openprom.c

来自「linux 内核源代码」· C语言 代码 · 共 753 行 · 第 1/2 页

/* Copy in a whole string from userspace into kernelspace. */
static int copyin_string(char __user *user, size_t len, char **ptr)
{
	char *tmp;

	if ((ssize_t)len < 0 || (ssize_t)(len + 1) < 0)
		return -EINVAL;

	tmp = kmalloc(len + 1, GFP_KERNEL);
	if (!tmp)
		return -ENOMEM;

	if (copy_from_user(tmp, user, len)) {
		kfree(tmp);
		return -EFAULT;
	}

	tmp[len] = '\0';

	*ptr = tmp;

	return 0;
}

/*
 *	NetBSD /dev/openprom ioctl calls.
 */
static int opiocget(void __user *argp, DATA *data)
{
	struct opiocdesc op;
	struct device_node *dp;
	char *str;
	const void *pval;
	int err, len;

	if (copy_from_user(&op, argp, sizeof(op)))
		return -EFAULT;

	dp = get_node(op.op_nodeid, data);

	err = copyin_string(op.op_name, op.op_namelen, &str);
	if (err)
		return err;

	pval = of_get_property(dp, str, &len);
	err = 0;
	if (!pval || len > op.op_buflen) {
		err = -EINVAL;
	} else {
		op.op_buflen = len;
		if (copy_to_user(argp, &op, sizeof(op)) ||
		    copy_to_user(op.op_buf, pval, len))
			err = -EFAULT;
	}
	kfree(str);

	return err;
}

static int opiocnextprop(void __user *argp, DATA *data)
{
	struct opiocdesc op;
	struct device_node *dp;
	struct property *prop;
	char *str;
	int err, len;

	if (copy_from_user(&op, argp, sizeof(op)))
		return -EFAULT;

	dp = get_node(op.op_nodeid, data);
	if (!dp)
		return -EINVAL;

	err = copyin_string(op.op_name, op.op_namelen, &str);
	if (err)
		return err;

	if (str[0] == '\0') {
		prop = dp->properties;
	} else {
		prop = of_find_property(dp, str, NULL);
		if (prop)
			prop = prop->next;
	}
	kfree(str);

	if (!prop)
		len = 0;
	else
		len = prop->length;

	if (len > op.op_buflen)
		len = op.op_buflen;

	if (copy_to_user(argp, &op, sizeof(op)))
		return -EFAULT;

	if (len &&
	    copy_to_user(op.op_buf, prop->value, len))
		return -EFAULT;

	return 0;
}

static int opiocset(void __user *argp, DATA *data)
{
	struct opiocdesc op;
	struct device_node *dp;
	char *str, *tmp;
	int err;

	if (copy_from_user(&op, argp, sizeof(op)))
		return -EFAULT;

	dp = get_node(op.op_nodeid, data);
	if (!dp)
		return -EINVAL;

	err = copyin_string(op.op_name, op.op_namelen, &str);
	if (err)
		return err;

	err = copyin_string(op.op_buf, op.op_buflen, &tmp);
	if (err) {
		kfree(str);
		return err;
	}

	err = of_set_property(dp, str, tmp, op.op_buflen);

	kfree(str);
	kfree(tmp);

	return err;
}

static int opiocgetnext(unsigned int cmd, void __user *argp)
{
	struct device_node *dp;
	phandle nd;

	BUILD_BUG_ON(sizeof(phandle) != sizeof(int));

	if (copy_from_user(&nd, argp, sizeof(phandle)))
		return -EFAULT;

	if (nd == 0) {
		if (cmd != OPIOCGETNEXT)
			return -EINVAL;
		dp = of_find_node_by_path("/");
	} else {
		dp = of_find_node_by_phandle(nd);
		nd = 0;
		if (dp) {
			if (cmd == OPIOCGETNEXT)
				dp = dp->sibling;
			else
				dp = dp->child;
		}
	}
	if (dp)
		nd = dp->node;
	if (copy_to_user(argp, &nd, sizeof(phandle)))
		return -EFAULT;

	return 0;
}

static int openprom_bsd_ioctl(struct inode * inode, struct file * file,
			      unsigned int cmd, unsigned long arg)
{
	DATA *data = (DATA *) file->private_data;
	void __user *argp = (void __user *)arg;
	int err;

	switch (cmd) {
	case OPIOCGET:
		err = opiocget(argp, data);
		break;

	case OPIOCNEXTPROP:
		err = opiocnextprop(argp, data);
		break;

	case OPIOCSET:
		err = opiocset(argp, data);
		break;

	case OPIOCGETOPTNODE:
		BUILD_BUG_ON(sizeof(phandle) != sizeof(int));

		if (copy_to_user(argp, &options_node->node, sizeof(phandle)))
			return -EFAULT;

		return 0;

	case OPIOCGETNEXT:
	case OPIOCGETCHILD:
		err = opiocgetnext(cmd, argp);
		break;

	default:
		return -EINVAL;

