drivers/net/wireless/hostap/hostap_80211_tx.c

   1 #include "hostap_80211.h"
   2 #include "hostap_common.h"
   3 #include "hostap_wlan.h"
   4 #include "hostap.h"
   5 #include "hostap_ap.h"
   6
   7 /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
   8 /* Ethernet-II snap header (RFC1042 for most EtherTypes) */
   9 static unsigned char rfc1042_header[] =
  10 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
  11 /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
  12 static unsigned char bridge_tunnel_header[] =
  13 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
  14 /* No encapsulation header if EtherType < 0x600 (=length) */
  15
  16 void hostap_dump_tx_80211(const char *name, struct sk_buff *skb)
  17 {
  18         struct ieee80211_hdr_4addr *hdr;
  19         u16 fc;
  20
  21         hdr = (struct ieee80211_hdr_4addr *) skb->data;
  22
  23         printk(KERN_DEBUG "%s: TX len=%d jiffies=%ld\n",
  24                name, skb->len, jiffies);
  25
  26         if (skb->len < 2)
  27                 return;
  28
  29         fc = le16_to_cpu(hdr->frame_ctl);
  30         printk(KERN_DEBUG "   FC=0x%04x (type=%d:%d)%s%s",
  31                fc, WLAN_FC_GET_TYPE(fc) >> 2, WLAN_FC_GET_STYPE(fc) >> 4,
  32                fc & IEEE80211_FCTL_TODS ? " [ToDS]" : "",
  33                fc & IEEE80211_FCTL_FROMDS ? " [FromDS]" : "");
  34
  35         if (skb->len < IEEE80211_DATA_HDR3_LEN) {
  36                 printk("\n");
  37                 return;
  38         }
  39
  40         printk(" dur=0x%04x seq=0x%04x\n", le16_to_cpu(hdr->duration_id),
  41                le16_to_cpu(hdr->seq_ctl));
  42
  43         printk(KERN_DEBUG "   A1=" MACSTR " A2=" MACSTR " A3=" MACSTR,
  44                MAC2STR(hdr->addr1), MAC2STR(hdr->addr2), MAC2STR(hdr->addr3));
  45         if (skb->len >= 30)
  46                 printk(" A4=" MACSTR, MAC2STR(hdr->addr4));
  47         printk("\n");
  48 }
  49
  50
  51 /* hard_start_xmit function for data interfaces (wlan#, wlan#wds#, wlan#sta)
  52  * Convert Ethernet header into a suitable IEEE 802.11 header depending on
  53  * device configuration. */
  54 int hostap_data_start_xmit(struct sk_buff *skb, struct net_device *dev)
  55 {
  56         struct hostap_interface *iface;
  57         local_info_t *local;
  58         int need_headroom, need_tailroom = 0;
  59         struct ieee80211_hdr_4addr hdr;
  60         u16 fc, ethertype = 0;
  61         enum {
  62                 WDS_NO = 0, WDS_OWN_FRAME, WDS_COMPLIANT_FRAME
  63         } use_wds = WDS_NO;
  64         u8 *encaps_data;
  65         int hdr_len, encaps_len, skip_header_bytes;
  66         int to_assoc_ap = 0;
  67         struct hostap_skb_tx_data *meta;
  68
  69         iface = netdev_priv(dev);
  70         local = iface->local;
  71
  72         if (skb->len < ETH_HLEN) {
  73                 printk(KERN_DEBUG "%s: hostap_data_start_xmit: short skb "
  74                        "(len=%d)\n", dev->name, skb->len);
  75                 kfree_skb(skb);
  76                 return 0;
  77         }
  78
  79         if (local->ddev != dev) {
  80                 use_wds = (local->iw_mode == IW_MODE_MASTER &&
  81                            !(local->wds_type & HOSTAP_WDS_STANDARD_FRAME)) ?
