xref: /src/sys/dev/bio.c

/*	$NetBSD: bio.c,v 1.2.2.1 2007/12/08 18:19:17 mjf Exp $ */
/*	$OpenBSD: bio.c,v 1.9 2007/03/20 02:35:55 marco Exp $	*/

/*
 * Copyright (c) 2002 Niklas Hallqvist.  All rights reserved.
 *
 * 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 AUTHOR ``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 AUTHOR 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.
 */

/* A device controller ioctl tunnelling device.  */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: bio.c,v 1.2.2.1 2007/12/08 18:19:17 mjf Exp $");

#include <sys/param.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/event.h>
#include <sys/ioctl.h>
#include <sys/malloc.h>
#include <sys/queue.h>
#include <sys/systm.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/kauth.h>

#include <dev/biovar.h>

struct bio_mapping {
	LIST_ENTRY(bio_mapping) bm_link;
	struct device *bm_dev;
	int (*bm_ioctl)(struct device *, u_long, void *);
};

LIST_HEAD(, bio_mapping) bios = LIST_HEAD_INITIALIZER(bios);
static kmutex_t bio_lock;
static bool bio_lock_initialized = false;

static void bio_initialize(void);
void	bioattach(int);
int	bioclose(dev_t, int, int, struct lwp *);
int	bioioctl(dev_t, u_long, void *, int, struct lwp *);
int	bioopen(dev_t, int, int, struct lwp *);

int	bio_delegate_ioctl(struct bio_mapping *, u_long, void *);
struct	bio_mapping *bio_lookup(char *);
int	bio_validate(void *);

const struct cdevsw bio_cdevsw = {
        bioopen, bioclose, noread, nowrite, bioioctl,
        nostop, notty, nopoll, nommap, nokqfilter, 0
};


void
bio_initialize(void)
{
	if (bio_lock_initialized)
		return;

	mutex_init(&bio_lock, MUTEX_DEFAULT, IPL_VM);
	bio_lock_initialized = true;
}

void
bioattach(int nunits)
{
	if (!bio_lock_initialized)
		bio_initialize();
}

int
bioopen(dev_t dev, int flags, int mode, struct lwp *l)
{
	return 0;
}

int
bioclose(dev_t dev, int flags, int mode, struct lwp *l)
{
	return 0;
}

int
bioioctl(dev_t dev, u_long cmd, void *addr, int flag, struct  lwp *l)
{
	struct bio_locate *locate;
	struct bio_common *common;
	char name[16];
	int error;

	switch(cmd) {
	case BIOCLOCATE:
	case BIOCINQ:
	case BIOCDISK:
	case BIOCVOL:
		error = kauth_authorize_device_passthru(l->l_cred, dev,
		    KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_READCONF, addr);
		if (error)
			return error;
		break;
	case BIOCBLINK:
	case BIOCSETSTATE:
		error = kauth_authorize_device_passthru(l->l_cred, dev,
		    KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_WRITECONF, addr);
		if (error)
			return error;
		break;
	case BIOCALARM: {
		struct bioc_alarm *alarm = (struct bioc_alarm *)addr;
		switch (alarm->ba_opcode) {
		case BIOC_SADISABLE:
		case BIOC_SAENABLE:
		case BIOC_SASILENCE:
		case BIOC_SATEST:
			error = kauth_authorize_device_passthru(l->l_cred, dev,
			    KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_WRITECONF, addr);
			if (error)
				return error;
			break;
		case BIOC_GASTATUS:
			error = kauth_authorize_device_passthru(l->l_cred, dev,
			    KAUTH_REQ_DEVICE_RAWIO_PASSTHRU_READCONF, addr);
			if (error)
				return error;
			break;
		default:
			return EINVAL;
		}
		break;
	}
	default:
		return ENOTTY;
	}

	switch (cmd) {
	case BIOCLOCATE:
		locate = (struct bio_locate *)addr;
		error = copyinstr(locate->bl_name, name, 16, NULL);
		if (error != 0)
			return error;
		locate->bl_cookie = bio_lookup(name);
		if (locate->bl_cookie == NULL)
			return ENOENT;
		break;

	default:
		common = (struct bio_common *)addr;
		mutex_enter(&bio_lock);
		if (!bio_validate(common->bc_cookie)) {
			mutex_exit(&bio_lock);
			return ENOENT;
		}
		mutex_exit(&bio_lock);
		error = bio_delegate_ioctl(
		    (struct bio_mapping *)common->bc_cookie, cmd, addr);
		return error;
	}
	return 0;
}

int
bio_register(struct device *dev, int (*ioctl)(struct device *, u_long, void *))
{
	struct bio_mapping *bm;

	if (!bio_lock_initialized)
		bio_initialize();

	bm = (struct bio_mapping *)malloc(sizeof(*bm), M_DEVBUF,
	    M_NOWAIT|M_ZERO);
	if (bm == NULL)
		return ENOMEM;
	bm->bm_dev = dev;
	bm->bm_ioctl = ioctl;
	mutex_enter(&bio_lock);
	LIST_INSERT_HEAD(&bios, bm, bm_link);
	mutex_exit(&bio_lock);
	return 0;
}

void
bio_unregister(struct device *dev)
{
	struct bio_mapping *bm, *next;

	mutex_enter(&bio_lock);
	for (bm = LIST_FIRST(&bios); bm != NULL; bm = next) {
		next = LIST_NEXT(bm, bm_link);

		if (dev == bm->bm_dev) {
			LIST_REMOVE(bm, bm_link);
			free(bm, M_DEVBUF);
		}
	}
	mutex_exit(&bio_lock);
}

struct bio_mapping *
bio_lookup(char *name)
{
	struct bio_mapping *bm;

	mutex_enter(&bio_lock);
	LIST_FOREACH(bm, &bios, bm_link) {
		if (strcmp(name, bm->bm_dev->dv_xname) == 0) {
			mutex_exit(&bio_lock);
			return bm;
		}
	}
	mutex_exit(&bio_lock);
	return NULL;
}

int
bio_validate(void *cookie)
{
	struct bio_mapping *bm;

	LIST_FOREACH(bm, &bios, bm_link)
		if (bm == cookie)
			return 1;

	return 0;
}

int
bio_delegate_ioctl(struct bio_mapping *bm, u_long cmd, void *addr)
{

	return bm->bm_ioctl(bm->bm_dev, cmd, addr);
}