/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2005-2008 Sam Leffler, Errno Consulting
 * 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.
 */

#include <sys/cdefs.h>
/*
 * IEEE 802.11 regdomain support.
 */
#include "opt_wlan.h"

#include <sys/param.h>
#include <sys/systm.h> 
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/socket.h>

#include <net/if.h>
#include <net/if_var.h>
#include <net/if_media.h>
#include <net/ethernet.h>

#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_regdomain.h>

static void
null_getradiocaps(struct ieee80211com *ic, int maxchan,
        int *n, struct ieee80211_channel *c)
{
        /* just feed back the current channel list */
        if (maxchan > ic->ic_nchans)
                maxchan = ic->ic_nchans;
        memcpy(c, ic->ic_channels, maxchan*sizeof(struct ieee80211_channel));
        *n = maxchan;
}

static int
null_setregdomain(struct ieee80211com *ic,
        struct ieee80211_regdomain *rd,
        int nchans, struct ieee80211_channel chans[])
{
        return 0;               /* accept anything */
}

void
ieee80211_regdomain_attach(struct ieee80211com *ic)
{
        if (ic->ic_regdomain.regdomain == 0 &&
            ic->ic_regdomain.country == CTRY_DEFAULT) {
                ic->ic_regdomain.location = ' ';                /* both */
                /* NB: driver calls ieee80211_init_channels or similar */
        }
        ic->ic_getradiocaps = null_getradiocaps;
        ic->ic_setregdomain = null_setregdomain;
}

void
ieee80211_regdomain_detach(struct ieee80211com *ic)
{
        if (ic->ic_countryie != NULL) {
                IEEE80211_FREE(ic->ic_countryie, M_80211_NODE_IE);
                ic->ic_countryie = NULL;
        }
}

void
ieee80211_regdomain_vattach(struct ieee80211vap *vap)
{
}

void
ieee80211_regdomain_vdetach(struct ieee80211vap *vap)
{
}

static const uint8_t def_chan_2ghz[] =
    { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 };
static const uint8_t def_chan_5ghz_band1[] =
    { 36, 40, 44, 48, 52, 56, 60, 64 };
static const uint8_t def_chan_5ghz_band2[] =
    { 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140 };
static const uint8_t def_chan_5ghz_band3[] =
    { 149, 153, 157, 161 };

/*
 * Setup the channel list for the specified regulatory domain,
 * country code, and operating modes.  This interface is used
 * when a driver does not obtain the channel list from another
 * source (such as firmware).
 */
int
ieee80211_init_channels(struct ieee80211com *ic,
        const struct ieee80211_regdomain *rd, const uint8_t bands[])
{
        struct ieee80211_channel *chans = ic->ic_channels;
        int *nchans = &ic->ic_nchans;
        int cbw_flags;

        /* XXX just do something for now */
        cbw_flags = (ic->ic_htcaps & IEEE80211_HTCAP_CHWIDTH40) ?
            NET80211_CBW_FLAG_HT40 : 0;
        *nchans = 0;
        if (isset(bands, IEEE80211_MODE_11B) ||
            isset(bands, IEEE80211_MODE_11G) ||
            isset(bands, IEEE80211_MODE_11NG)) {
                int nchan = nitems(def_chan_2ghz);
                if (!(rd != NULL && rd->ecm))
                        nchan -= 3;

                ieee80211_add_channel_list_2ghz(chans, IEEE80211_CHAN_MAX,
                    nchans, def_chan_2ghz, nchan, bands, cbw_flags);
        }
        /* XXX IEEE80211_MODE_VHT_2GHZ if we really want to. */

