net/mac80211/agg-rx.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * HT handling
   4  *
   5  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
   6  * Copyright 2002-2005, Instant802 Networks, Inc.
   7  * Copyright 2005-2006, Devicescape Software, Inc.
   8  * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   9  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
  10  * Copyright 2007-2010, Intel Corporation
  11  * Copyright(c) 2015-2017 Intel Deutschland GmbH
  12  * Copyright (C) 2018-2023 Intel Corporation
  13  */
  14
  15 /**
  16  * DOC: RX A-MPDU aggregation
  17  *
  18  * Aggregation on the RX side requires only implementing the
  19  * @ampdu_action callback that is invoked to start/stop any
  20  * block-ack sessions for RX aggregation.
  21  *
  22  * When RX aggregation is started by the peer, the driver is
  23  * notified via @ampdu_action function, with the
  24  * %IEEE80211_AMPDU_RX_START action, and may reject the request
  25  * in which case a negative response is sent to the peer, if it
  26  * accepts it a positive response is sent.
  27  *
  28  * While the session is active, the device/driver are required
  29  * to de-aggregate frames and pass them up one by one to mac80211,
  30  * which will handle the reorder buffer.
  31  *
  32  * When the aggregation session is stopped again by the peer or
  33  * ourselves, the driver's @ampdu_action function will be called
  34  * with the action %IEEE80211_AMPDU_RX_STOP. In this case, the
  35  * call must not fail.
  36  */
  37
  38 #include <linux/ieee80211.h>
  39 #include <linux/slab.h>
  40 #include <linux/export.h>
  41 #include <net/mac80211.h>
  42 #include "ieee80211_i.h"
  43 #include "driver-ops.h"
  44
  45 static void ieee80211_free_tid_rx(struct rcu_head *h)
  46 {
  47         struct tid_ampdu_rx *tid_rx =
  48                 container_of(h, struct tid_ampdu_rx, rcu_head);
  49         int i;
  50
  51         for (i = 0; i < tid_rx->buf_size; i++)
  52                 __skb_queue_purge(&tid_rx->reorder_buf[i]);
  53         kfree(tid_rx->reorder_buf);
  54         kfree(tid_rx->reorder_time);
  55         kfree(tid_rx);
  56 }
  57
  58 void __ieee80211_stop_rx_ba_session(struct sta_info *sta, u16 tid,
  59                                     u16 initiator, u16 reason, bool tx)
  60 {
  61         struct ieee80211_local *local = sta->local;
  62         struct tid_ampdu_rx *tid_rx;
  63         struct ieee80211_ampdu_params params = {
  64                 .sta = &sta->sta,
  65                 .action = IEEE80211_AMPDU_RX_STOP,
  66                 .tid = tid,
  67                 .amsdu = false,
  68                 .timeout = 0,
  69                 .ssn = 0,
  70         };
  71
  72         lockdep_assert_wiphy(sta->local->hw.wiphy);
  73
  74         tid_rx = rcu_dereference_protected(sta->ampdu_mlme.tid_rx[tid],
  75                                         lockdep_is_held(&sta->local->hw.wiphy->mtx));
  76
  77         if (!test_bit(tid, sta->ampdu_mlme.agg_session_valid))
  78                 return;
  79
  80         RCU_INIT_POINTER(sta->ampdu_mlme.tid_rx[tid], NULL);
  81         __clear_bit(tid, sta->ampdu_mlme.agg_session_valid);
  82
  83         ht_dbg(sta->sdata,
  84                "Rx BA session stop requested for %pM tid %u %s reason: %d\n",
  85                sta->sta.addr, tid,
  86                initiator == WLAN_BACK_RECIPIENT ? "recipient" : "initiator",
  87                (int)reason);
  88
  89         if (drv_ampdu_action(local, sta->sdata, &params))
  90                 sdata_info(sta->sdata,
  91                            "HW problem - can not stop rx aggregation for %pM tid %d\n",
  92                            sta->sta.addr, tid);
  93
  94         /* check if this is a self generated aggregation halt */
  95         if (initiator == WLAN_BACK_RECIPIENT && tx)
  96                 ieee80211_send_delba(sta->sdata, sta->sta.addr,
  97                                      tid, WLAN_BACK_RECIPIENT, reason);
  98
  99         /*
 100          * return here in case tid_rx is not assigned - which will happen if
 101          * IEEE80211_HW_SUPPORTS_REORDERING_BUFFER is set.
