1 files changed, 333 insertions, 0 deletions
diff --git a/src/openrc-init/openrc-init.c b/src/openrc-init/openrc-init.c
new file mode 100644
index 00000000..2e6d3677
--- /dev/null
+++ b/src/openrc-init/openrc-init.c
@@ -0,0 +1,333 @@
+/*
+ * openrc-init.c
+ * This is the init process (pid 1) for OpenRC.
+ *
+ * This is based on code written by James Hammons <jlhamm@acm.org>, so
+ * I would like to publically thank him for his work.
+ */
+
+/*
+ * Copyright (c) 2017 The OpenRC Authors.
+ * See the Authors file at the top-level directory of this distribution and
+ * https://github.com/OpenRC/openrc/blob/HEAD/AUTHORS
+ *
+ * This file is part of OpenRC. It is subject to the license terms in
+ * the LICENSE file found in the top-level directory of this
+ * distribution and at https://github.com/OpenRC/openrc/blob/HEAD/LICENSE
+ * This file may not be copied, modified, propagated, or distributed
+ *    except according to the terms contained in the LICENSE file.
+ */
+
+#include <errno.h>
+#include <pwd.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/reboot.h>
+#include <sys/wait.h>
+
+#ifdef HAVE_SELINUX
+#  include <selinux/selinux.h>
+#endif
+
+#include "helpers.h"
+#include "rc.h"
+#include "plugin.h"
+#include "wtmp.h"
+#include "version.h"
+
+static const char *path_default = "/sbin:/usr/sbin:/bin:/usr/bin";
+static const char *rc_default_runlevel = "default";
+
+static void do_openrc(const char *runlevel)
+{
+	pid_t pid;
+	sigset_t all_signals;
+	sigset_t our_signals;
+
+	sigfillset(&all_signals);
+	/* block all signals */
+	sigprocmask(SIG_BLOCK, &all_signals, &our_signals);
+	pid = fork();
+	switch (pid) {
+		case -1:
+			perror("fork");
+			exit(1);
+			break;
+		case 0:
+			setsid();
+			/* unblock all signals */
+			sigprocmask(SIG_UNBLOCK, &all_signals, NULL);
+			printf("Starting %s runlevel\n", runlevel);
+			execlp("openrc", "openrc", runlevel, NULL);
+			perror("exec");
+			exit(1);
+			break;
+		default:
+			/* restore our signal mask */
+			sigprocmask(SIG_SETMASK, &our_signals, NULL);
+			while (waitpid(pid, NULL, 0) != pid)
+				if (errno == ECHILD)
+					break;
+			break;
+	}
+}
+
+static void init(const char *default_runlevel)
+{
+	const char *runlevel = NULL;
+	do_openrc("sysinit");
+	do_openrc("boot");
+	if (default_runlevel)
+		runlevel = default_runlevel;
+	else
+		runlevel = rc_conf_value("rc_default_runlevel");
+	if (!runlevel)
+		runlevel = rc_default_runlevel;
+	if (!rc_runlevel_exists(runlevel)) {
+		printf("%s is an invalid runlevel\n", runlevel);
+		runlevel = rc_default_runlevel;
+	}
+	do_openrc(runlevel);
+	log_wtmp("reboot", "~~", 0, RUN_LVL, "~~");
+}
+
+static void handle_reexec(char *my_name)
+{
+	execlp(my_name, my_name, "reexec", NULL);
+	return;
+}
+
+static void handle_shutdown(const char *runlevel, int cmd)
+{
+	struct timespec ts;
+
+	do_openrc(runlevel);
+	printf("Sending the final term signal\n");
+	kill(-1, SIGTERM);
+	ts.tv_sec = 3;
+	ts.tv_nsec = 0;
+	nanosleep(&ts, NULL);
+	printf("Sending the final kill signal\n");
+	kill(-1, SIGKILL);
+	sync();
+	reboot(cmd);
+}
+
+static void run_program(const char *prog)
+{
+	sigset_t full;
+	sigset_t old;
+	pid_t pid;
+
+	/* We need to block signals until we have forked */
+	sigfillset(&full);
+	sigprocmask(SIG_SETMASK, &full, &old);
+	pid = fork();
+	if (pid == -1) {
+		perror("init");
+		return;
+	}
+	if (pid == 0) {
+		/* Unmask signals */
+		sigprocmask(SIG_SETMASK, &old, NULL);
+		execl(prog, prog, (char *)NULL);
+		perror("init");
+		exit(1);
+	}
+	/* Unmask signals and wait for child */
+	sigprocmask(SIG_SETMASK, &old, NULL);
+	if (rc_waitpid(pid) == -1)
+		perror("init");
+}
+
+static void open_shell(void)
+{
+	const char *shell;
+	struct passwd *pw;
+
+#ifdef __linux__
+	const char *sys = rc_sys();
+
+	/* VSERVER systems cannot really drop to shells */