        if (isset(bands, IEEE80211_MODE_11A) ||
            isset(bands, IEEE80211_MODE_11NA)) {
                ieee80211_add_channel_list_5ghz(chans, IEEE80211_CHAN_MAX,
                    nchans, def_chan_5ghz_band1, nitems(def_chan_5ghz_band1),
                    bands, cbw_flags);
                ieee80211_add_channel_list_5ghz(chans, IEEE80211_CHAN_MAX,
                    nchans, def_chan_5ghz_band2, nitems(def_chan_5ghz_band2),
                    bands, cbw_flags);
                ieee80211_add_channel_list_5ghz(chans, IEEE80211_CHAN_MAX,
                    nchans, def_chan_5ghz_band3, nitems(def_chan_5ghz_band3),
                    bands, cbw_flags);
        }
        if (isset(bands, IEEE80211_MODE_VHT_5GHZ)) {
                cbw_flags |= NET80211_CBW_FLAG_HT40;  /* Make sure this is set; or assert?  */
                cbw_flags |= NET80211_CBW_FLAG_VHT80;
                if (IEEE80211_VHTCAP_SUPP_CHAN_WIDTH_IS_160MHZ(ic->ic_vht_cap.vht_cap_info))
                        cbw_flags |= NET80211_CBW_FLAG_VHT160;
                if (IEEE80211_VHTCAP_SUPP_CHAN_WIDTH_IS_160_80P80MHZ(
                    ic->ic_vht_cap.vht_cap_info))
                        cbw_flags |= NET80211_CBW_FLAG_VHT80P80;
                ieee80211_add_channel_list_5ghz(chans, IEEE80211_CHAN_MAX,
                    nchans, def_chan_5ghz_band1, nitems(def_chan_5ghz_band1),
                    bands, cbw_flags);
                ieee80211_add_channel_list_5ghz(chans, IEEE80211_CHAN_MAX,
                    nchans, def_chan_5ghz_band2, nitems(def_chan_5ghz_band2),
                    bands, cbw_flags);
                ieee80211_add_channel_list_5ghz(chans, IEEE80211_CHAN_MAX,
                    nchans, def_chan_5ghz_band3, nitems(def_chan_5ghz_band3),
                    bands, cbw_flags);
        }
        if (rd != NULL)
                ic->ic_regdomain = *rd;

        return 0;
}

static __inline int
chancompar(const void *a, const void *b)
{
        const struct ieee80211_channel *ca = a;
        const struct ieee80211_channel *cb = b;

        return (ca->ic_freq == cb->ic_freq) ?
                (ca->ic_flags & IEEE80211_CHAN_ALL) -
                    (cb->ic_flags & IEEE80211_CHAN_ALL) :
                ca->ic_freq - cb->ic_freq;
}

/*
 * Insertion sort.
 */
#define swap(_a, _b, _size) {                   \
        uint8_t *s = _b;                        \
        int i = _size;                          \
        do {                                    \
                uint8_t tmp = *_a;              \
                *_a++ = *s;                     \
                *s++ = tmp;                     \
        } while (--i);                          \
        _a -= _size;                            \
}

static void
sort_channels(void *a, size_t n, size_t size)
{
        uint8_t *aa = a;
        uint8_t *ai, *t;

        KASSERT(n > 0, ("no channels"));
        for (ai = aa+size; --n >= 1; ai += size)
                for (t = ai; t > aa; t -= size) {
                        uint8_t *u = t - size;
                        if (chancompar(u, t) <= 0)
                                break;
                        swap(u, t, size);
                }
}
#undef swap

/*
 * Order channels w/ the same frequency so that
 * b < g < htg and a < hta.  This is used to optimize
 * channel table lookups and some user applications
 * may also depend on it (though they should not).
 */
void
ieee80211_sort_channels(struct ieee80211_channel chans[], int nchans)
{
        if (nchans > 0)
                sort_channels(chans, nchans, sizeof(struct ieee80211_channel));
}

/*
 * Allocate and construct a Country Information IE.
 */
struct ieee80211_appie *
ieee80211_alloc_countryie(struct ieee80211com *ic)
{
#define CHAN_UNINTERESTING \
    (IEEE80211_CHAN_TURBO | IEEE80211_CHAN_STURBO | \
     IEEE80211_CHAN_HALF | IEEE80211_CHAN_QUARTER)
        /* XXX what about auto? */
        /* flag set of channels to be excluded (band added below) */
        static const int skipflags[IEEE80211_MODE_MAX] = {
            [IEEE80211_MODE_AUTO]       = CHAN_UNINTERESTING,
            [IEEE80211_MODE_11A]        = CHAN_UNINTERESTING,
            [IEEE80211_MODE_11B]        = CHAN_UNINTERESTING,
            [IEEE80211_MODE_11G]        = CHAN_UNINTERESTING,
            [IEEE80211_MODE_FH]         = CHAN_UNINTERESTING
                                        | IEEE80211_CHAN_OFDM
                                        | IEEE80211_CHAN_CCK
                                        | IEEE80211_CHAN_DYN,
            [IEEE80211_MODE_TURBO_A]    = CHAN_UNINTERESTING,
            [IEEE80211_MODE_TURBO_G]    = CHAN_UNINTERESTING,
            [IEEE80211_MODE_STURBO_A]   = CHAN_UNINTERESTING,
            [IEEE80211_MODE_HALF]       = IEEE80211_CHAN_TURBO
                                        | IEEE80211_CHAN_STURBO,
            [IEEE80211_MODE_QUARTER]    = IEEE80211_CHAN_TURBO
                                        | IEEE80211_CHAN_STURBO,
            [IEEE80211_MODE_11NA]       = CHAN_UNINTERESTING,
            [IEEE80211_MODE_11NG]       = CHAN_UNINTERESTING,
        };
        const struct ieee80211_regdomain *rd = &ic->ic_regdomain;
        uint8_t nextchan, chans[IEEE80211_CHAN_BYTES], *frm;
        struct ieee80211_appie *aie;
        struct ieee80211_country_ie *ie;
        int i, skip, nruns;

