net/mac80211/tdls.c

   1 /*
   2  * mac80211 TDLS handling code
   3  *
   4  * Copyright 2006-2010  Johannes Berg <johannes@sipsolutions.net>
   5  * Copyright 2014, Intel Corporation
   6  *
   7  * This file is GPLv2 as found in COPYING.
   8  */
   9
  10 #include <linux/ieee80211.h>
  11 #include <net/cfg80211.h>
  12 #include "ieee80211_i.h"
  13 #include "driver-ops.h"
  14
  15 /* give usermode some time for retries in setting up the TDLS session */
  16 #define TDLS_PEER_SETUP_TIMEOUT (15 * HZ)
  17
  18 void ieee80211_tdls_peer_del_work(struct work_struct *wk)
  19 {
  20         struct ieee80211_sub_if_data *sdata;
  21         struct ieee80211_local *local;
  22
  23         sdata = container_of(wk, struct ieee80211_sub_if_data,
  24                              tdls_peer_del_work.work);
  25         local = sdata->local;
  26
  27         mutex_lock(&local->mtx);
  28         if (!is_zero_ether_addr(sdata->tdls_peer)) {
  29                 tdls_dbg(sdata, "TDLS del peer %pM\n", sdata->tdls_peer);
  30                 sta_info_destroy_addr(sdata, sdata->tdls_peer);
  31                 eth_zero_addr(sdata->tdls_peer);
  32         }
  33         mutex_unlock(&local->mtx);
  34 }
  35
  36 static void ieee80211_tdls_add_ext_capab(struct sk_buff *skb)
  37 {
  38         u8 *pos = (void *)skb_put(skb, 7);
  39
  40         *pos++ = WLAN_EID_EXT_CAPABILITY;
  41         *pos++ = 5; /* len */
  42         *pos++ = 0x0;
  43         *pos++ = 0x0;
  44         *pos++ = 0x0;
  45         *pos++ = 0x0;
  46         *pos++ = WLAN_EXT_CAPA5_TDLS_ENABLED;
  47 }
  48
  49 static u16 ieee80211_get_tdls_sta_capab(struct ieee80211_sub_if_data *sdata)
  50 {
  51         struct ieee80211_local *local = sdata->local;
  52         u16 capab;
  53
  54         capab = 0;
  55         if (ieee80211_get_sdata_band(sdata) != IEEE80211_BAND_2GHZ)
  56                 return capab;
  57
  58         if (!(local->hw.flags & IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE))
  59                 capab |= WLAN_CAPABILITY_SHORT_SLOT_TIME;
  60         if (!(local->hw.flags & IEEE80211_HW_2GHZ_SHORT_PREAMBLE_INCAPABLE))
  61                 capab |= WLAN_CAPABILITY_SHORT_PREAMBLE;
  62
  63         return capab;
  64 }
  65
  66 static void ieee80211_tdls_add_link_ie(struct sk_buff *skb, const u8 *src_addr,
  67                                        const u8 *peer, const u8 *bssid)
  68 {
  69         struct ieee80211_tdls_lnkie *lnkid;
  70
  71         lnkid = (void *)skb_put(skb, sizeof(struct ieee80211_tdls_lnkie));
  72
  73         lnkid->ie_type = WLAN_EID_LINK_ID;
  74         lnkid->ie_len = sizeof(struct ieee80211_tdls_lnkie) - 2;
  75
  76         memcpy(lnkid->bssid, bssid, ETH_ALEN);
  77         memcpy(lnkid->init_sta, src_addr, ETH_ALEN);
  78         memcpy(lnkid->resp_sta, peer, ETH_ALEN);
  79 }
  80
  81 static int
  82 ieee80211_prep_tdls_encap_data(struct wiphy *wiphy, struct net_device *dev,
  83                                const u8 *peer, u8 action_code, u8 dialog_token,
  84                                u16 status_code, struct sk_buff *skb)
  85 {
  86         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  87         enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
  88         struct ieee80211_tdls_data *tf;
  89
  90         tf = (void *)skb_put(skb, offsetof(struct ieee80211_tdls_data, u));
  91
  92         memcpy(tf->da, peer, ETH_ALEN);
  93         memcpy(tf->sa, sdata->vif.addr, ETH_ALEN);
  94         tf->ether_type = cpu_to_be16(ETH_P_TDLS);
  95         tf->payload_type = WLAN_TDLS_SNAP_RFTYPE;
  96
  97         switch (action_code) {
  98         case WLAN_TDLS_SETUP_REQUEST:
  99                 tf->category = WLAN_CATEGORY_TDLS;
