drivers/net/wireless/marvell/mwifiex/uap_txrx.c

   1 /*
   2  * Marvell Wireless LAN device driver: AP TX and RX data handling
   3  *
   4  * Copyright (C) 2012-2014, Marvell International Ltd.
   5  *
   6  * This software file (the "File") is distributed by Marvell International
   7  * Ltd. under the terms of the GNU General Public License Version 2, June 1991
   8  * (the "License").  You may use, redistribute and/or modify this File in
   9  * accordance with the terms and conditions of the License, a copy of which
  10  * is available by writing to the Free Software Foundation, Inc.,
  11  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or on the
  12  * worldwide web at http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
  13  *
  14  * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
  16  * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
  17  * this warranty disclaimer.
  18  */
  19
  20 #include "decl.h"
  21 #include "ioctl.h"
  22 #include "main.h"
  23 #include "wmm.h"
  24 #include "11n_aggr.h"
  25 #include "11n_rxreorder.h"
  26
  27 /* This function checks if particular RA list has packets more than low bridge
  28  * packet threshold and then deletes packet from this RA list.
  29  * Function deletes packets from such RA list and returns true. If no such list
  30  * is found, false is returned.
  31  */
  32 static bool
  33 mwifiex_uap_del_tx_pkts_in_ralist(struct mwifiex_private *priv,
  34                                   struct list_head *ra_list_head,
  35                                   int tid)
  36 {
  37         struct mwifiex_ra_list_tbl *ra_list;
  38         struct sk_buff *skb, *tmp;
  39         bool pkt_deleted = false;
  40         struct mwifiex_txinfo *tx_info;
  41         struct mwifiex_adapter *adapter = priv->adapter;
  42
  43         list_for_each_entry(ra_list, ra_list_head, list) {
  44                 if (skb_queue_empty(&ra_list->skb_head))
  45                         continue;
  46
  47                 skb_queue_walk_safe(&ra_list->skb_head, skb, tmp) {
  48                         tx_info = MWIFIEX_SKB_TXCB(skb);
  49                         if (tx_info->flags & MWIFIEX_BUF_FLAG_BRIDGED_PKT) {
  50                                 __skb_unlink(skb, &ra_list->skb_head);
  51                                 mwifiex_write_data_complete(adapter, skb, 0,
  52                                                             -1);
  53                                 if (ra_list->tx_paused)
  54                                         priv->wmm.pkts_paused[tid]--;
  55                                 else
  56                                         atomic_dec(&priv->wmm.tx_pkts_queued);
  57                                 pkt_deleted = true;
  58                         }
  59                         if ((atomic_read(&adapter->pending_bridged_pkts) <=
  60                                              MWIFIEX_BRIDGED_PKTS_THR_LOW))
  61                                 break;
  62                 }
  63         }
  64
  65         return pkt_deleted;
  66 }
  67
  68 /* This function deletes packets from particular RA List. RA list index
  69  * from which packets are deleted is preserved so that packets from next RA
  70  * list are deleted upon subsequent call thus maintaining fairness.
