linux/net/mac80211/tx.c
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   1/*
   2 * Copyright 2002-2005, Instant802 Networks, Inc.
   3 * Copyright 2005-2006, Devicescape Software, Inc.
   4 * Copyright 2006-2007  Jiri Benc <jbenc@suse.cz>
   5 * Copyright 2007       Johannes Berg <johannes@sipsolutions.net>
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License version 2 as
   9 * published by the Free Software Foundation.
  10 *
  11 *
  12 * Transmit and frame generation functions.
  13 */
  14
  15#include <linux/kernel.h>
  16#include <linux/slab.h>
  17#include <linux/skbuff.h>
  18#include <linux/etherdevice.h>
  19#include <linux/bitmap.h>
  20#include <linux/rcupdate.h>
  21#include <net/net_namespace.h>
  22#include <net/ieee80211_radiotap.h>
  23#include <net/cfg80211.h>
  24#include <net/mac80211.h>
  25#include <asm/unaligned.h>
  26
  27#include "ieee80211_i.h"
  28#include "led.h"
  29#include "mesh.h"
  30#include "wep.h"
  31#include "wpa.h"
  32#include "wme.h"
  33#include "rate.h"
  34
  35#define IEEE80211_TX_OK         0
  36#define IEEE80211_TX_AGAIN      1
  37#define IEEE80211_TX_PENDING    2
  38
  39/* misc utils */
  40
  41static __le16 ieee80211_duration(struct ieee80211_tx_data *tx, int group_addr,
  42                                 int next_frag_len)
  43{
  44        int rate, mrate, erp, dur, i;
  45        struct ieee80211_rate *txrate;
  46        struct ieee80211_local *local = tx->local;
  47        struct ieee80211_supported_band *sband;
  48        struct ieee80211_hdr *hdr;
  49        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
  50
  51        /* assume HW handles this */
  52        if (info->control.rates[0].flags & IEEE80211_TX_RC_MCS)
  53                return 0;
  54
  55        /* uh huh? */
  56        if (WARN_ON_ONCE(info->control.rates[0].idx < 0))
  57                return 0;
  58
  59        sband = local->hw.wiphy->bands[tx->channel->band];
  60        txrate = &sband->bitrates[info->control.rates[0].idx];
  61
  62        erp = txrate->flags & IEEE80211_RATE_ERP_G;
  63
  64        /*
  65         * data and mgmt (except PS Poll):
  66         * - during CFP: 32768
  67         * - during contention period:
  68         *   if addr1 is group address: 0
  69         *   if more fragments = 0 and addr1 is individual address: time to
  70         *      transmit one ACK plus SIFS
  71         *   if more fragments = 1 and addr1 is individual address: time to
  72         *      transmit next fragment plus 2 x ACK plus 3 x SIFS
  73         *
  74         * IEEE 802.11, 9.6:
  75         * - control response frame (CTS or ACK) shall be transmitted using the
  76         *   same rate as the immediately previous frame in the frame exchange
  77         *   sequence, if this rate belongs to the PHY mandatory rates, or else
  78         *   at the highest possible rate belonging to the PHY rates in the
  79         *   BSSBasicRateSet
  80         */
  81        hdr = (struct ieee80211_hdr *)tx->skb->data;
  82        if (ieee80211_is_ctl(hdr->frame_control)) {
  83                /* TODO: These control frames are not currently sent by
  84                 * mac80211, but should they be implemented, this function
  85                 * needs to be updated to support duration field calculation.