 102          */
 103         if (!tid_rx)
 104                 return;
 105
 106         del_timer_sync(&tid_rx->session_timer);
 107
 108         /* make sure ieee80211_sta_reorder_release() doesn't re-arm the timer */
 109         spin_lock_bh(&tid_rx->reorder_lock);
 110         tid_rx->removed = true;
 111         spin_unlock_bh(&tid_rx->reorder_lock);
 112         del_timer_sync(&tid_rx->reorder_timer);
 113
 114         call_rcu(&tid_rx->rcu_head, ieee80211_free_tid_rx);
 115 }
 116
 117 void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
 118                                   const u8 *addr)
 119 {
 120         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 121         struct sta_info *sta;
 122         int i;
 123
 124         rcu_read_lock();
 125         sta = sta_info_get_bss(sdata, addr);
 126         if (!sta) {
 127                 rcu_read_unlock();
 128                 return;
 129         }
 130
 131         for (i = 0; i < IEEE80211_NUM_TIDS; i++)
 132                 if (ba_rx_bitmap & BIT(i))
 133                         set_bit(i, sta->ampdu_mlme.tid_rx_stop_requested);
 134
 135         wiphy_work_queue(sta->local->hw.wiphy, &sta->ampdu_mlme.work);
 136         rcu_read_unlock();
 137 }
 138 EXPORT_SYMBOL(ieee80211_stop_rx_ba_session);
 139
 140 /*
 141  * After accepting the AddBA Request we activated a timer,
 142  * resetting it after each frame that arrives from the originator.
 143  */
 144 static void sta_rx_agg_session_timer_expired(struct timer_list *t)
 145 {
 146         struct tid_ampdu_rx *tid_rx = from_timer(tid_rx, t, session_timer);
 147         struct sta_info *sta = tid_rx->sta;
 148         u8 tid = tid_rx->tid;
 149         unsigned long timeout;
 150
 151         timeout = tid_rx->last_rx + TU_TO_JIFFIES(tid_rx->timeout);
 152         if (time_is_after_jiffies(timeout)) {
 153                 mod_timer(&tid_rx->session_timer, timeout);
 154                 return;
 155         }
 156
 157         ht_dbg(sta->sdata, "RX session timer expired on %pM tid %d\n",
 158                sta->sta.addr, tid);
 159
 160         set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
 161         wiphy_work_queue(sta->local->hw.wiphy, &sta->ampdu_mlme.work);
 162 }
 163
 164 static void sta_rx_agg_reorder_timer_expired(struct timer_list *t)
 165 {
 166         struct tid_ampdu_rx *tid_rx = from_timer(tid_rx, t, reorder_timer);
 167
 168         rcu_read_lock();
 169         ieee80211_release_reorder_timeout(tid_rx->sta, tid_rx->tid);
 170         rcu_read_unlock();
 171 }
 172
 173 void ieee80211_add_addbaext(struct sk_buff *skb,
 174                             const u8 req_addba_ext_data,
 175                             u16 buf_size)
 176 {
 177         struct ieee80211_addba_ext_ie *addba_ext;
 178         u8 *pos;
 179
 180         pos = skb_put_zero(skb, 2 + sizeof(struct ieee80211_addba_ext_ie));
 181         *pos++ = WLAN_EID_ADDBA_EXT;
 182         *pos++ = sizeof(struct ieee80211_addba_ext_ie);
 183         addba_ext = (struct ieee80211_addba_ext_ie *)pos;
 184
 185         addba_ext->data = IEEE80211_ADDBA_EXT_NO_FRAG;
 186         if (req_addba_ext_data)
 187                 addba_ext->data &= req_addba_ext_data;
 188
 189         addba_ext->data |=
 190                 u8_encode_bits(buf_size >> IEEE80211_ADDBA_EXT_BUF_SIZE_SHIFT,
 191                                IEEE80211_ADDBA_EXT_BUF_SIZE_MASK);
 192 }
 193
 194 u8 ieee80211_retrieve_addba_ext_data(struct sta_info *sta,
 195                                      const void *elem_data, ssize_t elem_len,
 196                                      u16 *buf_size)
 197 {