  71  */
  72 static void mwifiex_uap_cleanup_tx_queues(struct mwifiex_private *priv)
  73 {
  74         unsigned long flags;
  75         struct list_head *ra_list;
  76         int i;
  77
  78         spin_lock_irqsave(&priv->wmm.ra_list_spinlock, flags);
  79
  80         for (i = 0; i < MAX_NUM_TID; i++, priv->del_list_idx++) {
  81                 if (priv->del_list_idx == MAX_NUM_TID)
  82                         priv->del_list_idx = 0;
  83                 ra_list = &priv->wmm.tid_tbl_ptr[priv->del_list_idx].ra_list;
  84                 if (mwifiex_uap_del_tx_pkts_in_ralist(priv, ra_list, i)) {
  85                         priv->del_list_idx++;
  86                         break;
  87                 }
  88         }
  89
  90         spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock, flags);
  91 }
  92
  93
  94 static void mwifiex_uap_queue_bridged_pkt(struct mwifiex_private *priv,
  95                                          struct sk_buff *skb)
  96 {
  97         struct mwifiex_adapter *adapter = priv->adapter;
  98         struct uap_rxpd *uap_rx_pd;
  99         struct rx_packet_hdr *rx_pkt_hdr;
 100         struct sk_buff *new_skb;
 101         struct mwifiex_txinfo *tx_info;
 102         int hdr_chop;
 103         struct ethhdr *p_ethhdr;
 104         struct mwifiex_sta_node *src_node;
 105         int index;
 106
 107         uap_rx_pd = (struct uap_rxpd *)(skb->data);
 108         rx_pkt_hdr = (void *)uap_rx_pd + le16_to_cpu(uap_rx_pd->rx_pkt_offset);
 109
 110         if ((atomic_read(&adapter->pending_bridged_pkts) >=
 111                                              MWIFIEX_BRIDGED_PKTS_THR_HIGH)) {
 112                 mwifiex_dbg(priv->adapter, ERROR,
 113                             "Tx: Bridge packet limit reached. Drop packet!\n");
 114                 kfree_skb(skb);
 115                 mwifiex_uap_cleanup_tx_queues(priv);
 116                 return;
 117         }
 118
 119         if ((!memcmp(&rx_pkt_hdr->rfc1042_hdr, bridge_tunnel_header,
 120                      sizeof(bridge_tunnel_header))) ||
 121             (!memcmp(&rx_pkt_hdr->rfc1042_hdr, rfc1042_header,
 122                      sizeof(rfc1042_header)) &&
 123              ntohs(rx_pkt_hdr->rfc1042_hdr.snap_type) != ETH_P_AARP &&
 124              ntohs(rx_pkt_hdr->rfc1042_hdr.snap_type) != ETH_P_IPX)) {
 125                 /* Replace the 803 header and rfc1042 header (llc/snap) with
 126                  * an Ethernet II header, keep the src/dst and snap_type
 127                  * (ethertype).
 128                  *
 129                  * The firmware only passes up SNAP frames converting all RX
 130                  * data from 802.11 to 802.2/LLC/SNAP frames.
 131                  *
 132                  * To create the Ethernet II, just move the src, dst address
 133                  * right before the snap_type.
 134                  */
 135                 p_ethhdr = (struct ethhdr *)
 136                         ((u8 *)(&rx_pkt_hdr->eth803_hdr)
 137                          + sizeof(rx_pkt_hdr->eth803_hdr)
 138                          + sizeof(rx_pkt_hdr->rfc1042_hdr)
 139                          - sizeof(rx_pkt_hdr->eth803_hdr.h_dest)
 140                          - sizeof(rx_pkt_hdr->eth803_hdr.h_source)
 141                          - sizeof(rx_pkt_hdr->rfc1042_hdr.snap_type));
 142                 memcpy(p_ethhdr->h_source, rx_pkt_hdr->eth803_hdr.h_source,
 143                        sizeof(p_ethhdr->h_source));
 144                 memcpy(p_ethhdr->h_dest, rx_pkt_hdr->eth803_hdr.h_dest,
 145                        sizeof(p_ethhdr->h_dest));
 146                 /* Chop off the rxpd + the excess memory from
 147                  * 802.2/llc/snap header that was removed.
 148                  */
 149                 hdr_chop = (u8 *)p_ethhdr - (u8 *)uap_rx_pd;
 150         } else {
 151                 /* Chop off the rxpd */
 152                 hdr_chop = (u8 *)&rx_pkt_hdr->eth803_hdr - (u8 *)uap_rx_pd;
 153         }
 154
 155         /* Chop off the leading header bytes so that it points
 156          * to the start of either the reconstructed EthII frame
 157          * or the 802.2/llc/snap frame.