  86                 *
  87                 * RTS: time needed to transmit pending data/mgmt frame plus
  88                 *    one CTS frame plus one ACK frame plus 3 x SIFS
  89                 * CTS: duration of immediately previous RTS minus time
  90                 *    required to transmit CTS and its SIFS
  91                 * ACK: 0 if immediately previous directed data/mgmt had
  92                 *    more=0, with more=1 duration in ACK frame is duration
  93                 *    from previous frame minus time needed to transmit ACK
  94                 *    and its SIFS
  95                 * PS Poll: BIT(15) | BIT(14) | aid
  96                 */
  97                return 0;
  98        }
  99
 100        /* data/mgmt */
 101        if (0 /* FIX: data/mgmt during CFP */)
 102                return cpu_to_le16(32768);
 103
 104        if (group_addr) /* Group address as the destination - no ACK */
 105                return 0;
 106
 107        /* Individual destination address:
 108         * IEEE 802.11, Ch. 9.6 (after IEEE 802.11g changes)
 109         * CTS and ACK frames shall be transmitted using the highest rate in
 110         * basic rate set that is less than or equal to the rate of the
 111         * immediately previous frame and that is using the same modulation
 112         * (CCK or OFDM). If no basic rate set matches with these requirements,
 113         * the highest mandatory rate of the PHY that is less than or equal to
 114         * the rate of the previous frame is used.
 115         * Mandatory rates for IEEE 802.11g PHY: 1, 2, 5.5, 11, 6, 12, 24 Mbps
 116         */
 117        rate = -1;
 118        /* use lowest available if everything fails */
 119        mrate = sband->bitrates[0].bitrate;
 120        for (i = 0; i < sband->n_bitrates; i++) {
 121                struct ieee80211_rate *r = &sband->bitrates[i];
 122
 123                if (r->bitrate > txrate->bitrate)
 124                        break;
 125
 126                if (tx->sdata->vif.bss_conf.basic_rates & BIT(i))
 127                        rate = r->bitrate;
 128
 129                switch (sband->band) {
 130                case IEEE80211_BAND_2GHZ: {
 131                        u32 flag;
 132                        if (tx->sdata->flags & IEEE80211_SDATA_OPERATING_GMODE)
 133                                flag = IEEE80211_RATE_MANDATORY_G;
 134                        else
 135                                flag = IEEE80211_RATE_MANDATORY_B;
 136                        if (r->flags & flag)
 137                                mrate = r->bitrate;
 138                        break;
 139                }
 140                case IEEE80211_BAND_5GHZ:
 141                        if (r->flags & IEEE80211_RATE_MANDATORY_A)
 142                                mrate = r->bitrate;
 143                        break;
 144                case IEEE80211_NUM_BANDS:
 145                        WARN_ON(1);
 146                        break;
 147                }
 148        }
 149        if (rate == -1) {
 150                /* No matching basic rate found; use highest suitable mandatory
 151                 * PHY rate */
 152                rate = mrate;
 153        }
 154
 155        /* Time needed to transmit ACK
 156         * (10 bytes + 4-byte FCS = 112 bits) plus SIFS; rounded up
 157         * to closest integer */
 158
 159        dur = ieee80211_frame_duration(local, 10, rate, erp,
 160                                tx->sdata->vif.bss_conf.use_short_preamble);
 161
 162        if (next_frag_len) {
 163                /* Frame is fragmented: duration increases with time needed to
 164                 * transmit next fragment plus ACK and 2 x SIFS. */
 165                dur *= 2; /* ACK + SIFS */
 166                /* next fragment */
 167                dur += ieee80211_frame_duration(local, next_frag_len,
 168                                txrate->bitrate, erp,
 169                                tx->sdata->vif.bss_conf.use_short_preamble);
 170        }
 171
 172        return cpu_to_le16(dur);
 173}
 174
 175static int inline is_ieee80211_device(struct ieee80211_local *local,
 176                                      struct net_device *dev)
 177{
 178        return local == wdev_priv(dev->ieee80211_ptr);
 179}
 180
 181/* tx handlers */
 182
 183static ieee80211_tx_result debug_noinline
 184ieee80211_tx_h_check_assoc(struct ieee80211_tx_data *tx)
 185{
 186
 187        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
 188        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
 189        u32 sta_flags;
 190
 191        if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED))
 192                return TX_CONTINUE;
 193
 194        if (unlikely(tx->local->sw_scanning) &&
 195            !ieee80211_is_probe_req(hdr->frame_control) &&
 196            !ieee80211_is_nullfunc(hdr->frame_control))
 197                /*
 198                 * When software scanning only nullfunc frames (to notify
 199                 * the sleep state to the AP) and probe requests (for the
 200                 * active scan) are allowed, all other frames should not be
 201                 * sent and we should not get here, but if we do
 202                 * nonetheless, drop them to avoid sending them
 203                 * off-channel. See the link below and
 204                 * ieee80211_start_scan() for more.