 198         struct ieee802_11_elems *elems;
 199         u8 buf_size_1k, data = 0;
 200
 201         if (!sta->sta.deflink.he_cap.has_he)
 202                 return 0;
 203
 204         if (elem_len <= 0)
 205                 return 0;
 206
 207         elems = ieee802_11_parse_elems(elem_data, elem_len, true, NULL);
 208
 209         if (elems && !elems->parse_error && elems->addba_ext_ie) {
 210                 data = elems->addba_ext_ie->data;
 211
 212                 if (!sta->sta.deflink.eht_cap.has_eht || !buf_size)
 213                         goto free;
 214
 215                 buf_size_1k = u8_get_bits(elems->addba_ext_ie->data,
 216                                           IEEE80211_ADDBA_EXT_BUF_SIZE_MASK);
 217                 *buf_size |= (u16)buf_size_1k <<
 218                              IEEE80211_ADDBA_EXT_BUF_SIZE_SHIFT;
 219         }
 220 free:
 221         kfree(elems);
 222
 223         return data;
 224 }
 225
 226 static void ieee80211_send_addba_resp(struct sta_info *sta, u8 *da, u16 tid,
 227                                       u8 dialog_token, u16 status, u16 policy,
 228                                       u16 buf_size, u16 timeout,
 229                                       const u8 req_addba_ext_data)
 230 {
 231         struct ieee80211_sub_if_data *sdata = sta->sdata;
 232         struct ieee80211_local *local = sdata->local;
 233         struct sk_buff *skb;
 234         struct ieee80211_mgmt *mgmt;
 235         bool amsdu = ieee80211_hw_check(&local->hw, SUPPORTS_AMSDU_IN_AMPDU);
 236         u16 capab;
 237
 238         skb = dev_alloc_skb(sizeof(*mgmt) +
 239                     2 + sizeof(struct ieee80211_addba_ext_ie) +
 240                     local->hw.extra_tx_headroom);
 241         if (!skb)
 242                 return;
 243
 244         skb_reserve(skb, local->hw.extra_tx_headroom);
 245         mgmt = ieee80211_mgmt_ba(skb, da, sdata);
 246
 247         skb_put(skb, 1 + sizeof(mgmt->u.action.u.addba_resp));
 248         mgmt->u.action.category = WLAN_CATEGORY_BACK;
 249         mgmt->u.action.u.addba_resp.action_code = WLAN_ACTION_ADDBA_RESP;
 250         mgmt->u.action.u.addba_resp.dialog_token = dialog_token;
 251
 252         capab = u16_encode_bits(amsdu, IEEE80211_ADDBA_PARAM_AMSDU_MASK);
 253         capab |= u16_encode_bits(policy, IEEE80211_ADDBA_PARAM_POLICY_MASK);
 254         capab |= u16_encode_bits(tid, IEEE80211_ADDBA_PARAM_TID_MASK);
 255         capab |= u16_encode_bits(buf_size, IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK);
 256
 257         mgmt->u.action.u.addba_resp.capab = cpu_to_le16(capab);
 258         mgmt->u.action.u.addba_resp.timeout = cpu_to_le16(timeout);
 259         mgmt->u.action.u.addba_resp.status = cpu_to_le16(status);
 260
 261         if (sta->sta.deflink.he_cap.has_he)
 262                 ieee80211_add_addbaext(skb, req_addba_ext_data, buf_size);
 263
 264         ieee80211_tx_skb(sdata, skb);
 265 }
 266
 267 void __ieee80211_start_rx_ba_session(struct sta_info *sta,
 268                                      u8 dialog_token, u16 timeout,
 269                                      u16 start_seq_num, u16 ba_policy, u16 tid,
 270                                      u16 buf_size, bool tx, bool auto_seq,
 271                                      const u8 addba_ext_data)
 272 {
 273         struct ieee80211_local *local = sta->sdata->local;
 274         struct tid_ampdu_rx *tid_agg_rx;
 275         struct ieee80211_ampdu_params params = {
 276                 .sta = &sta->sta,
 277                 .action = IEEE80211_AMPDU_RX_START,
 278                 .tid = tid,
 279                 .amsdu = false,
