Fix #147: refactor reboot as multi-call to initctl

This patch drops the stand-alone reboot binary and folds it into the initctl tool, which now becomes a multi-call binary. With this change the reboot/shutdown/poweroff/halt/suspend commands also no longer default to sending signals to PID 1, instead it now uses the initctl <--> finit UNIX domain socket API. Signals are only used as a fallback in case of non-working domain socket. The -f,--force mode of operation still works, where `reboot(2)` is called directly. Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
2026-10-01 13:33:09 +07:00 · 2021-02-21 10:59:08 +01:00
parent 649a269526
commit 7e42203627
4 changed files with 117 additions and 66 deletions
@@ -12,6 +12,11 @@ to service conditions.  There are other significant changes as well, so
 make sure to read the whole changelog when upgrading.

 ### Changes
+* The stand-alone `reboot` tool has been replaced with a symlink to
+  `initctl`, like its siblings: halt, shutdown, poweroff, and suspend.
+  Calling `reboot` & C:o now defaults to the corresponding `initctl cmd`
+  with a fallback to sending signals as per traditional SysV init.  The
+  `-f` (force) flag remains, where `reboot(2)` is called directly
 * Introducing Finit progress 𝓜𝓸𝓭𝓮𝓻𝓷
 * Removed built-in inetd super server.  If you need this functionality,
  use an external inetd, like xinetd, instead.  A pull request for a
@@ -8,7 +8,7 @@ else
 AM_LDFLAGS         = -export-dynamic
 endif

-sbin_PROGRAMS      = finit initctl reboot
+sbin_PROGRAMS      = finit initctl
 pkglibexec_SCRIPTS = cgreaper.sh
 if WATCHDOGD
 pkglibexec_PROGRAMS = watchdogd
@@ -49,19 +49,15 @@ else
 finit_LDADD       += -ldl
 endif

-initctl_SOURCES    = initctl.c client.c client.h \
-		     serv.c serv.h svc.h   \
+initctl_SOURCES    = initctl.c client.c client.h 	\
+		     reboot.c serv.c serv.h svc.h	\
 		     cond.c cond.h util.c util.h
 initctl_CFLAGS     = -W -Wall -Wextra -Wno-unused-parameter -std=gnu99
 initctl_CFLAGS    += $(lite_CFLAGS)
 initctl_LDADD      = $(lite_LIBS)

-reboot_SOURCES     = reboot.c util.c util.h
-reboot_CFLAGS      = $(lite_CFLAGS)
-reboot_LDADD       = $(lite_LIBS)
-
 INIT_LNKS          = init
-REBOOT_LNKS        = shutdown halt poweroff suspend
+REBOOT_LNKS        = reboot shutdown halt poweroff suspend

 if WATCHDOGD
 watchdogd_SOURCES  = watchdog.c watchdog.h
@@ -72,46 +68,38 @@ endif
 # Hook in install to add finit and reboot symlink(s)
 install-exec-hook:
 	@$(INSTALL_DATA) $(srcdir)/rescue.conf $(DESTDIR)$(pkglibdir)
-	@for file in $(INIT_LNKS); do				\
-		lnk=$(DESTDIR)$(sbindir)/$$file;		\
-		if [ -e $$lnk ]; then				\
-			echo "Skipping $$lnk exists.";		\
-		else						\
-			$(LN_S) finit $$lnk;			\
-		fi;						\
+	@for file in $(INIT_LNKS); do			\
+		lnk=$(DESTDIR)$(sbindir)/$$file;	\
+		if [ -e $$lnk ]; then			\
+			echo "Skipping $$lnk exists.";	\
+		else					\
+			$(LN_S) finit $$lnk;		\
+		fi;					\
+	done
+	@for file in $(REBOOT_LNKS); do			\
+		lnk=$(DESTDIR)$(sbindir)/$$file;	\
+		if [ -e $$lnk ]; then			\
+			echo "Skipping $$lnk exists.";	\
+		else					\
+			$(LN_S) initctl $$lnk;		\
+		fi;					\
 	done
-	@if [ -L $(DESTDIR)$(sbindir)/reboot ]; then		\
-		echo "Non-finit reboot, skipping install.";	\
-	else							\
-		for file in $(REBOOT_LNKS); do			\
-			lnk=$(DESTDIR)$(sbindir)/$$file;	\
-			if [ -e $$lnk ]; then			\
-				echo "Skipping $$lnk exists.";	\
-			else					\
-				$(LN_S) reboot $$lnk;		\
-			fi;					\
-		done;						\
-	fi

