--- /dev/null
+/***
+ This file is part of systemd.
+
+ Copyright 2017 Felipe Sateler
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <sys/prctl.h>
+
+#include "bus-util.h"
+#include "bus-error.h"
+#include "log.h"
+#include "process-util.h"
+#include "sd-bus.h"
+#include "signal-util.h"
+
+static int start_default_target(void) {
+ _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+ _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+ int r;
+
+ r = bus_connect_system_systemd(&bus);
+ if (r < 0) {
+ log_error_errno(r, "Failed to get D-Bus connection: %m");
+ return false;
+ }
+
+ log_info("Starting default target");
+
+ /* Start these units only if we can replace base.target with it */
+ r = sd_bus_call_method(bus,
+ "org.freedesktop.systemd1",
+ "/org/freedesktop/systemd1",
+ "org.freedesktop.systemd1.Manager",
+ "StartUnit",
+ &error,
+ NULL,
+ "ss", "default.target", "isolate");
+
+ if (r < 0)
+ log_error("Failed to start default target: %s", bus_error_message(&error, r));
+
+ return r;
+}
+
+static void fork_wait(const char* const cmdline[]) {
+ pid_t pid;
+
+ pid = fork();
+ if (pid < 0) {
+ log_error_errno(errno, "fork(): %m");
+ return;
+ }
+ if (pid == 0) {
+
+ /* Child */
+
+ (void) reset_all_signal_handlers();
+ (void) reset_signal_mask();
+ assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0);
+
+ execv(cmdline[0], (char**) cmdline);
+ log_error_errno(errno, "Failed to execute %s: %m", cmdline[0]);
+ _exit(EXIT_FAILURE); /* Operational error */
+ }
+
+ wait_for_terminate_and_warn(cmdline[0], pid, false);
+}
+
+static void print_mode(const char* mode) {
+ printf("You are in %s mode. After logging in, type \"journalctl -xb\" to view\n"
+ "system logs, \"systemctl reboot\" to reboot, \"systemctl default\" or ^D to boot\n"
+ "into default mode.\n", mode);
+ fflush(stdout);
+}
+
+int main(int argc, char *argv[]) {
+ static const char* const sulogin_cmdline[] = {SULOGIN, NULL};
+ int r;
+
+ log_set_target(LOG_TARGET_AUTO);
+ log_parse_environment();
+ log_open();
+
+ print_mode(argc > 1 ? argv[1] : "");
+
+ fork_wait(sulogin_cmdline);
+
+ r = start_default_target();
+
+ return r >= 0 ? EXIT_SUCCESS : EXIT_FAILURE;
+}