#define _POSIX_C_SOURCE 200809L

#include <stdio.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

void create_vfs(void) {
	mkdir("/proc", 0755);
	mkdir("/sys", 0755);
	mkdir("/dev", 0755);
	mkdir("/run", 0755);
}

void mount_vfs(void) {
	if (mount("proc", "/proc", "proc",
			  MS_NOSUID | MS_NODEV | MS_NOEXEC | MS_RELATIME, NULL) != 0) {
		perror("mount /proc");
	}

	if (mount("sys", "/sys", "sysfs",
			  MS_NOSUID | MS_NODEV | MS_NOEXEC | MS_RELATIME, NULL) != 0) {
		perror("mount /sys");
	}

	if (mount("dev", "/dev", "devtmpfs", MS_NOSUID | MS_RELATIME, "mode=755") !=
		0) {
		perror("mount /dev");
	}

	if (mount("run", "/run", "tmpfs", MS_NOSUID | MS_NODEV | MS_RELATIME,
			  "mode=755") != 0) {
		perror("mount /run");
	}

	mkdir("/dev/pts", 0755);
	mkdir("/dev/shm", 1777);

	if (mount("devpts", "/dev/pts", "devpts",
			  MS_NOSUID | MS_NOEXEC | MS_RELATIME, "gid=5,mode=620") != 0) {
		perror("mount /dev/pts");
	}

	if (mount("shm", "/dev/shm", "tmpfs", MS_NOSUID | MS_NODEV | MS_RELATIME,
			  "mode=1777") != 0) {
		perror("mount /dev/shm");
	}
}

int main(void) {
	create_vfs();
	mount_vfs();

	return 0;
}