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); 555