drivers/net/wireless/hostap/hostap_80211_tx.c

   1 void hostap_dump_tx_80211(const char *name, struct sk_buff *skb)
   2 {
   3         struct hostap_ieee80211_hdr *hdr;
   4         u16 fc;
   5
   6         hdr = (struct hostap_ieee80211_hdr *) skb->data;
   7
   8         printk(KERN_DEBUG "%s: TX len=%d jiffies=%ld\n",
   9                name, skb->len, jiffies);
  10
  11         if (skb->len < 2)
  12                 return;
  13
  14         fc = le16_to_cpu(hdr->frame_control);
  15         printk(KERN_DEBUG "   FC=0x%04x (type=%d:%d)%s%s",
  16                fc, WLAN_FC_GET_TYPE(fc), WLAN_FC_GET_STYPE(fc),
  17                fc & WLAN_FC_TODS ? " [ToDS]" : "",
  18                fc & WLAN_FC_FROMDS ? " [FromDS]" : "");
  19
  20         if (skb->len < IEEE80211_DATA_HDR3_LEN) {
  21                 printk("\n");
  22                 return;
  23         }
  24
  25         printk(" dur=0x%04x seq=0x%04x\n", le16_to_cpu(hdr->duration_id),
  26                le16_to_cpu(hdr->seq_ctrl));
  27
  28         printk(KERN_DEBUG "   A1=" MACSTR " A2=" MACSTR " A3=" MACSTR,
  29                MAC2STR(hdr->addr1), MAC2STR(hdr->addr2), MAC2STR(hdr->addr3));
  30         if (skb->len >= 30)
  31                 printk(" A4=" MACSTR, MAC2STR(hdr->addr4));
  32         printk("\n");
  33 }
  34
  35
  36 /* hard_start_xmit function for data interfaces (wlan#, wlan#wds#, wlan#sta)
  37  * Convert Ethernet header into a suitable IEEE 802.11 header depending on
  38  * device configuration. */
  39 int hostap_data_start_xmit(struct sk_buff *skb, struct net_device *dev)
  40 {
  41         struct hostap_interface *iface;
  42         local_info_t *local;
  43         int need_headroom, need_tailroom = 0;
  44         struct hostap_ieee80211_hdr hdr;
  45         u16 fc, ethertype = 0;
  46         enum {
  47                 WDS_NO = 0, WDS_OWN_FRAME, WDS_COMPLIANT_FRAME
  48         } use_wds = WDS_NO;
  49         u8 *encaps_data;
  50         int hdr_len, encaps_len, skip_header_bytes;
  51         int to_assoc_ap = 0;
  52         struct hostap_skb_tx_data *meta;
  53
  54         iface = netdev_priv(dev);
  55         local = iface->local;
  56
  57         if (skb->len < ETH_HLEN) {
  58                 printk(KERN_DEBUG "%s: hostap_data_start_xmit: short skb "
  59                        "(len=%d)\n", dev->name, skb->len);
  60                 kfree_skb(skb);
  61                 return 0;
  62         }
  63
  64         if (local->ddev != dev) {
  65                 use_wds = (local->iw_mode == IW_MODE_MASTER &&
  66                            !(local->wds_type & HOSTAP_WDS_STANDARD_FRAME)) ?