 158          */
 159         skb_pull(skb, hdr_chop);
 160
 161         if (skb_headroom(skb) < MWIFIEX_MIN_DATA_HEADER_LEN) {
 162                 mwifiex_dbg(priv->adapter, ERROR,
 163                             "data: Tx: insufficient skb headroom %d\n",
 164                             skb_headroom(skb));
 165                 /* Insufficient skb headroom - allocate a new skb */
 166                 new_skb =
 167                         skb_realloc_headroom(skb, MWIFIEX_MIN_DATA_HEADER_LEN);
 168                 if (unlikely(!new_skb)) {
 169                         mwifiex_dbg(priv->adapter, ERROR,
 170                                     "Tx: cannot allocate new_skb\n");
 171                         kfree_skb(skb);
 172                         priv->stats.tx_dropped++;
 173                         return;
 174                 }
 175
 176                 kfree_skb(skb);
 177                 skb = new_skb;
 178                 mwifiex_dbg(priv->adapter, INFO,
 179                             "info: new skb headroom %d\n",
 180                             skb_headroom(skb));
 181         }
 182
 183         tx_info = MWIFIEX_SKB_TXCB(skb);
 184         memset(tx_info, 0, sizeof(*tx_info));
 185         tx_info->bss_num = priv->bss_num;
 186         tx_info->bss_type = priv->bss_type;
 187         tx_info->flags |= MWIFIEX_BUF_FLAG_BRIDGED_PKT;
 188
 189         src_node = mwifiex_get_sta_entry(priv, rx_pkt_hdr->eth803_hdr.h_source);
 190         if (src_node) {
 191                 src_node->stats.last_rx = jiffies;
 192                 src_node->stats.rx_bytes += skb->len;
 193                 src_node->stats.rx_packets++;
 194                 src_node->stats.last_tx_rate = uap_rx_pd->rx_rate;
 195                 src_node->stats.last_tx_htinfo = uap_rx_pd->ht_info;
 196         }
 197
 198         if (is_unicast_ether_addr(rx_pkt_hdr->eth803_hdr.h_dest)) {
 199                 /* Update bridge packet statistics as the
 200                  * packet is not going to kernel/upper layer.
 201                  */
 202                 priv->stats.rx_bytes += skb->len;
 203                 priv->stats.rx_packets++;
 204
 205                 /* Sending bridge packet to TX queue, so save the packet
 206                  * length in TXCB to update statistics in TX complete.
 207                  */
 208                 tx_info->pkt_len = skb->len;
 209         }
 210
 211         __net_timestamp(skb);
 212
 213         index = mwifiex_1d_to_wmm_queue[skb->priority];
 214         atomic_inc(&priv->wmm_tx_pending[index]);
 215         mwifiex_wmm_add_buf_txqueue(priv, skb);
 216         atomic_inc(&adapter->tx_pending);
 217         atomic_inc(&adapter->pending_bridged_pkts);
 218
 219         mwifiex_queue_main_work(priv->adapter);
 220
 221         return;
 222 }
 223
 224 /*
 225  * This function contains logic for AP packet forwarding.
 226  *
 227  * If a packet is multicast/broadcast, it is sent to kernel/upper layer
 228  * as well as queued back to AP TX queue so that it can be sent to other
 229  * associated stations.
 230  * If a packet is unicast and RA is present in associated station list,
 231  * it is again requeued into AP TX queue.
 232  * If a packet is unicast and RA is not in associated station list,
 233  * packet is forwarded to kernel to handle routing logic.
 234  */
 235 int mwifiex_handle_uap_rx_forward(struct mwifiex_private *priv,
 236                                   struct sk_buff *skb)
 237 {
 238         struct mwifiex_adapter *adapter = priv->adapter;
 239         struct uap_rxpd *uap_rx_pd;
 240         struct rx_packet_hdr *rx_pkt_hdr;
 241         u8 ra[ETH_ALEN];
 242         struct sk_buff *skb_uap;
 243
 244         uap_rx_pd = (struct uap_rxpd *)(skb->data);
 245         rx_pkt_hdr = (void *)uap_rx_pd + le16_to_cpu(uap_rx_pd->rx_pkt_offset);
 246
 247         /* don't do packet forwarding in disconnected state */
 248         if (!priv->media_connected) {
 249                 mwifiex_dbg(adapter, ERROR,
 250                             "drop packet in disconnected state.\n");
 251                 dev_kfree_skb_any(skb);
 252                 return 0;
 253         }
 254
 255         memcpy(ra, rx_pkt_hdr->eth803_hdr.h_dest, ETH_ALEN);
 256
 257         if (is_multicast_ether_addr(ra)) {
 258                 skb_uap = skb_copy(skb, GFP_ATOMIC);
 259                 mwifiex_uap_queue_bridged_pkt(priv, skb_uap);
 260         } else {
 261                 if (mwifiex_get_sta_entry(priv, ra)) {
 262                         /* Requeue Intra-BSS packet */
 263                         mwifiex_uap_queue_bridged_pkt(priv, skb);
