// SPDX-License-Identifier: GPL-2.0-only
/*
 * spectrum management
 *
 * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
 * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
 * Copyright 2007-2008, Intel Corporation
 * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
 * Copyright (C) 2018, 2020, 2022-2024 Intel Corporation
 */

#include <linux/ieee80211.h>
#include <net/cfg80211.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "sta_info.h"
#include "wme.h"

static bool
wbcs_elem_to_chandef(const struct ieee80211_wide_bw_chansw_ie *wbcs_elem,
                     struct cfg80211_chan_def *chandef)
{
        u8 ccfs0 = wbcs_elem->new_center_freq_seg0;
        u8 ccfs1 = wbcs_elem->new_center_freq_seg1;
        u32 cf0 = ieee80211_channel_to_frequency(ccfs0, chandef->chan->band);
        u32 cf1 = ieee80211_channel_to_frequency(ccfs1, chandef->chan->band);

        switch (wbcs_elem->new_channel_width) {
        case IEEE80211_VHT_CHANWIDTH_160MHZ:
                /* deprecated encoding */
                chandef->width = NL80211_CHAN_WIDTH_160;
                chandef->center_freq1 = cf0;
                break;
        case IEEE80211_VHT_CHANWIDTH_80P80MHZ:
                /* deprecated encoding */
                chandef->width = NL80211_CHAN_WIDTH_80P80;
                chandef->center_freq1 = cf0;
                chandef->center_freq2 = cf1;
                break;
        case IEEE80211_VHT_CHANWIDTH_80MHZ:
                chandef->width = NL80211_CHAN_WIDTH_80;
                chandef->center_freq1 = cf0;

                if (ccfs1) {
                        u8 diff = abs(ccfs0 - ccfs1);

                        if (diff == 8) {
                                chandef->width = NL80211_CHAN_WIDTH_160;
                                chandef->center_freq1 = cf1;
                        } else if (diff > 8) {
                                chandef->width = NL80211_CHAN_WIDTH_80P80;
                                chandef->center_freq2 = cf1;
                        }
                }
                break;
        case IEEE80211_VHT_CHANWIDTH_USE_HT:
        default:
                /* If the WBCS Element is present, new channel bandwidth is
                 * at least 40 MHz.
                 */
                chandef->width = NL80211_CHAN_WIDTH_40;
                chandef->center_freq1 = cf0;
                break;
        }

        return cfg80211_chandef_valid(chandef);
}

static void
validate_chandef_by_ht_vht_oper(struct ieee80211_sub_if_data *sdata,
                                struct ieee80211_conn_settings *conn,
                                u32 vht_cap_info,
                                struct cfg80211_chan_def *chandef)
{
        u32 control_freq, center_freq1, center_freq2;
        enum nl80211_chan_width chan_width;
        struct ieee80211_ht_operation ht_oper;
        struct ieee80211_vht_operation vht_oper;

        if (conn->mode < IEEE80211_CONN_MODE_HT ||
            conn->bw_limit < IEEE80211_CONN_BW_LIMIT_40) {
                chandef->chan = NULL;
                return;
        }

        control_freq = chandef->chan->center_freq;
        center_freq1 = chandef->center_freq1;
        center_freq2 = chandef->center_freq2;
        chan_width = chandef->width;

        ht_oper.primary_chan = ieee80211_frequency_to_channel(control_freq);
        if (control_freq != center_freq1)
                ht_oper.ht_param = control_freq > center_freq1 ?
                        IEEE80211_HT_PARAM_CHA_SEC_BELOW :
                        IEEE80211_HT_PARAM_CHA_SEC_ABOVE;
        else
                ht_oper.ht_param = IEEE80211_HT_PARAM_CHA_SEC_NONE;

        ieee80211_chandef_ht_oper(&ht_oper, chandef);

        if (conn->mode < IEEE80211_CONN_MODE_VHT)
                return;