  82                         WDS_OWN_FRAME : WDS_COMPLIANT_FRAME;
  83                 if (dev == local->stadev) {
  84                         to_assoc_ap = 1;
  85                         use_wds = WDS_NO;
  86                 } else if (dev == local->apdev) {
  87                         printk(KERN_DEBUG "%s: prism2_tx: trying to use "
  88                                "AP device with Ethernet net dev\n", dev->name);
  89                         kfree_skb(skb);
  90                         return 0;
  91                 }
  92         } else {
  93                 if (local->iw_mode == IW_MODE_REPEAT) {
  94                         printk(KERN_DEBUG "%s: prism2_tx: trying to use "
  95                                "non-WDS link in Repeater mode\n", dev->name);
  96                         kfree_skb(skb);
  97                         return 0;
  98                 } else if (local->iw_mode == IW_MODE_INFRA &&
  99                            (local->wds_type & HOSTAP_WDS_AP_CLIENT) &&
 100                            memcmp(skb->data + ETH_ALEN, dev->dev_addr,
 101                                   ETH_ALEN) != 0) {
 102                         /* AP client mode: send frames with foreign src addr
 103                          * using 4-addr WDS frames */
 104                         use_wds = WDS_COMPLIANT_FRAME;
 105                 }
 106         }
 107
 108         /* Incoming skb->data: dst_addr[6], src_addr[6], proto[2], payload
 109          * ==>
 110          * Prism2 TX frame with 802.11 header:
 111          * txdesc (address order depending on used mode; includes dst_addr and
 112          * src_addr), possible encapsulation (RFC1042/Bridge-Tunnel;
 113          * proto[2], payload {, possible addr4[6]} */
 114
 115         ethertype = (skb->data[12] << 8) | skb->data[13];
 116
 117         memset(&hdr, 0, sizeof(hdr));
 118
 119         /* Length of data after IEEE 802.11 header */
 120         encaps_data = NULL;
 121         encaps_len = 0;
 122         skip_header_bytes = ETH_HLEN;
 123         if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
 124                 encaps_data = bridge_tunnel_header;
 125                 encaps_len = sizeof(bridge_tunnel_header);
 126                 skip_header_bytes -= 2;
 127         } else if (ethertype >= 0x600) {
 128                 encaps_data = rfc1042_header;
 129                 encaps_len = sizeof(rfc1042_header);
 130                 skip_header_bytes -= 2;
 131         }
 132
 133         fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA;
 134         hdr_len = IEEE80211_DATA_HDR3_LEN;
 135
 136         if (use_wds != WDS_NO) {
 137                 /* Note! Prism2 station firmware has problems with sending real
 138                  * 802.11 frames with four addresses; until these problems can
 139                  * be fixed or worked around, 4-addr frames needed for WDS are
 140                  * using incompatible format: FromDS flag is not set and the
 141                  * fourth address is added after the frame payload; it is
 142                  * assumed, that the receiving station knows how to handle this
 143                  * frame format */
 144
 145                 if (use_wds == WDS_COMPLIANT_FRAME) {
 146                         fc |= IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS;
 147                         /* From&To DS: Addr1 = RA, Addr2 = TA, Addr3 = DA,
 148                          * Addr4 = SA */
 149                         memcpy(&hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
 150                         hdr_len += ETH_ALEN;
 151                 } else {
 152                         /* bogus 4-addr format to workaround Prism2 station
 153                          * f/w bug */
 154                         fc |= IEEE80211_FCTL_TODS;
 155                         /* From DS: Addr1 = DA (used as RA),
 156                          * Addr2 = BSSID (used as TA), Addr3 = SA (used as DA),
 157                          */
 158
 159                         /* SA from skb->data + ETH_ALEN will be added after
 160                          * frame payload; use hdr.addr4 as a temporary buffer
 161                          */
 162                         memcpy(&hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
 163                         need_tailroom += ETH_ALEN;
 164                 }
 165
 166                 /* send broadcast and multicast frames to broadcast RA, if
 167                  * configured; otherwise, use unicast RA of the WDS link */
 168                 if ((local->wds_type & HOSTAP_WDS_BROADCAST_RA) &&
 169                     skb->data[0] & 0x01)
 170                         memset(&hdr.addr1, 0xff, ETH_ALEN);
 171                 else if (iface->type == HOSTAP_INTERFACE_WDS)
 172                         memcpy(&hdr.addr1, iface->u.wds.remote_addr,
 173                                ETH_ALEN);
 174                 else
 175                         memcpy(&hdr.addr1, local->bssid, ETH_ALEN);
 176                 memcpy(&hdr.addr2, dev->dev_addr, ETH_ALEN);
 177                 memcpy(&hdr.addr3, skb->data, ETH_ALEN);
 178         } else if (local->iw_mode == IW_MODE_MASTER && !to_assoc_ap) {
 179                 fc |= IEEE80211_FCTL_FROMDS;
 180                 /* From DS: Addr1 = DA, Addr2 = BSSID, Addr3 = SA */
 181                 memcpy(&hdr.addr1, skb->data, ETH_ALEN);
 182                 memcpy(&hdr.addr2, dev->dev_addr, ETH_ALEN);
 183                 memcpy(&hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
 184         } else if (local->iw_mode == IW_MODE_INFRA || to_assoc_ap) {
 185                 fc |= IEEE80211_FCTL_TODS;
 186                 /* To DS: Addr1 = BSSID, Addr2 = SA, Addr3 = DA */
 187                 memcpy(&hdr.addr1, to_assoc_ap ?
