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 "ieee80211_i.h"
  12
  13 /* give usermode some time for retries in setting up the TDLS session */
  14 #define TDLS_PEER_SETUP_TIMEOUT (15 * HZ)
  15
  16 void ieee80211_tdls_peer_del_work(struct work_struct *wk)
  17 {
  18         struct ieee80211_sub_if_data *sdata;
  19         struct ieee80211_local *local;
  20
  21         sdata = container_of(wk, struct ieee80211_sub_if_data,
  22                              tdls_peer_del_work.work);
  23         local = sdata->local;
  24
  25         mutex_lock(&local->mtx);
  26         if (!is_zero_ether_addr(sdata->tdls_peer)) {
  27                 tdls_dbg(sdata, "TDLS del peer %pM\n", sdata->tdls_peer);
  28                 sta_info_destroy_addr(sdata, sdata->tdls_peer);
  29                 eth_zero_addr(sdata->tdls_peer);
  30         }
  31         mutex_unlock(&local->mtx);
  32 }
  33
  34 static void ieee80211_tdls_add_ext_capab(struct sk_buff *skb)
  35 {
  36         u8 *pos = (void *)skb_put(skb, 7);
  37
  38         *pos++ = WLAN_EID_EXT_CAPABILITY;
  39         *pos++ = 5; /* len */
  40         *pos++ = 0x0;
  41         *pos++ = 0x0;
  42         *pos++ = 0x0;
  43         *pos++ = 0x0;
  44         *pos++ = WLAN_EXT_CAPA5_TDLS_ENABLED;
  45 }
  46
  47 static u16 ieee80211_get_tdls_sta_capab(struct ieee80211_sub_if_data *sdata)
  48 {
  49         struct ieee80211_local *local = sdata->local;
  50         u16 capab;
  51
  52         capab = 0;
  53         if (ieee80211_get_sdata_band(sdata) != IEEE80211_BAND_2GHZ)
  54                 return capab;
  55
  56         if (!(local->hw.flags & IEEE80211_HW_2GHZ_SHORT_SLOT_INCAPABLE))
  57                 capab |= WLAN_CAPABILITY_SHORT_SLOT_TIME;
  58         if (!(local->hw.flags & IEEE80211_HW_2GHZ_SHORT_PREAMBLE_INCAPABLE))
  59                 capab |= WLAN_CAPABILITY_SHORT_PREAMBLE;
  60
  61         return capab;
  62 }
  63
  64 static void ieee80211_tdls_add_link_ie(struct sk_buff *skb, const u8 *src_addr,
  65                                        const u8 *peer, const u8 *bssid)
  66 {
  67         struct ieee80211_tdls_lnkie *lnkid;
  68
  69         lnkid = (void *)skb_put(skb, sizeof(struct ieee80211_tdls_lnkie));
  70
  71         lnkid->ie_type = WLAN_EID_LINK_ID;
  72         lnkid->ie_len = sizeof(struct ieee80211_tdls_lnkie) - 2;
  73
  74         memcpy(lnkid->bssid, bssid, ETH_ALEN);
  75         memcpy(lnkid->init_sta, src_addr, ETH_ALEN);
  76         memcpy(lnkid->resp_sta, peer, ETH_ALEN);
  77 }
  78
  79 static int
  80 ieee80211_prep_tdls_encap_data(struct wiphy *wiphy, struct net_device *dev,
  81                                const u8 *peer, u8 action_code, u8 dialog_token,
  82                                u16 status_code, struct sk_buff *skb)
  83 {
  84         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
  85         enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
  86         struct ieee80211_tdls_data *tf;
  87
  88         tf = (void *)skb_put(skb, offsetof(struct ieee80211_tdls_data, u));
  89
  90         memcpy(tf->da, peer, ETH_ALEN);
  91         memcpy(tf->sa, sdata->vif.addr, ETH_ALEN);
  92         tf->ether_type = cpu_to_be16(ETH_P_TDLS);
  93         tf->payload_type = WLAN_TDLS_SNAP_RFTYPE;
  94
  95         switch (action_code) {
  96         case WLAN_TDLS_SETUP_REQUEST:
  97                 tf->category = WLAN_CATEGORY_TDLS;
  98                 tf->action_code = WLAN_TDLS_SETUP_REQUEST;
  99
 100                 skb_put(skb, sizeof(tf->u.setup_req));
 101                 tf->u.setup_req.dialog_token = dialog_token;
 102                 tf->u.setup_req.capability =
 103                         cpu_to_le16(ieee80211_get_tdls_sta_capab(sdata));
 104
