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         int ret;
 207
 208         skb = dev_alloc_skb(local->hw.extra_tx_headroom +
 209                             max(sizeof(struct ieee80211_mgmt),
 210                                 sizeof(struct ieee80211_tdls_data)) +
 211                             50 + /* supported rates */
 212                             7 + /* ext capab */
 213                             extra_ies_len +
 214                             sizeof(struct ieee80211_tdls_lnkie));
 215         if (!skb)
 216                 return -ENOMEM;
 217
 218         skb_reserve(skb, local->hw.extra_tx_headroom);
 219
 220         switch (action_code) {
 221         case WLAN_TDLS_SETUP_REQUEST:
 222         case WLAN_TDLS_SETUP_RESPONSE:
 223         case WLAN_TDLS_SETUP_CONFIRM:
 224         case WLAN_TDLS_TEARDOWN:
 225         case WLAN_TDLS_DISCOVERY_REQUEST:
 226                 ret = ieee80211_prep_tdls_encap_data(wiphy, dev, peer,
 227                                                      action_code, dialog_token,
 228                                                      status_code, skb);
 229                 send_direct = false;
 230                 break;
 231         case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
 232                 ret = ieee80211_prep_tdls_direct(wiphy, dev, peer, action_code,
 233                                                  dialog_token, status_code,
 234                                                  skb);
 235                 send_direct = true;
 236                 break;
 237         default:
 238                 ret = -ENOTSUPP;
 239                 break;
 240         }
 241
 242         if (ret < 0)
 243                 goto fail;
 244
 245         if (extra_ies_len)
 246                 memcpy(skb_put(skb, extra_ies_len), extra_ies, extra_ies_len);
 247
 248         /* sanity check for initiator */
 249         switch (action_code) {
 250         case WLAN_TDLS_SETUP_REQUEST:
 251         case WLAN_TDLS_SETUP_CONFIRM:
 252         case WLAN_TDLS_DISCOVERY_REQUEST:
 253                 if (!initiator) {
 254                         ret = -EINVAL;
 255                         goto fail;
 256                 }
 257                 break;
 258         case WLAN_TDLS_SETUP_RESPONSE:
 259         case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
 260                 if (initiator) {
 261                         ret = -EINVAL;
 262                         goto fail;
 263                 }
 264                 break;
 265         case WLAN_TDLS_TEARDOWN:
 266                 /* any value is ok */
 267                 break;
 268         default:
 269                 ret = -ENOTSUPP;
 270                 goto fail;
 271         }
 272
 273         if (initiator) {
 274                 init_addr = sdata->vif.addr;
 275                 rsp_addr = peer;
 276         } else {
 277                 init_addr = peer;
 278                 rsp_addr = sdata->vif.addr;
 279         }
 280
 281         ieee80211_tdls_add_link_ie(skb, init_addr, rsp_addr,
 282                                    sdata->u.mgd.bssid);
 283
 284         if (send_direct) {
 285                 ieee80211_tx_skb(sdata, skb);
 286                 return 0;
 287         }
 288
 289         /*
 290          * According to 802.11z: Setup req/resp are sent in AC_BK, otherwise
 291          * we should default to AC_VI.
