drivers/net/wireless/intersil/hostap/hostap_80211_tx.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/slab.h>
   3 #include <linux/export.h>
   4 #include <linux/etherdevice.h>
   5
   6 #include "hostap_80211.h"
   7 #include "hostap_common.h"
   8 #include "hostap_wlan.h"
   9 #include "hostap.h"
  10 #include "hostap_ap.h"
  11
  12 /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
  13 /* Ethernet-II snap header (RFC1042 for most EtherTypes) */
  14 static unsigned char rfc1042_header[] =
  15 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
  16 /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
  17 static unsigned char bridge_tunnel_header[] =
  18 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
  19 /* No encapsulation header if EtherType < 0x600 (=length) */
  20
  21 void hostap_dump_tx_80211(const char *name, struct sk_buff *skb)
  22 {
  23         struct ieee80211_hdr *hdr;
  24         u16 fc;
  25
  26         hdr = (struct ieee80211_hdr *) skb->data;
  27
  28         printk(KERN_DEBUG "%s: TX len=%d jiffies=%ld\n",
  29                name, skb->len, jiffies);
  30
  31         if (skb->len < 2)
  32                 return;
  33
  34         fc = le16_to_cpu(hdr->frame_control);
  35         printk(KERN_DEBUG "   FC=0x%04x (type=%d:%d)%s%s",
  36                fc, (fc & IEEE80211_FCTL_FTYPE) >> 2,
  37                (fc & IEEE80211_FCTL_STYPE) >> 4,
  38                fc & IEEE80211_FCTL_TODS ? " [ToDS]" : "",
  39                fc & IEEE80211_FCTL_FROMDS ? " [FromDS]" : "");
  40
  41         if (skb->len < IEEE80211_DATA_HDR3_LEN) {
  42                 printk("\n");
  43                 return;
  44         }
  45
  46         printk(" dur=0x%04x seq=0x%04x\n", le16_to_cpu(hdr->duration_id),
  47                le16_to_cpu(hdr->seq_ctrl));
  48
  49         printk(KERN_DEBUG "   A1=%pM", hdr->addr1);
  50         printk(" A2=%pM", hdr->addr2);
  51         printk(" A3=%pM", hdr->addr3);
  52         if (skb->len >= 30)
  53                 printk(" A4=%pM", hdr->addr4);
  54         printk("\n");
  55 }
  56
  57
  58 /* hard_start_xmit function for data interfaces (wlan#, wlan#wds#, wlan#sta)
  59  * Convert Ethernet header into a suitable IEEE 802.11 header depending on
  60  * device configuration. */
  61 netdev_tx_t hostap_data_start_xmit(struct sk_buff *skb,
  62                                    struct net_device *dev)
  63 {
  64         struct hostap_interface *iface;
  65         local_info_t *local;
  66         int need_headroom, need_tailroom = 0;
  67         struct ieee80211_hdr hdr;
  68         u16 fc, ethertype = 0;
  69         enum {
  70                 WDS_NO = 0, WDS_OWN_FRAME, WDS_COMPLIANT_FRAME
  71         } use_wds = WDS_NO;
  72         u8 *encaps_data;
  73         int hdr_len, encaps_len, skip_header_bytes;
  74         int to_assoc_ap = 0;
  75         struct hostap_skb_tx_data *meta;
  76
  77         iface = netdev_priv(dev);
  78         local = iface->local;
  79
  80         if (skb->len < ETH_HLEN) {
  81                 printk(KERN_DEBUG "%s: hostap_data_start_xmit: short skb "
  82                        "(len=%d)\n", dev->name, skb->len);
  83                 kfree_skb(skb);
  84                 return NETDEV_TX_OK;
  85         }
  86
  87         if (local->ddev != dev) {
  88                 use_wds = (local->iw_mode == IW_MODE_MASTER &&
  89                            !(local->wds_type & HOSTAP_WDS_STANDARD_FRAME)) ?
