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         DECLARE_MAC_BUF(mac);
  21
  22         hdr = (struct ieee80211_hdr_4addr *) skb->data;
  23
  24         printk(KERN_DEBUG "%s: TX len=%d jiffies=%ld\n",
  25                name, skb->len, jiffies);
  26
  27         if (skb->len < 2)
  28                 return;
  29
  30         fc = le16_to_cpu(hdr->frame_ctl);
  31         printk(KERN_DEBUG "   FC=0x%04x (type=%d:%d)%s%s",
  32                fc, WLAN_FC_GET_TYPE(fc) >> 2, WLAN_FC_GET_STYPE(fc) >> 4,
  33                fc & IEEE80211_FCTL_TODS ? " [ToDS]" : "",
  34                fc & IEEE80211_FCTL_FROMDS ? " [FromDS]" : "");
  35
  36         if (skb->len < IEEE80211_DATA_HDR3_LEN) {
  37                 printk("\n");
  38                 return;
  39         }
  40
  41         printk(" dur=0x%04x seq=0x%04x\n", le16_to_cpu(hdr->duration_id),
  42                le16_to_cpu(hdr->seq_ctl));
  43
  44         printk(KERN_DEBUG "   A1=%s", print_mac(mac, hdr->addr1));
  45         printk(" A2=%s", print_mac(mac, hdr->addr2));
  46         printk(" A3=%s", print_mac(mac, hdr->addr3));
  47         if (skb->len >= 30)
  48                 printk(" A4=%s", print_mac(mac, hdr->addr4));
  49         printk("\n");
  50 }
  51
  52
  53 /* hard_start_xmit function for data interfaces (wlan#, wlan#wds#, wlan#sta)
  54  * Convert Ethernet header into a suitable IEEE 802.11 header depending on
  55  * device configuration. */
  56 int hostap_data_start_xmit(struct sk_buff *skb, struct net_device *dev)
  57 {
  58         struct hostap_interface *iface;
  59         local_info_t *local;
  60         int need_headroom, need_tailroom = 0;
  61         struct ieee80211_hdr_4addr hdr;
  62         u16 fc, ethertype = 0;
  63         enum {
  64                 WDS_NO = 0, WDS_OWN_FRAME, WDS_COMPLIANT_FRAME
  65         } use_wds = WDS_NO;
  66         u8 *encaps_data;
  67         int hdr_len, encaps_len, skip_header_bytes;
  68         int to_assoc_ap = 0;
  69         struct hostap_skb_tx_data *meta;
  70
  71         iface = netdev_priv(dev);
  72         local = iface->local;
  73
  74         if (skb->len < ETH_HLEN) {
  75                 printk(KERN_DEBUG "%s: hostap_data_start_xmit: short skb "
  76                        "(len=%d)\n", dev->name, skb->len);
  77                 kfree_skb(skb);
  78                 return 0;
  79         }
  80
  81         if (local->ddev != dev) {
  82                 use_wds = (local->iw_mode == IW_MODE_MASTER &&
  83                            !(local->wds_type & HOSTAP_WDS_STANDARD_FRAME)) ?
