// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2012 - 2018 Microchip Technology Inc., and its subsidiaries.
 * All rights reserved.
 */

#include "cfg80211.h"

struct wilc_wfi_radiotap_hdr {
        struct ieee80211_radiotap_header_fixed hdr;
        u8 rate;
} __packed;

struct wilc_wfi_radiotap_cb_hdr {
        struct ieee80211_radiotap_header_fixed hdr;
        u8 rate;
        u8 dump;
        u16 tx_flags;
} __packed;

#define TX_RADIOTAP_PRESENT ((1 << IEEE80211_RADIOTAP_RATE) |   \
                             (1 << IEEE80211_RADIOTAP_TX_FLAGS))

void wilc_wfi_monitor_rx(struct net_device *mon_dev, u8 *buff, u32 size)
{
        u32 header, pkt_offset;
        struct sk_buff *skb = NULL;
        struct wilc_wfi_radiotap_hdr *hdr;
        struct wilc_wfi_radiotap_cb_hdr *cb_hdr;

        if (!mon_dev)
                return;

        if (!netif_running(mon_dev))
                return;

        /* Get WILC header */
        header = get_unaligned_le32(buff - HOST_HDR_OFFSET);
        /*
         * The packet offset field contain info about what type of management
         * the frame we are dealing with and ack status
         */
        pkt_offset = FIELD_GET(WILC_PKT_HDR_OFFSET_FIELD, header);

        if (pkt_offset & IS_MANAGMEMENT_CALLBACK) {
                /* hostapd callback mgmt frame */

                skb = dev_alloc_skb(size + sizeof(*cb_hdr));
                if (!skb)
                        return;

                skb_put_data(skb, buff, size);

                cb_hdr = skb_push(skb, sizeof(*cb_hdr));
                memset(cb_hdr, 0, sizeof(*cb_hdr));

                cb_hdr->hdr.it_version = 0; /* PKTHDR_RADIOTAP_VERSION; */

                cb_hdr->hdr.it_len = cpu_to_le16(sizeof(*cb_hdr));

                cb_hdr->hdr.it_present = cpu_to_le32(TX_RADIOTAP_PRESENT);

                cb_hdr->rate = 5;

                if (pkt_offset & IS_MGMT_STATUS_SUCCES) {
                        /* success */
                        cb_hdr->tx_flags = IEEE80211_RADIOTAP_F_TX_RTS;
                } else {
                        cb_hdr->tx_flags = IEEE80211_RADIOTAP_F_TX_FAIL;
                }

        } else {
                skb = dev_alloc_skb(size + sizeof(*hdr));

                if (!skb)
                        return;

                skb_put_data(skb, buff, size);
                hdr = skb_push(skb, sizeof(*hdr));
                memset(hdr, 0, sizeof(struct wilc_wfi_radiotap_hdr));
                hdr->hdr.it_version = 0; /* PKTHDR_RADIOTAP_VERSION; */
                hdr->hdr.it_len = cpu_to_le16(sizeof(*hdr));
                hdr->hdr.it_present = cpu_to_le32
                                (1 << IEEE80211_RADIOTAP_RATE);
                hdr->rate = 5;
        }

        skb->dev = mon_dev;
        skb_reset_mac_header(skb);
        skb->ip_summed = CHECKSUM_UNNECESSARY;
        skb->pkt_type = PACKET_OTHERHOST;
        skb->protocol = htons(ETH_P_802_2);
        memset(skb->cb, 0, sizeof(skb->cb));

        netif_rx(skb);
}

struct tx_complete_mon_data {
        int size;
        void *buff;
};

static void mgmt_tx_complete(void *priv, int status)
{
        struct tx_complete_mon_data *pv_data = priv;
        /*
         * in case of fully hosting mode, the freeing will be done
         * in response to the cfg packet
         */
        kfree(pv_data->buff);

        kfree(pv_data);
}

static int mon_mgmt_tx(struct net_device *dev, const u8 *buf, size_t len)
{
        struct tx_complete_mon_data *mgmt_tx = NULL;

        if (!dev)
                return -EFAULT;

        netif_stop_queue(dev);
        mgmt_tx = kmalloc_obj(*mgmt_tx, GFP_ATOMIC);
        if (!mgmt_tx)
                return -ENOMEM;

        mgmt_tx->buff = kmemdup(buf, len, GFP_ATOMIC);
        if (!mgmt_tx->buff) {
                kfree(mgmt_tx);
                return -ENOMEM;
        }

        mgmt_tx->size = len;

