/*      $NetBSD: openfirmio.c,v 1.4 2002/09/06 13:23:19 gehenna Exp $ */

#include <sys/cdefs.h>
/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This software was developed by the Computer Systems Engineering group
 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
 * contributed to Berkeley.
 *
 * All advertising materials mentioning features or use of this software
 * must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Lawrence Berkeley Laboratory.
 *
 * 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/errno.h>
#include <sys/fcntl.h>
#include <sys/ioccom.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>

#include <dev/ofw/openfirmio.h>

static struct cdev *openfirm_dev;

static d_ioctl_t openfirm_ioctl;

#define OPENFIRM_MINOR  0

static struct cdevsw openfirm_cdevsw = {
        .d_version =    D_VERSION,
        .d_flags =      D_NEEDGIANT | D_GIANTOK,
        .d_ioctl =      openfirm_ioctl,
        .d_name =       "openfirm",
};

static phandle_t lastnode;      /* speed hack */

static int openfirm_checkid(phandle_t, phandle_t);
static int openfirm_getstr(int, const char *, char **);

/*
 * Verify target ID is valid (exists in the OPENPROM tree), as
 * listed from node ID sid forward.
 */
static int
openfirm_checkid(phandle_t sid, phandle_t tid)
{

        for (; sid != 0; sid = OF_peer(sid))
                if (sid == tid || openfirm_checkid(OF_child(sid), tid))
                        return (1);

        return (0);
}

static int
openfirm_getstr(int len, const char *user, char **cpp)
{
        int error;
        char *cp;

        /* Reject obvious bogus requests. */
        if ((u_int)len > OFIOCMAXNAME)
                return (ENAMETOOLONG);

        *cpp = cp = malloc(len + 1, M_TEMP, M_WAITOK);
        error = copyin(user, cp, len);
        cp[len] = '\0';
        return (error);
}

int
openfirm_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags,
    struct thread *td)
{
        struct ofiocdesc *of;
        phandle_t node;
        int len, ok, error;
        char *name, *value;
        char newname[OFIOCSUGGPROPNAMELEN];

        if ((flags & FREAD) == 0)
                return (EBADF);

        of = (struct ofiocdesc *)data;
        switch (cmd) {
        case OFIOCGETOPTNODE:
                *(phandle_t *) data = OF_finddevice("/options");
                return (0);
        case OFIOCGET:
        case OFIOCSET:
        case OFIOCNEXTPROP:
        case OFIOCFINDDEVICE:
        case OFIOCGETPROPLEN:
                node = of->of_nodeid;
                break;
        case OFIOCGETNEXT:
        case OFIOCGETCHILD:
                node = *(phandle_t *)data;
                break;
        default:
                return (ENOIOCTL);
        }

        if (node != 0 && node != lastnode) {
                /* Not an easy one, we must search for it. */
                ok = openfirm_checkid(OF_peer(0), node);
                if (!ok)
                        return (EINVAL);
                lastnode = node;
        }

        name = value = NULL;
        error = 0;
        switch (cmd) {
        case OFIOCGET:
        case OFIOCGETPROPLEN:
                if (node == 0)
                        return (EINVAL);
                error = openfirm_getstr(of->of_namelen, of->of_name, &name);
                if (error)
                        break;
                len = OF_getproplen(node, name);
                if (cmd == OFIOCGETPROPLEN) {
                        of->of_buflen = len;
                        break;
                }
                if (len > of->of_buflen) {
                        error = ENOMEM;
                        break;
                }
                of->of_buflen = len;
                /* -1 means no entry; 0 means no value. */
                if (len <= 0)
                        break;
                value = malloc(len, M_TEMP, M_WAITOK);
                len = OF_getprop(node, name, (void *)value, len);
                error = copyout(value, of->of_buf, len);
                break;

        case OFIOCSET:
                /*
                 * Note: Text string values for at least the /options node
                 * have to be null-terminated and the length parameter must
                 * include this terminating null.  However, like OF_getprop(),
                 * OF_setprop() will return the actual length of the text
                 * string, i.e. omitting the terminating null.
                 */
                if ((flags & FWRITE) == 0)
                        return (EBADF);
                if (node == 0)
                        return (EINVAL);
                if ((u_int)of->of_buflen > OFIOCMAXVALUE)
                        return (ENAMETOOLONG);
                error = openfirm_getstr(of->of_namelen, of->of_name, &name);
                if (error)
                        break;
                value = malloc(of->of_buflen, M_TEMP, M_WAITOK);
                error = copyin(of->of_buf, value, of->of_buflen);
                if (error)
                        break;
                len = OF_setprop(node, name, value, of->of_buflen);
                if (len < 0)
                        error = EINVAL;
                of->of_buflen = len;
                break;

        case OFIOCNEXTPROP:
                if (node == 0 || of->of_buflen < 0)
                        return (EINVAL);
                if (of->of_namelen != 0) {
                        error = openfirm_getstr(of->of_namelen, of->of_name,
                            &name);
                        if (error)
                                break;
                }
                ok = OF_nextprop(node, name, newname, sizeof(newname));
                if (ok == 0) {
                        error = ENOENT;
                        break;
                }
                if (ok == -1) {
                        error = EINVAL;
                        break;
                }
                len = strlen(newname) + 1;
                if (len > of->of_buflen) {
                        /*
                         * Passed buffer was insufficient.
                         *
                         * Instead of returning an error here, truncate the
                         * property name to fit the buffer.
                         *
                         * This allows us to retain compatibility with old
                         * tools which always pass a 32 character buffer.
                         */
                        len = of->of_buflen;
                        newname[len - 1] = '\0';
                }
                else
                        of->of_buflen = len;
                error = copyout(newname, of->of_buf, len);
                break;

        case OFIOCGETNEXT:
                node = OF_peer(node);
                *(phandle_t *)data = lastnode = node;
                break;

        case OFIOCGETCHILD:
                if (node == 0)
                        return (EINVAL);
                node = OF_child(node);
                *(phandle_t *)data = lastnode = node;
                break;

        case OFIOCFINDDEVICE:
                error = openfirm_getstr(of->of_namelen, of->of_name, &name);
                if (error)
                        break;
                node = OF_finddevice(name);
                if (node == -1) {
                        error = ENOENT;
                        break;
                }
                of->of_nodeid = lastnode = node;
                break;
        }

        if (name != NULL)
                free(name, M_TEMP);
        if (value != NULL)
                free(value, M_TEMP);

        return (error);
}

static int
openfirm_modevent(module_t mod, int type, void *data)
{

        switch(type) {
        case MOD_LOAD:
                if (bootverbose)
                        printf("openfirm: <Open Firmware control device>\n");
                /*
                 * Allow only root access by default; this device may allow
                 * users to peek into firmware passwords, and likely to crash
                 * the machine on some boxen due to firmware quirks.
                 */
                openfirm_dev = make_dev(&openfirm_cdevsw, OPENFIRM_MINOR,
                    UID_ROOT, GID_WHEEL, 0600, "openfirm");
                return 0;

        case MOD_UNLOAD:
                destroy_dev(openfirm_dev);
                return 0;

        case MOD_SHUTDOWN:
                return 0;

        default:
                return EOPNOTSUPP;
        }
}

DEV_MODULE(openfirm, openfirm_modevent, NULL);