 205                 *
 206                 * http://article.gmane.org/gmane.linux.kernel.wireless.general/30089
 207                 */
 208                return TX_DROP;
 209
 210        if (tx->sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
 211                return TX_CONTINUE;
 212
 213        if (tx->flags & IEEE80211_TX_PS_BUFFERED)
 214                return TX_CONTINUE;
 215
 216        sta_flags = tx->sta ? get_sta_flags(tx->sta) : 0;
 217
 218        if (likely(tx->flags & IEEE80211_TX_UNICAST)) {
 219                if (unlikely(!(sta_flags & WLAN_STA_ASSOC) &&
 220                             tx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
 221                             ieee80211_is_data(hdr->frame_control))) {
 222#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
 223                        printk(KERN_DEBUG "%s: dropped data frame to not "
 224                               "associated station %pM\n",
 225                               tx->dev->name, hdr->addr1);
 226#endif /* CONFIG_MAC80211_VERBOSE_DEBUG */
 227                        I802_DEBUG_INC(tx->local->tx_handlers_drop_not_assoc);
 228                        return TX_DROP;
 229                }
 230        } else {
 231                if (unlikely(ieee80211_is_data(hdr->frame_control) &&
 232                             tx->local->num_sta == 0 &&
 233                             tx->sdata->vif.type != NL80211_IFTYPE_ADHOC)) {
 234                        /*
 235                         * No associated STAs - no need to send multicast
 236                         * frames.
 237                         */
 238                        return TX_DROP;
 239                }
 240                return TX_CONTINUE;
 241        }
 242
 243        return TX_CONTINUE;
 244}
 245
 246/* This function is called whenever the AP is about to exceed the maximum limit
 247 * of buffered frames for power saving STAs. This situation should not really
 248 * happen often during normal operation, so dropping the oldest buffered packet
 249 * from each queue should be OK to make some room for new frames. */
 250static void purge_old_ps_buffers(struct ieee80211_local *local)
 251{
 252        int total = 0, purged = 0;
 253        struct sk_buff *skb;
 254        struct ieee80211_sub_if_data *sdata;
 255        struct sta_info *sta;
 256
 257        /*
 258         * virtual interfaces are protected by RCU
 259         */
 260        rcu_read_lock();
 261
 262        list_for_each_entry_rcu(sdata, &local->interfaces, list) {
 263                struct ieee80211_if_ap *ap;
 264                if (sdata->vif.type != NL80211_IFTYPE_AP)
 265                        continue;
 266                ap = &sdata->u.ap;
 267                skb = skb_dequeue(&ap->ps_bc_buf);
 268                if (skb) {
 269                        purged++;
 270                        dev_kfree_skb(skb);
 271                }
 272                total += skb_queue_len(&ap->ps_bc_buf);
 273        }
 274
 275        list_for_each_entry_rcu(sta, &local->sta_list, list) {
 276                skb = skb_dequeue(&sta->ps_tx_buf);
 277                if (skb) {
 278                        purged++;
 279                        dev_kfree_skb(skb);
 280                }
 281                total += skb_queue_len(&sta->ps_tx_buf);
 282        }
 283
 284        rcu_read_unlock();
 285
 286        local->total_ps_buffered = total;
 287#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 288        printk(KERN_DEBUG "%s: PS buffers full - purged %d frames\n",
 289               wiphy_name(local->hw.wiphy), purged);
 290#endif
 291}
 292
 293static ieee80211_tx_result
 294ieee80211_tx_h_multicast_ps_buf(struct ieee80211_tx_data *tx)
 295{
 296        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
 297        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
 298
 299        /*
 300         * broadcast/multicast frame
 301         *
 302         * If any of the associated stations is in power save mode,
 303         * the frame is buffered to be sent after DTIM beacon frame.
