/*
 * Marvell Wireless LAN device driver: station RX data handling
 *
 * Copyright (C) 2011, Marvell International Ltd.
 *
 * This software file (the "File") is distributed by Marvell International
 * Ltd. under the terms of the GNU General Public License Version 2, June 1991
 * (the "License").  You may use, redistribute and/or modify this File in
 * accordance with the terms and conditions of the License, a copy of which
 * is available by writing to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or on the
 * worldwide web at http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
 *
 * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
 * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
 * this warranty disclaimer.
 */

#include "decl.h"
#include "ioctl.h"
#include "util.h"
#include "fw.h"
#include "main.h"
#include "11n_aggr.h"
#include "11n_rxreorder.h"

/*
 * This function processes the received packet and forwards it
 * to kernel/upper layer.
 *
 * This function parses through the received packet and determines
 * if it is a debug packet or normal packet.
 *
 * For non-debug packets, the function chops off unnecessary leading
 * header bytes, reconstructs the packet as an ethernet frame or
 * 802.2/llc/snap frame as required, and sends it to kernel/upper layer.
 *
 * The completion callback is called after processing in complete.
 */
int mwifiex_process_rx_packet(struct mwifiex_private *priv,
                              struct sk_buff *skb)
{
        int ret;
        struct rx_packet_hdr *rx_pkt_hdr;
        struct rxpd *local_rx_pd;
        int hdr_chop;
        struct ethhdr *eth_hdr;
        u8 rfc1042_eth_hdr[ETH_ALEN] = { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };

        local_rx_pd = (struct rxpd *) (skb->data);

        rx_pkt_hdr = (void *)local_rx_pd +
                     le16_to_cpu(local_rx_pd->rx_pkt_offset);

        if (!memcmp(&rx_pkt_hdr->rfc1042_hdr,
                    rfc1042_eth_hdr, sizeof(rfc1042_eth_hdr))) {
                /*
                 *  Replace the 803 header and rfc1042 header (llc/snap) with an
                 *    EthernetII header, keep the src/dst and snap_type
                 *    (ethertype).
                 *  The firmware only passes up SNAP frames converting
                 *    all RX Data from 802.11 to 802.2/LLC/SNAP frames.
                 *  To create the Ethernet II, just move the src, dst address
                 *    right before the snap_type.
                 */
                eth_hdr = (struct ethhdr *)
                        ((u8 *) &rx_pkt_hdr->eth803_hdr
                         + sizeof(rx_pkt_hdr->eth803_hdr) +
                         sizeof(rx_pkt_hdr->rfc1042_hdr)
                         - sizeof(rx_pkt_hdr->eth803_hdr.h_dest)
                         - sizeof(rx_pkt_hdr->eth803_hdr.h_source)
                         - sizeof(rx_pkt_hdr->rfc1042_hdr.snap_type));

                memcpy(eth_hdr->h_source, rx_pkt_hdr->eth803_hdr.h_source,
                       sizeof(eth_hdr->h_source));
                memcpy(eth_hdr->h_dest, rx_pkt_hdr->eth803_hdr.h_dest,
                       sizeof(eth_hdr->h_dest));

                /* Chop off the rxpd + the excess memory from the 802.2/llc/snap
                   header that was removed. */
                hdr_chop = (u8 *) eth_hdr - (u8 *) local_rx_pd;
        } else {
                /* Chop off the rxpd */
                hdr_chop = (u8 *) &rx_pkt_hdr->eth803_hdr -
                        (u8 *) local_rx_pd;
        }