  90                         WDS_OWN_FRAME : WDS_COMPLIANT_FRAME;
  91                 if (dev == local->stadev) {
  92                         to_assoc_ap = 1;
  93                         use_wds = WDS_NO;
  94                 } else if (dev == local->apdev) {
  95                         printk(KERN_DEBUG "%s: prism2_tx: trying to use "
  96                                "AP device with Ethernet net dev\n", dev->name);
  97                         kfree_skb(skb);
  98                         return NETDEV_TX_OK;
  99                 }
 100         } else {
 101                 if (local->iw_mode == IW_MODE_REPEAT) {
 102                         printk(KERN_DEBUG "%s: prism2_tx: trying to use "
 103                                "non-WDS link in Repeater mode\n", dev->name);
 104                         kfree_skb(skb);
 105                         return NETDEV_TX_OK;
 106                 } else if (local->iw_mode == IW_MODE_INFRA &&
 107                            (local->wds_type & HOSTAP_WDS_AP_CLIENT) &&
 108                            !ether_addr_equal(skb->data + ETH_ALEN, dev->dev_addr)) {
 109                         /* AP client mode: send frames with foreign src addr
 110                          * using 4-addr WDS frames */
 111                         use_wds = WDS_COMPLIANT_FRAME;
 112                 }
 113         }
 114
 115         /* Incoming skb->data: dst_addr[6], src_addr[6], proto[2], payload
 116          * ==>
 117          * Prism2 TX frame with 802.11 header:
 118          * txdesc (address order depending on used mode; includes dst_addr and
 119          * src_addr), possible encapsulation (RFC1042/Bridge-Tunnel;
 120          * proto[2], payload {, possible addr4[6]} */
 121
 122         ethertype = (skb->data[12] << 8) | skb->data[13];
 123
 124         memset(&hdr, 0, sizeof(hdr));
 125
 126         /* Length of data after IEEE 802.11 header */
 127         encaps_data = NULL;
 128         encaps_len = 0;
 129         skip_header_bytes = ETH_HLEN;
 130         if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
 131                 encaps_data = bridge_tunnel_header;
 132                 encaps_len = sizeof(bridge_tunnel_header);
 133                 skip_header_bytes -= 2;
 134         } else if (ethertype >= 0x600) {
 135                 encaps_data = rfc1042_header;
 136                 encaps_len = sizeof(rfc1042_header);
 137                 skip_header_bytes -= 2;
 138         }
 139
 140         fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA;
 141         hdr_len = IEEE80211_DATA_HDR3_LEN;
 142
 143         if (use_wds != WDS_NO) {
 144                 /* Note! Prism2 station firmware has problems with sending real
 145                  * 802.11 frames with four addresses; until these problems can
 146                  * be fixed or worked around, 4-addr frames needed for WDS are
 147                  * using incompatible format: FromDS flag is not set and the
 148                  * fourth address is added after the frame payload; it is
 149                  * assumed, that the receiving station knows how to handle this
 150                  * frame format */
 151
 152                 if (use_wds == WDS_COMPLIANT_FRAME) {
 153                         fc |= IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS;
 154                         /* From&To DS: Addr1 = RA, Addr2 = TA, Addr3 = DA,
 155                          * Addr4 = SA */
 156                         skb_copy_from_linear_data_offset(skb, ETH_ALEN,
 157                                                          &hdr.addr4, ETH_ALEN);
 158                         hdr_len += ETH_ALEN;
 159                 } else {
 160                         /* bogus 4-addr format to workaround Prism2 station
 161                          * f/w bug */
 162                         fc |= IEEE80211_FCTL_TODS;
 163                         /* From DS: Addr1 = DA (used as RA),
 164                          * Addr2 = BSSID (used as TA), Addr3 = SA (used as DA),
 165                          */
 166
 167                         /* SA from skb->data + ETH_ALEN will be added after
 168                          * frame payload; use hdr.addr4 as a temporary buffer
 169                          */
 170                         skb_copy_from_linear_data_offset(skb, ETH_ALEN,
 171                                                          &hdr.addr4, ETH_ALEN);
 172                         need_tailroom += ETH_ALEN;
 173                 }
 174
 175                 /* send broadcast and multicast frames to broadcast RA, if
 176                  * configured; otherwise, use unicast RA of the WDS link */
 177                 if ((local->wds_type & HOSTAP_WDS_BROADCAST_RA) &&
 178                     is_multicast_ether_addr(skb->data))
 179                         eth_broadcast_addr(hdr.addr1);
 180                 else if (iface->type == HOSTAP_INTERFACE_WDS)
 181                         memcpy(&hdr.addr1, iface->u.wds.remote_addr,
 182                                ETH_ALEN);
 183                 else
 184                         memcpy(&hdr.addr1, local->bssid, ETH_ALEN);
 185                 memcpy(&hdr.addr2, dev->dev_addr, ETH_ALEN);
 186                 skb_copy_from_linear_data(skb, &hdr.addr3, ETH_ALEN);
 187         } else if (local->iw_mode == IW_MODE_MASTER && !to_assoc_ap) {
 188                 fc |= IEEE80211_FCTL_FROMDS;
 189                 /* From DS: Addr1 = DA, Addr2 = BSSID, Addr3 = SA */
 190                 skb_copy_from_linear_data(skb, &hdr.addr1, ETH_ALEN);
 191                 memcpy(&hdr.addr2, dev->dev_addr, ETH_ALEN);
 192                 skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr3,
 193                                                  ETH_ALEN);
 194         } else if (local->iw_mode == IW_MODE_INFRA || to_assoc_ap) {
 195                 fc |= IEEE80211_FCTL_TODS;
 196                 /* To DS: Addr1 = BSSID, Addr2 = SA, Addr3 = DA */
 197                 memcpy(&hdr.addr1, to_assoc_ap ?