 105                 ieee80211_add_srates_ie(sdata, skb, false, band);
 106                 ieee80211_add_ext_srates_ie(sdata, skb, false, band);
 107                 ieee80211_tdls_add_ext_capab(skb);
 108                 break;
 109         case WLAN_TDLS_SETUP_RESPONSE:
 110                 tf->category = WLAN_CATEGORY_TDLS;
 111                 tf->action_code = WLAN_TDLS_SETUP_RESPONSE;
 112
 113                 skb_put(skb, sizeof(tf->u.setup_resp));
 114                 tf->u.setup_resp.status_code = cpu_to_le16(status_code);
 115                 tf->u.setup_resp.dialog_token = dialog_token;
 116                 tf->u.setup_resp.capability =
 117                         cpu_to_le16(ieee80211_get_tdls_sta_capab(sdata));
 118
 119                 ieee80211_add_srates_ie(sdata, skb, false, band);
 120                 ieee80211_add_ext_srates_ie(sdata, skb, false, band);
 121                 ieee80211_tdls_add_ext_capab(skb);
 122                 break;
 123         case WLAN_TDLS_SETUP_CONFIRM:
 124                 tf->category = WLAN_CATEGORY_TDLS;
 125                 tf->action_code = WLAN_TDLS_SETUP_CONFIRM;
 126
 127                 skb_put(skb, sizeof(tf->u.setup_cfm));
 128                 tf->u.setup_cfm.status_code = cpu_to_le16(status_code);
 129                 tf->u.setup_cfm.dialog_token = dialog_token;
 130                 break;
 131         case WLAN_TDLS_TEARDOWN:
 132                 tf->category = WLAN_CATEGORY_TDLS;
 133                 tf->action_code = WLAN_TDLS_TEARDOWN;
 134
 135                 skb_put(skb, sizeof(tf->u.teardown));
 136                 tf->u.teardown.reason_code = cpu_to_le16(status_code);
 137                 break;
 138         case WLAN_TDLS_DISCOVERY_REQUEST:
 139                 tf->category = WLAN_CATEGORY_TDLS;
 140                 tf->action_code = WLAN_TDLS_DISCOVERY_REQUEST;
 141
 142                 skb_put(skb, sizeof(tf->u.discover_req));
 143                 tf->u.discover_req.dialog_token = dialog_token;
 144                 break;
 145         default:
 146                 return -EINVAL;
 147         }
 148
 149         return 0;
 150 }
 151
 152 static int
 153 ieee80211_prep_tdls_direct(struct wiphy *wiphy, struct net_device *dev,
 154                            const u8 *peer, u8 action_code, u8 dialog_token,
 155                            u16 status_code, struct sk_buff *skb)
 156 {
 157         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 158         enum ieee80211_band band = ieee80211_get_sdata_band(sdata);
 159         struct ieee80211_mgmt *mgmt;
 160
 161         mgmt = (void *)skb_put(skb, 24);
 162         memset(mgmt, 0, 24);
 163         memcpy(mgmt->da, peer, ETH_ALEN);
 164         memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
 165         memcpy(mgmt->bssid, sdata->u.mgd.bssid, ETH_ALEN);
 166
 167         mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 168                                           IEEE80211_STYPE_ACTION);
 169
 170         switch (action_code) {
 171         case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
 172                 skb_put(skb, 1 + sizeof(mgmt->u.action.u.tdls_discover_resp));
 173                 mgmt->u.action.category = WLAN_CATEGORY_PUBLIC;
 174                 mgmt->u.action.u.tdls_discover_resp.action_code =
 175                         WLAN_PUB_ACTION_TDLS_DISCOVER_RES;
 176                 mgmt->u.action.u.tdls_discover_resp.dialog_token =
 177                         dialog_token;
 178                 mgmt->u.action.u.tdls_discover_resp.capability =
 179                         cpu_to_le16(ieee80211_get_tdls_sta_capab(sdata));
 180
 181                 ieee80211_add_srates_ie(sdata, skb, false, band);
 182                 ieee80211_add_ext_srates_ie(sdata, skb, false, band);