 304         * This is done either by the hardware or us.
 305         */
 306
 307        /* powersaving STAs only in AP/VLAN mode */
 308        if (!tx->sdata->bss)
 309                return TX_CONTINUE;
 310
 311        /* no buffering for ordered frames */
 312        if (ieee80211_has_order(hdr->frame_control))
 313                return TX_CONTINUE;
 314
 315        /* no stations in PS mode */
 316        if (!atomic_read(&tx->sdata->bss->num_sta_ps))
 317                return TX_CONTINUE;
 318
 319        /* buffered in mac80211 */
 320        if (tx->local->hw.flags & IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING) {
 321                if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
 322                        purge_old_ps_buffers(tx->local);
 323                if (skb_queue_len(&tx->sdata->bss->ps_bc_buf) >=
 324                    AP_MAX_BC_BUFFER) {
 325#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 326                        if (net_ratelimit()) {
 327                                printk(KERN_DEBUG "%s: BC TX buffer full - "
 328                                       "dropping the oldest frame\n",
 329                                       tx->dev->name);
 330                        }
 331#endif
 332                        dev_kfree_skb(skb_dequeue(&tx->sdata->bss->ps_bc_buf));
 333                } else
 334                        tx->local->total_ps_buffered++;
 335                skb_queue_tail(&tx->sdata->bss->ps_bc_buf, tx->skb);
 336                return TX_QUEUED;
 337        }
 338
 339        /* buffered in hardware */
 340        info->flags |= IEEE80211_TX_CTL_SEND_AFTER_DTIM;
 341
 342        return TX_CONTINUE;
 343}
 344
 345static int ieee80211_use_mfp(__le16 fc, struct sta_info *sta,
 346                             struct sk_buff *skb)
 347{
 348        if (!ieee80211_is_mgmt(fc))
 349                return 0;
 350
 351        if (sta == NULL || !test_sta_flags(sta, WLAN_STA_MFP))
 352                return 0;
 353
 354        if (!ieee80211_is_robust_mgmt_frame((struct ieee80211_hdr *)
 355                                            skb->data))
 356                return 0;
 357
 358        return 1;
 359}
 360
 361static ieee80211_tx_result
 362ieee80211_tx_h_unicast_ps_buf(struct ieee80211_tx_data *tx)
 363{
 364        struct sta_info *sta = tx->sta;
 365        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
 366        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
 367        u32 staflags;
 368
 369        if (unlikely(!sta || ieee80211_is_probe_resp(hdr->frame_control)))
 370                return TX_CONTINUE;
 371
 372        staflags = get_sta_flags(sta);
 373
 374        if (unlikely((staflags & WLAN_STA_PS) &&
 375                     !(staflags & WLAN_STA_PSPOLL))) {
 376#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 377                printk(KERN_DEBUG "STA %pM aid %d: PS buffer (entries "
 378                       "before %d)\n",
 379                       sta->sta.addr, sta->sta.aid,
 380                       skb_queue_len(&sta->ps_tx_buf));
 381#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 382                if (tx->local->total_ps_buffered >= TOTAL_MAX_TX_BUFFER)
 383                        purge_old_ps_buffers(tx->local);
 384                if (skb_queue_len(&sta->ps_tx_buf) >= STA_MAX_TX_BUFFER) {
 385                        struct sk_buff *old = skb_dequeue(&sta->ps_tx_buf);
 386#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 387                        if (net_ratelimit()) {
 388                                printk(KERN_DEBUG "%s: STA %pM TX "
 389                                       "buffer full - dropping oldest frame\n",
 390                                       tx->dev->name, sta->sta.addr);
 391                        }
 392#endif
 393                        dev_kfree_skb(old);
 394                } else
 395                        tx->local->total_ps_buffered++;
 396
 397                /* Queue frame to be sent after STA sends an PS Poll frame */
 398                if (skb_queue_empty(&sta->ps_tx_buf))
 399                        sta_info_set_tim_bit(sta);
 400
