uap_txrx.c

Go to the documentation of this file.

/*
 * Marvell Wireless LAN device driver: AP TX and RX data handling
 *
 * Copyright (C) 2012, 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 "main.h"
#include "wmm.h"
#include "11n_aggr.h"
#include "11n_rxreorder.h"

static void mwifiex_uap_queue_bridged_pkt(struct mwifiex_private *priv,
                     struct sk_buff *skb)
{
    struct mwifiex_adapter *adapter = priv->adapter;
    struct uap_rxpd *uap_rx_pd;
    struct rx_packet_hdr *rx_pkt_hdr;
    struct sk_buff *new_skb;
    struct mwifiex_txinfo *tx_info;
    int hdr_chop;
    struct timeval tv;
    u8 rfc1042_eth_hdr[ETH_ALEN] = { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };

    uap_rx_pd = (struct uap_rxpd *)(skb->data);
    rx_pkt_hdr = (void *)uap_rx_pd + le16_to_cpu(uap_rx_pd->rx_pkt_offset);

    if ((atomic_read(&adapter->pending_bridged_pkts) >=
                         MWIFIEX_BRIDGED_PKTS_THRESHOLD)) {
        dev_err(priv->adapter->dev,
            "Tx: Bridge packet limit reached. Drop packet!\n");
        kfree_skb(skb);
        return;
    }

    if (!memcmp(&rx_pkt_hdr->rfc1042_hdr,
            rfc1042_eth_hdr, sizeof(rfc1042_eth_hdr)))
        /* Chop off the rxpd + the excess memory from
         * 802.2/llc/snap header that was removed.
         */
        hdr_chop = (u8 *)eth_hdr - (u8 *)uap_rx_pd;
    else
        /* Chop off the rxpd */
        hdr_chop = (u8 *)&rx_pkt_hdr->eth803_hdr - (u8 *)uap_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);

    if (skb_headroom(skb) < MWIFIEX_MIN_DATA_HEADER_LEN) {
        dev_dbg(priv->adapter->dev,
            "data: Tx: insufficient skb headroom %d\n",
            skb_headroom(skb));
        /* Insufficient skb headroom - allocate a new skb */
        new_skb =
            skb_realloc_headroom(skb, MWIFIEX_MIN_DATA_HEADER_LEN);
        if (unlikely(!new_skb)) {
            dev_err(priv->adapter->dev,
                "Tx: cannot allocate new_skb\n");
            kfree_skb(skb);
            priv->stats.tx_dropped++;
            return;
        }

        kfree_skb(skb);
        skb = new_skb;
        dev_dbg(priv->adapter->dev, "info: new skb headroom %d\n",
            skb_headroom(skb));
    }

    tx_info = MWIFIEX_SKB_TXCB(skb);
    tx_info->bss_num = priv->bss_num;
    tx_info->bss_type = priv->bss_type;
    tx_info->flags |= MWIFIEX_BUF_FLAG_BRIDGED_PKT;

    do_gettimeofday(&tv);
    skb->tstamp = timeval_to_ktime(tv);
    mwifiex_wmm_add_buf_txqueue(priv, skb);
    atomic_inc(&adapter->tx_pending);
    atomic_inc(&adapter->pending_bridged_pkts);

    if ((atomic_read(&adapter->tx_pending) >= MAX_TX_PENDING)) {
        mwifiex_set_trans_start(priv->netdev);
        mwifiex_stop_net_dev_queue(priv->netdev, priv->adapter);
    }
    return;
}

/*
 * This function contains logic for AP packet forwarding.
 *
 * If a packet is multicast/broadcast, it is sent to kernel/upper layer
 * as well as queued back to AP TX queue so that it can be sent to other
 * associated stations.
 * If a packet is unicast and RA is present in associated station list,
 * it is again requeued into AP TX queue.
 * If a packet is unicast and RA is not in associated station list,
 * packet is forwarded to kernel to handle routing logic.
 */
int mwifiex_handle_uap_rx_forward(struct mwifiex_private *priv,
                  struct sk_buff *skb)
{
    struct mwifiex_adapter *adapter = priv->adapter;
    struct uap_rxpd *uap_rx_pd;
    struct rx_packet_hdr *rx_pkt_hdr;
    u8 ra[ETH_ALEN];
    struct sk_buff *skb_uap;

    uap_rx_pd = (struct uap_rxpd *)(skb->data);
    rx_pkt_hdr = (void *)uap_rx_pd + le16_to_cpu(uap_rx_pd->rx_pkt_offset);

    /* don't do packet forwarding in disconnected state */
    if (!priv->media_connected) {
        dev_err(adapter->dev, "drop packet in disconnected state.\n");
        dev_kfree_skb_any(skb);
        return 0;
    }

    memcpy(ra, rx_pkt_hdr->eth803_hdr.h_dest, ETH_ALEN);

    if (is_multicast_ether_addr(ra)) {
        skb_uap = skb_copy(skb, GFP_ATOMIC);
        mwifiex_uap_queue_bridged_pkt(priv, skb_uap);
    } else {
        if (mwifiex_get_sta_entry(priv, ra)) {
            /* Requeue Intra-BSS packet */
            mwifiex_uap_queue_bridged_pkt(priv, skb);
            return 0;
        }
    }

    /* Forward unicat/Inter-BSS packets to kernel. */
    return mwifiex_process_rx_packet(adapter, skb);
}