 188                        local->assoc_ap_addr : local->bssid, ETH_ALEN);
 189                 memcpy(&hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
 190                 memcpy(&hdr.addr3, skb->data, ETH_ALEN);
 191         } else if (local->iw_mode == IW_MODE_ADHOC) {
 192                 /* not From/To DS: Addr1 = DA, Addr2 = SA, Addr3 = BSSID */
 193                 memcpy(&hdr.addr1, skb->data, ETH_ALEN);
 194                 memcpy(&hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
 195                 memcpy(&hdr.addr3, local->bssid, ETH_ALEN);
 196         }
 197
 198         hdr.frame_ctl = cpu_to_le16(fc);
 199
 200         skb_pull(skb, skip_header_bytes);
 201         need_headroom = local->func->need_tx_headroom + hdr_len + encaps_len;
 202         if (skb_tailroom(skb) < need_tailroom) {
 203                 skb = skb_unshare(skb, GFP_ATOMIC);
 204                 if (skb == NULL) {
 205                         iface->stats.tx_dropped++;
 206                         return 0;
 207                 }
 208                 if (pskb_expand_head(skb, need_headroom, need_tailroom,
 209                                      GFP_ATOMIC)) {
 210                         kfree_skb(skb);
 211                         iface->stats.tx_dropped++;
 212                         return 0;
 213                 }
 214         } else if (skb_headroom(skb) < need_headroom) {
 215                 struct sk_buff *tmp = skb;
 216                 skb = skb_realloc_headroom(skb, need_headroom);
 217                 kfree_skb(tmp);
 218                 if (skb == NULL) {
 219                         iface->stats.tx_dropped++;
 220                         return 0;
 221                 }
 222         } else {
 223                 skb = skb_unshare(skb, GFP_ATOMIC);
 224                 if (skb == NULL) {
 225                         iface->stats.tx_dropped++;
 226                         return 0;
 227                 }
 228         }
 229
 230         if (encaps_data)
 231                 memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
 232         memcpy(skb_push(skb, hdr_len), &hdr, hdr_len);
 233         if (use_wds == WDS_OWN_FRAME) {
 234                 memcpy(skb_put(skb, ETH_ALEN), &hdr.addr4, ETH_ALEN);
 235         }
 236
 237         iface->stats.tx_packets++;
 238         iface->stats.tx_bytes += skb->len;
 239
 240         skb->mac.raw = skb->data;
 241         meta = (struct hostap_skb_tx_data *) skb->cb;
 242         memset(meta, 0, sizeof(*meta));
 243         meta->magic = HOSTAP_SKB_TX_DATA_MAGIC;
 244         if (use_wds)
 245                 meta->flags |= HOSTAP_TX_FLAGS_WDS;
 246         meta->ethertype = ethertype;
 247         meta->iface = iface;
 248
 249         /* Send IEEE 802.11 encapsulated frame using the master radio device */
 250         skb->dev = local->dev;
 251         dev_queue_xmit(skb);
 252         return 0;
 253 }
 254
 255
 256 /* hard_start_xmit function for hostapd wlan#ap interfaces */
 257 int hostap_mgmt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 258 {
 259         struct hostap_interface *iface;
 260         local_info_t *local;
 261         struct hostap_skb_tx_data *meta;
 262         struct ieee80211_hdr_4addr *hdr;
 263         u16 fc;
 264
 265         iface = netdev_priv(dev);
 266         local = iface->local;
 267
 268         if (skb->len < 10) {
 269                 printk(KERN_DEBUG "%s: hostap_mgmt_start_xmit: short skb "
 270                        "(len=%d)\n", dev->name, skb->len);
 271                 kfree_skb(skb);
 272                 return 0;
 273         }
 274
 275         iface->stats.tx_packets++;