 264                         return 0;
 265                 }
 266         }
 267
 268         /* Forward unicat/Inter-BSS packets to kernel. */
 269         return mwifiex_process_rx_packet(priv, skb);
 270 }
 271
 272 int mwifiex_uap_recv_packet(struct mwifiex_private *priv,
 273                             struct sk_buff *skb)
 274 {
 275         struct mwifiex_adapter *adapter = adapter;
 276         struct mwifiex_sta_node *src_node;
 277         struct ethhdr *p_ethhdr;
 278         struct sk_buff *skb_uap;
 279         struct mwifiex_txinfo *tx_info;
 280
 281         if (!skb)
 282                 return -1;
 283
 284         p_ethhdr = (void *)skb->data;
 285         src_node = mwifiex_get_sta_entry(priv, p_ethhdr->h_source);
 286         if (src_node) {
 287                 src_node->stats.last_rx = jiffies;
 288                 src_node->stats.rx_bytes += skb->len;
 289                 src_node->stats.rx_packets++;
 290         }
 291
 292         skb->dev = priv->netdev;
 293         skb->protocol = eth_type_trans(skb, priv->netdev);
 294         skb->ip_summed = CHECKSUM_NONE;
 295
 296         /* This is required only in case of 11n and USB/PCIE as we alloc
 297          * a buffer of 4K only if its 11N (to be able to receive 4K
 298          * AMSDU packets). In case of SD we allocate buffers based
 299          * on the size of packet and hence this is not needed.
 300          *
 301          * Modifying the truesize here as our allocation for each
 302          * skb is 4K but we only receive 2K packets and this cause
 303          * the kernel to start dropping packets in case where
 304          * application has allocated buffer based on 2K size i.e.
 305          * if there a 64K packet received (in IP fragments and
 306          * application allocates 64K to receive this packet but
 307          * this packet would almost double up because we allocate
 308          * each 1.5K fragment in 4K and pass it up. As soon as the
 309          * 64K limit hits kernel will start to drop rest of the
 310          * fragments. Currently we fail the Filesndl-ht.scr script
 311          * for UDP, hence this fix
 312          */
 313         if ((adapter->iface_type == MWIFIEX_USB ||
 314              adapter->iface_type == MWIFIEX_PCIE) &&
 315             (skb->truesize > MWIFIEX_RX_DATA_BUF_SIZE))
 316                 skb->truesize += (skb->len - MWIFIEX_RX_DATA_BUF_SIZE);
 317
 318         if (is_multicast_ether_addr(p_ethhdr->h_dest) ||
 319             mwifiex_get_sta_entry(priv, p_ethhdr->h_dest)) {
 320                 if (skb_headroom(skb) < MWIFIEX_MIN_DATA_HEADER_LEN)
 321                         skb_uap =
 322                         skb_realloc_headroom(skb, MWIFIEX_MIN_DATA_HEADER_LEN);
 323                 else
 324                         skb_uap = skb_copy(skb, GFP_ATOMIC);
 325
 326                 if (likely(skb_uap)) {
 327                         tx_info = MWIFIEX_SKB_TXCB(skb_uap);
 328                         memset(tx_info, 0, sizeof(*tx_info));
 329                         tx_info->bss_num = priv->bss_num;
 330                         tx_info->bss_type = priv->bss_type;
 331                         tx_info->flags |= MWIFIEX_BUF_FLAG_BRIDGED_PKT;
 332                         __net_timestamp(skb_uap);
 333                         mwifiex_wmm_add_buf_txqueue(priv, skb_uap);
 334                         atomic_inc(&adapter->tx_pending);
 335                         atomic_inc(&adapter->pending_bridged_pkts);
 336                         if ((atomic_read(&adapter->pending_bridged_pkts) >=
 337                                         MWIFIEX_BRIDGED_PKTS_THR_HIGH)) {
 338                                 mwifiex_dbg(adapter, ERROR,
 339                                             "Tx: Bridge packet limit reached. Drop packet!\n");
 340                                 mwifiex_uap_cleanup_tx_queues(priv);
 341                         }
 342
 343                 } else {
 344                         mwifiex_dbg(adapter, ERROR, "failed to allocate skb_uap");
 345                 }
 346
 347                 mwifiex_queue_main_work(adapter);
 348                 /* Don't forward Intra-BSS unicast packet to upper layer*/
 349                 if (mwifiex_get_sta_entry(priv, p_ethhdr->h_dest))
 350                         return 0;
 351         }
 352
 353         /* Forward multicast/broadcast packet to upper layer*/
 354         if (in_interrupt())
 355                 netif_rx(skb);
 356         else
 357                 netif_rx_ni(skb);
 358
 359         return 0;
 360 }
 361
 362 /*
 363  * This function processes the packet received on AP interface.