  67                         WDS_OWN_FRAME : WDS_COMPLIANT_FRAME;
  68                 if (dev == local->stadev) {
  69                         to_assoc_ap = 1;
  70                         use_wds = WDS_NO;
  71                 } else if (dev == local->apdev) {
  72                         printk(KERN_DEBUG "%s: prism2_tx: trying to use "
  73                                "AP device with Ethernet net dev\n", dev->name);
  74                         kfree_skb(skb);
  75                         return 0;
  76                 }
  77         } else {
  78                 if (local->iw_mode == IW_MODE_REPEAT) {
  79                         printk(KERN_DEBUG "%s: prism2_tx: trying to use "
  80                                "non-WDS link in Repeater mode\n", dev->name);
  81                         kfree_skb(skb);
  82                         return 0;
  83                 } else if (local->iw_mode == IW_MODE_INFRA &&
  84                            (local->wds_type & HOSTAP_WDS_AP_CLIENT) &&
  85                            memcmp(skb->data + ETH_ALEN, dev->dev_addr,
  86                                   ETH_ALEN) != 0) {
  87                         /* AP client mode: send frames with foreign src addr
  88                          * using 4-addr WDS frames */
  89                         use_wds = WDS_COMPLIANT_FRAME;
  90                 }
  91         }
  92
  93         /* Incoming skb->data: dst_addr[6], src_addr[6], proto[2], payload
  94          * ==>
  95          * Prism2 TX frame with 802.11 header:
  96          * txdesc (address order depending on used mode; includes dst_addr and
  97          * src_addr), possible encapsulation (RFC1042/Bridge-Tunnel;
  98          * proto[2], payload {, possible addr4[6]} */
  99
 100         ethertype = (skb->data[12] << 8) | skb->data[13];
 101
 102         memset(&hdr, 0, sizeof(hdr));
 103
 104         /* Length of data after IEEE 802.11 header */
 105         encaps_data = NULL;
 106         encaps_len = 0;
 107         skip_header_bytes = ETH_HLEN;
 108         if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
 109                 encaps_data = bridge_tunnel_header;
 110                 encaps_len = sizeof(bridge_tunnel_header);
 111                 skip_header_bytes -= 2;
 112         } else if (ethertype >= 0x600) {
 113                 encaps_data = rfc1042_header;
 114                 encaps_len = sizeof(rfc1042_header);
 115                 skip_header_bytes -= 2;
 116         }
 117
 118         fc = (WLAN_FC_TYPE_DATA << 2) | (WLAN_FC_STYPE_DATA << 4);
 119         hdr_len = IEEE80211_DATA_HDR3_LEN;
 120
 121         if (use_wds != WDS_NO) {
 122                 /* Note! Prism2 station firmware has problems with sending real
 123                  * 802.11 frames with four addresses; until these problems can
 124                  * be fixed or worked around, 4-addr frames needed for WDS are
 125                  * using incompatible format: FromDS flag is not set and the
 126                  * fourth address is added after the frame payload; it is
 127                  * assumed, that the receiving station knows how to handle this
 128                  * frame format */
 129
 130                 if (use_wds == WDS_COMPLIANT_FRAME) {
 131                         fc |= WLAN_FC_FROMDS | WLAN_FC_TODS;
 132                         /* From&To DS: Addr1 = RA, Addr2 = TA, Addr3 = DA,
 133                          * Addr4 = SA */
 134                         memcpy(&hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
 135                         hdr_len += ETH_ALEN;
 136                 } else {
 137                         /* bogus 4-addr format to workaround Prism2 station
 138                          * f/w bug */
 139                         fc |= WLAN_FC_TODS;
 140                         /* From DS: Addr1 = DA (used as RA),
 141                          * Addr2 = BSSID (used as TA), Addr3 = SA (used as DA),
 142                          */
 143
 144                         /* SA from skb->data + ETH_ALEN will be added after
 145                          * frame payload; use hdr.addr4 as a temporary buffer
 146                          */
 147                         memcpy(&hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
 148                         need_tailroom += ETH_ALEN;
 149                 }
 150
 151                 /* send broadcast and multicast frames to broadcast RA, if
 152                  * configured; otherwise, use unicast RA of the WDS link */
 153                 if ((local->wds_type & HOSTAP_WDS_BROADCAST_RA) &&
 154                     skb->data[0] & 0x01)
 155                         memset(&hdr.addr1, 0xff, ETH_ALEN);
 156                 else if (iface->type == HOSTAP_INTERFACE_WDS)
 157                         memcpy(&hdr.addr1, iface->u.wds.remote_addr,
 158                                ETH_ALEN);
 159                 else
 160                         memcpy(&hdr.addr1, local->bssid, ETH_ALEN);
 161                 memcpy(&hdr.addr2, dev->dev_addr, ETH_ALEN);
 162                 memcpy(&hdr.addr3, skb->data, ETH_ALEN);
 163         } else if (local->iw_mode == IW_MODE_MASTER && !to_assoc_ap) {
 164                 fc |= WLAN_FC_FROMDS;
 165                 /* From DS: Addr1 = DA, Addr2 = BSSID, Addr3 = SA */
 166                 memcpy(&hdr.addr1, skb->data, ETH_ALEN);
 167                 memcpy(&hdr.addr2, dev->dev_addr, ETH_ALEN);
 168                 memcpy(&hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
 169         } else if (local->iw_mode == IW_MODE_INFRA || to_assoc_ap) {
 170                 fc |= WLAN_FC_TODS;
 171                 /* To DS: Addr1 = BSSID, Addr2 = SA, Addr3 = DA */
 172                 memcpy(&hdr.addr1, to_assoc_ap ?