 276         iface->stats.tx_bytes += skb->len;
 277
 278         meta = (struct hostap_skb_tx_data *) skb->cb;
 279         memset(meta, 0, sizeof(*meta));
 280         meta->magic = HOSTAP_SKB_TX_DATA_MAGIC;
 281         meta->iface = iface;
 282
 283         if (skb->len >= IEEE80211_DATA_HDR3_LEN + sizeof(rfc1042_header) + 2) {
 284                 hdr = (struct ieee80211_hdr_4addr *) skb->data;
 285                 fc = le16_to_cpu(hdr->frame_ctl);
 286                 if (WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA &&
 287                     WLAN_FC_GET_STYPE(fc) == IEEE80211_STYPE_DATA) {
 288                         u8 *pos = &skb->data[IEEE80211_DATA_HDR3_LEN +
 289                                              sizeof(rfc1042_header)];
 290                         meta->ethertype = (pos[0] << 8) | pos[1];
 291                 }
 292         }
 293
 294         /* Send IEEE 802.11 encapsulated frame using the master radio device */
 295         skb->dev = local->dev;
 296         dev_queue_xmit(skb);
 297         return 0;
 298 }
 299
 300
 301 /* Called only from software IRQ */
 302 static struct sk_buff * hostap_tx_encrypt(struct sk_buff *skb,
 303                                           struct ieee80211_crypt_data *crypt)
 304 {
 305         struct hostap_interface *iface;
 306         local_info_t *local;
 307         struct ieee80211_hdr_4addr *hdr;
 308         u16 fc;
 309         int hdr_len, res;
 310
 311         iface = netdev_priv(skb->dev);
 312         local = iface->local;
 313
 314         if (skb->len < IEEE80211_DATA_HDR3_LEN) {
 315                 kfree_skb(skb);
 316                 return NULL;
 317         }
 318
 319         if (local->tkip_countermeasures &&
 320             strcmp(crypt->ops->name, "TKIP") == 0) {
 321                 hdr = (struct ieee80211_hdr_4addr *) skb->data;
 322                 if (net_ratelimit()) {
 323                         printk(KERN_DEBUG "%s: TKIP countermeasures: dropped "
 324                                "TX packet to " MACSTR "\n",
 325                                local->dev->name, MAC2STR(hdr->addr1));
 326                 }
 327                 kfree_skb(skb);
 328                 return NULL;
 329         }
 330
 331         skb = skb_unshare(skb, GFP_ATOMIC);
 332         if (skb == NULL)
 333                 return NULL;
 334
 335         if ((skb_headroom(skb) < crypt->ops->extra_mpdu_prefix_len ||
 336              skb_tailroom(skb) < crypt->ops->extra_mpdu_postfix_len) &&
 337             pskb_expand_head(skb, crypt->ops->extra_mpdu_prefix_len,
 338                              crypt->ops->extra_mpdu_postfix_len, GFP_ATOMIC)) {
 339                 kfree_skb(skb);
 340                 return NULL;
 341         }
 342
 343         hdr = (struct ieee80211_hdr_4addr *) skb->data;
 344         fc = le16_to_cpu(hdr->frame_ctl);
 345         hdr_len = hostap_80211_get_hdrlen(fc);
 346
 347         /* Host-based IEEE 802.11 fragmentation for TX is not yet supported, so
 348          * call both MSDU and MPDU encryption functions from here. */
 349         atomic_inc(&crypt->refcnt);
 350         res = 0;
 351         if (crypt->ops->encrypt_msdu)
 352                 res = crypt->ops->encrypt_msdu(skb, hdr_len, crypt->priv);
 353         if (res == 0 && crypt->ops->encrypt_mpdu)
 354                 res = crypt->ops->encrypt_mpdu(skb, hdr_len, crypt->priv);
 355         atomic_dec(&crypt->refcnt);
 356         if (res < 0) {
 357                 kfree_skb(skb);
 358                 return NULL;
 359         }
 360
 361         return skb;
 362 }
 363
 364
 365 /* hard_start_xmit function for master radio interface wifi#.
