/*	$OpenBSD: devopen.c,v 1.1 2013/06/05 01:02:29 jasper Exp $	*/

/*-
 * Copyright (c) 2003 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Rolf Grossmann.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "libsa.h"

#define MAXDEVNAME      16

/*
 * Parse a device spec.
 *
 * [A-Za-z]*[0-9]*[A-Za-z]:file
 *    dev   uint    part
 */
int
devparse(const char *fname, int *dev, int *unit, int *part, const char **file)
{
	const char *s;

	*unit = 0;	/* default to wd0a */
	*part = 0;
	*dev  = 0;

	s = strchr(fname, ':');
	if (s != NULL) {
		int devlen;
		int i, u, p = 0;
		struct devsw *dp;
		char devname[MAXDEVNAME];

		devlen = s - fname;
		if (devlen > MAXDEVNAME)
			return (EINVAL);

		/* extract device name */
		for (i = 0; isalpha(fname[i]) && (i < devlen); i++)
			devname[i] = fname[i];
		devname[i] = 0;

		if (!isdigit(fname[i]))
			return (EUNIT);

		/* device number */
		for (u = 0; isdigit(fname[i]) && (i < devlen); i++)
			u = u * 10 + (fname[i] - '0');

		if (!isalpha(fname[i]))
			return (EPART);

		/* partition number */
		if (i < devlen)
			p = fname[i++] - 'a';

		if (i != devlen)
			return (ENXIO);

		/* check device name */
		for (dp = devsw, i = 0; i < ndevs; dp++, i++) {
			if (dp->dv_name && !strcmp(devname, dp->dv_name))
				break;
		}

		if (i >= ndevs)
			return (ENXIO);

		*unit = u;
		*part = p;
		*dev  = i;
		fname = ++s;
	}

	*file = fname;

	return (0);
}

int
devopen(struct open_file *f, const char *fname, char **file)
{
	struct devsw *dp;
	int dev, unit, part, error;

	error = devparse(fname, &dev, &unit, &part, (const char **)file);
	if (error)
		return (error);

	dp = &devsw[dev];
	if ((void *)dp->dv_open == (void *)nodev)
		return (ENXIO);

	f->f_dev = dp;

	return (*dp->dv_open)(f, unit, part);
}