 100                 tf->action_code = WLAN_TDLS_SETUP_REQUEST;
 101
 102                 skb_put(skb, sizeof(tf->u.setup_req));
 103                 tf->u.setup_req.dialog_token = dialog_token;
 104                 tf->u.setup_req.capability =
 105                         cpu_to_le16(ieee80211_get_tdls_sta_capab(sdata));
 106
 107                 ieee80211_add_srates_ie(sdata, skb, false, band);
 108                 ieee80211_add_ext_srates_ie(sdata, skb, false, band);
 109                 ieee80211_tdls_add_ext_capab(skb);
 110                 break;
 111         case WLAN_TDLS_SETUP_RESPONSE:
 112                 tf->category = WLAN_CATEGORY_TDLS;
 113                 tf->action_code = WLAN_TDLS_SETUP_RESPONSE;
 114
 115                 skb_put(skb, sizeof(tf->u.setup_resp));
 116                 tf->u.setup_resp.status_code = cpu_to_le16(status_code);
 117                 tf->u.setup_resp.dialog_token = dialog_token;
 118                 tf->u.setup_resp.capability =
 119                         cpu_to_le16(ieee80211_get_tdls_sta_capab(sdata));
 120
 121                 ieee80211_add_srates_ie(sdata, skb, false, band);
 122                 ieee80211_add_ext_srates_ie(sdata, skb, false, band);
 123                 ieee80211_tdls_add_ext_capab(skb);
 124                 break;
 125         case WLAN_TDLS_SETUP_CONFIRM:
 126                 tf->category = WLAN_CATEGORY_TDLS;
 127                 tf->action_code = WLAN_TDLS_SETUP_CONFIRM;
 128
 129                 skb_put(skb, sizeof(tf->u.setup_cfm));
 130                 tf->u.setup_cfm.status_code = cpu_to_le16(status_code);
 131                 tf->u.setup_cfm.dialog_token = dialog_token;
 132                 break;
 133         case WLAN_TDLS_TEARDOWN:
 134                 tf->category = WLAN_CATEGORY_TDLS;
 135                 tf->action_code = WLAN_TDLS_TEARDOWN;
 136
 137                 skb_put(skb, sizeof(tf->u.teardown));
 138                 tf->u.teardown.reason_code = cpu_to_le16(status_code);
 139                 break;
 140         case WLAN_TDLS_DISCOVERY_REQUEST:
 141                 tf->category = WLAN_CATEGORY_TDLS;
 142                 tf->action_code = WLAN_TDLS_DISCOVERY_REQUEST;
 143
 144                 skb_put(skb, sizeof(tf->u.discover_req));
 145                 tf->u.discover_req.dialog_token = dialog_token;
 146                 break;
 147         default:
 148                 return -EINVAL;
 149         }
 150
 151         return 0;
 152 }
 153
 154 static int
 155 ieee80211_prep_tdls_direct(struct wiphy *wiphy, struct net_device *dev,
 156                            const u8 *peer, u8 action_code, u8 dialog_token,
 157                            u16 status_code, struct sk_buff *skb)
 158 {
 159         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 160         enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
 161         struct ieee80211_mgmt *mgmt;
 162
 163         mgmt = (void *)skb_put(skb, 24);
 164         memset(mgmt, 0, 24);
 165         memcpy(mgmt->da, peer, ETH_ALEN);
 166         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 167         memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 168
 169         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 170                                           IEEE80211_STYPE_ACTION);
 171
 172         switch (action_code) {
 173         case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
 174                 skb_put(skb, 1 + sizeof(mgmt->u.action.u.tdls_discover_resp));
 175                 mgmt->u.action.category = WLAN_CATEGORY_PUBLIC;
 176                 mgmt->u.action.u.tdls_discover_resp.action_code =
 177                         WLAN_PUB_ACTION_TDLS_DISCOVER_RES;
 178                 mgmt->u.action.u.tdls_discover_resp.dialog_token =