/*
 * This function processes the packet received on AP interface.
 *
 * 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. Then skb is passed to AP packet forwarding logic.
 *
 * The completion callback is called after processing is complete.
 */
int mwifiex_process_uap_rx_packet(struct mwifiex_adapter *adapter,
                  struct sk_buff *skb)
{
    int ret;
    struct uap_rxpd *uap_rx_pd;
    struct mwifiex_rxinfo *rx_info = MWIFIEX_SKB_RXCB(skb);
    struct rx_packet_hdr *rx_pkt_hdr;
    u16 rx_pkt_type;
    u8 ta[ETH_ALEN], pkt_type;
    struct mwifiex_sta_node *node;

    struct mwifiex_private *priv =
            mwifiex_get_priv_by_id(adapter, rx_info->bss_num,
                           rx_info->bss_type);

    if (!priv)
        return -1;

    uap_rx_pd = (struct uap_rxpd *)(skb->data);
    rx_pkt_type = le16_to_cpu(uap_rx_pd->rx_pkt_type);
    rx_pkt_hdr = (void *)uap_rx_pd + le16_to_cpu(uap_rx_pd->rx_pkt_offset);

    if ((le16_to_cpu(uap_rx_pd->rx_pkt_offset) +
         le16_to_cpu(uap_rx_pd->rx_pkt_length)) > (u16) skb->len) {
        dev_err(adapter->dev,
            "wrong rx packet: len=%d, offset=%d, length=%d\n",
            skb->len, le16_to_cpu(uap_rx_pd->rx_pkt_offset),
            le16_to_cpu(uap_rx_pd->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 0;
    }

    if (le16_to_cpu(uap_rx_pd->rx_pkt_type) == PKT_TYPE_AMSDU) {
        struct sk_buff_head list;
        struct sk_buff *rx_skb;

        __skb_queue_head_init(&list);
        skb_pull(skb, le16_to_cpu(uap_rx_pd->rx_pkt_offset));
        skb_trim(skb, le16_to_cpu(uap_rx_pd->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)
                dev_err(adapter->dev,
                    "AP:Rx 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;
    }

    memcpy(ta, rx_pkt_hdr->eth803_hdr.h_source, ETH_ALEN);

    if (rx_pkt_type != PKT_TYPE_BAR && uap_rx_pd->priority < MAX_NUM_TID) {
        node = mwifiex_get_sta_entry(priv, ta);
        if (node)
            node->rx_seq[uap_rx_pd->priority] =
                        le16_to_cpu(uap_rx_pd->seq_num);
    }

    if (!priv->ap_11n_enabled ||
        (!mwifiex_11n_get_rx_reorder_tbl(priv, uap_rx_pd->priority, ta) &&
        (le16_to_cpu(uap_rx_pd->rx_pkt_type) != PKT_TYPE_AMSDU))) {
        ret = mwifiex_handle_uap_rx_forward(priv, skb);
        return ret;
    }

    /* Reorder and send to kernel */
    pkt_type = (u8)le16_to_cpu(uap_rx_pd->rx_pkt_type);
    ret = mwifiex_11n_rx_reorder_pkt(priv, le16_to_cpu(uap_rx_pd->seq_num),
                     uap_rx_pd->priority, ta, 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;
}

/*
 * This function fills the TxPD for AP tx packets.
 *
 * The Tx buffer received by this function should already have the
 * header space allocated for TxPD.
 *
 * This function inserts the TxPD in between interface header and actual
 * data and adjusts the buffer pointers accordingly.
 *
 * The following TxPD fields are set by this function, as required -
 *      - BSS number
 *      - Tx packet length and offset
 *      - Priority
 *      - Packet delay
 *      - Priority specific Tx control
 *      - Flags
 */
void *mwifiex_process_uap_txpd(struct mwifiex_private *priv,
                   struct sk_buff *skb)
{
    struct mwifiex_adapter *adapter = priv->adapter;
    struct uap_txpd *txpd;
    struct mwifiex_txinfo *tx_info = MWIFIEX_SKB_TXCB(skb);
    int pad, len;
    u16 pkt_type;

    if (!skb->len) {
        dev_err(adapter->dev, "Tx: bad packet length: %d\n", skb->len);
        tx_info->status_code = -1;
        return skb->data;
    }

    pkt_type = mwifiex_is_skb_mgmt_frame(skb) ? PKT_TYPE_MGMT : 0;

    /* If skb->data is not aligned, add padding */
    pad = (4 - (((void *)skb->data - NULL) & 0x3)) % 4;

    len = sizeof(*txpd) + pad;

    BUG_ON(skb_headroom(skb) < len + INTF_HEADER_LEN);

    skb_push(skb, len);

    txpd = (struct uap_txpd *)skb->data;
    memset(txpd, 0, sizeof(*txpd));
    txpd->bss_num = priv->bss_num;
    txpd->bss_type = priv->bss_type;
    txpd->tx_pkt_length = cpu_to_le16((u16)(skb->len - len));

    txpd->priority = (u8)skb->priority;
    txpd->pkt_delay_2ms = mwifiex_wmm_compute_drv_pkt_delay(priv, skb);

    if (txpd->priority < ARRAY_SIZE(priv->wmm.user_pri_pkt_tx_ctrl))
        /*
         * Set the priority specific tx_control field, setting of 0 will
         * cause the default value to be used later in this function.
         */
        txpd->tx_control =
            cpu_to_le32(priv->wmm.user_pri_pkt_tx_ctrl[txpd->priority]);

    /* Offset of actual data */
    if (pkt_type == PKT_TYPE_MGMT) {
        /* Set the packet type and add header for management frame */
        txpd->tx_pkt_type = cpu_to_le16(pkt_type);
        len += MWIFIEX_MGMT_FRAME_HEADER_SIZE;
    }

    txpd->tx_pkt_offset = cpu_to_le16(len);

    /* make space for INTF_HEADER_LEN */
    skb_push(skb, INTF_HEADER_LEN);

    if (!txpd->tx_control)
        /* TxCtrl set by user or default */
        txpd->tx_control = cpu_to_le32(priv->pkt_tx_ctrl);

    return skb->data;
}