        vht_oper.center_freq_seg0_idx =
                ieee80211_frequency_to_channel(center_freq1);
        vht_oper.center_freq_seg1_idx = center_freq2 ?
                ieee80211_frequency_to_channel(center_freq2) : 0;

        switch (chan_width) {
        case NL80211_CHAN_WIDTH_320:
                WARN_ON(1);
                break;
        case NL80211_CHAN_WIDTH_160:
                vht_oper.chan_width = IEEE80211_VHT_CHANWIDTH_80MHZ;
                vht_oper.center_freq_seg1_idx = vht_oper.center_freq_seg0_idx;
                vht_oper.center_freq_seg0_idx +=
                        control_freq < center_freq1 ? -8 : 8;
                break;
        case NL80211_CHAN_WIDTH_80P80:
                vht_oper.chan_width = IEEE80211_VHT_CHANWIDTH_80MHZ;
                break;
        case NL80211_CHAN_WIDTH_80:
                vht_oper.chan_width = IEEE80211_VHT_CHANWIDTH_80MHZ;
                break;
        default:
                vht_oper.chan_width = IEEE80211_VHT_CHANWIDTH_USE_HT;
                break;
        }

        ht_oper.operation_mode =
                le16_encode_bits(vht_oper.center_freq_seg1_idx,
                                 IEEE80211_HT_OP_MODE_CCFS2_MASK);

        if (!ieee80211_chandef_vht_oper(&sdata->local->hw, vht_cap_info,
                                        &vht_oper, &ht_oper, chandef))
                chandef->chan = NULL;
}

static void
validate_chandef_by_6ghz_he_eht_oper(struct ieee80211_sub_if_data *sdata,
                                     struct ieee80211_conn_settings *conn,
                                     struct cfg80211_chan_def *chandef)
{
        struct ieee80211_local *local = sdata->local;
        u32 control_freq, center_freq1, center_freq2;
        enum nl80211_chan_width chan_width;
        DEFINE_RAW_FLEX(struct ieee80211_he_operation, he, optional,
                        sizeof(struct ieee80211_he_6ghz_oper));
        struct ieee80211_he_6ghz_oper *_6ghz_oper =
                                (struct ieee80211_he_6ghz_oper *)he->optional;
        DEFINE_RAW_FLEX(struct ieee80211_eht_operation, eht, optional,
                        sizeof(struct ieee80211_eht_operation_info));
        struct ieee80211_eht_operation_info *_oper_info =
                        (struct ieee80211_eht_operation_info *)eht->optional;
        const struct ieee80211_eht_operation *eht_oper;

        if (conn->mode < IEEE80211_CONN_MODE_HE) {
                chandef->chan = NULL;
                return;
        }

        control_freq = chandef->chan->center_freq;
        center_freq1 = chandef->center_freq1;
        center_freq2 = chandef->center_freq2;
        chan_width = chandef->width;

        he->he_oper_params =
                le32_encode_bits(1, IEEE80211_HE_OPERATION_6GHZ_OP_INFO);
        _6ghz_oper->primary =
                ieee80211_frequency_to_channel(control_freq);
        _6ghz_oper->ccfs0 = ieee80211_frequency_to_channel(center_freq1);
        _6ghz_oper->ccfs1 = center_freq2 ?
                ieee80211_frequency_to_channel(center_freq2) : 0;

