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