Add shutdown utility for rc.shutdown

2 files changed, 93 insertions, 1 deletions

diff --git a/util/gen.rc b/util/gen.rc
index 4dcbd052..aa7c175c 100644
--- a/util/gen.rc
+++ b/util/gen.rc
@@ -1,5 +1,10 @@
 set srcdir '$dir'
-cflags -Wall -Wextra '-std=c11' -pedantic
+cflags\
+	-Wall -Wextra -Wno-unused-parameter -pedantic\
+	'-std=c11'
 
 exe perms-hook perms-hook.c
 file libexec/oasis/perms-hook '$outdir'/perms-hook 755
+
+exe shutdown shutdown.c
+file libexec/oasis/shutdown '$outdir'/shutdown 755
diff --git a/util/shutdown.c b/util/shutdown.c
new file mode 100644
index 00000000..06ff3e55
--- /dev/null
+++ b/util/shutdown.c
@@ -0,0 +1,87 @@
+/* See LICENSE file for copyright and license details. */
+#define _XOPEN_SOURCE 700
+#include <errno.h>
+#include <mntent.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdnoreturn.h>
+#include <string.h>
+#include <sys/mount.h>
+#include <sys/reboot.h>
+#include <unistd.h>
+
+static noreturn void
+usage()
+{
+	fprintf(stderr, "usage: shutdown [-hpr]\n");
+	exit(2);
+}
+
+int
+main(int argc, char *argv[])
+{
+	FILE *fp;
+	char **dirs = NULL;
+	size_t n = 0;
+	struct mntent *mnt;
+	int cmd = RB_POWER_OFF;
+
+	while (*++argv && (*argv)[0] == '-' && (*argv)[1]) {
+		switch ((*argv)[1]) {
+		case 'h':
+			cmd = RB_HALT_SYSTEM;
+			break;
+		case 'p':
+			cmd = RB_POWER_OFF;
+			break;
+		case 'r':
+			cmd = RB_AUTOBOOT;
+			break;
+		default:
+			usage();
+		}
+	}
+	if (*argv)
+		usage();
+
+	if (getsid(0) != getpid()) {
+		fprintf(stderr, "must be session leader\n");
+		return 1;
+	}
+
+	sync();
+	kill(-1, SIGTERM);
+	sleep(2);
+	kill(-1, SIGKILL);
+
+	sync();
+	fp = setmntent("/proc/mounts", "r");
+	if (!fp) {
+		perror("setmntent");
+		goto reboot;
+	}
+	while ((mnt = getmntent(fp))) {
+		if (!(dirs = realloc(dirs, ++n * sizeof(*dirs)))) {
+			perror("realloc");
+			break;
+		}
+		if (!(dirs[n - 1] = strdup(mnt->mnt_dir))) {
+			perror("strdup");
+			break;
+		}
+	}
+	endmntent(fp);
+	while (n) {
+		if (umount(dirs[--n]) < 0)
+			fprintf(stderr, "umount %s: %s\n", dirs[n], strerror(errno));
+		free(dirs[n]);
+	}
+	free(dirs);
+
+reboot:
+	if (reboot(cmd) < 0) {
+		perror("reboot");
+		return 1;
+	}
+}