 uninstall-hook:
 	@$(RM) $(DESTDIR)$(pkglibdir)/rescue.conf
-	@for file in $(INIT_LNKS); do				\
-		lnk=`readlink $(DESTDIR)$(sbindir)/$$file`;	\
-		if [ "$$lnk" != "finit" ]; then			\
-			echo "Skipping non-finit $$file.";	\
-			continue;				\
-		fi;						\
-		$(RM) $(DESTDIR)$(sbindir)/$$file;		\
+	@for file in $(INIT_LNKS); do			\
+		lnk=$(DESTDIR)$(sbindir)/$$file;	\
+		dst=`readlink $$lnk`;			\
+		if [ "$$dst" != "finit" ]; then		\
+			continue;			\
+		fi;					\
+		$(RM) $(DESTDIR)$(sbindir)/$$file;	\
+	done
+	@for file in $(REBOOT_LNKS); do			\
+	        lnk=$(DESTDIR)$(sbindir)/$$file;	\
+		dst=`readlink $$lnk`;			\
+		if [ "$$dst" != "initctl" ]; then 	\
+			continue; 			\
+		fi;					\
+		$(RM) $$lnk;				\
 	done
-	@if [ -L $(DESTDIR)$(sbindir)/reboot ]; then		\
-		echo "Non-finit reboot, skipping uninstall.";	\
-	else							\
-		for file in $(REBOOT_LNKS); do			\
-		        lnk=$(DESTDIR)$(sbindir)/$$file;	\
-			dst=`readlink $$lnk`;			\
-			if [ "$$dst" != "reboot" ]; then 	\
-				continue; 			\
-			fi;					\
-			$(RM) $$lnk;				\
-		done;						\
-	fi
@@ -54,6 +54,9 @@ int verbose  = 0;
 int runlevel = 0;
 int iw, pw;

+extern int reboot_main(int argc, char *argv[]);
+
+
 /* figure ut width of IDENT and PID columns */
 static void col_widths(void)
 {
@@ -349,17 +352,30 @@ static int do_cond(char *cmd)
 	return do_cond_show(NULL);
 }

-static int do_signal(int signo, const char *msg)
+static int do_cmd(int cmd)
 {
-	if (kill(1, signo))
-		err(1, "Failed signalling init to %s", msg);
+	struct init_request rq = {
+		.magic = INIT_MAGIC,
+		.cmd = cmd,
+	};
+
+	if (client_send(&rq, sizeof(rq))) {
+		if (rq.cmd == INIT_CMD_NACK)
+			puts(rq.data);
+
+		return 1;
+	}
+
+	/* Wait here for systemd to shutdown/reboot */
+	sleep(5);

 	return 0;
 }

-static int do_halt    (char *arg) { return do_signal(SIGUSR1, "halt");      }
-static int do_poweroff(char *arg) { return do_signal(SIGUSR2, "power off"); }
-static int do_reboot  (char *arg) { return do_signal(SIGTERM, "reboot");    }
+int do_reboot  (char *arg) { return do_cmd(INIT_CMD_REBOOT);   }
+int do_halt    (char *arg) { return do_cmd(INIT_CMD_HALT);     }
+int do_poweroff(char *arg) { return do_cmd(INIT_CMD_POWEROFF); }
+int do_suspend (char *arg) { return do_cmd(INIT_CMD_SUSPEND);  }

 int utmp_show(char *file)
 {
@@ -605,6 +621,22 @@ static int show_cgroup(char *arg)
 	return 0;
 }