 198                        local->assoc_ap_addr : local->bssid, ETH_ALEN);
 199                 skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr2,
 200                                                  ETH_ALEN);
 201                 skb_copy_from_linear_data(skb, &hdr.addr3, ETH_ALEN);
 202         } else if (local->iw_mode == IW_MODE_ADHOC) {
 203                 /* not From/To DS: Addr1 = DA, Addr2 = SA, Addr3 = BSSID */
 204                 skb_copy_from_linear_data(skb, &hdr.addr1, ETH_ALEN);
 205                 skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr2,
 206                                                  ETH_ALEN);
 207                 memcpy(&hdr.addr3, local->bssid, ETH_ALEN);
 208         }
 209
 210         hdr.frame_control = cpu_to_le16(fc);
 211
 212         skb_pull(skb, skip_header_bytes);
 213         need_headroom = local->func->need_tx_headroom + hdr_len + encaps_len;
 214         if (skb_tailroom(skb) < need_tailroom) {
 215                 skb = skb_unshare(skb, GFP_ATOMIC);
 216                 if (skb == NULL) {
 217                         iface->stats.tx_dropped++;
 218                         return NETDEV_TX_OK;
 219                 }
 220                 if (pskb_expand_head(skb, need_headroom, need_tailroom,
 221                                      GFP_ATOMIC)) {
 222                         kfree_skb(skb);
 223                         iface->stats.tx_dropped++;
 224                         return NETDEV_TX_OK;
 225                 }
 226         } else if (skb_headroom(skb) < need_headroom) {
 227                 struct sk_buff *tmp = skb;
 228                 skb = skb_realloc_headroom(skb, need_headroom);
 229                 kfree_skb(tmp);
 230                 if (skb == NULL) {
 231                         iface->stats.tx_dropped++;
 232                         return NETDEV_TX_OK;
 233                 }
 234         } else {
 235                 skb = skb_unshare(skb, GFP_ATOMIC);
 236                 if (skb == NULL) {
 237                         iface->stats.tx_dropped++;
 238                         return NETDEV_TX_OK;
 239                 }
 240         }
 241
 242         if (encaps_data)
 243                 memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
 244         memcpy(skb_push(skb, hdr_len), &hdr, hdr_len);
 245         if (use_wds == WDS_OWN_FRAME) {
 246                 skb_put_data(skb, &hdr.addr4, ETH_ALEN);
 247         }
 248
 249         iface->stats.tx_packets++;
 250         iface->stats.tx_bytes += skb->len;
 251
 252         skb_reset_mac_header(skb);
 253         meta = (struct hostap_skb_tx_data *) skb->cb;
 254         memset(meta, 0, sizeof(*meta));
 255         meta->magic = HOSTAP_SKB_TX_DATA_MAGIC;
 256         if (use_wds)
 257                 meta->flags |= HOSTAP_TX_FLAGS_WDS;
 258         meta->ethertype = ethertype;
 259         meta->iface = iface;
 260
 261         /* Send IEEE 802.11 encapsulated frame using the master radio device */
 262         skb->dev = local->dev;
 263         dev_queue_xmit(skb);
 264         return NETDEV_TX_OK;
 265 }
 266
 267
 268 /* hard_start_xmit function for hostapd wlan#ap interfaces */
 269 netdev_tx_t hostap_mgmt_start_xmit(struct sk_buff *skb,
 270                                    struct net_device *dev)
 271 {
 272         struct hostap_interface *iface;
 273         local_info_t *local;
 274         struct hostap_skb_tx_data *meta;
 275         struct ieee80211_hdr *hdr;
 276         u16 fc;
 277
 278         iface = netdev_priv(dev);
 279         local = iface->local;
 280
 281         if (skb->len < 10) {
 282                 printk(KERN_DEBUG "%s: hostap_mgmt_start_xmit: short skb "
 283                        "(len=%d)\n", dev->name, skb->len);
 284                 kfree_skb(skb);