        switch (chan_width) {
        case NL80211_CHAN_WIDTH_320:
                _6ghz_oper->ccfs1 = _6ghz_oper->ccfs0;
                _6ghz_oper->ccfs0 += control_freq < center_freq1 ? -16 : 16;
                _6ghz_oper->control = IEEE80211_EHT_OPER_CHAN_WIDTH_320MHZ;
                break;
        case NL80211_CHAN_WIDTH_160:
                _6ghz_oper->ccfs1 = _6ghz_oper->ccfs0;
                _6ghz_oper->ccfs0 += control_freq < center_freq1 ? -8 : 8;
                fallthrough;
        case NL80211_CHAN_WIDTH_80P80:
                _6ghz_oper->control =
                        IEEE80211_HE_6GHZ_OPER_CTRL_CHANWIDTH_160MHZ;
                break;
        case NL80211_CHAN_WIDTH_80:
                _6ghz_oper->control =
                        IEEE80211_HE_6GHZ_OPER_CTRL_CHANWIDTH_80MHZ;
                break;
        case NL80211_CHAN_WIDTH_40:
                _6ghz_oper->control =
                        IEEE80211_HE_6GHZ_OPER_CTRL_CHANWIDTH_40MHZ;
                break;
        default:
                _6ghz_oper->control =
                        IEEE80211_HE_6GHZ_OPER_CTRL_CHANWIDTH_20MHZ;
                break;
        }

        if (conn->mode < IEEE80211_CONN_MODE_EHT) {
                eht_oper = NULL;
        } else {
                eht->params = IEEE80211_EHT_OPER_INFO_PRESENT;
                _oper_info->control = _6ghz_oper->control;
                _oper_info->ccfs0 = _6ghz_oper->ccfs0;
                _oper_info->ccfs1 = _6ghz_oper->ccfs1;
                eht_oper = eht;
        }

        if (!ieee80211_chandef_he_6ghz_oper(local, he, eht_oper, chandef))
                chandef->chan = NULL;
}

int ieee80211_parse_ch_switch_ie(struct ieee80211_sub_if_data *sdata,
                                 struct ieee802_11_elems *elems,
                                 enum nl80211_band current_band,
                                 u32 vht_cap_info,
                                 struct ieee80211_conn_settings *conn,
                                 u8 *bssid, bool unprot_action,
                                 struct ieee80211_csa_ie *csa_ie)
{
        enum nl80211_band new_band = current_band;
        int new_freq;
        u8 new_chan_no = 0, new_op_class = 0;
        struct ieee80211_channel *new_chan;
        struct cfg80211_chan_def new_chandef = {};
        const struct ieee80211_sec_chan_offs_ie *sec_chan_offs;
        const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie;
        const struct ieee80211_bandwidth_indication *bwi;
        const struct ieee80211_ext_chansw_ie *ext_chansw_elem;
        int secondary_channel_offset = -1;

        memset(csa_ie, 0, sizeof(*csa_ie));

        sec_chan_offs = elems->sec_chan_offs;
        wide_bw_chansw_ie = elems->wide_bw_chansw_ie;
        bwi = elems->bandwidth_indication;
        ext_chansw_elem = elems->ext_chansw_ie;

        if (conn->mode < IEEE80211_CONN_MODE_HT ||
            conn->bw_limit < IEEE80211_CONN_BW_LIMIT_40) {
                sec_chan_offs = NULL;
                wide_bw_chansw_ie = NULL;
        }

        if (conn->mode < IEEE80211_CONN_MODE_VHT)
                wide_bw_chansw_ie = NULL;

        if (ext_chansw_elem) {
                new_op_class = ext_chansw_elem->new_operating_class;

                if (!ieee80211_operating_class_to_band(new_op_class, &new_band)) {
                        new_op_class = 0;
                        if (!unprot_action)
                                sdata_info(sdata,
                                           "cannot understand ECSA IE operating class, %d, ignoring\n",
                                           ext_chansw_elem->new_operating_class);
                } else {
                        new_chan_no = ext_chansw_elem->new_ch_num;
                        csa_ie->count = ext_chansw_elem->count;
                        csa_ie->mode = ext_chansw_elem->mode;
                }
        }

        if (!new_op_class && elems->ch_switch_ie) {
                new_chan_no = elems->ch_switch_ie->new_ch_num;
                csa_ie->count = elems->ch_switch_ie->count;
                csa_ie->mode = elems->ch_switch_ie->mode;
        }

        /* nothing here we understand */
        if (!new_chan_no)
                return 1;