+	if (sys && strcmp(sys, RC_SYS_VSERVER) == 0)
+	{
+		execlp("halt", "halt", "-f", (char *) NULL);
+		perror("init");
+		return;
+	}
+#endif
+
+	shell = rc_conf_value("rc_shell");
+	/* No shell set, so obey env, then passwd, then default to /bin/sh */
+	if (!shell) {
+		shell = getenv("SHELL");
+		if (!shell) {
+			pw = getpwuid(getuid());
+			if (pw)
+				shell = pw->pw_shell;
+			if (!shell)
+				shell = "/bin/sh";
+		}
+	}
+	run_program(shell);
+}
+
+static void handle_single(void)
+{
+	do_openrc("single");
+}
+
+static void reap_zombies(void)
+{
+	pid_t pid;
+
+	for (;;) {
+		pid = waitpid(-1, NULL, WNOHANG);
+		if (pid == 0)
+			break;
+		else if (pid == -1) {
+			if (errno == ECHILD)
+				break;
+			perror("waitpid");
+			continue;
+		}
+	}
+}
+
+static void signal_handler(int sig)
+{
+	switch (sig) {
+		case SIGINT:
+			handle_shutdown("reboot", RB_AUTOBOOT);
+			break;
+		case SIGTERM:
+#ifdef SIGPWR
+		case SIGPWR:
+#endif
+			handle_shutdown("shutdown", RB_HALT_SYSTEM);
+			break;
+		case SIGCHLD:
+			reap_zombies();
+			break;
+		default:
+			printf("Unknown signal received, %d\n", sig);
+			break;
+	}
+}
+
+int main(int argc, char **argv)
+{
+	char *default_runlevel;
+	char buf[2048];
+	int count;
+	FILE *fifo;
+	bool reexec = false;
+	sigset_t signals;
+	struct sigaction sa;
+#ifdef HAVE_SELINUX
+	int			enforce = 0;
+#endif
+
+	if (getpid() != 1)
+		return 1;
+
+#ifdef HAVE_SELINUX
+	if (getenv("SELINUX_INIT") == NULL) {
+		if (is_selinux_enabled() != 1) {
+			if (selinux_init_load_policy(&enforce) == 0) {
+				putenv("SELINUX_INIT=YES");
+				execv(argv[0], argv);
+			} else {
+				if (enforce > 0) {
+					/*
+					 * SELinux in enforcing mode but load_policy failed
+					 * At this point, we probably can't open /dev/console,
+					 * so log() won't work
+					 */
+					fprintf(stderr,"Unable to load SELinux Policy.\n");
+					fprintf(stderr,"Machine is  in enforcing mode.\n");
+					fprintf(stderr,"Halting now.\n");
+					exit(1);
+				}
+			}
+		}
+	}
+#endif
+
+	printf("OpenRC init version %s starting\n", VERSION);
+
+	if (argc > 1)
+		default_runlevel = argv[1];
+	else
+		default_runlevel = NULL;
+
+	if (default_runlevel && strcmp(default_runlevel, "reexec") == 0)
+		reexec = true;
+
+	/* block all signals we do not handle */
+	sigfillset(&signals);
+	sigdelset(&signals, SIGCHLD);
+	sigdelset(&signals, SIGINT);
+	sigdelset(&signals, SIGTERM);
+#ifdef SIGPWR
+	sigdelset(&signals, SIGPWR);
+#endif
+	sigprocmask(SIG_SETMASK, &signals, NULL);
+
+	/* install signal  handler */
+	memset(&sa, 0, sizeof(sa));
+	sa.sa_handler = signal_handler;
+	sigaction(SIGCHLD, &sa, NULL);
+	sigaction(SIGINT, &sa, NULL);
+	sigaction(SIGTERM, &sa, NULL);
+#ifdef SIGPWR
+	sigaction(SIGPWR, &sa, NULL);
+#endif
+	reboot(RB_DISABLE_CAD);
+
+	/* set default path */
+	setenv("PATH", path_default, 1);
+
+	if (!reexec)
+		init(default_runlevel);
+
+	if (mkfifo(RC_INIT_FIFO, 0600) == -1 && errno != EEXIST)
+		perror("mkfifo");
+
+	for (;;) {
+		/* This will block until a command is sent down the pipe... */
+		fifo = fopen(RC_INIT_FIFO, "r");
+		if (!fifo) {
+			if (errno != EINTR)
+				perror("fopen");
+			continue;
+		}
+		count = fread(buf, 1, sizeof(buf) - 1, fifo);
+		buf[count] = 0;
+		fclose(fifo);
+		printf("PID1: Received \"%s\" from FIFO...\n", buf);
+		if (strcmp(buf, "halt") == 0)
+			handle_shutdown("shutdown", RB_HALT_SYSTEM);
+		else if (strcmp(buf, "kexec") == 0)
+			handle_shutdown("reboot", RB_KEXEC);
+		else if (strcmp(buf, "poweroff") == 0)
+			handle_shutdown("shutdown", RB_POWER_OFF);
+		else if (strcmp(buf, "reboot") == 0)
+			handle_shutdown("reboot", RB_AUTOBOOT);
+		else if (strcmp(buf, "reexec") == 0)
+			handle_reexec(argv[0]);
+		else if (strcmp(buf, "single") == 0) {
+			handle_single();
+			open_shell();
+			init(default_runlevel);
+		}
+	}
+	return 0;
+}