 280                 .timeout = timeout,
 281                 .ssn = start_seq_num,
 282         };
 283         int i, ret = -EOPNOTSUPP;
 284         u16 status = WLAN_STATUS_REQUEST_DECLINED;
 285         u16 max_buf_size;
 286
 287         lockdep_assert_wiphy(sta->local->hw.wiphy);
 288
 289         if (tid >= IEEE80211_FIRST_TSPEC_TSID) {
 290                 ht_dbg(sta->sdata,
 291                        "STA %pM requests BA session on unsupported tid %d\n",
 292                        sta->sta.addr, tid);
 293                 goto end;
 294         }
 295
 296         if (!sta->sta.deflink.ht_cap.ht_supported &&
 297             !sta->sta.deflink.he_cap.has_he) {
 298                 ht_dbg(sta->sdata,
 299                        "STA %pM erroneously requests BA session on tid %d w/o HT\n",
 300                        sta->sta.addr, tid);
 301                 /* send a response anyway, it's an error case if we get here */
 302                 goto end;
 303         }
 304
 305         if (test_sta_flag(sta, WLAN_STA_BLOCK_BA)) {
 306                 ht_dbg(sta->sdata,
 307                        "Suspend in progress - Denying ADDBA request (%pM tid %d)\n",
 308                        sta->sta.addr, tid);
 309                 goto end;
 310         }
 311
 312         if (sta->sta.deflink.eht_cap.has_eht)
 313                 max_buf_size = IEEE80211_MAX_AMPDU_BUF_EHT;
 314         else if (sta->sta.deflink.he_cap.has_he)
 315                 max_buf_size = IEEE80211_MAX_AMPDU_BUF_HE;
 316         else
 317                 max_buf_size = IEEE80211_MAX_AMPDU_BUF_HT;
 318
 319         /* sanity check for incoming parameters:
 320          * check if configuration can support the BA policy
 321          * and if buffer size does not exceeds max value */
 322         /* XXX: check own ht delayed BA capability?? */
 323         if (((ba_policy != 1) &&
 324              (!(sta->sta.deflink.ht_cap.cap & IEEE80211_HT_CAP_DELAY_BA))) ||
 325             (buf_size > max_buf_size)) {
 326                 status = WLAN_STATUS_INVALID_QOS_PARAM;
 327                 ht_dbg_ratelimited(sta->sdata,
 328                                    "AddBA Req with bad params from %pM on tid %u. policy %d, buffer size %d\n",
 329                                    sta->sta.addr, tid, ba_policy, buf_size);
 330                 goto end;
 331         }
 332         /* determine default buffer size */
 333         if (buf_size == 0)
 334                 buf_size = max_buf_size;
 335
 336         /* make sure the size doesn't exceed the maximum supported by the hw */
 337         if (buf_size > sta->sta.max_rx_aggregation_subframes)
 338                 buf_size = sta->sta.max_rx_aggregation_subframes;
 339         params.buf_size = buf_size;
 340
 341         ht_dbg(sta->sdata, "AddBA Req buf_size=%d for %pM\n",
 342                buf_size, sta->sta.addr);
 343
 344         if (test_bit(tid, sta->ampdu_mlme.agg_session_valid)) {
 345                 if (sta->ampdu_mlme.tid_rx_token[tid] == dialog_token) {
 346                         struct tid_ampdu_rx *tid_rx;
 347
 348                         ht_dbg_ratelimited(sta->sdata,
 349                                            "updated AddBA Req from %pM on tid %u\n",
 350                                            sta->sta.addr, tid);
 351                         /* We have no API to update the timeout value in the
 352                          * driver so reject the timeout update if the timeout
 353                          * changed. If it did not change, i.e., no real update,
 354                          * just reply with success.
