// SPDX-License-Identifier: GPL-2.0-only
/*
 * AP handling
 *
 * Partially
 * Copyright (C) 2026 Intel Corporation
 */

#include "driver-ops.h"
#include "ieee80211_i.h"
#include "rate.h"

static void
ieee80211_send_eml_op_mode_notif(struct ieee80211_sub_if_data *sdata,
                                 struct ieee80211_mgmt *req, int opt_len)
{
        int len = IEEE80211_MIN_ACTION_SIZE(eml_omn);
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_mgmt *mgmt;
        struct sk_buff *skb;

        len += opt_len; /* optional len */
        skb = dev_alloc_skb(local->tx_headroom + len);
        if (!skb)
                return;

        skb_reserve(skb, local->tx_headroom);
        mgmt = skb_put_zero(skb, len);
        mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
                                          IEEE80211_STYPE_ACTION);
        memcpy(mgmt->da, req->sa, ETH_ALEN);
        memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
        memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);

        mgmt->u.action.category = WLAN_CATEGORY_PROTECTED_EHT;
        mgmt->u.action.action_code =
                WLAN_PROTECTED_EHT_ACTION_EML_OP_MODE_NOTIF;
        mgmt->u.action.eml_omn.dialog_token =
                req->u.action.eml_omn.dialog_token;
        mgmt->u.action.eml_omn.control = req->u.action.eml_omn.control &
                ~(IEEE80211_EML_CTRL_EMLSR_PARAM_UPDATE |
                  IEEE80211_EML_CTRL_INDEV_COEX_ACT);
        /* Copy optional fields from the received notification frame */
        memcpy(mgmt->u.action.eml_omn.variable,
               req->u.action.eml_omn.variable, opt_len);

        ieee80211_tx_skb(sdata, skb);
}

static void
ieee80211_rx_eml_op_mode_notif(struct ieee80211_sub_if_data *sdata,
                               struct sk_buff *skb)
{
        int len = IEEE80211_MIN_ACTION_SIZE(eml_omn);
        enum nl80211_iftype type = ieee80211_vif_type_p2p(&sdata->vif);
        struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
        const struct wiphy_iftype_ext_capab *ift_ext_capa;
        struct ieee80211_mgmt *mgmt = (void *)skb->data;
        struct ieee80211_local *local = sdata->local;
        u8 control = mgmt->u.action.eml_omn.control;
        u8 *ptr = mgmt->u.action.eml_omn.variable;
        struct ieee80211_eml_params eml_params = {
                .link_id = status->link_id,
                .control = control,
        };
        struct sta_info *sta;
        int opt_len = 0;

        if (!ieee80211_vif_is_mld(&sdata->vif))
                return;

        /* eMLSR and eMLMR can't be enabled at the same time */
        if ((control & IEEE80211_EML_CTRL_EMLSR_MODE) &&
            (control & IEEE80211_EML_CTRL_EMLMR_MODE))
                return;

        if ((control & IEEE80211_EML_CTRL_EMLMR_MODE) &&
            (control & IEEE80211_EML_CTRL_EMLSR_PARAM_UPDATE))
                return;

        ift_ext_capa = cfg80211_get_iftype_ext_capa(local->hw.wiphy, type);
        if (!ift_ext_capa)
                return;

        if (!status->link_valid)
                return;

        sta = sta_info_get_bss(sdata, mgmt->sa);
        if (!sta)
                return;

        if (control & IEEE80211_EML_CTRL_EMLSR_MODE) {
                u8 emlsr_param_update_len;

                if (!(ift_ext_capa->eml_capabilities &
                      IEEE80211_EML_CAP_EMLSR_SUPP))
                        return;

                opt_len += sizeof(__le16); /* eMLSR link_bitmap */
                /*
                 * eMLSR param update field is not part of Notification frame
                 * sent by the AP to client so account it separately.
                 */
                emlsr_param_update_len =
                        !!(control & IEEE80211_EML_CTRL_EMLSR_PARAM_UPDATE);

                if (skb->len < len + opt_len + emlsr_param_update_len)
                        return;

                if (control & IEEE80211_EML_CTRL_EMLSR_PARAM_UPDATE) {
                        u8 pad_delay, trans_delay;

                        pad_delay = u8_get_bits(ptr[2],
                                                IEEE80211_EML_EMLSR_PAD_DELAY);
                        if (pad_delay >
                            IEEE80211_EML_CAP_EML_PADDING_DELAY_256US)
                                return;