 285                 return NETDEV_TX_OK;
 286         }
 287
 288         iface->stats.tx_packets++;
 289         iface->stats.tx_bytes += skb->len;
 290
 291         meta = (struct hostap_skb_tx_data *) skb->cb;
 292         memset(meta, 0, sizeof(*meta));
 293         meta->magic = HOSTAP_SKB_TX_DATA_MAGIC;
 294         meta->iface = iface;
 295
 296         if (skb->len >= IEEE80211_DATA_HDR3_LEN + sizeof(rfc1042_header) + 2) {
 297                 hdr = (struct ieee80211_hdr *) skb->data;
 298                 fc = le16_to_cpu(hdr->frame_control);
 299                 if (ieee80211_is_data(hdr->frame_control) &&
 300                     (fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_DATA) {
 301                         u8 *pos = &skb->data[IEEE80211_DATA_HDR3_LEN +
 302                                              sizeof(rfc1042_header)];
 303                         meta->ethertype = (pos[0] << 8) | pos[1];
 304                 }
 305         }
 306
 307         /* Send IEEE 802.11 encapsulated frame using the master radio device */
 308         skb->dev = local->dev;
 309         dev_queue_xmit(skb);
 310         return NETDEV_TX_OK;
 311 }
 312
 313
 314 /* Called only from software IRQ */
 315 static struct sk_buff * hostap_tx_encrypt(struct sk_buff *skb,
 316                                           struct lib80211_crypt_data *crypt)
 317 {
 318         struct hostap_interface *iface;
 319         local_info_t *local;
 320         struct ieee80211_hdr *hdr;
 321         int prefix_len, postfix_len, hdr_len, res;
 322
 323         iface = netdev_priv(skb->dev);
 324         local = iface->local;
 325
 326         if (skb->len < IEEE80211_DATA_HDR3_LEN) {
 327                 kfree_skb(skb);
 328                 return NULL;
 329         }
 330
 331         if (local->tkip_countermeasures &&
 332             strcmp(crypt->ops->name, "TKIP") == 0) {
 333                 hdr = (struct ieee80211_hdr *) skb->data;
 334                 if (net_ratelimit()) {
 335                         printk(KERN_DEBUG "%s: TKIP countermeasures: dropped "
 336                                "TX packet to %pM\n",
 337                                local->dev->name, hdr->addr1);
 338                 }
 339                 kfree_skb(skb);
 340                 return NULL;
 341         }
 342
 343         skb = skb_unshare(skb, GFP_ATOMIC);
 344         if (skb == NULL)
 345                 return NULL;
 346
 347         prefix_len = crypt->ops->extra_mpdu_prefix_len +
 348                 crypt->ops->extra_msdu_prefix_len;
 349         postfix_len = crypt->ops->extra_mpdu_postfix_len +
 350                 crypt->ops->extra_msdu_postfix_len;
 351         if ((skb_headroom(skb) < prefix_len ||
 352              skb_tailroom(skb) < postfix_len) &&
 353             pskb_expand_head(skb, prefix_len, postfix_len, GFP_ATOMIC)) {
 354                 kfree_skb(skb);
 355                 return NULL;
 356         }
 357
 358         hdr = (struct ieee80211_hdr *) skb->data;
 359         hdr_len = hostap_80211_get_hdrlen(hdr->frame_control);
 360
 361         /* Host-based IEEE 802.11 fragmentation for TX is not yet supported, so
 362          * call both MSDU and MPDU encryption functions from here. */
 363         atomic_inc(&crypt->refcnt);
 364         res = 0;
 365         if (crypt->ops->encrypt_msdu)
 366                 res = crypt->ops->encrypt_msdu(skb, hdr_len, crypt->priv);
 367         if (res == 0 && crypt->ops->encrypt_mpdu)
 368                 res = crypt->ops->encrypt_mpdu(skb, hdr_len, crypt->priv);
 369         atomic_dec(&crypt->refcnt);
 370         if (res < 0) {
 371                 kfree_skb(skb);
 372                 return NULL;
 373         }
 374
 375         return skb;
 376 }
 377
 378
 379 /* hard_start_xmit function for master radio interface wifi#.