        /* Chop off the leading header bytes so the it points to the start of
           either the reconstructed EthII frame or the 802.2/llc/snap frame */
        skb_pull(skb, hdr_chop);

        priv->rxpd_rate = local_rx_pd->rx_rate;

        priv->rxpd_htinfo = local_rx_pd->ht_info;

        ret = mwifiex_recv_packet(priv, skb);
        if (ret == -1)
                dev_err(priv->adapter->dev, "recv packet failed\n");

        return ret;
}

/*
 * This function processes the received buffer.
 *
 * The function looks into the RxPD and performs sanity tests on the
 * received buffer to ensure its a valid packet, before processing it
 * further. If the packet is determined to be aggregated, it is
 * de-aggregated accordingly. Non-unicast packets are sent directly to
 * the kernel/upper layers. Unicast packets are handed over to the
 * Rx reordering routine if 11n is enabled.
 *
 * The completion callback is called after processing in complete.
 */
int mwifiex_process_sta_rx_packet(struct mwifiex_private *priv,
                                  struct sk_buff *skb)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        int ret = 0;
        struct rxpd *local_rx_pd;
        struct rx_packet_hdr *rx_pkt_hdr;
        u8 ta[ETH_ALEN];
        u16 rx_pkt_type, rx_pkt_offset, rx_pkt_length, seq_num;

        local_rx_pd = (struct rxpd *) (skb->data);
        rx_pkt_type = le16_to_cpu(local_rx_pd->rx_pkt_type);
        rx_pkt_offset = le16_to_cpu(local_rx_pd->rx_pkt_offset);
        rx_pkt_length = le16_to_cpu(local_rx_pd->rx_pkt_length);
        seq_num = le16_to_cpu(local_rx_pd->seq_num);

        rx_pkt_hdr = (void *)local_rx_pd + rx_pkt_offset;

        if ((rx_pkt_offset + rx_pkt_length) > (u16) skb->len) {
                dev_err(adapter->dev,
                        "wrong rx packet: len=%d, rx_pkt_offset=%d, rx_pkt_length=%d\n",
                        skb->len, rx_pkt_offset, rx_pkt_length);
                priv->stats.rx_dropped++;

                if (adapter->if_ops.data_complete)
                        adapter->if_ops.data_complete(adapter, skb);
                else
                        dev_kfree_skb_any(skb);

                return ret;
        }

        if (rx_pkt_type == PKT_TYPE_AMSDU) {
                struct sk_buff_head list;
                struct sk_buff *rx_skb;

                __skb_queue_head_init(&list);

                skb_pull(skb, rx_pkt_offset);
                skb_trim(skb, rx_pkt_length);

                ieee80211_amsdu_to_8023s(skb, &list, priv->curr_addr,
                                         priv->wdev->iftype, 0, false);

                while (!skb_queue_empty(&list)) {
                        rx_skb = __skb_dequeue(&list);
                        ret = mwifiex_recv_packet(priv, rx_skb);
                        if (ret == -1)
                                dev_err(adapter->dev, "Rx of A-MSDU failed");
                }
                return 0;
        } else if (rx_pkt_type == PKT_TYPE_MGMT) {
                ret = mwifiex_process_mgmt_packet(priv, skb);
                if (ret)
                        dev_err(adapter->dev, "Rx of mgmt packet failed");
                dev_kfree_skb_any(skb);
                return ret;
        }

        /*
         * If the packet is not an unicast packet then send the packet
         * directly to os. Don't pass thru rx reordering
         */
        if (!IS_11N_ENABLED(priv) ||
            memcmp(priv->curr_addr, rx_pkt_hdr->eth803_hdr.h_dest, ETH_ALEN)) {
                mwifiex_process_rx_packet(priv, skb);
                return ret;
        }

        if (mwifiex_queuing_ra_based(priv)) {
                memcpy(ta, rx_pkt_hdr->eth803_hdr.h_source, ETH_ALEN);
        } else {
                if (rx_pkt_type != PKT_TYPE_BAR)
                        priv->rx_seq[local_rx_pd->priority] = seq_num;
                memcpy(ta, priv->curr_bss_params.bss_descriptor.mac_address,
                       ETH_ALEN);
        }

        /* Reorder and send to OS */
        ret = mwifiex_11n_rx_reorder_pkt(priv, seq_num, local_rx_pd->priority,
                                         ta, (u8) rx_pkt_type, skb);

        if (ret || (rx_pkt_type == PKT_TYPE_BAR)) {
                if (adapter->if_ops.data_complete)
                        adapter->if_ops.data_complete(adapter, skb);
                else
                        dev_kfree_skb_any(skb);
        }

        if (ret)
                priv->stats.rx_dropped++;

        return ret;
}