  84                         WDS_OWN_FRAME : WDS_COMPLIANT_FRAME;
  85                 if (dev == local->stadev) {
  86                         to_assoc_ap = 1;
  87                         use_wds = WDS_NO;
  88                 } else if (dev == local->apdev) {
  89                         printk(KERN_DEBUG "%s: prism2_tx: trying to use "
  90                                "AP device with Ethernet net dev\n", dev->name);
  91                         kfree_skb(skb);
  92                         return 0;
  93                 }
  94         } else {
  95                 if (local->iw_mode == IW_MODE_REPEAT) {
  96                         printk(KERN_DEBUG "%s: prism2_tx: trying to use "
  97                                "non-WDS link in Repeater mode\n", dev->name);
  98                         kfree_skb(skb);
  99                         return 0;
 100                 } else if (local->iw_mode == IW_MODE_INFRA &&
 101                            (local->wds_type & HOSTAP_WDS_AP_CLIENT) &&
 102                            memcmp(skb->data + ETH_ALEN, dev->dev_addr,
 103                                   ETH_ALEN) != 0) {
 104                         /* AP client mode: send frames with foreign src addr
 105                          * using 4-addr WDS frames */
 106                         use_wds = WDS_COMPLIANT_FRAME;
 107                 }
 108         }
 109
 110         /* Incoming skb->data: dst_addr[6], src_addr[6], proto[2], payload
 111          * ==>
 112          * Prism2 TX frame with 802.11 header:
 113          * txdesc (address order depending on used mode; includes dst_addr and
 114          * src_addr), possible encapsulation (RFC1042/Bridge-Tunnel;
 115          * proto[2], payload {, possible addr4[6]} */
 116
 117         ethertype = (skb->data[12] << 8) | skb->data[13];
 118
 119         memset(&hdr, 0, sizeof(hdr));
 120
 121         /* Length of data after IEEE 802.11 header */
 122         encaps_data = NULL;
 123         encaps_len = 0;
 124         skip_header_bytes = ETH_HLEN;
 125         if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
 126                 encaps_data = bridge_tunnel_header;
 127                 encaps_len = sizeof(bridge_tunnel_header);
 128                 skip_header_bytes -= 2;
 129         } else if (ethertype >= 0x600) {
 130                 encaps_data = rfc1042_header;
 131                 encaps_len = sizeof(rfc1042_header);
 132                 skip_header_bytes -= 2;
 133         }
 134
 135         fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA;
 136         hdr_len = IEEE80211_DATA_HDR3_LEN;
 137
 138         if (use_wds != WDS_NO) {
 139                 /* Note! Prism2 station firmware has problems with sending real
 140                  * 802.11 frames with four addresses; until these problems can
 141                  * be fixed or worked around, 4-addr frames needed for WDS are
 142                  * using incompatible format: FromDS flag is not set and the
 143                  * fourth address is added after the frame payload; it is
 144                  * assumed, that the receiving station knows how to handle this
 145                  * frame format */
 146
 147                 if (use_wds == WDS_COMPLIANT_FRAME) {
 148                         fc |= IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS;
 149                         /* From&To DS: Addr1 = RA, Addr2 = TA, Addr3 = DA,
 150                          * Addr4 = SA */
 151                         skb_copy_from_linear_data_offset(skb, ETH_ALEN,
 152                                                          &hdr.addr4, ETH_ALEN);
 153                         hdr_len += ETH_ALEN;
 154                 } else {
 155                         /* bogus 4-addr format to workaround Prism2 station
 156                          * f/w bug */
 157                         fc |= IEEE80211_FCTL_TODS;
 158                         /* From DS: Addr1 = DA (used as RA),
 159                          * Addr2 = BSSID (used as TA), Addr3 = SA (used as DA),
 160                          */
 161
 162                         /* SA from skb->data + ETH_ALEN will be added after
 163                          * frame payload; use hdr.addr4 as a temporary buffer
 164                          */
 165                         skb_copy_from_linear_data_offset(skb, ETH_ALEN,
 166                                                          &hdr.addr4, ETH_ALEN);
 167                         need_tailroom += ETH_ALEN;
 168                 }
 169
 170                 /* send broadcast and multicast frames to broadcast RA, if
 171                  * configured; otherwise, use unicast RA of the WDS link */
 172                 if ((local->wds_type & HOSTAP_WDS_BROADCAST_RA) &&
 173                     skb->data[0] & 0x01)
 174                         memset(&hdr.addr1, 0xff, ETH_ALEN);
 175                 else if (iface->type == HOSTAP_INTERFACE_WDS)
 176                         memcpy(&hdr.addr1, iface->u.wds.remote_addr,
 177                                ETH_ALEN);
 178                 else
 179                         memcpy(&hdr.addr1, local->bssid, ETH_ALEN);
 180                 memcpy(&hdr.addr2, dev->dev_addr, ETH_ALEN);
 181                 skb_copy_from_linear_data(skb, &hdr.addr3, ETH_ALEN);
 182         } else if (local->iw_mode == IW_MODE_MASTER && !to_assoc_ap) {
 183                 fc |= IEEE80211_FCTL_FROMDS;
 184                 /* From DS: Addr1 = DA, Addr2 = BSSID, Addr3 = SA */
 185                 skb_copy_from_linear_data(skb, &hdr.addr1, ETH_ALEN);
 186                 memcpy(&hdr.addr2, dev->dev_addr, ETH_ALEN);
 187                 skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr3,
 188                                                  ETH_ALEN);
 189         } else if (local->iw_mode == IW_MODE_INFRA || to_assoc_ap) {
 190                 fc |= IEEE80211_FCTL_TODS;
 191                 /* To DS: Addr1 = BSSID, Addr2 = SA, Addr3 = DA */
 192                 memcpy(&hdr.addr1, to_assoc_ap ?