 380  * AP processing (TX rate control, power save buffering, etc.).
 381  * Use hardware TX function to send the frame. */
 382 netdev_tx_t hostap_master_start_xmit(struct sk_buff *skb,
 383                                      struct net_device *dev)
 384 {
 385         struct hostap_interface *iface;
 386         local_info_t *local;
 387         netdev_tx_t ret = NETDEV_TX_BUSY;
 388         u16 fc;
 389         struct hostap_tx_data tx;
 390         ap_tx_ret tx_ret;
 391         struct hostap_skb_tx_data *meta;
 392         int no_encrypt = 0;
 393         struct ieee80211_hdr *hdr;
 394
 395         iface = netdev_priv(dev);
 396         local = iface->local;
 397
 398         tx.skb = skb;
 399         tx.sta_ptr = NULL;
 400
 401         meta = (struct hostap_skb_tx_data *) skb->cb;
 402         if (meta->magic != HOSTAP_SKB_TX_DATA_MAGIC) {
 403                 printk(KERN_DEBUG "%s: invalid skb->cb magic (0x%08x, "
 404                        "expected 0x%08x)\n",
 405                        dev->name, meta->magic, HOSTAP_SKB_TX_DATA_MAGIC);
 406                 ret = NETDEV_TX_OK;
 407                 iface->stats.tx_dropped++;
 408                 goto fail;
 409         }
 410
 411         if (local->host_encrypt) {
 412                 /* Set crypt to default algorithm and key; will be replaced in
 413                  * AP code if STA has own alg/key */
 414                 tx.crypt = local->crypt_info.crypt[local->crypt_info.tx_keyidx];
 415                 tx.host_encrypt = 1;
 416         } else {
 417                 tx.crypt = NULL;
 418                 tx.host_encrypt = 0;
 419         }
 420
 421         if (skb->len < 24) {
 422                 printk(KERN_DEBUG "%s: hostap_master_start_xmit: short skb "
 423                        "(len=%d)\n", dev->name, skb->len);
 424                 ret = NETDEV_TX_OK;
 425                 iface->stats.tx_dropped++;
 426                 goto fail;
 427         }
 428
 429         /* FIX (?):
 430          * Wi-Fi 802.11b test plan suggests that AP should ignore power save
 431          * bit in authentication and (re)association frames and assume tha
 432          * STA remains awake for the response. */
 433         tx_ret = hostap_handle_sta_tx(local, &tx);
 434         skb = tx.skb;
 435         meta = (struct hostap_skb_tx_data *) skb->cb;
 436         hdr = (struct ieee80211_hdr *) skb->data;
 437         fc = le16_to_cpu(hdr->frame_control);
 438         switch (tx_ret) {
 439         case AP_TX_CONTINUE:
 440                 break;
 441         case AP_TX_CONTINUE_NOT_AUTHORIZED:
 442                 if (local->ieee_802_1x &&
 443                     ieee80211_is_data(hdr->frame_control) &&
 444                     meta->ethertype != ETH_P_PAE &&
 445                     !(meta->flags & HOSTAP_TX_FLAGS_WDS)) {
 446                         printk(KERN_DEBUG "%s: dropped frame to unauthorized "
 447                                "port (IEEE 802.1X): ethertype=0x%04x\n",
 448                                dev->name, meta->ethertype);
 449                         hostap_dump_tx_80211(dev->name, skb);
 450
 451                         ret = NETDEV_TX_OK; /* drop packet */
 452                         iface->stats.tx_dropped++;
 453                         goto fail;
 454                 }
 455                 break;
 456         case AP_TX_DROP:
 457                 ret = NETDEV_TX_OK; /* drop packet */
 458                 iface->stats.tx_dropped++;
 459                 goto fail;
 460         case AP_TX_RETRY:
 461                 goto fail;
 462         case AP_TX_BUFFERED:
 463                 /* do not free skb here, it will be freed when the
 464                  * buffered frame is sent/timed out */
 465                 ret = NETDEV_TX_OK;
 466                 goto tx_exit;
 467         }