 364  *
 365  * The function looks into the RxPD and performs sanity tests on the
 366  * received buffer to ensure its a valid packet before processing it
 367  * further. If the packet is determined to be aggregated, it is
 368  * de-aggregated accordingly. Then skb is passed to AP packet forwarding logic.
 369  *
 370  * The completion callback is called after processing is complete.
 371  */
 372 int mwifiex_process_uap_rx_packet(struct mwifiex_private *priv,
 373                                   struct sk_buff *skb)
 374 {
 375         struct mwifiex_adapter *adapter = priv->adapter;
 376         int ret;
 377         struct uap_rxpd *uap_rx_pd;
 378         struct rx_packet_hdr *rx_pkt_hdr;
 379         u16 rx_pkt_type;
 380         u8 ta[ETH_ALEN], pkt_type;
 381         unsigned long flags;
 382         struct mwifiex_sta_node *node;
 383
 384         uap_rx_pd = (struct uap_rxpd *)(skb->data);
 385         rx_pkt_type = le16_to_cpu(uap_rx_pd->rx_pkt_type);
 386         rx_pkt_hdr = (void *)uap_rx_pd + le16_to_cpu(uap_rx_pd->rx_pkt_offset);
 387
 388         ether_addr_copy(ta, rx_pkt_hdr->eth803_hdr.h_source);
 389
 390         if ((le16_to_cpu(uap_rx_pd->rx_pkt_offset) +
 391              le16_to_cpu(uap_rx_pd->rx_pkt_length)) > (u16) skb->len) {
 392                 mwifiex_dbg(adapter, ERROR,
 393                             "wrong rx packet: len=%d, offset=%d, length=%d\n",
 394                             skb->len, le16_to_cpu(uap_rx_pd->rx_pkt_offset),
 395                             le16_to_cpu(uap_rx_pd->rx_pkt_length));
 396                 priv->stats.rx_dropped++;
 397
 398                 node = mwifiex_get_sta_entry(priv, ta);
 399                 if (node)
 400                         node->stats.tx_failed++;
 401
 402                 dev_kfree_skb_any(skb);
 403                 return 0;
 404         }
 405
 406         if (rx_pkt_type == PKT_TYPE_MGMT) {
 407                 ret = mwifiex_process_mgmt_packet(priv, skb);
 408                 if (ret)
 409                         mwifiex_dbg(adapter, DATA, "Rx of mgmt packet failed");
 410                 dev_kfree_skb_any(skb);
 411                 return ret;
 412         }
 413
 414
 415         if (rx_pkt_type != PKT_TYPE_BAR && uap_rx_pd->priority < MAX_NUM_TID) {
 416                 spin_lock_irqsave(&priv->sta_list_spinlock, flags);
 417                 node = mwifiex_get_sta_entry(priv, ta);
 418                 if (node)
 419                         node->rx_seq[uap_rx_pd->priority] =
 420                                                 le16_to_cpu(uap_rx_pd->seq_num);
 421                 spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
 422         }
 423
 424         if (!priv->ap_11n_enabled ||
 425             (!mwifiex_11n_get_rx_reorder_tbl(priv, uap_rx_pd->priority, ta) &&
 426             (le16_to_cpu(uap_rx_pd->rx_pkt_type) != PKT_TYPE_AMSDU))) {
 427                 ret = mwifiex_handle_uap_rx_forward(priv, skb);
 428                 return ret;
 429         }
 430
 431         /* Reorder and send to kernel */
 432         pkt_type = (u8)le16_to_cpu(uap_rx_pd->rx_pkt_type);
 433         ret = mwifiex_11n_rx_reorder_pkt(priv, le16_to_cpu(uap_rx_pd->seq_num),
 434                                          uap_rx_pd->priority, ta, pkt_type,
 435                                          skb);
 436
 437         if (ret || (rx_pkt_type == PKT_TYPE_BAR))
 438                 dev_kfree_skb_any(skb);
 439
 440         if (ret)
 441                 priv->stats.rx_dropped++;
 442
 443         return ret;
 444 }
 445
 446 /*
 447  * This function fills the TxPD for AP tx packets.