 355                          */
 356                         rcu_read_lock();
 357                         tid_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
 358                         if (tid_rx && tid_rx->timeout == timeout)
 359                                 status = WLAN_STATUS_SUCCESS;
 360                         else
 361                                 status = WLAN_STATUS_REQUEST_DECLINED;
 362                         rcu_read_unlock();
 363                         goto end;
 364                 }
 365
 366                 ht_dbg_ratelimited(sta->sdata,
 367                                    "unexpected AddBA Req from %pM on tid %u\n",
 368                                    sta->sta.addr, tid);
 369
 370                 /* delete existing Rx BA session on the same tid */
 371                 __ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_RECIPIENT,
 372                                                WLAN_STATUS_UNSPECIFIED_QOS,
 373                                                false);
 374         }
 375
 376         if (ieee80211_hw_check(&local->hw, SUPPORTS_REORDERING_BUFFER)) {
 377                 ret = drv_ampdu_action(local, sta->sdata, &params);
 378                 ht_dbg(sta->sdata,
 379                        "Rx A-MPDU request on %pM tid %d result %d\n",
 380                        sta->sta.addr, tid, ret);
 381                 if (!ret)
 382                         status = WLAN_STATUS_SUCCESS;
 383                 goto end;
 384         }
 385
 386         /* prepare A-MPDU MLME for Rx aggregation */
 387         tid_agg_rx = kzalloc(sizeof(*tid_agg_rx), GFP_KERNEL);
 388         if (!tid_agg_rx)
 389                 goto end;
 390
 391         spin_lock_init(&tid_agg_rx->reorder_lock);
 392
 393         /* rx timer */
 394         timer_setup(&tid_agg_rx->session_timer,
 395                     sta_rx_agg_session_timer_expired, TIMER_DEFERRABLE);
 396
 397         /* rx reorder timer */
 398         timer_setup(&tid_agg_rx->reorder_timer,
 399                     sta_rx_agg_reorder_timer_expired, 0);
 400
 401         /* prepare reordering buffer */
 402         tid_agg_rx->reorder_buf =
 403                 kcalloc(buf_size, sizeof(struct sk_buff_head), GFP_KERNEL);
 404         tid_agg_rx->reorder_time =
 405                 kcalloc(buf_size, sizeof(unsigned long), GFP_KERNEL);
 406         if (!tid_agg_rx->reorder_buf || !tid_agg_rx->reorder_time) {
 407                 kfree(tid_agg_rx->reorder_buf);
 408                 kfree(tid_agg_rx->reorder_time);
 409                 kfree(tid_agg_rx);
 410                 goto end;
 411         }
 412
 413         for (i = 0; i < buf_size; i++)
 414                 __skb_queue_head_init(&tid_agg_rx->reorder_buf[i]);
 415
 416         ret = drv_ampdu_action(local, sta->sdata, &params);
 417         ht_dbg(sta->sdata, "Rx A-MPDU request on %pM tid %d result %d\n",
 418                sta->sta.addr, tid, ret);
 419         if (ret) {
 420                 kfree(tid_agg_rx->reorder_buf);
 421                 kfree(tid_agg_rx->reorder_time);
 422                 kfree(tid_agg_rx);
 423                 goto end;
 424         }
 425
 426         /* update data */
 427         tid_agg_rx->ssn = start_seq_num;
 428         tid_agg_rx->head_seq_num = start_seq_num;
 429         tid_agg_rx->buf_size = buf_size;
 430         tid_agg_rx->timeout = timeout;
 431         tid_agg_rx->stored_mpdu_num = 0;
 432         tid_agg_rx->auto_seq = auto_seq;
 433         tid_agg_rx->started = false;
 434         tid_agg_rx->reorder_buf_filtered = 0;
 435         tid_agg_rx->tid = tid;
 436         tid_agg_rx->sta = sta;
 437         status = WLAN_STATUS_SUCCESS;
 438
 439         /* activate it for RX */
 440         rcu_assign_pointer(sta->ampdu_mlme.tid_rx[tid], tid_agg_rx);
