/*
Improved fast init

Copyright (c) 2008 Claudio Matsuoka

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <sys/mount.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <errno.h>
#include <signal.h>
#include <unistd.h>
#include <sys/reboot.h>
#include <sys/wait.h>
#include <linux/fs.h>

#include "helpers.h"

#ifndef DEFUSER
#define DEFUSER "user"
#endif

/* Distribution configuration */

#ifdef DIST_MDV		/* Mandriva */
#define RANDOMSEED	"/var/lib/random-seed"
#define SYSROOT		"/sysroot"
#define GETTY		"/usr/bin/openvt /sbin/mingetty tty2"
#define RUNPARTS	"/usr/bin/run-parts"
#define REMOUNT_ROOTFS_RW
#define MAKE_DEVICES
#define PAM_CONSOLE
#else			/* original Eeepc distribution */
#define RANDOMSEED	"/var/lib/urandom/random-seed"
#define SYSROOT		"/mnt"
#define GETTY		"/usr/bin/openvt /sbin/getty 38400 tty2"
#define RUNPARTS	"/bin/run-parts"
#define TOUCH_ETC_NETWORK_RUN_IFSTATE
#endif

#ifdef DIRECTISA
#define HWCLOCK_DIRECTISA " --directisa"
#else
#define HWCLOCK_DIRECTISA
#endif


/* From sysvinit */
/* Set a signal handler. */
#define SETSIG(sa, sig, fun, flags) \
		do { \
			sa.sa_handler = fun; \
			sa.sa_flags = flags; \
			sigemptyset(&sa.sa_mask); \
			sigaction(sig, &sa, NULL); \
		} while (0)

#ifdef LISTEN_INITCTL

#define INIT_MAGIC		0x03091969
#define INIT_CMD_RUNLVL		1

struct init_request {
	int	magic;			/* Magic number                 */
	int	cmd;			/* What kind of request         */
	int	runlevel;		/* Runlevel to change to        */
	int	sleeptime;		/* Time between TERM and KILL   */
	char	data[368];
};
#endif

#define touch(x) mknod((x), S_IFREG|0644, 0)
#define chardev(x,m,maj,min) mknod((x), S_IFCHR|(m), makedev((maj),(min)))
#define blkdev(x,m,maj,min) mknod((x), S_IFBLK|(m), makedev((maj),(min)))

#define MATCH_CMD(l,c,x) \
	((!strncmp((l), (c), strlen((c)))) && ((x) = (l) + strlen((c))))

#define LINE_SIZE 1024
#define CMD_SIZE 256
#define USERNAME_SIZE 16
#define HOSTNAME_SIZE 32

void shutdown(int);
void signal_handler(int);
void chld_handler(int);

static int debug = 0;

static void build_cmd(char *cmd, char *x, int len)
{
	int l;
	char *c;

	c = cmd + strlen(cmd);
	for (; *x && (*x == ' ' || *x == '\t'); x++); 
	for (l = 0; *x && *x != ' ' && *x != '\t' && l < len; l++)
		*c++ = *x++;
	*c = 0;
	if (debug)
		printf("cmd = %s\n", cmd);
}


int main()
{
	int i;
	FILE *f;
	char line[LINE_SIZE];
	int fd;
	DIR *dir;
	struct dirent *d;
	struct sigaction sa, act;
	sigset_t nmask, nmask2;
	char username[USERNAME_SIZE] = DEFUSER;
	char hostname[HOSTNAME_SIZE] = "eviltwin";
	char cmd[CMD_SIZE];
#ifdef LISTEN_INITCTL
	fd_set rfds;
	int ctl;
	struct init_request req;
#endif

	puts("finit-alt " VERSION " (built " __DATE__ " by " WHOAMI ")");

	chdir("/");
	umask(022);
	
	/*
	 * Signal management
	 */
	for (i = 1; i < NSIG; i++)
		SETSIG(sa, i, SIG_IGN, SA_RESTART);

	SETSIG(sa, SIGINT,  shutdown, 0);
	SETSIG(sa, SIGPWR,  SIG_IGN, 0);
	SETSIG(sa, SIGUSR1, shutdown, 0);
	SETSIG(sa, SIGUSR2, shutdown, 0);
	SETSIG(sa, SIGTERM, SIG_IGN, 0);
	SETSIG(sa, SIGALRM, SIG_IGN, 0);
	SETSIG(sa, SIGHUP,  SIG_IGN, 0);
	SETSIG(sa, SIGCONT, SIG_IGN, SA_RESTART);
	SETSIG(sa, SIGCHLD, chld_handler, SA_RESTART);
	
	/* Block sigchild while forking */
	sigemptyset(&nmask);
	sigaddset(&nmask, SIGCHLD);
	sigprocmask(SIG_BLOCK, &nmask, NULL);

	reboot(RB_DISABLE_CAD);

	mount("none", "/proc", "proc", 0, NULL);