 183                 ieee80211_tdls_add_ext_capab(skb);
 184                 break;
 185         default:
 186                 return -EINVAL;
 187         }
 188
 189         return 0;
 190 }
 191
 192 static int
 193 ieee80211_tdls_prep_mgmt_packet(struct wiphy *wiphy, struct net_device *dev,
 194                                 const u8 *peer, u8 action_code,
 195                                 u8 dialog_token, u16 status_code,
 196                                 u32 peer_capability, const u8 *extra_ies,
 197                                 size_t extra_ies_len)
 198 {
 199         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 200         struct ieee80211_local *local = sdata->local;
 201         struct sk_buff *skb = NULL;
 202         bool send_direct;
 203         int ret;
 204
 205         skb = dev_alloc_skb(local->hw.extra_tx_headroom +
 206                             max(sizeof(struct ieee80211_mgmt),
 207                                 sizeof(struct ieee80211_tdls_data)) +
 208                             50 + /* supported rates */
 209                             7 + /* ext capab */
 210                             extra_ies_len +
 211                             sizeof(struct ieee80211_tdls_lnkie));
 212         if (!skb)
 213                 return -ENOMEM;
 214
 215         skb_reserve(skb, local->hw.extra_tx_headroom);
 216
 217         switch (action_code) {
 218         case WLAN_TDLS_SETUP_REQUEST:
 219         case WLAN_TDLS_SETUP_RESPONSE:
 220         case WLAN_TDLS_SETUP_CONFIRM:
 221         case WLAN_TDLS_TEARDOWN:
 222         case WLAN_TDLS_DISCOVERY_REQUEST:
 223                 ret = ieee80211_prep_tdls_encap_data(wiphy, dev, peer,
 224                                                      action_code, dialog_token,
 225                                                      status_code, skb);
 226                 send_direct = false;
 227                 break;
 228         case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
 229                 ret = ieee80211_prep_tdls_direct(wiphy, dev, peer, action_code,
 230                                                  dialog_token, status_code,
 231                                                  skb);
 232                 send_direct = true;
 233                 break;
 234         default:
 235                 ret = -ENOTSUPP;
 236                 break;
 237         }
 238
 239         if (ret < 0)
 240                 goto fail;
 241
 242         if (extra_ies_len)
 243                 memcpy(skb_put(skb, extra_ies_len), extra_ies, extra_ies_len);
 244
 245         /* the TDLS link IE is always added last */
 246         switch (action_code) {
 247         case WLAN_TDLS_SETUP_REQUEST:
 248         case WLAN_TDLS_SETUP_CONFIRM:
 249         case WLAN_TDLS_TEARDOWN:
 250         case WLAN_TDLS_DISCOVERY_REQUEST:
 251                 /* we are the initiator */
 252                 ieee80211_tdls_add_link_ie(skb, sdata->vif.addr, peer,
 253                                            sdata->u.mgd.bssid);
 254                 break;
 255         case WLAN_TDLS_SETUP_RESPONSE:
 256         case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
 257                 /* we are the responder */
 258                 ieee80211_tdls_add_link_ie(skb, peer, sdata->vif.addr,
 259                                            sdata->u.mgd.bssid);
 260                 break;
 261         default:
 262                 ret = -ENOTSUPP;
 263                 goto fail;
 264         }
 265
 266         if (send_direct) {
 267                 ieee80211_tx_skb(sdata, skb);
 268                 return 0;
 269         }
 270
 271         /*
 272          * According to 802.11z: Setup req/resp are sent in AC_BK, otherwise
 273          * we should default to AC_VI.