 401                info->control.jiffies = jiffies;
 402                skb_queue_tail(&sta->ps_tx_buf, tx->skb);
 403                return TX_QUEUED;
 404        }
 405#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
 406        else if (unlikely(test_sta_flags(sta, WLAN_STA_PS))) {
 407                printk(KERN_DEBUG "%s: STA %pM in PS mode, but pspoll "
 408                       "set -> send frame\n", tx->dev->name,
 409                       sta->sta.addr);
 410        }
 411#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
 412        clear_sta_flags(sta, WLAN_STA_PSPOLL);
 413
 414        return TX_CONTINUE;
 415}
 416
 417static ieee80211_tx_result debug_noinline
 418ieee80211_tx_h_ps_buf(struct ieee80211_tx_data *tx)
 419{
 420        if (unlikely(tx->flags & IEEE80211_TX_PS_BUFFERED))
 421                return TX_CONTINUE;
 422
 423        if (tx->flags & IEEE80211_TX_UNICAST)
 424                return ieee80211_tx_h_unicast_ps_buf(tx);
 425        else
 426                return ieee80211_tx_h_multicast_ps_buf(tx);
 427}
 428
 429static ieee80211_tx_result debug_noinline
 430ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
 431{
 432        struct ieee80211_key *key;
 433        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
 434        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
 435
 436        if (unlikely(tx->skb->do_not_encrypt))
 437                tx->key = NULL;
 438        else if (tx->sta && (key = rcu_dereference(tx->sta->key)))
 439                tx->key = key;
 440        else if (ieee80211_is_mgmt(hdr->frame_control) &&
 441                 (key = rcu_dereference(tx->sdata->default_mgmt_key)))
 442                tx->key = key;
 443        else if ((key = rcu_dereference(tx->sdata->default_key)))
 444                tx->key = key;
 445        else if (tx->sdata->drop_unencrypted &&
 446                 (tx->skb->protocol != cpu_to_be16(ETH_P_PAE)) &&
 447                 !(info->flags & IEEE80211_TX_CTL_INJECTED) &&
 448                 (!ieee80211_is_robust_mgmt_frame(hdr) ||
 449                  (ieee80211_is_action(hdr->frame_control) &&
 450                   tx->sta && test_sta_flags(tx->sta, WLAN_STA_MFP)))) {
 451                I802_DEBUG_INC(tx->local->tx_handlers_drop_unencrypted);
 452                return TX_DROP;
 453        } else
 454                tx->key = NULL;
 455
 456        if (tx->key) {
 457                tx->key->tx_rx_count++;
 458                /* TODO: add threshold stuff again */
 459
 460                switch (tx->key->conf.alg) {
 461                case ALG_WEP:
 462                        if (ieee80211_is_auth(hdr->frame_control))
 463                                break;
 464                case ALG_TKIP:
 465                        if (!ieee80211_is_data_present(hdr->frame_control))
 466                                tx->key = NULL;
 467                        break;
 468                case ALG_CCMP:
 469                        if (!ieee80211_is_data_present(hdr->frame_control) &&
 470                            !ieee80211_use_mfp(hdr->frame_control, tx->sta,
 471                                               tx->skb))
 472                                tx->key = NULL;
 473                        break;
 474                case ALG_AES_CMAC:
 475                        if (!ieee80211_is_mgmt(hdr->frame_control))
 476                                tx->key = NULL;
 477                        break;
 478                }
 479        }
 480
 481        if (!tx->key || !(tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
 482                tx->skb->do_not_encrypt = 1;
 483
 484        return TX_CONTINUE;
 485}
 486
 487static ieee80211_tx_result debug_noinline
 488ieee80211_tx_h_rate_ctrl(struct ieee80211_tx_data *tx)
 489{
 490        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
 491        struct ieee80211_hdr *hdr = (void *)tx->skb->data;
 492        struct ieee80211_supported_band *sband;
 493        struct ieee80211_rate *rate;
 494        int i, len;
 495        bool inval = false, rts = false, short_preamble = false;
 496        struct ieee80211_tx_rate_control txrc;
 497
 498        memset(&txrc, 0, sizeof(txrc));