	/*
	 * Parse kernel parameters
	 */
	if ((f = fopen("/proc/cmdline", "r")) != NULL) {
		fgets(line, LINE_SIZE, f);
		if (strstr(line, "quiet")) {
			close(0);
			close(1);
			close(2);
		}
		if ((strstr(line, "finit_debug"))) {
			debug = 1;
		}
		fclose(f);
	}

	/*
	 * Parse configuration file
	 */
	if ((f = fopen("/etc/finit.conf", "r")) != NULL) {
		char *x;
		while (!feof(f)) {
			fgets(line, LINE_SIZE, f);
			chomp(line);

			if (debug)
				printf("conf: %s\n", line);

			if (MATCH_CMD(line, "check ", x)) {
				strcpy(cmd, "/sbin/fsck -C -a ");
				build_cmd(cmd, x, CMD_SIZE);
				system(cmd);
				continue;
			}
			if (MATCH_CMD(line, "user ", x)) {
				*username = 0;
				build_cmd(username, x, USERNAME_SIZE);
				continue;
			}
			if (MATCH_CMD(line, "host ", x)) {
				*hostname = 0;
				build_cmd(hostname, x, HOSTNAME_SIZE);
				continue;
			}
			if (MATCH_CMD(line, "module ", x)) {
				strcpy(cmd, "/sbin/modprobe ");
				build_cmd(cmd, x, CMD_SIZE);
				system(cmd);
				continue;
			}
		}
		fclose(f);
	}

	setsid();

	/*
	 * Mount filesystems
	 */
#ifdef REMOUNT_ROOTFS_RW
	system("/bin/mount -n -o remount,rw /");
#endif
	umask(0);

#ifdef MAKE_DEVICES
	mkdir("/dev/shm", 0755);
	mkdir("/dev/pts", 0755);
#endif

	mount("none", "/sys", "sysfs", 0, NULL);
	mount("none", "/dev/pts", "devpts", 0, "gid=5,mode=620");
	mount("none", "/dev/shm", "tmpfs", 0, NULL);
	mount("none", "/tmp", "tmpfs", 0, "mode=1777,size=128m");
	mount("none", "/var/run", "tmpfs", 0, "mode=0755");
	mount("none", "/var/lock", "tmpfs", 0, "mode=1777");
	mount("none", "/proc/bus/usb", "usbfs", 0, NULL);
	mount(SYSROOT, "/", NULL, MS_MOVE, NULL);

#ifdef MAKE_DEVICES
	mkdir("/dev/input", 0755);
	chardev("/dev/urandom", 0666, 1, 9);
	chardev("/dev/ptmx", 0666, 5, 2);
	chardev("/dev/null", 0666, 1, 3);
	chardev("/dev/mem",  0640, 1, 1);
	chmod("/dev/null", 0667);
	chmod("/dev/mem", 0640);
	chardev("/dev/tty0",  0660, 4, 0);
	chardev("/dev/input/mice",  0660, 13, 63);
	chardev("/dev/input/event0",  0660, 13, 64);
	chardev("/dev/agpgart",  0660, 10, 175);
	blkdev("/dev/loop0",  0600, 7, 0);
#endif

	unlink("/etc/mtab");
	system("mount -a");

	umask(0022);

	/*
	 * Time adjustments
	 */
	if ((fd = open("/etc/adjtime", O_CREAT|O_WRONLY|O_TRUNC, 0644)) >= 0) {
		write(fd, "0.0 0 0.0\n", 10);
		close(fd);
	}
#ifndef NO_HCTOSYS
	system("/sbin/hwclock --hctosys --localtime" HWCLOCK_DIRECTISA);
#endif

	/*
	 * Network stuff
	 */
	makepath("/dev/shm/network");
	makepath("/dev/shm/resolvconf/interface");

	if ((dir = opendir("/etc/resolvconf/run/interface")) != NULL) {
		while ((d = readdir(dir)) != NULL) {
			if (isalnum(d->d_name[0]))
				continue;
			snprintf(line, LINE_SIZE,
				"/etc/resolvconf/run/interface/%s", d->d_name);
			unlink(line);
		}

		closedir(dir);
	}

	touch("/var/run/utmp");
	touch("/etc/resolvconf/run/enable-updates");

	chdir("/etc/resolvconf/run/interface");
#ifdef BUILTIN_RUNPARTS
	run_parts("/etc/resolvconf/update.d", "-i", NULL);
#else
	system(RUNPARTS " --arg=i /etc/resolvconf/update.d");
#endif
	chdir("/");
	