 274          */
 275         switch (action_code) {
 276         case WLAN_TDLS_SETUP_REQUEST:
 277         case WLAN_TDLS_SETUP_RESPONSE:
 278                 skb_set_queue_mapping(skb, IEEE80211_AC_BK);
 279                 skb->priority = 2;
 280                 break;
 281         default:
 282                 skb_set_queue_mapping(skb, IEEE80211_AC_VI);
 283                 skb->priority = 5;
 284                 break;
 285         }
 286
 287         /* disable bottom halves when entering the Tx path */
 288         local_bh_disable();
 289         ret = ieee80211_subif_start_xmit(skb, dev);
 290         local_bh_enable();
 291
 292         return ret;
 293
 294 fail:
 295         dev_kfree_skb(skb);
 296         return ret;
 297 }
 298
 299 int ieee80211_tdls_mgmt(struct wiphy *wiphy, struct net_device *dev,
 300                         const u8 *peer, u8 action_code, u8 dialog_token,
 301                         u16 status_code, u32 peer_capability,
 302                         const u8 *extra_ies, size_t extra_ies_len)
 303 {
 304         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 305         struct ieee80211_local *local = sdata->local;
 306         int ret;
 307
 308         if (!(wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS))
 309                 return -ENOTSUPP;
 310
 311         /* make sure we are in managed mode, and associated */
 312         if (sdata->vif.type != NL80211_IFTYPE_STATION ||
 313             !sdata->u.mgd.associated)
 314                 return -EINVAL;
 315
 316         mutex_lock(&local->mtx);
 317
 318         /* we don't support concurrent TDLS peer setups */
 319         if (!is_zero_ether_addr(sdata->tdls_peer) &&
 320             !ether_addr_equal(sdata->tdls_peer, peer) &&
 321             (action_code == WLAN_TDLS_SETUP_REQUEST ||
 322              action_code == WLAN_TDLS_SETUP_RESPONSE)) {
 323                 ret = -EBUSY;
 324                 goto exit;
 325         }
 326
 327         ret = ieee80211_tdls_prep_mgmt_packet(wiphy, dev, peer, action_code,
 328                                               dialog_token, status_code,
 329                                               peer_capability, extra_ies,
 330                                               extra_ies_len);
 331         if (ret < 0)
 332                 goto exit;
 333
 334         if (action_code == WLAN_TDLS_SETUP_REQUEST ||
 335             action_code == WLAN_TDLS_SETUP_RESPONSE) {
 336                 memcpy(sdata->tdls_peer, peer, ETH_ALEN);
 337                 ieee80211_queue_delayed_work(&sdata->local->hw,
 338                                              &sdata->tdls_peer_del_work,
 339                                              TDLS_PEER_SETUP_TIMEOUT);
 340         }
 341
 342 exit:
 343         mutex_unlock(&local->mtx);
 344
 345         tdls_dbg(sdata, "TDLS mgmt action %d peer %pM status %d\n",
 346                  action_code, peer, ret);
 347         return ret;
 348 }
 349
 350 int ieee80211_tdls_oper(struct wiphy *wiphy, struct net_device *dev,
 351                         const u8 *peer, enum nl80211_tdls_operation oper)
 352 {
 353         struct sta_info *sta;
 354         struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 355         struct ieee80211_local *local = sdata->local;
 356         int ret;
 357
 358         if (!(wiphy->flags & WIPHY_FLAG_SUPPORTS_TDLS))
 359                 return -ENOTSUPP;
 360
 361         if (sdata->vif.type != NL80211_IFTYPE_STATION)
 362                 return -EINVAL;
 363
 364         switch (oper) {
 365         case NL80211_TDLS_ENABLE_LINK:
 366         case NL80211_TDLS_DISABLE_LINK:
 367                 break;
 368         case NL80211_TDLS_TEARDOWN:
 369         case NL80211_TDLS_SETUP:
 370         case NL80211_TDLS_DISCOVERY_REQ:
 371                 /* We don't support in-driver setup/teardown/discovery */
 372                 return -ENOTSUPP;
 373         }
 374
 375         mutex_lock(&local->mtx);
 376         tdls_dbg(sdata, "TDLS oper %d peer %pM\n", oper, peer);
 377
 378         switch (oper) {
 379         case NL80211_TDLS_ENABLE_LINK:
 380                 rcu_read_lock();
 381                 sta = sta_info_get(sdata, peer);
 382                 if (!sta) {
 383                         rcu_read_unlock();
 384                         ret = -ENOLINK;
 385                         break;
 386                 }
 387
 388                 set_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH);
 389                 rcu_read_unlock();
 390
 391                 WARN_ON_ONCE(is_zero_ether_addr(sdata->tdls_peer) ||
 392                              !ether_addr_equal(sdata->tdls_peer, peer));
 393                 ret = 0;
 394                 break;
 395         case NL80211_TDLS_DISABLE_LINK:
 396                 ret = sta_info_destroy_addr(sdata, peer);
 397                 break;
 398         default:
 399                 ret = -ENOTSUPP;
 400                 break;
 401         }
 402
 403         if (ret == 0 && ether_addr_equal(sdata->tdls_peer, peer)) {
 404                 cancel_delayed_work(&sdata->tdls_peer_del_work);
 405                 eth_zero_addr(sdata->tdls_peer);
 406         }
 407
 408         mutex_unlock(&local->mtx);
 409         return ret;
 410 }