                        trans_delay = u8_get_bits(ptr[2],
                                        IEEE80211_EML_EMLSR_TRANS_DELAY);
                        if (trans_delay >
                            IEEE80211_EML_CAP_EMLSR_TRANSITION_DELAY_256US)
                                return;

                        /* Update sta padding and transition delay */
                        sta->sta.eml_cap =
                                u8_replace_bits(sta->sta.eml_cap,
                                                pad_delay,
                                                IEEE80211_EML_CAP_EML_PADDING_DELAY);
                        sta->sta.eml_cap =
                                u8_replace_bits(sta->sta.eml_cap,
                                                trans_delay,
                                                IEEE80211_EML_CAP_EML_TRANSITION_DELAY);
                }
        }

        if (control & IEEE80211_EML_CTRL_EMLMR_MODE) {
                u8 mcs_map_size;
                int i;

                if (!(ift_ext_capa->eml_capabilities &
                      IEEE80211_EML_CAP_EMLMR_SUPPORT))
                        return;

                opt_len += sizeof(__le16); /* eMLMR link_bitmap */
                opt_len++; /* eMLMR mcs_map_count */
                if (skb->len < len + opt_len)
                        return;

                eml_params.emlmr_mcs_map_count = ptr[2];
                if (eml_params.emlmr_mcs_map_count > 2)
                        return;

                mcs_map_size = 3 * (1 + eml_params.emlmr_mcs_map_count);
                opt_len += mcs_map_size;
                if (skb->len < len + opt_len)
                        return;

                for (i = 0; i < mcs_map_size; i++) {
                        u8 rx_mcs, tx_mcs;

                        rx_mcs = u8_get_bits(ptr[3 + i],
                                             IEEE80211_EML_EMLMR_RX_MCS_MAP);
                        if (rx_mcs > 8)
                                return;

                        tx_mcs = u8_get_bits(ptr[3 + i],
                                             IEEE80211_EML_EMLMR_TX_MCS_MAP);
                        if (tx_mcs > 8)
                                return;
                }

                memcpy(eml_params.emlmr_mcs_map_bw, &ptr[3], mcs_map_size);
        }

        if ((control & IEEE80211_EML_CTRL_EMLSR_MODE) ||
            (control & IEEE80211_EML_CTRL_EMLMR_MODE)) {
                eml_params.link_bitmap = get_unaligned_le16(ptr);
                if ((eml_params.link_bitmap & sdata->vif.active_links) !=
                    eml_params.link_bitmap)
                        return;
        }

        if (drv_set_eml_op_mode(sdata, &sta->sta, &eml_params))
                return;

        ieee80211_send_eml_op_mode_notif(sdata, mgmt, opt_len);
}

static void
ieee80211_rx_uhr_link_reconfig_req(struct ieee80211_sub_if_data *sdata,
                                   struct sk_buff *skb)
{
        struct ieee80211_mgmt *mgmt = (void *)skb->data;
        const struct element *sub;
        struct sta_info *sta;

        /*
         * rx.c only accepts IEEE80211_UHR_LINK_RECONFIG_REQUEST_OMP_REQUEST
         * which is valid, so no need to check the frame type/format/etc.
         */

        sta = sta_info_get_bss(sdata, mgmt->sa);
        if (!sta)
                return;

        struct ieee802_11_elems *elems __free(kfree) =
                ieee802_11_parse_elems(mgmt->u.action.uhr_link_reconf_req.variable,
                                       skb->len - IEEE80211_MIN_ACTION_SIZE(uhr_link_reconf_req),
                                       IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_ACTION,
                                       NULL);
        /* STA will assume we processed it, not good */
        if (!elems)
                return;

        if (!elems->ml_reconf)
                return;

        for_each_mle_subelement(sub, (u8 *)elems->ml_reconf,
                                elems->ml_reconf_len) {
                const struct ieee80211_mle_per_sta_profile *prof =
                         (const void *)sub->data;
                struct ieee80211_chanctx_conf *chanctx_conf;
                struct ieee80211_chanctx *chanctx;
                struct ieee80211_link_data *link;
                struct link_sta_info *link_sta;
                const struct element *chg;
                u16 control;
                u8 link_id;

                if (sub->id != IEEE80211_MLE_SUBELEM_PER_STA_PROFILE)
                        continue;

                if (!ieee80211_mle_reconf_sta_prof_size_ok(sub->data,
                                                           sub->datalen))
                        return;

                control = le16_to_cpu(prof->control);
                link_id = control & IEEE80211_MLE_STA_RECONF_CONTROL_LINK_ID;

                if (link_id >= IEEE80211_MLD_MAX_NUM_LINKS)
                        return;

                link = sdata_dereference(sdata->link[link_id], sdata);
                if (!link)
                        continue;

                chanctx_conf = sdata_dereference(link->conf->chanctx_conf,
                                                 sdata);
                if (!chanctx_conf)
                        continue;
                chanctx = container_of(chanctx_conf, struct ieee80211_chanctx,
                                       conf);

                link_sta = sdata_dereference(sta->link[link_id], sdata);
                if (!link_sta)
                        continue;