        /* Mesh Channel Switch Parameters Element */
        if (elems->mesh_chansw_params_ie) {
                csa_ie->ttl = elems->mesh_chansw_params_ie->mesh_ttl;
                csa_ie->mode = elems->mesh_chansw_params_ie->mesh_flags;
                csa_ie->pre_value = le16_to_cpu(
                                elems->mesh_chansw_params_ie->mesh_pre_value);

                if (elems->mesh_chansw_params_ie->mesh_flags &
                                WLAN_EID_CHAN_SWITCH_PARAM_REASON)
                        csa_ie->reason_code = le16_to_cpu(
                                elems->mesh_chansw_params_ie->mesh_reason);
        }

        new_freq = ieee80211_channel_to_frequency(new_chan_no, new_band);
        new_chan = ieee80211_get_channel(sdata->local->hw.wiphy, new_freq);
        if (!new_chan || new_chan->flags & IEEE80211_CHAN_DISABLED) {
                if (!unprot_action)
                        sdata_info(sdata,
                                   "BSS %pM switches to unsupported channel (%d MHz), disconnecting\n",
                                   bssid, new_freq);
                return -EINVAL;
        }

        if (sec_chan_offs) {
                secondary_channel_offset = sec_chan_offs->sec_chan_offs;
        } else if (conn->mode >= IEEE80211_CONN_MODE_HT) {
                /* If the secondary channel offset IE is not present,
                 * we can't know what's the post-CSA offset, so the
                 * best we can do is use 20MHz.
                */
                secondary_channel_offset = IEEE80211_HT_PARAM_CHA_SEC_NONE;
        }

        switch (secondary_channel_offset) {
        default:
                /* secondary_channel_offset was present but is invalid */
        case IEEE80211_HT_PARAM_CHA_SEC_NONE:
                cfg80211_chandef_create(&csa_ie->chanreq.oper, new_chan,
                                        NL80211_CHAN_HT20);
                break;
        case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
                cfg80211_chandef_create(&csa_ie->chanreq.oper, new_chan,
                                        NL80211_CHAN_HT40PLUS);
                break;
        case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
                cfg80211_chandef_create(&csa_ie->chanreq.oper, new_chan,
                                        NL80211_CHAN_HT40MINUS);
                break;
        case -1:
                cfg80211_chandef_create(&csa_ie->chanreq.oper, new_chan,
                                        NL80211_CHAN_NO_HT);
                /* keep width for 5/10 MHz channels */
                switch (sdata->vif.bss_conf.chanreq.oper.width) {
                case NL80211_CHAN_WIDTH_5:
                case NL80211_CHAN_WIDTH_10:
                        csa_ie->chanreq.oper.width =
                                sdata->vif.bss_conf.chanreq.oper.width;
                        break;
                default:
                        break;
                }
                break;
        }

        /* capture the AP configuration */
        csa_ie->chanreq.ap = csa_ie->chanreq.oper;

        /* parse one of the Elements to build a new chandef */
        memset(&new_chandef, 0, sizeof(new_chandef));
        new_chandef.chan = new_chan;
        if (bwi) {
                /* start with the CSA one */
                new_chandef = csa_ie->chanreq.oper;
                /* and update the width accordingly */
                ieee80211_chandef_eht_oper(&bwi->info, &new_chandef);

                if (bwi->params & IEEE80211_BW_IND_DIS_SUBCH_PRESENT)
                        new_chandef.punctured =
                                get_unaligned_le16(bwi->info.optional);
        } else if (!wide_bw_chansw_ie || !wbcs_elem_to_chandef(wide_bw_chansw_ie,
                                                               &new_chandef)) {
                if (!ieee80211_operating_class_to_chandef(new_op_class, new_chan,
                                                          &new_chandef))
                        new_chandef = csa_ie->chanreq.oper;
        }