        aie = IEEE80211_MALLOC(IEEE80211_COUNTRY_MAX_SIZE, M_80211_NODE_IE,
            IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
        if (aie == NULL) {
                ic_printf(ic, "%s: unable to allocate memory for country ie\n",
                    __func__);
                /* XXX stat */
                return NULL;
        }
        ie = (struct ieee80211_country_ie *) aie->ie_data;
        ie->ie = IEEE80211_ELEMID_COUNTRY;
        if (rd->isocc[0] == '\0') {
                ic_printf(ic, "no ISO country string for cc %d; using blanks\n",
                    rd->country);
                ie->cc[0] = ie->cc[1] = ' ';
        } else {
                ie->cc[0] = rd->isocc[0];
                ie->cc[1] = rd->isocc[1];
        }
        /* 
         * Indoor/Outdoor portion of country string:
         *     'I' indoor only
         *     'O' outdoor only
         *     ' ' all environments
         */
        ie->cc[2] = (rd->location == 'I' ? 'I' :
                     rd->location == 'O' ? 'O' : ' ');
        /* 
         * Run-length encoded channel+max tx power info.
         */
        frm = (uint8_t *)&ie->band[0];
        nextchan = 0;                   /* NB: impossible channel # */
        nruns = 0;
        memset(chans, 0, sizeof(chans));
        skip = skipflags[ieee80211_chan2mode(ic->ic_bsschan)];
        if (IEEE80211_IS_CHAN_5GHZ(ic->ic_bsschan))
                skip |= IEEE80211_CHAN_2GHZ;
        else if (IEEE80211_IS_CHAN_2GHZ(ic->ic_bsschan))
                skip |= IEEE80211_CHAN_5GHZ;
        for (i = 0; i < ic->ic_nchans; i++) {
                const struct ieee80211_channel *c = &ic->ic_channels[i];

                if (isset(chans, c->ic_ieee))           /* suppress dup's */
                        continue;
                if (c->ic_flags & skip)                 /* skip band, etc. */
                        continue;
                setbit(chans, c->ic_ieee);
                if (c->ic_ieee != nextchan ||
                    c->ic_maxregpower != frm[-1]) {     /* new run */
                        if (nruns == IEEE80211_COUNTRY_MAX_BANDS) {
                                ic_printf(ic, "%s: country ie too big, "
                                    "runs > max %d, truncating\n",
                                    __func__, IEEE80211_COUNTRY_MAX_BANDS);
                                /* XXX stat? fail? */
                                break;
                        }
                        frm[0] = c->ic_ieee;            /* starting channel # */
                        frm[1] = 1;                     /* # channels in run */
                        frm[2] = c->ic_maxregpower;     /* tx power cap */
                        frm += 3;
                        nextchan = c->ic_ieee + 1;      /* overflow? */
                        nruns++;
                } else {                                /* extend run */
                        frm[-2]++;
                        nextchan++;
                }
        }
        ie->len = frm - ie->cc;
        if (ie->len & 1) {              /* Zero pad to multiple of 2 */
                ie->len++;
                *frm++ = 0;
        }
        aie->ie_len = frm - aie->ie_data;

        return aie;
#undef CHAN_UNINTERESTING
}

static int
allvapsdown(struct ieee80211com *ic)
{
        struct ieee80211vap *vap;

        IEEE80211_LOCK_ASSERT(ic);
        TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next)
                if (vap->iv_state != IEEE80211_S_INIT)
                        return 0;
        return 1;
}

int
ieee80211_setregdomain(struct ieee80211vap *vap,
    struct ieee80211_regdomain_req *reg)
{
        struct ieee80211com *ic = vap->iv_ic;
        struct ieee80211_channel *c;
        int desfreq = 0, desflags = 0;          /* XXX silence gcc complaint */
        int error, i;