#ifdef TOUCH_ETC_NETWORK_RUN_IFSTATE
	touch("/etc/network/run/ifstate");
#endif

	if ((f = fopen("/etc/hostname", "r")) != NULL) {
		fgets(hostname, HOSTNAME_SIZE, f);	
		chomp(hostname);
		fclose(f);
	}

	sethostname(hostname, strlen(hostname)); 

	ifconfig("lo", "127.0.0.1", "255.0.0.0", 1);

	/*
	 * Set random seed
	 */
	copyfile(RANDOMSEED, "/dev/urandom", 0);
	unlink(RANDOMSEED);
	umask(077);
	copyfile("/dev/urandom", RANDOMSEED, 4096);
	umask(0);

	/*
	 * Console setup (for X)
	 */
	makepath("/var/run/console");
	snprintf(line, LINE_SIZE, "/var/run/console/%s", username);
	touch(line);

#ifdef PAM_CONSOLE
	if ((fd = open("/var/run/console/console.lock", O_CREAT|O_WRONLY|O_TRUNC, 0644)) >= 0) {
		write(fd, username, strlen(username));
		close(fd);
		system("/sbin/pam_console_apply");
	}
#endif

	/*
	 * Misc setup
	 */
	mkdir("/tmp/.X11-unix", 01777);
	mkdir("/tmp/.ICE-unix", 01777);
	umask(022);

	system(GETTY "&");

	if (!fork()) {
		/* child process */

		vhangup();

		close(2);
		close(1);
		close(0);

		if (open("/dev/tty1", O_RDWR) != 0)
			exit(1);

		sigemptyset(&act.sa_mask);
		act.sa_handler = SIG_DFL;

		sigemptyset(&nmask2);
		sigaddset(&nmask2, SIGCHLD);
		sigprocmask(SIG_UNBLOCK, &nmask2, NULL);

		for (i = 1; i < NSIG; i++)
			sigaction(i, &sa, NULL);

		dup2(0, 0);
		dup2(0, 1);
		dup2(0, 2);

		touch("/tmp/nologin");

#ifdef AGPDRV
		system("/sbin/modprobe agpgart");
		system("/sbin/modprobe " AGPDRV);
#endif
		
		while (access("/tmp/shutdown", F_OK) < 0) {
			if (debug) {
				printf("Starting X as %s\n", username);
				snprintf(line, LINE_SIZE,
					"su -c startx -l %s\n", username);
				system(line);
				system("/bin/sh");
			} else {
				snprintf(line, LINE_SIZE,
					"su -c startx -l %s\n &> /dev/null",
					username);
				system(line);
			}
		}

		exit(0);
	}
	
	/* parent process */

	sleep(1);
	system("/usr/sbin/services.sh &>/dev/null&");

#ifdef LISTEN_INITCTL
	mkfifo("/dev/initctl", 0600);
	ctl = open("/dev/initctl", O_RDONLY);
#endif

	while (1) {
		sigemptyset(&nmask);
#ifdef LISTEN_INITCTL
		FD_ZERO(&rfds);
		FD_SET(ctl, &rfds);

		if (ctl < 0) {
			pselect(0, NULL, NULL, NULL, NULL, &nmask);
			continue;
		}

		if (pselect(ctl + 1, &rfds, NULL, NULL, NULL, &nmask) <= 0)
			continue;

		read(ctl, &req, sizeof (req));

		if (req.magic == INIT_MAGIC) {
			switch (req.cmd) {
			case INIT_CMD_RUNLVL:
				switch (req.runlevel) {
				case '0':
					raise(SIGUSR2);
					break;
				case '6':
					raise(SIGUSR1);
				}
			}
		}
#else
		pselect(0, NULL, NULL, NULL, NULL, &nmask);
#endif
	}
}


/*
 * Shut down on INT USR1 USR2
 */
void shutdown(int sig)
{
	touch("/tmp/shutdown");

	kill(-1, SIGTERM);

	write(1, "\033[?25l\033[30;40m", 14);
	copyfile("/boot/shutdown.fb", "/dev/fb/0", 0);
	sleep(2);

	system("/usr/sbin/alsactl store > /dev/null 2>&1");
	system("/sbin/hwclock --systohc --localtime" HWCLOCK_DIRECTISA);

	kill(-1, SIGKILL);

	sync();
	sync();
	system("/bin/mount -n -o remount,ro /");
	system("/sbin/unionctl.static / --remove / > /dev/null 2>&1");

	if (sig == SIGINT || sig == SIGUSR1)
		reboot(RB_AUTOBOOT);

	reboot(RB_POWER_OFF);
}


/*
 * SIGCHLD: one of our children has died
 */
void chld_handler(int sig)
{
	int status;

	while (waitpid(-1, &status, WNOHANG) != 0) {
		if (errno == ECHILD)
			break;
	}
}