 193                        local->assoc_ap_addr : local->bssid, ETH_ALEN);
 194                 skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr2,
 195                                                  ETH_ALEN);
 196                 skb_copy_from_linear_data(skb, &hdr.addr3, ETH_ALEN);
 197         } else if (local->iw_mode == IW_MODE_ADHOC) {
 198                 /* not From/To DS: Addr1 = DA, Addr2 = SA, Addr3 = BSSID */
 199                 skb_copy_from_linear_data(skb, &hdr.addr1, ETH_ALEN);
 200                 skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr2,
 201                                                  ETH_ALEN);
 202                 memcpy(&hdr.addr3, local->bssid, ETH_ALEN);
 203         }
 204
 205         hdr.frame_ctl = cpu_to_le16(fc);
 206
 207         skb_pull(skb, skip_header_bytes);
 208         need_headroom = local->func->need_tx_headroom + hdr_len + encaps_len;
 209         if (skb_tailroom(skb) < need_tailroom) {
 210                 skb = skb_unshare(skb, GFP_ATOMIC);
 211                 if (skb == NULL) {
 212                         iface->stats.tx_dropped++;
 213                         return 0;
 214                 }
 215                 if (pskb_expand_head(skb, need_headroom, need_tailroom,
 216                                      GFP_ATOMIC)) {
 217                         kfree_skb(skb);
 218                         iface->stats.tx_dropped++;
 219                         return 0;
 220                 }
 221         } else if (skb_headroom(skb) < need_headroom) {
 222                 struct sk_buff *tmp = skb;
 223                 skb = skb_realloc_headroom(skb, need_headroom);
 224                 kfree_skb(tmp);
 225                 if (skb == NULL) {
 226                         iface->stats.tx_dropped++;
 227                         return 0;
 228                 }
 229         } else {
 230                 skb = skb_unshare(skb, GFP_ATOMIC);
 231                 if (skb == NULL) {
 232                         iface->stats.tx_dropped++;
 233                         return 0;
 234                 }
 235         }
 236
 237         if (encaps_data)
 238                 memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
 239         memcpy(skb_push(skb, hdr_len), &hdr, hdr_len);
 240         if (use_wds == WDS_OWN_FRAME) {
 241                 memcpy(skb_put(skb, ETH_ALEN), &hdr.addr4, ETH_ALEN);
 242         }
 243
 244         iface->stats.tx_packets++;
 245         iface->stats.tx_bytes += skb->len;
 246
 247         skb_reset_mac_header(skb);
 248         meta = (struct hostap_skb_tx_data *) skb->cb;
 249         memset(meta, 0, sizeof(*meta));
 250         meta->magic = HOSTAP_SKB_TX_DATA_MAGIC;
 251         if (use_wds)
 252                 meta->flags |= HOSTAP_TX_FLAGS_WDS;
 253         meta->ethertype = ethertype;
 254         meta->iface = iface;
 255
 256         /* Send IEEE 802.11 encapsulated frame using the master radio device */
 257         skb->dev = local->dev;
 258         dev_queue_xmit(skb);
 259         return 0;
 260 }
 261
 262
 263 /* hard_start_xmit function for hostapd wlan#ap interfaces */
 264 int hostap_mgmt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 265 {
 266         struct hostap_interface *iface;
 267         local_info_t *local;
 268         struct hostap_skb_tx_data *meta;
 269         struct ieee80211_hdr_4addr *hdr;
 270         u16 fc;
 271
 272         iface = netdev_priv(dev);
 273         local = iface->local;
 274
 275         if (skb->len < 10) {
 276                 printk(KERN_DEBUG "%s: hostap_mgmt_start_xmit: short skb "
 277                        "(len=%d)\n", dev->name, skb->len);
 278                 kfree_skb(skb);
 279                 return 0;
 280         }
 281
 282         iface->stats.tx_packets++;