 292          */
 293         switch (action_code) {
 294         case WLAN_TDLS_SETUP_REQUEST:
 295         case WLAN_TDLS_SETUP_RESPONSE:
 296                 skb_set_queue_mapping(skb, IEEE80211_AC_BK);
 297                 skb->priority = 2;
 298                 break;
 299         default:
 300                 skb_set_queue_mapping(skb, IEEE80211_AC_VI);
 301                 skb->priority = 5;
 302                 break;
 303         }
 304
 305         /* disable bottom halves when entering the Tx path */
 306         local_bh_disable();
 307         ret = ieee80211_subif_start_xmit(skb, dev);
 308         local_bh_enable();
 309
 310         return ret;
 311
 312 fail:
 313         dev_kfree_skb(skb);
 314         return ret;
 315 }
 316
 317 static int
 318 ieee80211_tdls_mgmt_setup(struct wiphy *wiphy, struct net_device *dev,
 319                           const u8 *peer, u8 action_code, u8 dialog_token,
 320                           u16 status_code, u32 peer_capability, bool initiator,
 321                           const u8 *extra_ies, size_t extra_ies_len)
 322 {
 323         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 324         struct ieee80211_local *local = sdata->local;
 325         int ret;
 326
 327         mutex_lock(&local->mtx);
 328
 329         /* we don't support concurrent TDLS peer setups */
 330         if (!is_zero_ether_addr(sdata->tdls_peer) &&
 331             !ether_addr_equal(sdata->tdls_peer, peer)) {
 332                 ret = -EBUSY;
 333                 goto exit;
 334         }
 335
 336         /*
 337          * make sure we have a STA representing the peer so we drop or buffer
 338          * non-TDLS-setup frames to the peer. We can't send other packets
 339          * during setup through the AP path
 340          */
 341         rcu_read_lock();
 342         if (!sta_info_get(sdata, peer)) {
 343                 rcu_read_unlock();
 344                 ret = -ENOLINK;
 345                 goto exit;
 346         }
 347         rcu_read_unlock();
 348
 349         ieee80211_flush_queues(local, sdata);
 350
 351         ret = ieee80211_tdls_prep_mgmt_packet(wiphy, dev, peer, action_code,
 352                                               dialog_token, status_code,
 353                                               peer_capability, initiator,
 354                                               extra_ies, extra_ies_len);
 355         if (ret < 0)
 356                 goto exit;
 357
 358         memcpy(sdata->tdls_peer, peer, ETH_ALEN);
 359         ieee80211_queue_delayed_work(&sdata->local->hw,
 360                                      &sdata->tdls_peer_del_work,
 361                                      TDLS_PEER_SETUP_TIMEOUT);
 362
 363 exit:
 364         mutex_unlock(&local->mtx);
 365         return ret;
 366 }
 367
 368 static int
 369 ieee80211_tdls_mgmt_teardown(struct wiphy *wiphy, struct net_device *dev,
 370                              const u8 *peer, u8 action_code, u8 dialog_token,
 371                              u16 status_code, u32 peer_capability,
 372                              bool initiator, const u8 *extra_ies,
 373                              size_t extra_ies_len)
 374 {
 375         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 376         struct ieee80211_local *local = sdata->local;
 377         struct sta_info *sta;
 378         int ret;
 379
 380         /*
 381          * No packets can be transmitted to the peer via the AP during setup -
 382          * the STA is set as a TDLS peer, but is not authorized.
 383          * During teardown, we prevent direct transmissions by stopping the
 384          * queues and flushing all direct packets.
 385          */
 386         ieee80211_stop_vif_queues(local, sdata,
 387                                   IEEE80211_QUEUE_STOP_REASON_TDLS_TEARDOWN);
 388         ieee80211_flush_queues(local, sdata);
 389
 390         ret = ieee80211_tdls_prep_mgmt_packet(wiphy, dev, peer, action_code,
 391                                               dialog_token, status_code,
 392                                               peer_capability, initiator,
 393                                               extra_ies, extra_ies_len);
 394         if (ret < 0)
 395                 sdata_err(sdata, "Failed sending TDLS teardown packet %d\n",
 396                           ret);
 397
 398         /*
 399          * Remove the STA AUTH flag to force further traffic through the AP. If
 400          * the STA was unreachable, it was already removed.
 401          */
 402         rcu_read_lock();
 403         sta = sta_info_get(sdata, peer);
 404         if (sta)
 405                 clear_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH);
 406         rcu_read_unlock();
 407
 408         ieee80211_wake_vif_queues(local, sdata,
 409                                   IEEE80211_QUEUE_STOP_REASON_TDLS_TEARDOWN);
 410
 411         return 0;
 412 }
 413
 414 int ieee80211_tdls_mgmt(struct wiphy *wiphy, struct net_device *dev,
 415                         const u8 *peer, u8 action_code, u8 dialog_token,
 416                         u16 status_code, u32 peer_capability,
 417                         bool initiator, const u8 *extra_ies,
 418                         size_t extra_ies_len)
 419 {
 420         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 421         int ret;
 422
 423         if (!(wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS))
 424                 return -ENOTSUPP;
 425
 426         /* make sure we are in managed mode, and associated */
 427         if (sdata->vif.type != NL80211_IFTYPE_STATION ||
 428             !sdata->u.mgd.associated)
 429                 return -EINVAL;
 430
 431         switch (action_code) {
 432         case WLAN_TDLS_SETUP_REQUEST:
 433         case WLAN_TDLS_SETUP_RESPONSE:
 434                 ret = ieee80211_tdls_mgmt_setup(wiphy, dev, peer, action_code,
 435                                                 dialog_token, status_code,
 436                                                 peer_capability, initiator,
 437                                                 extra_ies, extra_ies_len);
 438                 break;
 439         case WLAN_TDLS_TEARDOWN:
 440                 ret = ieee80211_tdls_mgmt_teardown(wiphy, dev, peer,
 441                                                    action_code, dialog_token,
 442                                                    status_code,
 443                                                    peer_capability, initiator,
 444                                                    extra_ies, extra_ies_len);
 445                 break;
 446         case WLAN_TDLS_DISCOVERY_REQUEST:
 447                 /*
 448                  * Protect the discovery so we can hear the TDLS discovery
 449                  * response frame. It is transmitted directly and not buffered
 450                  * by the AP.
