sta_rx.c

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/*
 * 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_adapter *adapter,
                  struct sk_buff *skb)
{
    int ret;
    struct mwifiex_rxinfo *rx_info = MWIFIEX_SKB_RXCB(skb);
    struct mwifiex_private *priv =
            mwifiex_get_priv_by_id(adapter, rx_info->bss_num,
                           rx_info->bss_type);
    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(adapter, skb);
    if (ret == -1)
        dev_err(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_adapter *adapter,
                  struct sk_buff *skb)
{
    int ret = 0;
    struct rxpd *local_rx_pd;
    struct mwifiex_rxinfo *rx_info = MWIFIEX_SKB_RXCB(skb);
    struct rx_packet_hdr *rx_pkt_hdr;
    u8 ta[ETH_ALEN];
    u16 rx_pkt_type, rx_pkt_offset, rx_pkt_length, seq_num;
    struct mwifiex_private *priv =
            mwifiex_get_priv_by_id(adapter, rx_info->bss_num,
                           rx_info->bss_type);

    if (!priv)
        return -1;

    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(adapter, 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(adapter, 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(adapter, 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;
}