                /* do we need to handle any other bits? */
                if (control & ~(IEEE80211_MLE_STA_RECONF_CONTROL_LINK_ID |
                                IEEE80211_MLE_STA_RECONF_CONTROL_OPERATION_TYPE))
                        continue;

                if (u16_get_bits(control, IEEE80211_MLE_STA_RECONF_CONTROL_OPERATION_TYPE) !=
                                IEEE80211_MLE_STA_RECONF_CONTROL_OPERATION_TYPE_UHR_OMP_UPD)
                        continue;

                for_each_element_extid(chg, WLAN_EID_EXT_UHR_MODE_CHG,
                                       prof->variable + prof->sta_info_len - 1,
                                       sub->datalen - sizeof(*prof) -
                                       prof->sta_info_len + 1) {
                        const struct ieee80211_uhr_mode_change_tuple *tuple;

                        for_each_uhr_mode_change_tuple(chg->data + 1,
                                                       chg->datalen - 1,
                                                       tuple) {
                                u8 id = le16_get_bits(tuple->control,
                                                      IEEE80211_UHR_MODE_CHANGE_CONTROL_MODE_ID);
                                bool enabled = le16_get_bits(tuple->control,
                                                             IEEE80211_UHR_MODE_CHANGE_CONTROL_MODE_ENABLE);

                                /* only handle DBE (for now?) */
                                if (id != IEEE80211_UHR_MODE_CHANGE_MODE_ID_DBE)
                                        continue;

                                link_sta->uhr_dbe_enabled = enabled;
                                /* also recalculates and updates per-STA bw */
                                ieee80211_recalc_chanctx_min_def(sdata->local,
                                                                 chanctx);
                        }
                }
        }

        /* TODO: send a response */
}

void ieee80211_ap_rx_queued_frame(struct ieee80211_sub_if_data *sdata,
                                  struct sk_buff *skb)
{
        struct ieee80211_mgmt *mgmt = (void *)skb->data;

        /* rx.c cannot queue any non-action frames to AP interfaces */
        if (WARN_ON(!ieee80211_is_action(mgmt->frame_control)))
                return;

        switch (mgmt->u.action.category) {
        case WLAN_CATEGORY_PROTECTED_EHT:
                switch (mgmt->u.action.action_code) {
                case WLAN_PROTECTED_EHT_ACTION_EML_OP_MODE_NOTIF:
                        ieee80211_rx_eml_op_mode_notif(sdata, skb);
                        break;
                }
                break;
        case WLAN_CATEGORY_PROTECTED_UHR:
                switch (mgmt->u.action.action_code) {
                case IEEE80211_PROTECTED_UHR_ACTION_LINK_RECONFIG_REQUEST:
                        ieee80211_rx_uhr_link_reconfig_req(sdata, skb);
                        break;
                }
                break;
        }
}

void ieee80211_uhr_disable_dbe_all_stas(struct ieee80211_link_data *link)
{
        struct ieee80211_sub_if_data *sdata = link->sdata;
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_chanctx_conf *chanctx_conf;
        struct ieee80211_chanctx *chanctx;
        int link_id = link->link_id;
        struct sta_info *sta;

        chanctx_conf = sdata_dereference(link->conf->chanctx_conf, sdata);
        if (!chanctx_conf)
                return;
        chanctx = container_of(chanctx_conf, struct ieee80211_chanctx, conf);

        list_for_each_entry(sta, &local->sta_list, list) {
                struct link_sta_info *link_sta;

                if (sta->sdata->bss != sdata->bss)
                        continue;

                link_sta = sdata_dereference(sta->link[link_id], sdata);
                if (!link_sta)
                        continue;

                link_sta->uhr_dbe_enabled = false;
        }

        /* also recalculates and updates per-STA bw */
        ieee80211_recalc_chanctx_min_def(local, chanctx);
}