 173                        local->assoc_ap_addr : local->bssid, ETH_ALEN);
 174                 memcpy(&hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
 175                 memcpy(&hdr.addr3, skb->data, ETH_ALEN);
 176         } else if (local->iw_mode == IW_MODE_ADHOC) {
 177                 /* not From/To DS: Addr1 = DA, Addr2 = SA, Addr3 = BSSID */
 178                 memcpy(&hdr.addr1, skb->data, ETH_ALEN);
 179                 memcpy(&hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
 180                 memcpy(&hdr.addr3, local->bssid, ETH_ALEN);
 181         }
 182
 183         hdr.frame_control = cpu_to_le16(fc);
 184
 185         skb_pull(skb, skip_header_bytes);
 186         need_headroom = local->func->need_tx_headroom + hdr_len + encaps_len;
 187         if (skb_tailroom(skb) < need_tailroom) {
 188                 skb = skb_unshare(skb, GFP_ATOMIC);
 189                 if (skb == NULL) {
 190                         iface->stats.tx_dropped++;
 191                         return 0;
 192                 }
 193                 if (pskb_expand_head(skb, need_headroom, need_tailroom,
 194                                      GFP_ATOMIC)) {
 195                         kfree_skb(skb);
 196                         iface->stats.tx_dropped++;
 197                         return 0;
 198                 }
 199         } else if (skb_headroom(skb) < need_headroom) {
 200                 struct sk_buff *tmp = skb;
 201                 skb = skb_realloc_headroom(skb, need_headroom);
 202                 kfree_skb(tmp);
 203                 if (skb == NULL) {
 204                         iface->stats.tx_dropped++;
 205                         return 0;
 206                 }
 207         } else {
 208                 skb = skb_unshare(skb, GFP_ATOMIC);
 209                 if (skb == NULL) {
 210                         iface->stats.tx_dropped++;
 211                         return 0;
 212                 }
 213         }
 214
 215         if (encaps_data)
 216                 memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
 217         memcpy(skb_push(skb, hdr_len), &hdr, hdr_len);
 218         if (use_wds == WDS_OWN_FRAME) {
 219                 memcpy(skb_put(skb, ETH_ALEN), &hdr.addr4, ETH_ALEN);
 220         }
 221
 222         iface->stats.tx_packets++;
 223         iface->stats.tx_bytes += skb->len;
 224
 225         skb->mac.raw = skb->data;
 226         meta = (struct hostap_skb_tx_data *) skb->cb;
 227         memset(meta, 0, sizeof(*meta));
 228         meta->magic = HOSTAP_SKB_TX_DATA_MAGIC;
 229         meta->wds = use_wds;
 230         meta->ethertype = ethertype;
 231         meta->iface = iface;
 232
 233         /* Send IEEE 802.11 encapsulated frame using the master radio device */
 234         skb->dev = local->dev;
 235         dev_queue_xmit(skb);
 236         return 0;
 237 }
 238
 239
 240 /* hard_start_xmit function for hostapd wlan#ap interfaces */
 241 int hostap_mgmt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 242 {
 243         struct hostap_interface *iface;
 244         local_info_t *local;
 245         struct hostap_skb_tx_data *meta;
 246         struct hostap_ieee80211_hdr *hdr;
 247         u16 fc;
 248
 249         iface = netdev_priv(dev);
 250         local = iface->local;
 251
 252         if (skb->len < 10) {
 253                 printk(KERN_DEBUG "%s: hostap_mgmt_start_xmit: short skb "
 254                        "(len=%d)\n", dev->name, skb->len);
 255                 kfree_skb(skb);
 256                 return 0;
 257         }
 258
 259         iface->stats.tx_packets++;
 260         iface->stats.tx_bytes += skb->len;