 441
 442         if (timeout) {
 443                 mod_timer(&tid_agg_rx->session_timer, TU_TO_EXP_TIME(timeout));
 444                 tid_agg_rx->last_rx = jiffies;
 445         }
 446
 447 end:
 448         if (status == WLAN_STATUS_SUCCESS) {
 449                 __set_bit(tid, sta->ampdu_mlme.agg_session_valid);
 450                 __clear_bit(tid, sta->ampdu_mlme.unexpected_agg);
 451                 sta->ampdu_mlme.tid_rx_token[tid] = dialog_token;
 452         }
 453
 454         if (tx)
 455                 ieee80211_send_addba_resp(sta, sta->sta.addr, tid,
 456                                           dialog_token, status, 1, buf_size,
 457                                           timeout, addba_ext_data);
 458 }
 459
 460 void ieee80211_process_addba_request(struct ieee80211_local *local,
 461                                      struct sta_info *sta,
 462                                      struct ieee80211_mgmt *mgmt,
 463                                      size_t len)
 464 {
 465         u16 capab, tid, timeout, ba_policy, buf_size, start_seq_num;
 466         u8 dialog_token, addba_ext_data;
 467
 468         /* extract session parameters from addba request frame */
 469         dialog_token = mgmt->u.action.u.addba_req.dialog_token;
 470         timeout = le16_to_cpu(mgmt->u.action.u.addba_req.timeout);
 471         start_seq_num =
 472                 le16_to_cpu(mgmt->u.action.u.addba_req.start_seq_num) >> 4;
 473
 474         capab = le16_to_cpu(mgmt->u.action.u.addba_req.capab);
 475         ba_policy = (capab & IEEE80211_ADDBA_PARAM_POLICY_MASK) >> 1;
 476         tid = (capab & IEEE80211_ADDBA_PARAM_TID_MASK) >> 2;
 477         buf_size = (capab & IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK) >> 6;
 478
 479         addba_ext_data =
 480                 ieee80211_retrieve_addba_ext_data(sta,
 481                                                   mgmt->u.action.u.addba_req.variable,
 482                                                   len -
 483                                                   offsetof(typeof(*mgmt),
 484                                                            u.action.u.addba_req.variable),
 485                                                   &buf_size);
 486
 487         __ieee80211_start_rx_ba_session(sta, dialog_token, timeout,
 488                                         start_seq_num, ba_policy, tid,
 489                                         buf_size, true, false, addba_ext_data);
 490 }
 491
 492 void ieee80211_manage_rx_ba_offl(struct ieee80211_vif *vif,
 493                                  const u8 *addr, unsigned int tid)
 494 {
 495         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 496         struct sta_info *sta;
 497
 498         rcu_read_lock();
 499         sta = sta_info_get_bss(sdata, addr);
 500         if (!sta)
 501                 goto unlock;
 502
 503         set_bit(tid, sta->ampdu_mlme.tid_rx_manage_offl);
 504         wiphy_work_queue(sta->local->hw.wiphy, &sta->ampdu_mlme.work);
 505  unlock:
 506         rcu_read_unlock();
 507 }
 508 EXPORT_SYMBOL(ieee80211_manage_rx_ba_offl);
 509
 510 void ieee80211_rx_ba_timer_expired(struct ieee80211_vif *vif,
 511                                    const u8 *addr, unsigned int tid)
 512 {
 513         struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
 514         struct sta_info *sta;
 515
 516         rcu_read_lock();
 517         sta = sta_info_get_bss(sdata, addr);
 518         if (!sta)
 519                 goto unlock;
 520
 521         set_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired);
 522         wiphy_work_queue(sta->local->hw.wiphy, &sta->ampdu_mlme.work);
 523
 524  unlock:
 525         rcu_read_unlock();
 526 }
 527 EXPORT_SYMBOL(ieee80211_rx_ba_timer_expired);