 448  *
 449  * The Tx buffer received by this function should already have the
 450  * header space allocated for TxPD.
 451  *
 452  * This function inserts the TxPD in between interface header and actual
 453  * data and adjusts the buffer pointers accordingly.
 454  *
 455  * The following TxPD fields are set by this function, as required -
 456  *      - BSS number
 457  *      - Tx packet length and offset
 458  *      - Priority
 459  *      - Packet delay
 460  *      - Priority specific Tx control
 461  *      - Flags
 462  */
 463 void *mwifiex_process_uap_txpd(struct mwifiex_private *priv,
 464                                struct sk_buff *skb)
 465 {
 466         struct mwifiex_adapter *adapter = priv->adapter;
 467         struct uap_txpd *txpd;
 468         struct mwifiex_txinfo *tx_info = MWIFIEX_SKB_TXCB(skb);
 469         int pad;
 470         u16 pkt_type, pkt_offset;
 471         int hroom = (priv->adapter->iface_type == MWIFIEX_USB) ? 0 :
 472                        INTF_HEADER_LEN;
 473
 474         if (!skb->len) {
 475                 mwifiex_dbg(adapter, ERROR,
 476                             "Tx: bad packet length: %d\n", skb->len);
 477                 tx_info->status_code = -1;
 478                 return skb->data;
 479         }
 480
 481         BUG_ON(skb_headroom(skb) < MWIFIEX_MIN_DATA_HEADER_LEN);
 482
 483         pkt_type = mwifiex_is_skb_mgmt_frame(skb) ? PKT_TYPE_MGMT : 0;
 484
 485         pad = ((void *)skb->data - (sizeof(*txpd) + hroom) - NULL) &
 486                         (MWIFIEX_DMA_ALIGN_SZ - 1);
 487
 488         skb_push(skb, sizeof(*txpd) + pad);
 489
 490         txpd = (struct uap_txpd *)skb->data;
 491         memset(txpd, 0, sizeof(*txpd));
 492         txpd->bss_num = priv->bss_num;
 493         txpd->bss_type = priv->bss_type;
 494         txpd->tx_pkt_length = cpu_to_le16((u16)(skb->len - (sizeof(*txpd) +
 495                                                 pad)));
 496         txpd->priority = (u8)skb->priority;
 497
 498         txpd->pkt_delay_2ms = mwifiex_wmm_compute_drv_pkt_delay(priv, skb);
 499
 500         if (tx_info->flags & MWIFIEX_BUF_FLAG_EAPOL_TX_STATUS ||
 501             tx_info->flags & MWIFIEX_BUF_FLAG_ACTION_TX_STATUS) {
 502                 txpd->tx_token_id = tx_info->ack_frame_id;
 503                 txpd->flags |= MWIFIEX_TXPD_FLAGS_REQ_TX_STATUS;
 504         }
 505
 506         if (txpd->priority < ARRAY_SIZE(priv->wmm.user_pri_pkt_tx_ctrl))
 507                 /*
 508                  * Set the priority specific tx_control field, setting of 0 will
 509                  * cause the default value to be used later in this function.
 510                  */
 511                 txpd->tx_control =
 512                     cpu_to_le32(priv->wmm.user_pri_pkt_tx_ctrl[txpd->priority]);
 513
 514         /* Offset of actual data */
 515         pkt_offset = sizeof(*txpd) + pad;
 516         if (pkt_type == PKT_TYPE_MGMT) {
 517                 /* Set the packet type and add header for management frame */
 518                 txpd->tx_pkt_type = cpu_to_le16(pkt_type);
 519                 pkt_offset += MWIFIEX_MGMT_FRAME_HEADER_SIZE;
 520         }
 521
 522         txpd->tx_pkt_offset = cpu_to_le16(pkt_offset);
 523
 524         /* make space for INTF_HEADER_LEN */
 525         skb_push(skb, hroom);
 526
 527         if (!txpd->tx_control)
 528                 /* TxCtrl set by user or default */
 529                 txpd->tx_control = cpu_to_le32(priv->pkt_tx_ctrl);
 530
 531         return skb->data;
 532 }