        wilc_wlan_txq_add_mgmt_pkt(dev, mgmt_tx, mgmt_tx->buff, mgmt_tx->size,
                                   mgmt_tx_complete);

        netif_wake_queue(dev);
        return 0;
}

static netdev_tx_t wilc_wfi_mon_xmit(struct sk_buff *skb,
                                     struct net_device *dev)
{
        u32 rtap_len, ret = 0;
        struct wilc_wfi_mon_priv  *mon_priv;
        struct sk_buff *skb2;
        struct wilc_wfi_radiotap_cb_hdr *cb_hdr;
        u8 srcadd[ETH_ALEN];
        u8 bssid[ETH_ALEN];

        mon_priv = netdev_priv(dev);
        if (!mon_priv)
                return -EFAULT;

        rtap_len = ieee80211_get_radiotap_len(skb->data);
        if (skb->len < rtap_len)
                return -1;

        skb_pull(skb, rtap_len);

        if (skb->data[0] == 0xc0 && is_broadcast_ether_addr(&skb->data[4])) {
                skb2 = dev_alloc_skb(skb->len + sizeof(*cb_hdr));
                if (!skb2)
                        return -ENOMEM;

                skb_put_data(skb2, skb->data, skb->len);

                cb_hdr = skb_push(skb2, sizeof(*cb_hdr));
                memset(cb_hdr, 0, sizeof(struct wilc_wfi_radiotap_cb_hdr));

                cb_hdr->hdr.it_version = 0; /* PKTHDR_RADIOTAP_VERSION; */

                cb_hdr->hdr.it_len = cpu_to_le16(sizeof(*cb_hdr));

                cb_hdr->hdr.it_present = cpu_to_le32(TX_RADIOTAP_PRESENT);

                cb_hdr->rate = 5;
                cb_hdr->tx_flags = 0x0004;

                skb2->dev = dev;
                skb_reset_mac_header(skb2);
                skb2->ip_summed = CHECKSUM_UNNECESSARY;
                skb2->pkt_type = PACKET_OTHERHOST;
                skb2->protocol = htons(ETH_P_802_2);
                memset(skb2->cb, 0, sizeof(skb2->cb));

                netif_rx(skb2);

                return 0;
        }
        skb->dev = mon_priv->real_ndev;

        ether_addr_copy(srcadd, &skb->data[10]);
        ether_addr_copy(bssid, &skb->data[16]);
        /*
         * Identify if data or mgmt packet, if source address and bssid
         * fields are equal send it to mgmt frames handler
         */
        if (!(memcmp(srcadd, bssid, 6))) {
                ret = mon_mgmt_tx(mon_priv->real_ndev, skb->data, skb->len);
                if (ret)
                        netdev_err(dev, "fail to mgmt tx\n");
                dev_kfree_skb(skb);
        } else {
                ret = wilc_mac_xmit(skb, mon_priv->real_ndev);
        }

        return ret;
}

static const struct net_device_ops wilc_wfi_netdev_ops = {
        .ndo_start_xmit         = wilc_wfi_mon_xmit,

};

struct net_device *wilc_wfi_init_mon_interface(struct wilc *wl,
                                               const char *name,
                                               struct net_device *real_dev)
{
        struct wilc_wfi_mon_priv *priv;

        /* If monitor interface is already initialized, return it */
        if (wl->monitor_dev)
                return wl->monitor_dev;

        wl->monitor_dev = alloc_etherdev(sizeof(struct wilc_wfi_mon_priv));
        if (!wl->monitor_dev)
                return NULL;

        wl->monitor_dev->type = ARPHRD_IEEE80211_RADIOTAP;
        strscpy(wl->monitor_dev->name, name, IFNAMSIZ);
        wl->monitor_dev->netdev_ops = &wilc_wfi_netdev_ops;
        wl->monitor_dev->needs_free_netdev = true;

        if (register_netdevice(wl->monitor_dev)) {
                netdev_err(real_dev, "register_netdevice failed\n");
                free_netdev(wl->monitor_dev);
                return NULL;
        }
        priv = netdev_priv(wl->monitor_dev);

        priv->real_ndev = real_dev;

        return wl->monitor_dev;
}

void wilc_wfi_deinit_mon_interface(struct wilc *wl, bool rtnl_locked)
{
        if (!wl->monitor_dev)
                return;

        if (rtnl_locked)
                unregister_netdevice(wl->monitor_dev);
        else
                unregister_netdev(wl->monitor_dev);
        wl->monitor_dev = NULL;
}