 179                         dialog_token;
 180                 mgmt->u.action.u.tdls_discover_resp.capability =
 181                         cpu_to_le16(ieee80211_get_tdls_sta_capab(sdata));
 182
 183                 ieee80211_add_srates_ie(sdata, skb, false, band);
 184                 ieee80211_add_ext_srates_ie(sdata, skb, false, band);
 185                 ieee80211_tdls_add_ext_capab(skb);
 186                 break;
 187         default:
 188                 return -EINVAL;
 189         }
 190
 191         return 0;
 192 }
 193
 194 static int
 195 ieee80211_tdls_prep_mgmt_packet(struct wiphy *wiphy, struct net_device *dev,
 196                                 const u8 *peer, u8 action_code,
 197                                 u8 dialog_token, u16 status_code,
 198                                 u32 peer_capability, bool initiator,
 199                                 const u8 *extra_ies, size_t extra_ies_len)
 200 {
 201         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 202         struct ieee80211_local *local = sdata->local;
 203         struct sk_buff *skb = NULL;
 204         bool send_direct;
 205         const u8 *init_addr, *rsp_addr;
 206         struct sta_info *sta;
 207         int ret;
 208
 209         skb = dev_alloc_skb(local->hw.extra_tx_headroom +
 210                             max(sizeof(struct ieee80211_mgmt),
 211                                 sizeof(struct ieee80211_tdls_data)) +
 212                             50 + /* supported rates */
 213                             7 + /* ext capab */
 214                             extra_ies_len +
 215                             sizeof(struct ieee80211_tdls_lnkie));
 216         if (!skb)
 217                 return -ENOMEM;
 218
 219         skb_reserve(skb, local->hw.extra_tx_headroom);
 220
 221         switch (action_code) {
 222         case WLAN_TDLS_SETUP_REQUEST:
 223         case WLAN_TDLS_SETUP_RESPONSE:
 224         case WLAN_TDLS_SETUP_CONFIRM:
 225         case WLAN_TDLS_TEARDOWN:
 226         case WLAN_TDLS_DISCOVERY_REQUEST:
 227                 ret = ieee80211_prep_tdls_encap_data(wiphy, dev, peer,
 228                                                      action_code, dialog_token,
 229                                                      status_code, skb);
 230                 send_direct = false;
 231                 break;
 232         case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
 233                 ret = ieee80211_prep_tdls_direct(wiphy, dev, peer, action_code,
 234                                                  dialog_token, status_code,
 235                                                  skb);
 236                 send_direct = true;
 237                 break;
 238         default:
 239                 ret = -ENOTSUPP;
 240                 break;
 241         }
 242
 243         if (ret < 0)
 244                 goto fail;
 245
 246         if (extra_ies_len)
 247                 memcpy(skb_put(skb, extra_ies_len), extra_ies, extra_ies_len);
 248
 249         rcu_read_lock();
 250         sta = sta_info_get(sdata, peer);
 251
 252         /* infer the initiator if we can, to support old userspace */
 253         switch (action_code) {
 254         case WLAN_TDLS_SETUP_REQUEST:
 255                 if (sta)
 256                         set_sta_flag(sta, WLAN_STA_TDLS_INITIATOR);
 257                 /* fall-through */
 258         case WLAN_TDLS_SETUP_CONFIRM:
 259         case WLAN_TDLS_DISCOVERY_REQUEST:
 260                 initiator = true;
 261                 break;
 262         case WLAN_TDLS_SETUP_RESPONSE:
 263                 /*
 264                  * In some testing scenarios, we send a request and response.