        if (reg->rd.location != 'I' && reg->rd.location != 'O' &&
            reg->rd.location != ' ') {
                IEEE80211_DPRINTF(vap, IEEE80211_MSG_IOCTL,
                    "%s: invalid location 0x%x\n", __func__, reg->rd.location);
                return EINVAL;
        }
        if (reg->rd.isocc[0] == '\0' || reg->rd.isocc[1] == '\0') {
                IEEE80211_DPRINTF(vap, IEEE80211_MSG_IOCTL,
                    "%s: invalid iso cc 0x%x:0x%x\n", __func__,
                    reg->rd.isocc[0], reg->rd.isocc[1]);
                return EINVAL;
        }
        if (reg->chaninfo.ic_nchans > IEEE80211_CHAN_MAX) {
                IEEE80211_DPRINTF(vap, IEEE80211_MSG_IOCTL,
                    "%s: too many channels %u, max %u\n", __func__,
                    reg->chaninfo.ic_nchans, IEEE80211_CHAN_MAX);
                return EINVAL;
        }
        /*
         * Calculate freq<->IEEE mapping and default max tx power
         * for channels not setup.  The driver can override these
         * setting to reflect device properties/requirements.
         */
        for (i = 0; i < reg->chaninfo.ic_nchans; i++) {
                c = &reg->chaninfo.ic_chans[i];
                if (c->ic_freq == 0 || c->ic_flags == 0) {
                        IEEE80211_DPRINTF(vap, IEEE80211_MSG_IOCTL,
                            "%s: invalid channel spec at [%u]\n", __func__, i);
                        return EINVAL;
                }
                if (c->ic_maxregpower == 0) {
                        IEEE80211_DPRINTF(vap, IEEE80211_MSG_IOCTL,
                            "%s: invalid channel spec, zero maxregpower, "
                            "freq %u flags 0x%x\n", __func__,
                            c->ic_freq, c->ic_flags);
                        return EINVAL;
                }
                if (c->ic_ieee == 0)
                        c->ic_ieee = ieee80211_mhz2ieee(c->ic_freq,c->ic_flags);
                if (IEEE80211_IS_CHAN_HT40(c) && c->ic_extieee == 0)
                        c->ic_extieee = ieee80211_mhz2ieee(c->ic_freq +
                            (IEEE80211_IS_CHAN_HT40U(c) ? 20 : -20),
                            c->ic_flags);
                if (c->ic_maxpower == 0)
                        c->ic_maxpower = 2*c->ic_maxregpower;
        }
        IEEE80211_LOCK(ic);
        /* XXX bandaid; a running vap will likely crash */
        if (!allvapsdown(ic)) {
                IEEE80211_UNLOCK(ic);
                IEEE80211_DPRINTF(vap, IEEE80211_MSG_IOCTL,
                    "%s: reject: vaps are running\n", __func__);
                return EBUSY;
        }
        error = ic->ic_setregdomain(ic, &reg->rd,
            reg->chaninfo.ic_nchans, reg->chaninfo.ic_chans);
        if (error != 0) {
                IEEE80211_UNLOCK(ic);
                IEEE80211_DPRINTF(vap, IEEE80211_MSG_IOCTL,
                    "%s: driver rejected request, error %u\n", __func__, error);
                return error;
        }
        /*
         * Commit: copy in new channel table and reset media state.
         * On return the state machines will be clocked so all vaps
         * will reset their state.
         *
         * XXX ic_bsschan is marked undefined, must have vap's in
         *     INIT state or we blow up forcing stations off
         */
        /*
         * Save any desired channel for restore below.  Note this
         * needs to be done for all vaps but for now we only do
         * the one where the ioctl is issued.
         */
        if (vap->iv_des_chan != IEEE80211_CHAN_ANYC) {
                desfreq = vap->iv_des_chan->ic_freq;
                desflags = vap->iv_des_chan->ic_flags;
        }
        /* regdomain parameters */
        memcpy(&ic->ic_regdomain, &reg->rd, sizeof(reg->rd));
        /* channel table */
        memcpy(ic->ic_channels, reg->chaninfo.ic_chans,
            reg->chaninfo.ic_nchans * sizeof(struct ieee80211_channel));
        ic->ic_nchans = reg->chaninfo.ic_nchans;
        memset(&ic->ic_channels[ic->ic_nchans], 0,
            (IEEE80211_CHAN_MAX - ic->ic_nchans) *
               sizeof(struct ieee80211_channel));
        ieee80211_chan_init(ic);

        /*
         * Invalidate channel-related state.
         */
        if (ic->ic_countryie != NULL) {
                IEEE80211_FREE(ic->ic_countryie, M_80211_NODE_IE);
                ic->ic_countryie = NULL;
        }
        ieee80211_scan_flush(vap);
        ieee80211_dfs_reset(ic);
        if (vap->iv_des_chan != IEEE80211_CHAN_ANYC) {
                c = ieee80211_find_channel(ic, desfreq, desflags);
                /* NB: may be NULL if not present in new channel list */
                vap->iv_des_chan = (c != NULL) ? c : IEEE80211_CHAN_ANYC;
        }
        IEEE80211_UNLOCK(ic);

        return 0;
}