `reboot -f` to force reboot.
 
 * `single`, or `S`: Single user mode, runlevel 1, in Finit.  Useful to
     debug problems with the regular runlevel.  All services and TTYs in
diff --git a/doc/config.md b/doc/config.md
index 11eb9910..e593eb34 100644
--- a/doc/config.md
+++ b/doc/config.md
@@ -645,6 +645,9 @@ activate it.
 
 The rescue mode comes in two flavors; *traditional* and *fallback*.
 
+> **Note:** in this mode `initctl` will not work.  Use the `-f` flag to
+> force `reboot`, `shutdown`, or `poweroff`.
+
 
 ### Traditional
 
diff --git a/src/reboot.c b/src/reboot.c
index c047ceb4..69930155 100644
--- a/src/reboot.c
+++ b/src/reboot.c
@@ -26,6 +26,7 @@
 #include <getopt.h>
 #include <signal.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #include "util.h"
@@ -159,6 +160,10 @@ int reboot_main(int argc, char *argv[])
 	/* Check for any overrides */
 	transform(NULL);
 
+	/* Check if we're in sulogin shell */
+	if (getenv("SULOGIN"))
+		force = 1;
+
 	if (force) {
 		sync();
 
diff --git a/src/sulogin.c b/src/sulogin.c
index cd407217..62cb9360 100644
--- a/src/sulogin.c
+++ b/src/sulogin.c
@@ -193,6 +193,9 @@ int main(void)
 		nopass:
 			freepw(&pw);
 
+			/* tell initctl/reboot to trigger force mode */
+			setenv("SULOGIN", "finit", 1);
+
 			return sh();
 		}
 	}