示例#1
0
/* ioctl dispatcher */
static int _autofs_dev_ioctl(unsigned int command, struct autofs_dev_ioctl __user *user)
{
	struct autofs_dev_ioctl *param;
	struct file *fp;
	struct autofs_sb_info *sbi;
	unsigned int cmd_first, cmd;
	ioctl_fn fn = NULL;
	int err = 0;

	/* only root can play with this */
	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	cmd_first = _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST);
	cmd = _IOC_NR(command);

	if (_IOC_TYPE(command) != _IOC_TYPE(AUTOFS_DEV_IOCTL_IOC_FIRST) ||
	    cmd - cmd_first >= AUTOFS_DEV_IOCTL_IOC_COUNT) {
		return -ENOTTY;
	}

	/* Copy the parameters into kernel space. */
	param = copy_dev_ioctl(user);
	if (IS_ERR(param))
		return PTR_ERR(param);

	err = validate_dev_ioctl(command, param);
	if (err)
		goto out;

	/* The validate routine above always sets the version */
	if (cmd == AUTOFS_DEV_IOCTL_VERSION_CMD)
		goto done;

	fn = lookup_dev_ioctl(cmd);
	if (!fn) {
		AUTOFS_WARN("unknown command 0x%08x", command);
		return -ENOTTY;
	}

	fp = NULL;
	sbi = NULL;

	/*
	 * For obvious reasons the openmount can't have a file
	 * descriptor yet. We don't take a reference to the
	 * file during close to allow for immediate release.
	 */
	if (cmd != AUTOFS_DEV_IOCTL_OPENMOUNT_CMD &&
	    cmd != AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD) {
		fp = fget(param->ioctlfd);
		if (!fp) {
			if (cmd == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD)
				goto cont;
			err = -EBADF;
			goto out;
		}

		if (!fp->f_op) {
			err = -ENOTTY;
			fput(fp);
			goto out;
		}

		sbi = autofs_dev_ioctl_sbi(fp);
		if (!sbi || sbi->magic != AUTOFS_SBI_MAGIC) {
			err = -EINVAL;
			fput(fp);
			goto out;
		}

		/*
		 * Admin needs to be able to set the mount catatonic in
		 * order to be able to perform the re-open.
		 */
		if (!autofs4_oz_mode(sbi) &&
		    cmd != AUTOFS_DEV_IOCTL_CATATONIC_CMD) {
			err = -EACCES;
			fput(fp);
			goto out;
		}
	}
cont:
	err = fn(fp, sbi, param);

	if (fp)
		fput(fp);
done:
	if (err >= 0 && copy_to_user(user, param, AUTOFS_DEV_IOCTL_SIZE))
		err = -EFAULT;
out:
	free_dev_ioctl(param);
	return err;
}
示例#2
0
文件: dev-ioctl.c 项目: avagin/linux
/* ioctl dispatcher */
static int _autofs_dev_ioctl(unsigned int command,
			     struct autofs_dev_ioctl __user *user)
{
	struct autofs_dev_ioctl *param;
	struct file *fp;
	struct autofs_sb_info *sbi;
	unsigned int cmd_first, cmd;
	ioctl_fn fn = NULL;
	int err = 0;

	cmd_first = _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST);
	cmd = _IOC_NR(command);

	if (_IOC_TYPE(command) != _IOC_TYPE(AUTOFS_DEV_IOCTL_IOC_FIRST) ||
	    cmd - cmd_first > AUTOFS_DEV_IOCTL_IOC_COUNT) {
		return -ENOTTY;
	}

	/* Only root can use ioctls other than AUTOFS_DEV_IOCTL_VERSION_CMD
	 * and AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD
	 */
	if (cmd != AUTOFS_DEV_IOCTL_VERSION_CMD &&
	    cmd != AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD &&
	    !capable(CAP_SYS_ADMIN))
		return -EPERM;

	/* Copy the parameters into kernel space. */
	param = copy_dev_ioctl(user);
	if (IS_ERR(param))
		return PTR_ERR(param);

	err = validate_dev_ioctl(command, param);
	if (err)
		goto out;

	fn = lookup_dev_ioctl(cmd);
	if (!fn) {
		pr_warn("unknown command 0x%08x\n", command);
		err = -ENOTTY;
		goto out;
	}

	fp = NULL;
	sbi = NULL;

	/*
	 * For obvious reasons the openmount can't have a file
	 * descriptor yet. We don't take a reference to the
	 * file during close to allow for immediate release,
	 * and the same for retrieving ioctl version.
	 */
	if (cmd != AUTOFS_DEV_IOCTL_VERSION_CMD &&
	    cmd != AUTOFS_DEV_IOCTL_OPENMOUNT_CMD &&
	    cmd != AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD) {
		struct super_block *sb;

		fp = fget(param->ioctlfd);
		if (!fp) {
			if (cmd == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD)
				goto cont;
			err = -EBADF;
			goto out;
		}

		sb = file_inode(fp)->i_sb;
		if (sb->s_type != &autofs_fs_type) {
			err = -EINVAL;
			fput(fp);
			goto out;
		}
		sbi = autofs_sbi(sb);

		/*
		 * Admin needs to be able to set the mount catatonic in
		 * order to be able to perform the re-open.
		 */
		if (!autofs_oz_mode(sbi) &&
		    cmd != AUTOFS_DEV_IOCTL_CATATONIC_CMD) {
			err = -EACCES;
			fput(fp);
			goto out;
		}
	}
cont:
	err = fn(fp, sbi, param);

	if (fp)
		fput(fp);
	if (err >= 0 && copy_to_user(user, param, AUTOFS_DEV_IOCTL_SIZE))
		err = -EFAULT;
out:
	free_dev_ioctl(param);
	return err;
}