 468
 469         /* Request TX callback if protocol version is 2 in 802.11 header;
 470          * this version 2 is a special case used between hostapd and kernel
 471          * driver */
 472         if (((fc & IEEE80211_FCTL_VERS) == BIT(1)) &&
 473             local->ap && local->ap->tx_callback_idx && meta->tx_cb_idx == 0) {
 474                 meta->tx_cb_idx = local->ap->tx_callback_idx;
 475
 476                 /* remove special version from the frame header */
 477                 fc &= ~IEEE80211_FCTL_VERS;
 478                 hdr->frame_control = cpu_to_le16(fc);
 479         }
 480
 481         if (!ieee80211_is_data(hdr->frame_control)) {
 482                 no_encrypt = 1;
 483                 tx.crypt = NULL;
 484         }
 485
 486         if (local->ieee_802_1x && meta->ethertype == ETH_P_PAE && tx.crypt &&
 487             !(fc & IEEE80211_FCTL_PROTECTED)) {
 488                 no_encrypt = 1;
 489                 PDEBUG(DEBUG_EXTRA2, "%s: TX: IEEE 802.1X - passing "
 490                        "unencrypted EAPOL frame\n", dev->name);
 491                 tx.crypt = NULL; /* no encryption for IEEE 802.1X frames */
 492         }
 493
 494         if (tx.crypt && (!tx.crypt->ops || !tx.crypt->ops->encrypt_mpdu))
 495                 tx.crypt = NULL;
 496         else if ((tx.crypt ||
 497                  local->crypt_info.crypt[local->crypt_info.tx_keyidx]) &&
 498                  !no_encrypt) {
 499                 /* Add ISWEP flag both for firmware and host based encryption
 500                  */
 501                 fc |= IEEE80211_FCTL_PROTECTED;
 502                 hdr->frame_control = cpu_to_le16(fc);
 503         } else if (local->drop_unencrypted &&
 504                    ieee80211_is_data(hdr->frame_control) &&
 505                    meta->ethertype != ETH_P_PAE) {
 506                 if (net_ratelimit()) {
 507                         printk(KERN_DEBUG "%s: dropped unencrypted TX data "
 508                                "frame (drop_unencrypted=1)\n", dev->name);
 509                 }
 510                 iface->stats.tx_dropped++;
 511                 ret = NETDEV_TX_OK;
 512                 goto fail;
 513         }
 514
 515         if (tx.crypt) {
 516                 skb = hostap_tx_encrypt(skb, tx.crypt);
 517                 if (skb == NULL) {
 518                         printk(KERN_DEBUG "%s: TX - encryption failed\n",
 519                                dev->name);
 520                         ret = NETDEV_TX_OK;
 521                         goto fail;
 522                 }
 523                 meta = (struct hostap_skb_tx_data *) skb->cb;
 524                 if (meta->magic != HOSTAP_SKB_TX_DATA_MAGIC) {
 525                         printk(KERN_DEBUG "%s: invalid skb->cb magic (0x%08x, "
 526                                "expected 0x%08x) after hostap_tx_encrypt\n",
 527                                dev->name, meta->magic,
 528                                HOSTAP_SKB_TX_DATA_MAGIC);
 529                         ret = NETDEV_TX_OK;
 530                         iface->stats.tx_dropped++;
 531                         goto fail;
 532                 }
 533         }
 534
 535         if (local->func->tx == NULL || local->func->tx(skb, dev)) {
 536                 ret = NETDEV_TX_OK;
 537                 iface->stats.tx_dropped++;
 538         } else {
 539                 ret = NETDEV_TX_OK;
 540                 iface->stats.tx_packets++;
 541                 iface->stats.tx_bytes += skb->len;
 542         }
 543
 544  fail:
 545         if (ret == NETDEV_TX_OK && skb)
 546                 dev_kfree_skb(skb);
 547  tx_exit:
 548         if (tx.sta_ptr)
 549                 hostap_handle_sta_release(tx.sta_ptr);
 550         return ret;
 551 }
 552
 553
 554 EXPORT_SYMBOL(hostap_master_start_xmit);