 261
 262         meta = (struct hostap_skb_tx_data *) skb->cb;
 263         memset(meta, 0, sizeof(*meta));
 264         meta->magic = HOSTAP_SKB_TX_DATA_MAGIC;
 265         meta->iface = iface;
 266
 267         if (skb->len >= IEEE80211_DATA_HDR3_LEN + sizeof(rfc1042_header) + 2) {
 268                 hdr = (struct hostap_ieee80211_hdr *) skb->data;
 269                 fc = le16_to_cpu(hdr->frame_control);
 270                 if (WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_DATA &&
 271                     WLAN_FC_GET_STYPE(fc) == WLAN_FC_STYPE_DATA) {
 272                         u8 *pos = &skb->data[IEEE80211_DATA_HDR3_LEN +
 273                                              sizeof(rfc1042_header)];
 274                         meta->ethertype = (pos[0] << 8) | pos[1];
 275                 }
 276         }
 277
 278         /* Send IEEE 802.11 encapsulated frame using the master radio device */
 279         skb->dev = local->dev;
 280         dev_queue_xmit(skb);
 281         return 0;
 282 }
 283
 284
 285 /* Called only from software IRQ */
 286 struct sk_buff * hostap_tx_encrypt(struct sk_buff *skb,
 287                                    struct prism2_crypt_data *crypt)
 288 {
 289         struct hostap_interface *iface;
 290         local_info_t *local;
 291         struct hostap_ieee80211_hdr *hdr;
 292         u16 fc;
 293         int hdr_len, res;
 294
 295         iface = netdev_priv(skb->dev);
 296         local = iface->local;
 297
 298         if (skb->len < IEEE80211_DATA_HDR3_LEN) {
 299                 kfree_skb(skb);
 300                 return NULL;
 301         }
 302
 303         if (local->tkip_countermeasures &&
 304             crypt && crypt->ops && strcmp(crypt->ops->name, "TKIP") == 0) {
 305                 hdr = (struct hostap_ieee80211_hdr *) skb->data;
 306                 if (net_ratelimit()) {
 307                         printk(KERN_DEBUG "%s: TKIP countermeasures: dropped "
 308                                "TX packet to " MACSTR "\n",
 309                                local->dev->name, MAC2STR(hdr->addr1));
 310                 }
 311                 kfree_skb(skb);
 312                 return NULL;
 313         }
 314
 315         skb = skb_unshare(skb, GFP_ATOMIC);
 316         if (skb == NULL)
 317                 return NULL;
 318
 319         if ((skb_headroom(skb) < crypt->ops->extra_prefix_len ||
 320              skb_tailroom(skb) < crypt->ops->extra_postfix_len) &&
 321             pskb_expand_head(skb, crypt->ops->extra_prefix_len,
 322                              crypt->ops->extra_postfix_len, GFP_ATOMIC)) {
 323                 kfree_skb(skb);
 324                 return NULL;
 325         }
 326
 327         hdr = (struct hostap_ieee80211_hdr *) skb->data;
 328         fc = le16_to_cpu(hdr->frame_control);
 329         hdr_len = hostap_80211_get_hdrlen(fc);
 330
 331         /* Host-based IEEE 802.11 fragmentation for TX is not yet supported, so
 332          * call both MSDU and MPDU encryption functions from here. */
 333         atomic_inc(&crypt->refcnt);
 334         res = 0;
 335         if (crypt->ops->encrypt_msdu)
 336                 res = crypt->ops->encrypt_msdu(skb, hdr_len, crypt->priv);
 337         if (res == 0 && crypt->ops->encrypt_mpdu)
 338                 res = crypt->ops->encrypt_mpdu(skb, hdr_len, crypt->priv);
 339         atomic_dec(&crypt->refcnt);
 340         if (res < 0) {
 341                 kfree_skb(skb);
 342                 return NULL;
 343         }
 344
 345         return skb;
 346 }
 347
 348
 349 /* hard_start_xmit function for master radio interface wifi#.