+static int transform(char *nm)
+{
+	char *names[] = {
+		"reboot", "shutdown", "poweroff", "halt", "suspend",
+		NULL
+	};
+	size_t i;
+
+	for (i = 0; names[i]; i++) {
+		if (!strcmp(nm, names[i]))
+			return 1;
+	}
+
+	return 0;
+}
+
 static int usage(int rc)
 {
 	fprintf(stderr,
@@ -644,7 +676,8 @@ static int usage(int rc)
 		"  runlevel [0-9]            Show or set runlevel: 0 halt, 6 reboot\n"
 		"  reboot                    Reboot system\n"
 		"  halt                      Halt system\n"
-		"  poweroff                  Halt and power off system\n", prognm);
+		"  poweroff                  Halt and power off system\n"
+		"  suspend                   Suspend system\n", prognm);

 	if (has_utmp())
 		fprintf(stderr,
@@ -693,6 +726,7 @@ int main(int argc, char *argv[])
 		{ "reboot",   do_reboot    },
 		{ "halt",     do_halt      },
 		{ "poweroff", do_poweroff  },
+		{ "suspend",  do_suspend   },

 		{ "utmp",     do_utmp      },
 		{ NULL, NULL }
@@ -706,7 +740,9 @@ int main(int argc, char *argv[])
 		{ NULL, 0, NULL, 0 }
 	};

-	progname(argv[0]);
+	if (transform(progname(argv[0])))
+		return reboot_main(argc, argv);
+
 	while ((c = getopt_long(argc, argv, "bh?ntv", long_options, NULL)) != EOF) {
 		switch(c) {
 		case 'b':
@@ -22,6 +22,7 @@
 */

 #include <err.h>
+#include <errno.h>
 #include <getopt.h>
 #include <signal.h>
 #include <stdio.h>
@@ -40,6 +41,13 @@ typedef enum {
 static cmd_t cmd = CMD_UNKNOWN;
 static char *msg = NULL;

+/* initctl API */
+extern int do_reboot  (char *arg);
+extern int do_halt    (char *arg);
+extern int do_poweroff(char *arg);
+extern int do_suspend (char *arg);
+
+
 static void transform(char *nm)
 {
 	if (!nm)
@@ -80,6 +88,16 @@ static void transform(char *nm)
 	}
 }

+/*
+ * fallback in case of initctl API failure
+ */
+static void do_kill(int signo, char *msg)
+{
+	if (kill(1, signo))
+		err(1, "Failed signalling init to %s", msg);
+	do_sleep(5);
+}
+
 static void sig(int signo)
 {
 	(void)signo;		/* NOP */
@@ -100,7 +118,7 @@ static int usage(int rc)
 	return rc;
 }

-int main(int argc, char *argv[])
+int reboot_main(int argc, char *argv[])
 {
 	int c, force = 0;
 	struct option long_options[] = {
@@ -113,7 +131,7 @@ int main(int argc, char *argv[])
 	};

 	/* Initial command taken from program name */
-	transform(progname(argv[0]));
+	transform(prognm);

 	while ((c = getopt_long(argc, argv, "h?fHPpr", long_options, NULL)) != EOF) {
 		switch(c) {
@@ -165,6 +183,8 @@ int main(int argc, char *argv[])

 		case CMD_SUSPEND:
 			c = reboot(RB_SW_SUSPEND);
+			if (c && errno == EINVAL)
+				errx(1, "Kernel does not support suspend.");
 			break;

 		case CMD_UNKNOWN:
@@ -173,22 +193,25 @@ int main(int argc, char *argv[])
 		}

 		if (c)
-			warn("Failed forced %s", msg);
-		else
-			return 0;
+			err(1, "Failed forced %s", msg);
+
+		return 0;
 	}

 	switch (cmd) {
 	case CMD_REBOOT:
-		c = kill(1, SIGTERM);
+		if (do_reboot(NULL))
+			do_kill(SIGTERM, msg);
 		break;

 	case CMD_HALT:
-		c = kill(1, SIGUSR1);
+		if (do_halt(NULL))
+			do_kill(SIGUSR1, msg);
 		break;

 	case CMD_POWEROFF:
-		c = kill(1, SIGUSR2);
+		if (do_poweroff(NULL))
+			do_kill(SIGUSR2, msg);
 		break;

 	case CMD_SUSPEND:
@@ -196,16 +219,15 @@ int main(int argc, char *argv[])
 		 * Only initctl supports suspend, we avoid adding
 		 * another signal to finit for compat reasons.
 		 */
+		do_suspend(NULL);
+		break;
+

 	case CMD_UNKNOWN:
 		errx(1, "Invalid command");
 		break;
 	}

-	if (c)
-		err(1, "Failed signalling init to %s", msg);
-	do_sleep(5);
-
 	return 0;
 }