	};

	return err;
}


/*
 *	Handoff control to the correct ioctl handler.
 */
static int openprom_ioctl(struct inode * inode, struct file * file,
			  unsigned int cmd, unsigned long arg)
{
	DATA *data = (DATA *) file->private_data;

	switch (cmd) {
	case OPROMGETOPT:
	case OPROMNXTOPT:
		if ((file->f_mode & FMODE_READ) == 0)
			return -EPERM;
		return openprom_sunos_ioctl(inode, file, cmd, arg,
					    options_node);

	case OPROMSETOPT:
	case OPROMSETOPT2:
		if ((file->f_mode & FMODE_WRITE) == 0)
			return -EPERM;
		return openprom_sunos_ioctl(inode, file, cmd, arg,
					    options_node);

	case OPROMNEXT:
	case OPROMCHILD:
	case OPROMGETPROP:
	case OPROMNXTPROP:
		if ((file->f_mode & FMODE_READ) == 0)
			return -EPERM;
		return openprom_sunos_ioctl(inode, file, cmd, arg,
					    data->current_node);

	case OPROMU2P:
	case OPROMGETCONS:
	case OPROMGETFBNAME:
	case OPROMGETBOOTARGS:
	case OPROMSETCUR:
	case OPROMPCI2NODE:
	case OPROMPATH2NODE:
		if ((file->f_mode & FMODE_READ) == 0)
			return -EPERM;
		return openprom_sunos_ioctl(inode, file, cmd, arg, NULL);

	case OPIOCGET:
	case OPIOCNEXTPROP:
	case OPIOCGETOPTNODE:
	case OPIOCGETNEXT:
	case OPIOCGETCHILD:
		if ((file->f_mode & FMODE_READ) == 0)
			return -EBADF;
		return openprom_bsd_ioctl(inode,file,cmd,arg);

	case OPIOCSET:
		if ((file->f_mode & FMODE_WRITE) == 0)
			return -EBADF;
		return openprom_bsd_ioctl(inode,file,cmd,arg);

	default:
		return -EINVAL;
	};
}

static long openprom_compat_ioctl(struct file *file, unsigned int cmd,
		unsigned long arg)
{
	long rval = -ENOTTY;

	/*
	 * SunOS/Solaris only, the NetBSD one's have embedded pointers in
	 * the arg which we'd need to clean up...
	 */
	switch (cmd) {
	case OPROMGETOPT:
	case OPROMSETOPT:
	case OPROMNXTOPT:
	case OPROMSETOPT2:
	case OPROMNEXT:
	case OPROMCHILD:
	case OPROMGETPROP:
	case OPROMNXTPROP:
	case OPROMU2P:
	case OPROMGETCONS:
	case OPROMGETFBNAME:
	case OPROMGETBOOTARGS:
	case OPROMSETCUR:
	case OPROMPCI2NODE:
	case OPROMPATH2NODE:
		rval = openprom_ioctl(file->f_path.dentry->d_inode, file, cmd, arg);
		break;
	}

	return rval;
}

static int openprom_open(struct inode * inode, struct file * file)
{
	DATA *data;

	data = kmalloc(sizeof(DATA), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->current_node = of_find_node_by_path("/");
	data->lastnode = data->current_node;
	file->private_data = (void *) data;

	return 0;
}

static int openprom_release(struct inode * inode, struct file * file)
{
	kfree(file->private_data);
	return 0;
}

static const struct file_operations openprom_fops = {
	.owner =	THIS_MODULE,
	.llseek =	no_llseek,
	.ioctl =	openprom_ioctl,
	.compat_ioctl =	openprom_compat_ioctl,
	.open =		openprom_open,
	.release =	openprom_release,
};

static struct miscdevice openprom_dev = {
	.minor		= SUN_OPENPROM_MINOR,
	.name		= "openprom",
	.fops		= &openprom_fops,
};

static int __init openprom_init(void)
{
	struct device_node *dp;
	int err;

	err = misc_register(&openprom_dev);
	if (err)
		return err;

	dp = of_find_node_by_path("/");
	dp = dp->child;
	while (dp) {
		if (!strcmp(dp->name, "options"))
			break;
		dp = dp->sibling;
	}
	options_node = dp;

	if (!options_node) {
		misc_deregister(&openprom_dev);
		return -EIO;
	}

	return 0;
}

static void __exit openprom_cleanup(void)
{
	misc_deregister(&openprom_dev);
}

module_init(openprom_init);
module_exit(openprom_cleanup);