 350  * AP processing (TX rate control, power save buffering, etc.).
 351  * Use hardware TX function to send the frame. */
 352 int hostap_master_start_xmit(struct sk_buff *skb, struct net_device *dev)
 353 {
 354         struct hostap_interface *iface;
 355         local_info_t *local;
 356         int ret = 1;
 357         u16 fc;
 358         struct hostap_tx_data tx;
 359         ap_tx_ret tx_ret;
 360         struct hostap_skb_tx_data *meta;
 361         int no_encrypt = 0;
 362         struct hostap_ieee80211_hdr *hdr;
 363
 364         iface = netdev_priv(dev);
 365         local = iface->local;
 366
 367         tx.skb = skb;
 368         tx.sta_ptr = NULL;
 369
 370         meta = (struct hostap_skb_tx_data *) skb->cb;
 371         if (meta->magic != HOSTAP_SKB_TX_DATA_MAGIC) {
 372                 printk(KERN_DEBUG "%s: invalid skb->cb magic (0x%08x, "
 373                        "expected 0x%08x)\n",
 374                        dev->name, meta->magic, HOSTAP_SKB_TX_DATA_MAGIC);
 375                 ret = 0;
 376                 iface->stats.tx_dropped++;
 377                 goto fail;
 378         }
 379
 380         if (local->host_encrypt) {
 381                 /* Set crypt to default algorithm and key; will be replaced in
 382                  * AP code if STA has own alg/key */
 383                 tx.crypt = local->crypt[local->tx_keyidx];
 384                 tx.host_encrypt = 1;
 385         } else {
 386                 tx.crypt = NULL;
 387                 tx.host_encrypt = 0;
 388         }
 389
 390         if (skb->len < 24) {
 391                 printk(KERN_DEBUG "%s: hostap_master_start_xmit: short skb "
 392                        "(len=%d)\n", dev->name, skb->len);
 393                 ret = 0;
 394                 iface->stats.tx_dropped++;
 395                 goto fail;
 396         }
 397
 398         /* FIX (?):
 399          * Wi-Fi 802.11b test plan suggests that AP should ignore power save
 400          * bit in authentication and (re)association frames and assume tha
 401          * STA remains awake for the response. */
 402         tx_ret = hostap_handle_sta_tx(local, &tx);
 403         skb = tx.skb;
 404         meta = (struct hostap_skb_tx_data *) skb->cb;
 405         hdr = (struct hostap_ieee80211_hdr *) skb->data;
 406         fc = le16_to_cpu(hdr->frame_control);
 407         switch (tx_ret) {
 408         case AP_TX_CONTINUE:
 409                 break;
 410         case AP_TX_CONTINUE_NOT_AUTHORIZED:
 411                 if (local->ieee_802_1x &&
 412                     WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_DATA &&
 413                     meta->ethertype != ETH_P_PAE && !meta->wds) {
 414                         printk(KERN_DEBUG "%s: dropped frame to unauthorized "
 415                                "port (IEEE 802.1X): ethertype=0x%04x\n",
 416                                dev->name, meta->ethertype);
 417                         hostap_dump_tx_80211(dev->name, skb);
 418
 419                         ret = 0; /* drop packet */
 420                         iface->stats.tx_dropped++;
 421                         goto fail;
 422                 }
 423                 break;
 424         case AP_TX_DROP:
 425                 ret = 0; /* drop packet */
 426                 iface->stats.tx_dropped++;
 427                 goto fail;
 428         case AP_TX_RETRY:
 429                 goto fail;
 430         case AP_TX_BUFFERED:
 431                 /* do not free skb here, it will be freed when the
 432                  * buffered frame is sent/timed out */
 433                 ret = 0;
 434                 goto tx_exit;
 435         }
 436