 265                  * Make the last packet sent take effect for the initiator
 266                  * value.
 267                  */
 268                 if (sta)
 269                         clear_sta_flag(sta, WLAN_STA_TDLS_INITIATOR);
 270                 /* fall-through */
 271         case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
 272                 initiator = false;
 273                 break;
 274         case WLAN_TDLS_TEARDOWN:
 275                 /* any value is ok */
 276                 break;
 277         default:
 278                 ret = -ENOTSUPP;
 279                 break;
 280         }
 281
 282         if (initiator || (sta && test_sta_flag(sta, WLAN_STA_TDLS_INITIATOR))) {
 283                 init_addr = sdata->vif.addr;
 284                 rsp_addr = peer;
 285         } else {
 286                 init_addr = peer;
 287                 rsp_addr = sdata->vif.addr;
 288         }
 289
 290         rcu_read_unlock();
 291         if (ret < 0)
 292                 goto fail;
 293
 294         ieee80211_tdls_add_link_ie(skb, init_addr, rsp_addr,
 295                                    sdata->u.mgd.bssid);
 296
 297         if (send_direct) {
 298                 ieee80211_tx_skb(sdata, skb);
 299                 return 0;
 300         }
 301
 302         /*
 303          * According to 802.11z: Setup req/resp are sent in AC_BK, otherwise
 304          * we should default to AC_VI.
 305          */
 306         switch (action_code) {
 307         case WLAN_TDLS_SETUP_REQUEST:
 308         case WLAN_TDLS_SETUP_RESPONSE:
 309                 skb_set_queue_mapping(skb, IEEE80211_AC_BK);
 310                 skb->priority = 2;
 311                 break;
 312         default:
 313                 skb_set_queue_mapping(skb, IEEE80211_AC_VI);
 314                 skb->priority = 5;
 315                 break;
 316         }
 317
 318         /* disable bottom halves when entering the Tx path */
 319         local_bh_disable();
 320         ret = ieee80211_subif_start_xmit(skb, dev);
 321         local_bh_enable();
 322
 323         return ret;
 324
 325 fail:
 326         dev_kfree_skb(skb);
 327         return ret;
 328 }
 329
 330 static int
 331 ieee80211_tdls_mgmt_setup(struct wiphy *wiphy, struct net_device *dev,
 332                           const u8 *peer, u8 action_code, u8 dialog_token,
 333                           u16 status_code, u32 peer_capability, bool initiator,
 334                           const u8 *extra_ies, size_t extra_ies_len)
 335 {
 336         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 337         struct ieee80211_local *local = sdata->local;
 338         int ret;
 339
 340         mutex_lock(&local->mtx);
 341
 342         /* we don't support concurrent TDLS peer setups */
 343         if (!is_zero_ether_addr(sdata->tdls_peer) &&
 344             !ether_addr_equal(sdata->tdls_peer, peer)) {
 345                 ret = -EBUSY;
 346                 goto exit;
 347         }
 348
 349         /*
 350          * make sure we have a STA representing the peer so we drop or buffer
 351          * non-TDLS-setup frames to the peer. We can't send other packets
 352          * during setup through the AP path
 353          */
 354         rcu_read_lock();
 355         if (!sta_info_get(sdata, peer)) {
 356                 rcu_read_unlock();
 357                 ret = -ENOLINK;
 358                 goto exit;
 359         }
 360         rcu_read_unlock();
 361
 362         ieee80211_flush_queues(local, sdata);
 363
 364         ret = ieee80211_tdls_prep_mgmt_packet(wiphy, dev, peer, action_code,
 365                                               dialog_token, status_code,
 366                                               peer_capability, initiator,
 367                                               extra_ies, extra_ies_len);
 368         if (ret < 0)
 369                 goto exit;
 370
 371         memcpy(sdata->tdls_peer, peer, ETH_ALEN);
 372         ieee80211_queue_delayed_work(&sdata->local->hw,
 373                                      &sdata->tdls_peer_del_work,
 374                                      TDLS_PEER_SETUP_TIMEOUT);
 375
 376 exit:
 377         mutex_unlock(&local->mtx);
 378         return ret;
 379 }
 380
 381 static int
 382 ieee80211_tdls_mgmt_teardown(struct wiphy *wiphy, struct net_device *dev,
 383                              const u8 *peer, u8 action_code, u8 dialog_token,
 384                              u16 status_code, u32 peer_capability,
 385                              bool initiator, const u8 *extra_ies,
 386                              size_t extra_ies_len)
 387 {
 388         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 389         struct ieee80211_local *local = sdata->local;
 390         struct sta_info *sta;
 391         int ret;
 392
 393         /*
 394          * No packets can be transmitted to the peer via the AP during setup -
 395          * the STA is set as a TDLS peer, but is not authorized.