 283         iface->stats.tx_bytes += skb->len;
 284
 285         meta = (struct hostap_skb_tx_data *) skb->cb;
 286         memset(meta, 0, sizeof(*meta));
 287         meta->magic = HOSTAP_SKB_TX_DATA_MAGIC;
 288         meta->iface = iface;
 289
 290         if (skb->len >= IEEE80211_DATA_HDR3_LEN + sizeof(rfc1042_header) + 2) {
 291                 hdr = (struct ieee80211_hdr_4addr *) skb->data;
 292                 fc = le16_to_cpu(hdr->frame_ctl);
 293                 if (WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA &&
 294                     WLAN_FC_GET_STYPE(fc) == IEEE80211_STYPE_DATA) {
 295                         u8 *pos = &skb->data[IEEE80211_DATA_HDR3_LEN +
 296                                              sizeof(rfc1042_header)];
 297                         meta->ethertype = (pos[0] << 8) | pos[1];
 298                 }
 299         }
 300
 301         /* Send IEEE 802.11 encapsulated frame using the master radio device */
 302         skb->dev = local->dev;
 303         dev_queue_xmit(skb);
 304         return 0;
 305 }
 306
 307
 308 /* Called only from software IRQ */
 309 static struct sk_buff * hostap_tx_encrypt(struct sk_buff *skb,
 310                                           struct ieee80211_crypt_data *crypt)
 311 {
 312         struct hostap_interface *iface;
 313         local_info_t *local;
 314         struct ieee80211_hdr_4addr *hdr;
 315         u16 fc;
 316         int prefix_len, postfix_len, hdr_len, res;
 317         DECLARE_MAC_BUF(mac);
 318
 319         iface = netdev_priv(skb->dev);
 320         local = iface->local;
 321
 322         if (skb->len < IEEE80211_DATA_HDR3_LEN) {
 323                 kfree_skb(skb);
 324                 return NULL;
 325         }
 326
 327         if (local->tkip_countermeasures &&
 328             strcmp(crypt->ops->name, "TKIP") == 0) {
 329                 hdr = (struct ieee80211_hdr_4addr *) skb->data;
 330                 if (net_ratelimit()) {
 331                         printk(KERN_DEBUG "%s: TKIP countermeasures: dropped "
 332                                "TX packet to %s\n",
 333                                local->dev->name, print_mac(mac, hdr->addr1));
 334                 }
 335                 kfree_skb(skb);
 336                 return NULL;
 337         }
 338
 339         skb = skb_unshare(skb, GFP_ATOMIC);
 340         if (skb == NULL)
 341                 return NULL;
 342
 343         prefix_len = crypt->ops->extra_mpdu_prefix_len +
 344                 crypt->ops->extra_msdu_prefix_len;
 345         postfix_len = crypt->ops->extra_mpdu_postfix_len +
 346                 crypt->ops->extra_msdu_postfix_len;
 347         if ((skb_headroom(skb) < prefix_len ||
 348              skb_tailroom(skb) < postfix_len) &&
 349             pskb_expand_head(skb, prefix_len, postfix_len, GFP_ATOMIC)) {
 350                 kfree_skb(skb);
 351                 return NULL;
 352         }
 353
 354         hdr = (struct ieee80211_hdr_4addr *) skb->data;
 355         fc = le16_to_cpu(hdr->frame_ctl);
 356         hdr_len = hostap_80211_get_hdrlen(fc);
 357
 358         /* Host-based IEEE 802.11 fragmentation for TX is not yet supported, so
 359          * call both MSDU and MPDU encryption functions from here. */
 360         atomic_inc(&crypt->refcnt);
 361         res = 0;
 362         if (crypt->ops->encrypt_msdu)
 363                 res = crypt->ops->encrypt_msdu(skb, hdr_len, crypt->priv);
 364         if (res == 0 && crypt->ops->encrypt_mpdu)
 365                 res = crypt->ops->encrypt_mpdu(skb, hdr_len, crypt->priv);
 366         atomic_dec(&crypt->refcnt);
 367         if (res < 0) {
 368                 kfree_skb(skb);
 369                 return NULL;
 370         }
 371
 372         return skb;
 373 }
 374
 375
 376 /* hard_start_xmit function for master radio interface wifi#.
