/*-
 * Copyright (c) 2016 Netflix, Inc.
 *
 * 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
 *    in this position and unchanged.
 * 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.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>

#include <machine/efi.h>
#include <sys/efiio.h>

static d_ioctl_t efidev_ioctl;

static struct cdevsw efi_cdevsw = {
        .d_name = "efi",
        .d_version = D_VERSION,
        .d_ioctl = efidev_ioctl,
};
        
static int
efidev_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t addr,
    int flags __unused, struct thread *td __unused)
{
        int error;

        switch (cmd) {
        case EFIIOC_GET_TABLE:
        {
                struct efi_get_table_ioctl *egtioc =
                    (struct efi_get_table_ioctl *)addr;
                void *buf = NULL;

                error = efi_copy_table(&egtioc->guid,
                    egtioc->buf != NULL ? &buf : NULL, egtioc->buf_len,
                    &egtioc->table_len);

                if (error != 0 || egtioc->buf == NULL)
                        break;

                if (egtioc->buf_len < egtioc->table_len) {
                        error = EINVAL;
                        free(buf, M_TEMP);
                        break;
                }

                error = copyout(buf, egtioc->buf, egtioc->buf_len);
                free(buf, M_TEMP);

                break;
        }
        case EFIIOC_GET_TIME:
        {
                struct efi_tm *tm = (struct efi_tm *)addr;

                error = efi_get_time(tm);
                break;
        }
        case EFIIOC_SET_TIME:
        {
                struct efi_tm *tm = (struct efi_tm *)addr;

                error = efi_set_time(tm);
                break;
        }
        case EFIIOC_GET_WAKETIME:
        {
                struct efi_waketime_ioctl *wt = (struct efi_waketime_ioctl *)addr;

                error = efi_get_waketime(&wt->enabled, &wt->pending,
                    &wt->waketime);
                break;
        }
        case EFIIOC_SET_WAKETIME:
        {
                struct efi_waketime_ioctl *wt = (struct efi_waketime_ioctl *)addr;

                error = efi_set_waketime(wt->enabled, &wt->waketime);
                break;
        }
        case EFIIOC_VAR_GET:
        {
                struct efi_var_ioctl *ev = (struct efi_var_ioctl *)addr;
                void *data;
                efi_char *name;

                data = malloc(ev->datasize, M_TEMP, M_WAITOK);
                name = malloc(ev->namesize, M_TEMP, M_WAITOK);
                error = copyin(ev->name, name, ev->namesize);
                if (error)
                        goto vg_out;
                if (name[ev->namesize / sizeof(efi_char) - 1] != 0) {
                        error = EINVAL;
                        goto vg_out;
                }

                error = efi_var_get(name, &ev->vendor, &ev->attrib,
                    &ev->datasize, data);

                if (error == 0) {
                        error = copyout(data, ev->data, ev->datasize);
                } else if (error == EOVERFLOW) {
                        /*
                         * Pass back the size we really need, but
                         * convert the error to 0 so the copyout
                         * happens. datasize was updated in the
                         * efi_var_get call.
                         */
                        ev->data = NULL;
                        error = 0;
                }
vg_out:
                free(data, M_TEMP);
                free(name, M_TEMP);
                break;
        }
        case EFIIOC_VAR_NEXT:
        {
                struct efi_var_ioctl *ev = (struct efi_var_ioctl *)addr;
                efi_char *name;

                name = malloc(ev->namesize, M_TEMP, M_WAITOK);
                error = copyin(ev->name, name, ev->namesize);
                if (error)
                        goto vn_out;
                /* Note: namesize is the buffer size, not the string lenght */

                error = efi_var_nextname(&ev->namesize, name, &ev->vendor);
                if (error == 0) {
                        error = copyout(name, ev->name, ev->namesize);
                } else if (error == EOVERFLOW) {
                        ev->name = NULL;
                        error = 0;
                }
        vn_out:
                free(name, M_TEMP);
                break;
        }
        case EFIIOC_VAR_SET:
        {
                struct efi_var_ioctl *ev = (struct efi_var_ioctl *)addr;
                void *data = NULL;
                efi_char *name;

                /* datasize == 0 -> delete (more or less) */
                if (ev->datasize > 0)
                        data = malloc(ev->datasize, M_TEMP, M_WAITOK);
                name = malloc(ev->namesize, M_TEMP, M_WAITOK);
                if (ev->datasize) {
                        error = copyin(ev->data, data, ev->datasize);
                        if (error)
                                goto vs_out;
                }
                error = copyin(ev->name, name, ev->namesize);
                if (error)
                        goto vs_out;
                if (name[ev->namesize / sizeof(efi_char) - 1] != 0) {
                        error = EINVAL;
                        goto vs_out;
                }

                error = efi_var_set(name, &ev->vendor, ev->attrib, ev->datasize,
                    data);
vs_out:
                free(data, M_TEMP);
                free(name, M_TEMP);
                break;
        }
        default:
                error = ENOTTY;
                break;
        }

        return (error);
}

static struct cdev *efidev;

static int
efidev_modevents(module_t m, int event, void *arg __unused)
{
        struct make_dev_args mda;
        int error;

        switch (event) {
        case MOD_LOAD:
                /*
                 * If we have no efi environment, then don't create the device.
                 */
                if (efi_rt_ok() != 0)
                        return (0);
                make_dev_args_init(&mda);
                mda.mda_flags = MAKEDEV_WAITOK | MAKEDEV_CHECKNAME;
                mda.mda_devsw = &efi_cdevsw;
                mda.mda_uid = UID_ROOT;
                mda.mda_gid = GID_WHEEL;
                mda.mda_mode = 0700;
                error = make_dev_s(&mda, &efidev, "efi");
                return (error);

        case MOD_UNLOAD:
                if (efidev != NULL)
                        destroy_dev(efidev);
                efidev = NULL;
                return (0);

        case MOD_SHUTDOWN:
                return (0);

        default:
                return (EOPNOTSUPP);
        }
}

static moduledata_t efidev_moddata = {
        .name = "efidev",
        .evhand = efidev_modevents,
        .priv = NULL,
};

DECLARE_MODULE(efidev, efidev_moddata, SI_SUB_DRIVERS, SI_ORDER_ANY);
MODULE_VERSION(efidev, 1);
MODULE_DEPEND(efidev, efirt, 1, 1, 1);