 366  * AP processing (TX rate control, power save buffering, etc.).
 367  * Use hardware TX function to send the frame. */
 368 int hostap_master_start_xmit(struct sk_buff *skb, struct net_device *dev)
 369 {
 370         struct hostap_interface *iface;
 371         local_info_t *local;
 372         int ret = 1;
 373         u16 fc;
 374         struct hostap_tx_data tx;
 375         ap_tx_ret tx_ret;
 376         struct hostap_skb_tx_data *meta;
 377         int no_encrypt = 0;
 378         struct ieee80211_hdr_4addr *hdr;
 379
 380         iface = netdev_priv(dev);
 381         local = iface->local;
 382
 383         tx.skb = skb;
 384         tx.sta_ptr = NULL;
 385
 386         meta = (struct hostap_skb_tx_data *) skb->cb;
 387         if (meta->magic != HOSTAP_SKB_TX_DATA_MAGIC) {
 388                 printk(KERN_DEBUG "%s: invalid skb->cb magic (0x%08x, "
 389                        "expected 0x%08x)\n",
 390                        dev->name, meta->magic, HOSTAP_SKB_TX_DATA_MAGIC);
 391                 ret = 0;
 392                 iface->stats.tx_dropped++;
 393                 goto fail;
 394         }
 395
 396         if (local->host_encrypt) {
 397                 /* Set crypt to default algorithm and key; will be replaced in
 398                  * AP code if STA has own alg/key */
 399                 tx.crypt = local->crypt[local->tx_keyidx];
 400                 tx.host_encrypt = 1;
 401         } else {
 402                 tx.crypt = NULL;
 403                 tx.host_encrypt = 0;
 404         }
 405
 406         if (skb->len < 24) {
 407                 printk(KERN_DEBUG "%s: hostap_master_start_xmit: short skb "
 408                        "(len=%d)\n", dev->name, skb->len);
 409                 ret = 0;
 410                 iface->stats.tx_dropped++;
 411                 goto fail;
 412         }
 413
 414         /* FIX (?):
 415          * Wi-Fi 802.11b test plan suggests that AP should ignore power save
 416          * bit in authentication and (re)association frames and assume tha
 417          * STA remains awake for the response. */
 418         tx_ret = hostap_handle_sta_tx(local, &tx);
 419         skb = tx.skb;
 420         meta = (struct hostap_skb_tx_data *) skb->cb;
 421         hdr = (struct ieee80211_hdr_4addr *) skb->data;
 422         fc = le16_to_cpu(hdr->frame_ctl);
 423         switch (tx_ret) {
 424         case AP_TX_CONTINUE:
 425                 break;
 426         case AP_TX_CONTINUE_NOT_AUTHORIZED:
 427                 if (local->ieee_802_1x &&
 428                     WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA &&
 429                     meta->ethertype != ETH_P_PAE &&
 430                     !(meta->flags & HOSTAP_TX_FLAGS_WDS)) {
 431                         printk(KERN_DEBUG "%s: dropped frame to unauthorized "
 432                                "port (IEEE 802.1X): ethertype=0x%04x\n",
 433                                dev->name, meta->ethertype);
 434                         hostap_dump_tx_80211(dev->name, skb);
 435
 436                         ret = 0; /* drop packet */
 437                         iface->stats.tx_dropped++;
 438                         goto fail;
 439                 }
 440                 break;
 441         case AP_TX_DROP:
 442                 ret = 0; /* drop packet */
 443                 iface->stats.tx_dropped++;
 444                 goto fail;
 445         case AP_TX_RETRY:
 446                 goto fail;
 447         case AP_TX_BUFFERED:
 448                 /* do not free skb here, it will be freed when the
 449                  * buffered frame is sent/timed out */
 450                 ret = 0;
 451                 goto tx_exit;
 452         }