 377  * AP processing (TX rate control, power save buffering, etc.).
 378  * Use hardware TX function to send the frame. */
 379 int hostap_master_start_xmit(struct sk_buff *skb, struct net_device *dev)
 380 {
 381         struct hostap_interface *iface;
 382         local_info_t *local;
 383         int ret = 1;
 384         u16 fc;
 385         struct hostap_tx_data tx;
 386         ap_tx_ret tx_ret;
 387         struct hostap_skb_tx_data *meta;
 388         int no_encrypt = 0;
 389         struct ieee80211_hdr_4addr *hdr;
 390
 391         iface = netdev_priv(dev);
 392         local = iface->local;
 393
 394         tx.skb = skb;
 395         tx.sta_ptr = NULL;
 396
 397         meta = (struct hostap_skb_tx_data *) skb->cb;
 398         if (meta->magic != HOSTAP_SKB_TX_DATA_MAGIC) {
 399                 printk(KERN_DEBUG "%s: invalid skb->cb magic (0x%08x, "
 400                        "expected 0x%08x)\n",
 401                        dev->name, meta->magic, HOSTAP_SKB_TX_DATA_MAGIC);
 402                 ret = 0;
 403                 iface->stats.tx_dropped++;
 404                 goto fail;
 405         }
 406
 407         if (local->host_encrypt) {
 408                 /* Set crypt to default algorithm and key; will be replaced in
 409                  * AP code if STA has own alg/key */
 410                 tx.crypt = local->crypt[local->tx_keyidx];
 411                 tx.host_encrypt = 1;
 412         } else {
 413                 tx.crypt = NULL;
 414                 tx.host_encrypt = 0;
 415         }
 416
 417         if (skb->len < 24) {
 418                 printk(KERN_DEBUG "%s: hostap_master_start_xmit: short skb "
 419                        "(len=%d)\n", dev->name, skb->len);
 420                 ret = 0;
 421                 iface->stats.tx_dropped++;
 422                 goto fail;
 423         }
 424
 425         /* FIX (?):
 426          * Wi-Fi 802.11b test plan suggests that AP should ignore power save
 427          * bit in authentication and (re)association frames and assume tha
 428          * STA remains awake for the response. */
 429         tx_ret = hostap_handle_sta_tx(local, &tx);
 430         skb = tx.skb;
 431         meta = (struct hostap_skb_tx_data *) skb->cb;
 432         hdr = (struct ieee80211_hdr_4addr *) skb->data;
 433         fc = le16_to_cpu(hdr->frame_ctl);
 434         switch (tx_ret) {
 435         case AP_TX_CONTINUE:
 436                 break;
 437         case AP_TX_CONTINUE_NOT_AUTHORIZED:
 438                 if (local->ieee_802_1x &&
 439                     WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA &&
 440                     meta->ethertype != ETH_P_PAE &&
 441                     !(meta->flags & HOSTAP_TX_FLAGS_WDS)) {
 442                         printk(KERN_DEBUG "%s: dropped frame to unauthorized "
 443                                "port (IEEE 802.1X): ethertype=0x%04x\n",
 444                                dev->name, meta->ethertype);
 445                         hostap_dump_tx_80211(dev->name, skb);
 446
 447                         ret = 0; /* drop packet */
 448                         iface->stats.tx_dropped++;
 449                         goto fail;
 450                 }
 451                 break;
 452         case AP_TX_DROP:
 453                 ret = 0; /* drop packet */
 454                 iface->stats.tx_dropped++;
 455                 goto fail;
 456         case AP_TX_RETRY:
 457                 goto fail;
 458         case AP_TX_BUFFERED:
 459                 /* do not free skb here, it will be freed when the
 460                  * buffered frame is sent/timed out */
 461                 ret = 0;
 462                 goto tx_exit;
 463         }