 396          * During teardown, we prevent direct transmissions by stopping the
 397          * queues and flushing all direct packets.
 398          */
 399         ieee80211_stop_vif_queues(local, sdata,
 400                                   IEEE80211_QUEUE_STOP_REASON_TDLS_TEARDOWN);
 401         ieee80211_flush_queues(local, sdata);
 402
 403         ret = ieee80211_tdls_prep_mgmt_packet(wiphy, dev, peer, action_code,
 404                                               dialog_token, status_code,
 405                                               peer_capability, initiator,
 406                                               extra_ies, extra_ies_len);
 407         if (ret < 0)
 408                 sdata_err(sdata, "Failed sending TDLS teardown packet %d\n",
 409                           ret);
 410
 411         /*
 412          * Remove the STA AUTH flag to force further traffic through the AP. If
 413          * the STA was unreachable, it was already removed.
 414          */
 415         rcu_read_lock();
 416         sta = sta_info_get(sdata, peer);
 417         if (sta)
 418                 clear_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH);
 419         rcu_read_unlock();
 420
 421         ieee80211_wake_vif_queues(local, sdata,
 422                                   IEEE80211_QUEUE_STOP_REASON_TDLS_TEARDOWN);
 423
 424         return 0;
 425 }
 426
 427 int ieee80211_tdls_mgmt(struct wiphy *wiphy, struct net_device *dev,
 428                         const u8 *peer, u8 action_code, u8 dialog_token,
 429                         u16 status_code, u32 peer_capability,
 430                         bool initiator, const u8 *extra_ies,
 431                         size_t extra_ies_len)
 432 {
 433         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 434         int ret;
 435
 436         if (!(wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS))
 437                 return -ENOTSUPP;
 438
 439         /* make sure we are in managed mode, and associated */
 440         if (sdata->vif.type != NL80211_IFTYPE_STATION ||
 441             !sdata->u.mgd.associated)
 442                 return -EINVAL;
 443
 444         switch (action_code) {
 445         case WLAN_TDLS_SETUP_REQUEST:
 446         case WLAN_TDLS_SETUP_RESPONSE:
 447                 ret = ieee80211_tdls_mgmt_setup(wiphy, dev, peer, action_code,
 448                                                 dialog_token, status_code,
 449                                                 peer_capability, initiator,
 450                                                 extra_ies, extra_ies_len);
 451                 break;
 452         case WLAN_TDLS_TEARDOWN:
 453                 ret = ieee80211_tdls_mgmt_teardown(wiphy, dev, peer,
 454                                                    action_code, dialog_token,
 455                                                    status_code,
 456                                                    peer_capability, initiator,
 457                                                    extra_ies, extra_ies_len);
 458                 break;
 459         case WLAN_TDLS_DISCOVERY_REQUEST:
 460                 /*
 461                  * Protect the discovery so we can hear the TDLS discovery
 462                  * response frame. It is transmitted directly and not buffered
 463                  * by the AP.