        /* check if the new chandef fits the capabilities */
        if (new_band == NL80211_BAND_6GHZ)
                validate_chandef_by_6ghz_he_eht_oper(sdata, conn, &new_chandef);
        else
                validate_chandef_by_ht_vht_oper(sdata, conn, vht_cap_info,
                                                &new_chandef);

        /* if data is there validate the bandwidth & use it */
        if (new_chandef.chan) {
                /* capture the AP chandef before (potential) downgrading */
                csa_ie->chanreq.ap = new_chandef;

                while (conn->bw_limit <
                               ieee80211_min_bw_limit_from_chandef(&new_chandef))
                        ieee80211_chandef_downgrade(&new_chandef, NULL);

                if (!cfg80211_chandef_compatible(&new_chandef,
                                                 &csa_ie->chanreq.oper)) {
                        sdata_info(sdata,
                                   "BSS %pM: CSA has inconsistent channel data, disconnecting\n",
                                   bssid);
                        return -EINVAL;
                }

                csa_ie->chanreq.oper = new_chandef;
        }

        if (elems->max_channel_switch_time)
                csa_ie->max_switch_time =
                        (elems->max_channel_switch_time[0] << 0) |
                        (elems->max_channel_switch_time[1] <<  8) |
                        (elems->max_channel_switch_time[2] << 16);

        return 0;
}

static void ieee80211_send_refuse_measurement_request(struct ieee80211_sub_if_data *sdata,
                                        struct ieee80211_msrment_ie *request_ie,
                                        const u8 *da, const u8 *bssid,
                                        u8 dialog_token)
{
        struct ieee80211_local *local = sdata->local;
        struct sk_buff *skb;
        struct ieee80211_mgmt *msr_report;

        skb = dev_alloc_skb(sizeof(*msr_report) + local->hw.extra_tx_headroom +
                                sizeof(struct ieee80211_msrment_ie));
        if (!skb)
                return;

        skb_reserve(skb, local->hw.extra_tx_headroom);
        msr_report = skb_put_zero(skb, 24);
        memcpy(msr_report->da, da, ETH_ALEN);
        memcpy(msr_report->sa, sdata->vif.addr, ETH_ALEN);
        memcpy(msr_report->bssid, bssid, ETH_ALEN);
        msr_report->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
                                                IEEE80211_STYPE_ACTION);

        skb_put(skb, 1 + sizeof(msr_report->u.action.u.measurement));
        msr_report->u.action.category = WLAN_CATEGORY_SPECTRUM_MGMT;
        msr_report->u.action.u.measurement.action_code =
                                WLAN_ACTION_SPCT_MSR_RPRT;
        msr_report->u.action.u.measurement.dialog_token = dialog_token;

        msr_report->u.action.u.measurement.element_id = WLAN_EID_MEASURE_REPORT;
        msr_report->u.action.u.measurement.length =
                        sizeof(struct ieee80211_msrment_ie);

        memset(&msr_report->u.action.u.measurement.msr_elem, 0,
                sizeof(struct ieee80211_msrment_ie));
        msr_report->u.action.u.measurement.msr_elem.token = request_ie->token;
        msr_report->u.action.u.measurement.msr_elem.mode |=
                        IEEE80211_SPCT_MSR_RPRT_MODE_REFUSED;
        msr_report->u.action.u.measurement.msr_elem.type = request_ie->type;

        ieee80211_tx_skb(sdata, skb);
}

void ieee80211_process_measurement_req(struct ieee80211_sub_if_data *sdata,
                                       struct ieee80211_mgmt *mgmt,
                                       size_t len)
{
        /*
         * Ignoring measurement request is spec violation.
         * Mandatory measurements must be reported optional
         * measurements might be refused or reported incapable
         * For now just refuse
         * TODO: Answer basic measurement as unmeasured
         */
        ieee80211_send_refuse_measurement_request(sdata,
                        &mgmt->u.action.u.measurement.msr_elem,
                        mgmt->sa, mgmt->bssid,
                        mgmt->u.action.u.measurement.dialog_token);
}