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