 451                  */
 452                 drv_mgd_protect_tdls_discover(sdata->local, sdata);
 453                 /* fall-through */
 454         case WLAN_TDLS_SETUP_CONFIRM:
 455         case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
 456                 /* no special handling */
 457                 ret = ieee80211_tdls_prep_mgmt_packet(wiphy, dev, peer,
 458                                                       action_code,
 459                                                       dialog_token,
 460                                                       status_code,
 461                                                       peer_capability,
 462                                                       initiator, extra_ies,
 463                                                       extra_ies_len);
 464                 break;
 465         default:
 466                 ret = -EOPNOTSUPP;
 467                 break;
 468         }
 469
 470         tdls_dbg(sdata, "TDLS mgmt action %d peer %pM status %d\n",
 471                  action_code, peer, ret);
 472         return ret;
 473 }
 474
 475 int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev,
 476                         const u8 *peer, enum nl80211_tdls_operation oper)
 477 {
 478         struct sta_info *sta;
 479         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 480         struct ieee80211_local *local = sdata->local;
 481         int ret;
 482
 483         if (!(wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS))
 484                 return -ENOTSUPP;
 485
 486         if (sdata->vif.type != NL80211_IFTYPE_STATION)
 487                 return -EINVAL;
 488
 489         switch (oper) {
 490         case NL80211_TDLS_ENABLE_LINK:
 491         case NL80211_TDLS_DISABLE_LINK:
 492                 break;
 493         case NL80211_TDLS_TEARDOWN:
 494         case NL80211_TDLS_SETUP:
 495         case NL80211_TDLS_DISCOVERY_REQ:
 496                 /* We don't support in-driver setup/teardown/discovery */
 497                 return -ENOTSUPP;
 498         }
 499
 500         mutex_lock(&local->mtx);
 501         tdls_dbg(sdata, "TDLS oper %d peer %pM\n", oper, peer);
 502
 503         switch (oper) {
 504         case NL80211_TDLS_ENABLE_LINK:
 505                 rcu_read_lock();
 506                 sta = sta_info_get(sdata, peer);
 507                 if (!sta) {
 508                         rcu_read_unlock();
 509                         ret = -ENOLINK;
 510                         break;
 511                 }
 512
 513                 set_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH);
 514                 rcu_read_unlock();
 515
 516                 WARN_ON_ONCE(is_zero_ether_addr(sdata->tdls_peer) ||
 517                              !ether_addr_equal(sdata->tdls_peer, peer));
 518                 ret = 0;
 519                 break;
 520         case NL80211_TDLS_DISABLE_LINK:
 521                 /* flush a potentially queued teardown packet */
 522                 ieee80211_flush_queues(local, sdata);
 523
 524                 ret = sta_info_destroy_addr(sdata, peer);
 525                 break;
 526         default:
 527                 ret = -ENOTSUPP;
 528                 break;
 529         }
 530
 531         if (ret == 0 && ether_addr_equal(sdata->tdls_peer, peer)) {
 532                 cancel_delayed_work(&sdata->tdls_peer_del_work);
 533                 eth_zero_addr(sdata->tdls_peer);
 534         }
 535
 536         mutex_unlock(&local->mtx);
 537         return ret;
 538 }
 539
 540 void ieee80211_tdls_oper_request(struct ieee80211_vif *vif, const u8 *peer,
 541                                  enum nl80211_tdls_operation oper,
 542                                  u16 reason_code, gfp_t gfp)
 543 {
 544         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 545
 546         if (vif->type != NL80211_IFTYPE_STATION || !vif->bss_conf.assoc) {
 547                 sdata_err(sdata, "Discarding TDLS oper %d - not STA or disconnected\n",
 548                           oper);
 549                 return;
 550         }
 551
 552         cfg80211_tdls_oper_request(sdata->dev, peer, oper, reason_code, gfp);
 553 }
 554 EXPORT_SYMBOL(ieee80211_tdls_oper_request);