 464
 465         /* Request TX callback if protocol version is 2 in 802.11 header;
 466          * this version 2 is a special case used between hostapd and kernel
 467          * driver */
 468         if (((fc & IEEE80211_FCTL_VERS) == BIT(1)) &&
 469             local->ap && local->ap->tx_callback_idx && meta->tx_cb_idx == 0) {
 470                 meta->tx_cb_idx = local->ap->tx_callback_idx;
 471
 472                 /* remove special version from the frame header */
 473                 fc &= ~IEEE80211_FCTL_VERS;
 474                 hdr->frame_ctl = cpu_to_le16(fc);
 475         }
 476
 477         if (WLAN_FC_GET_TYPE(fc) != IEEE80211_FTYPE_DATA) {
 478                 no_encrypt = 1;
 479                 tx.crypt = NULL;
 480         }
 481
 482         if (local->ieee_802_1x && meta->ethertype == ETH_P_PAE && tx.crypt &&
 483             !(fc & IEEE80211_FCTL_PROTECTED)) {
 484                 no_encrypt = 1;
 485                 PDEBUG(DEBUG_EXTRA2, "%s: TX: IEEE 802.1X - passing "
 486                        "unencrypted EAPOL frame\n", dev->name);
 487                 tx.crypt = NULL; /* no encryption for IEEE 802.1X frames */
 488         }
 489
 490         if (tx.crypt && (!tx.crypt->ops || !tx.crypt->ops->encrypt_mpdu))
 491                 tx.crypt = NULL;
 492         else if ((tx.crypt || local->crypt[local->tx_keyidx]) && !no_encrypt) {
 493                 /* Add ISWEP flag both for firmware and host based encryption
 494                  */
 495                 fc |= IEEE80211_FCTL_PROTECTED;
 496                 hdr->frame_ctl = cpu_to_le16(fc);
 497         } else if (local->drop_unencrypted &&
 498                    WLAN_FC_GET_TYPE(fc) == IEEE80211_FTYPE_DATA &&
 499                    meta->ethertype != ETH_P_PAE) {
 500                 if (net_ratelimit()) {
 501                         printk(KERN_DEBUG "%s: dropped unencrypted TX data "
 502                                "frame (drop_unencrypted=1)\n", dev->name);
 503                 }
 504                 iface->stats.tx_dropped++;
 505                 ret = 0;
 506                 goto fail;
 507         }
 508
 509         if (tx.crypt) {
 510                 skb = hostap_tx_encrypt(skb, tx.crypt);
 511                 if (skb == NULL) {
 512                         printk(KERN_DEBUG "%s: TX - encryption failed\n",
 513                                dev->name);
 514                         ret = 0;
 515                         goto fail;
 516                 }
 517                 meta = (struct hostap_skb_tx_data *) skb->cb;
 518                 if (meta->magic != HOSTAP_SKB_TX_DATA_MAGIC) {
 519                         printk(KERN_DEBUG "%s: invalid skb->cb magic (0x%08x, "
 520                                "expected 0x%08x) after hostap_tx_encrypt\n",
 521                                dev->name, meta->magic,
 522                                HOSTAP_SKB_TX_DATA_MAGIC);
 523                         ret = 0;
 524                         iface->stats.tx_dropped++;
 525                         goto fail;
 526                 }
 527         }
 528
 529         if (local->func->tx == NULL || local->func->tx(skb, dev)) {
 530                 ret = 0;
 531                 iface->stats.tx_dropped++;
 532         } else {
 533                 ret = 0;
 534                 iface->stats.tx_packets++;
 535                 iface->stats.tx_bytes += skb->len;
 536         }
 537
 538  fail:
 539         if (!ret && skb)
 540                 dev_kfree_skb(skb);
 541  tx_exit:
 542         if (tx.sta_ptr)
 543                 hostap_handle_sta_release(tx.sta_ptr);
 544         return ret;
 545 }
 546
 547
 548 EXPORT_SYMBOL(hostap_master_start_xmit);