 437         /* Request TX callback if protocol version is 2 in 802.11 header;
 438          * this version 2 is a special case used between hostapd and kernel
 439          * driver */
 440         if (((fc & WLAN_FC_PVER) == BIT(1)) &&
 441             local->ap && local->ap->tx_callback_idx && meta->tx_cb_idx == 0) {
 442                 meta->tx_cb_idx = local->ap->tx_callback_idx;
 443
 444                 /* remove special version from the frame header */
 445                 fc &= ~WLAN_FC_PVER;
 446                 hdr->frame_control = cpu_to_le16(fc);
 447         }
 448
 449         if (WLAN_FC_GET_TYPE(fc) != WLAN_FC_TYPE_DATA) {
 450                 no_encrypt = 1;
 451                 tx.crypt = NULL;
 452         }
 453
 454         if (local->ieee_802_1x && meta->ethertype == ETH_P_PAE && tx.crypt &&
 455             !(fc & WLAN_FC_ISWEP)) {
 456                 no_encrypt = 1;
 457                 PDEBUG(DEBUG_EXTRA2, "%s: TX: IEEE 802.1X - passing "
 458                        "unencrypted EAPOL frame\n", dev->name);
 459                 tx.crypt = NULL; /* no encryption for IEEE 802.1X frames */
 460         }
 461
 462         if (tx.crypt && (!tx.crypt->ops || !tx.crypt->ops->encrypt_mpdu))
 463                 tx.crypt = NULL;
 464         else if ((tx.crypt || local->crypt[local->tx_keyidx]) && !no_encrypt) {
 465                 /* Add ISWEP flag both for firmware and host based encryption
 466                  */
 467                 fc |= WLAN_FC_ISWEP;
 468                 hdr->frame_control = cpu_to_le16(fc);
 469         } else if (local->drop_unencrypted &&
 470                    WLAN_FC_GET_TYPE(fc) == WLAN_FC_TYPE_DATA &&
 471                    meta->ethertype != ETH_P_PAE) {
 472                 if (net_ratelimit()) {
 473                         printk(KERN_DEBUG "%s: dropped unencrypted TX data "
 474                                "frame (drop_unencrypted=1)\n", dev->name);
 475                 }
 476                 iface->stats.tx_dropped++;
 477                 ret = 0;
 478                 goto fail;
 479         }
 480
 481         if (tx.crypt) {
 482                 skb = hostap_tx_encrypt(skb, tx.crypt);
 483                 if (skb == NULL) {
 484                         printk(KERN_DEBUG "%s: TX - encryption failed\n",
 485                                dev->name);
 486                         ret = 0;
 487                         goto fail;
 488                 }
 489                 meta = (struct hostap_skb_tx_data *) skb->cb;
 490                 if (meta->magic != HOSTAP_SKB_TX_DATA_MAGIC) {
 491                         printk(KERN_DEBUG "%s: invalid skb->cb magic (0x%08x, "
 492                                "expected 0x%08x) after hostap_tx_encrypt\n",
 493                                dev->name, meta->magic,
 494                                HOSTAP_SKB_TX_DATA_MAGIC);
 495                         ret = 0;
 496                         iface->stats.tx_dropped++;
 497                         goto fail;
 498                 }
 499         }
 500
 501         if (local->func->tx == NULL || local->func->tx(skb, dev)) {
 502                 ret = 0;
 503                 iface->stats.tx_dropped++;
 504         } else {
 505                 ret = 0;
 506                 iface->stats.tx_packets++;
 507                 iface->stats.tx_bytes += skb->len;
 508         }
 509
 510  fail:
 511         if (!ret && skb)
 512                 dev_kfree_skb(skb);
 513  tx_exit:
 514         if (tx.sta_ptr)
 515                 hostap_handle_sta_release(tx.sta_ptr);
 516         return ret;
 517 }
 518
 519
 520 EXPORT_SYMBOL(hostap_dump_tx_80211);
 521 EXPORT_SYMBOL(hostap_tx_encrypt);
 522 EXPORT_SYMBOL(hostap_master_start_xmit);