 464                  */
 465                 drv_mgd_protect_tdls_discover(sdata->local, sdata);
 466                 /* fall-through */
 467         case WLAN_TDLS_SETUP_CONFIRM:
 468         case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
 469                 /* no special handling */
 470                 ret = ieee80211_tdls_prep_mgmt_packet(wiphy, dev, peer,
 471                                                       action_code,
 472                                                       dialog_token,
 473                                                       status_code,
 474                                                       peer_capability,
 475                                                       initiator, extra_ies,
 476                                                       extra_ies_len);
 477                 break;
 478         default:
 479                 ret = -EOPNOTSUPP;
 480                 break;
 481         }
 482
 483         tdls_dbg(sdata, "TDLS mgmt action %d peer %pM status %d\n",
 484                  action_code, peer, ret);
 485         return ret;
 486 }
 487
 488 int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev,
 489                         const u8 *peer, enum nl80211_tdls_operation oper)
 490 {
 491         struct sta_info *sta;
 492         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 493         struct ieee80211_local *local = sdata->local;
 494         int ret;
 495
 496         if (!(wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS))
 497                 return -ENOTSUPP;
 498
 499         if (sdata->vif.type != NL80211_IFTYPE_STATION)
 500                 return -EINVAL;
 501
 502         switch (oper) {
 503         case NL80211_TDLS_ENABLE_LINK:
 504         case NL80211_TDLS_DISABLE_LINK:
 505                 break;
 506         case NL80211_TDLS_TEARDOWN:
 507         case NL80211_TDLS_SETUP:
 508         case NL80211_TDLS_DISCOVERY_REQ:
 509                 /* We don't support in-driver setup/teardown/discovery */
 510                 return -ENOTSUPP;
 511         }
 512
 513         mutex_lock(&local->mtx);
 514         tdls_dbg(sdata, "TDLS oper %d peer %pM\n", oper, peer);
 515
 516         switch (oper) {
 517         case NL80211_TDLS_ENABLE_LINK:
 518                 rcu_read_lock();
 519                 sta = sta_info_get(sdata, peer);
 520                 if (!sta) {
 521                         rcu_read_unlock();
 522                         ret = -ENOLINK;
 523                         break;
 524                 }
 525
 526                 set_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH);
 527                 rcu_read_unlock();
 528
 529                 WARN_ON_ONCE(is_zero_ether_addr(sdata->tdls_peer) ||
 530                              !ether_addr_equal(sdata->tdls_peer, peer));
 531                 ret = 0;
 532                 break;
 533         case NL80211_TDLS_DISABLE_LINK:
 534                 /* flush a potentially queued teardown packet */
 535                 ieee80211_flush_queues(local, sdata);
 536
 537                 ret = sta_info_destroy_addr(sdata, peer);
 538                 break;
 539         default:
 540                 ret = -ENOTSUPP;
 541                 break;
 542         }
 543
 544         if (ret == 0 && ether_addr_equal(sdata->tdls_peer, peer)) {
 545                 cancel_delayed_work(&sdata->tdls_peer_del_work);
 546                 eth_zero_addr(sdata->tdls_peer);
 547         }
 548
 549         mutex_unlock(&local->mtx);
 550         return ret;
 551 }
 552
 553 void ieee80211_tdls_oper_request(struct ieee80211_vif *vif, const u8 *peer,
 554                                  enum nl80211_tdls_operation oper,
 555                                  u16 reason_code, gfp_t gfp)
 556 {
 557         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 558
 559         if (vif->type != NL80211_IFTYPE_STATION || !vif->bss_conf.assoc) {
 560                 sdata_err(sdata, "Discarding TDLS oper %d - not STA or disconnected\n",
 561                           oper);
 562                 return;
 563         }
 564
 565         cfg80211_tdls_oper_request(sdata->dev, peer, oper, reason_code, gfp);
 566 }
 567 EXPORT_SYMBOL(ieee80211_tdls_oper_request);