 453
 454         /* Request TX callback if protocol version is 2 in 802.11 header;
 455          * this version 2 is a special case used between hostapd and kernel
 456          * driver */
 457         if (((fc & IEEE80211_FCTL_VERS) == BIT(1)) &&
 458             local->ap && local->ap->tx_callback_idx && meta->tx_cb_idx == 0) {
 459                 meta->tx_cb_idx = local->ap->tx_callback_idx;
 460
 461                 /* remove special version from the frame header */
 462                 fc &= ~IEEE80211_FCTL_VERS;
 463                 hdr->frame_ctl = cpu_to_le16(fc);
 464         }
 465
 466         if (WLAN_FC_GET_TYPE(fc) != IEEE80211_FTYPE_DATA) {
 467                 no_encrypt = 1;
 468                 tx.crypt = NULL;
 469         }
 470
 471         if (local->ieee_802_1x && meta->ethertype == ETH_P_PAE && tx.crypt &&
 472             !(fc & IEEE80211_FCTL_PROTECTED)) {
 473                 no_encrypt = 1;
 474                 PDEBUG(DEBUG_EXTRA2, "%s: TX: IEEE 802.1X - passing "
 475                        "unencrypted EAPOL frame\n", dev->name);
 476                 tx.crypt = NULL; /* no encryption for IEEE 802.1X frames */
 477         }
 478
 479         if (tx.crypt && (!tx.crypt->ops || !tx.crypt->ops->encrypt_mpdu))
 480                 tx.crypt = NULL;
 481         else if ((tx.crypt || local->crypt[local->tx_keyidx]) && !no_encrypt) {
 482                 /* Add ISWEP flag both for firmware and host based encryption
 483                  */
 484                 fc |= IEEE80211_FCTL_PROTECTED;
 485                 hdr->frame_ctl = cpu_to_le16(fc);
 486         } else if (local->drop_unencrypted &&
 487                    WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA &&
 488                    meta->ethertype != ETH_P_PAE) {
 489                 if (net_ratelimit()) {
 490                         printk(KERN_DEBUG "%s: dropped unencrypted TX data "
 491                                "frame (drop_unencrypted=1)\n", dev->name);
 492                 }
 493                 iface->stats.tx_dropped++;
 494                 ret = 0;
 495                 goto fail;
 496         }
 497
 498         if (tx.crypt) {
 499                 skb = hostap_tx_encrypt(skb, tx.crypt);
 500                 if (skb == NULL) {
 501                         printk(KERN_DEBUG "%s: TX - encryption failed\n",
 502                                dev->name);
 503                         ret = 0;
 504                         goto fail;
 505                 }
 506                 meta = (struct hostap_skb_tx_data *) skb->cb;
 507                 if (meta->magic != HOSTAP_SKB_TX_DATA_MAGIC) {
 508                         printk(KERN_DEBUG "%s: invalid skb->cb magic (0x%08x, "
 509                                "expected 0x%08x) after hostap_tx_encrypt\n",
 510                                dev->name, meta->magic,
 511                                HOSTAP_SKB_TX_DATA_MAGIC);
 512                         ret = 0;
 513                         iface->stats.tx_dropped++;
 514                         goto fail;
 515                 }
 516         }
 517
 518         if (local->func->tx == NULL || local->func->tx(skb, dev)) {
 519                 ret = 0;
 520                 iface->stats.tx_dropped++;
 521         } else {
 522                 ret = 0;
 523                 iface->stats.tx_packets++;
 524                 iface->stats.tx_bytes += skb->len;
 525         }
 526
 527  fail:
 528         if (!ret && skb)
 529                 dev_kfree_skb(skb);
 530  tx_exit:
 531         if (tx.sta_ptr)
 532                 hostap_handle_sta_release(tx.sta_ptr);
 533         return ret;
 534 }
 535
 536
 537 EXPORT_SYMBOL(hostap_master_start_xmit);