 499
 500        sband = tx->local->hw.wiphy->bands[tx->channel->band];
 501
 502        len = min_t(int, tx->skb->len + FCS_LEN,
 503                         tx->local->fragmentation_threshold);
 504
 505        /* set up the tx rate control struct we give the RC algo */
 506        txrc.hw = local_to_hw(tx->local);
 507        txrc.sband = sband;
 508        txrc.bss_conf = &tx->sdata->vif.bss_conf;
 509        txrc.skb = tx->skb;
 510        txrc.reported_rate.idx = -1;
 511        txrc.max_rate_idx = tx->sdata->max_ratectrl_rateidx;
 512
 513        /* set up RTS protection if desired */
 514        if (tx->local->rts_threshold < IEEE80211_MAX_RTS_THRESHOLD &&
 515            len > tx->local->rts_threshold) {
 516                txrc.rts = rts = true;
 517        }
 518
 519        /*
 520         * Use short preamble if the BSS can handle it, but not for
 521         * management frames unless we know the receiver can handle
 522         * that -- the management frame might be to a station that
 523         * just wants a probe response.
 524         */
 525        if (tx->sdata->vif.bss_conf.use_short_preamble &&
 526            (ieee80211_is_data(hdr->frame_control) ||
 527             (tx->sta && test_sta_flags(tx->sta, WLAN_STA_SHORT_PREAMBLE))))
 528                txrc.short_preamble = short_preamble = true;
 529
 530
 531        rate_control_get_rate(tx->sdata, tx->sta, &txrc);
 532
 533        if (unlikely(info->control.rates[0].idx < 0))
 534                return TX_DROP;
 535
 536        if (txrc.reported_rate.idx < 0)
 537                txrc.reported_rate = info->control.rates[0];
 538
 539        if (tx->sta)
 540                tx->sta->last_tx_rate = txrc.reported_rate;
 541
 542        if (unlikely(!info->control.rates[0].count))
 543                info->control.rates[0].count = 1;
 544
 545        if (is_multicast_ether_addr(hdr->addr1)) {
 546                /*
 547                 * XXX: verify the rate is in the basic rateset
 548                 */
 549                return TX_CONTINUE;
 550        }
 551
 552        /*
 553         * set up the RTS/CTS rate as the fastest basic rate
 554         * that is not faster than the data rate
 555         *
 556         * XXX: Should this check all retry rates?
 557         */
 558        if (!(info->control.rates[0].flags & IEEE80211_TX_RC_MCS)) {
 559                s8 baserate = 0;
 560
 561                rate = &sband->bitrates[info->control.rates[0].idx];
 562
 563                for (i = 0; i < sband->n_bitrates; i++) {
 564                        /* must be a basic rate */
 565                        if (!(tx->sdata->vif.bss_conf.basic_rates & BIT(i)))
 566                                continue;
 567                        /* must not be faster than the data rate */
 568                        if (sband->bitrates[i].bitrate > rate->bitrate)
 569                                continue;
 570                        /* maximum */
 571                        if (sband->bitrates[baserate].bitrate <
 572                             sband->bitrates[i].bitrate)
 573                                baserate = i;
 574                }
 575
 576                info->control.rts_cts_rate_idx = baserate;
 577        }
 578
 579        for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 580                /*
 581                 * make sure there's no valid rate following
 582                 * an invalid one, just in case drivers don't
 583                 * take the API seriously to stop at -1.
 584                 */
 585                if (inval) {
 586                        info->control.rates[i].idx = -1;
 587                        continue;
 588                }
 589                if (info->control.rates[i].idx < 0) {
 590                        inval = true;
 591                        continue;
 592                }
 593
 594                /*
 595                 * For now assume MCS is already set up correctly, this
 596                 * needs to be fixed.
 597                 */
 598                if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS) {
 599                        WARN_ON(info->control.rates[i].idx > 76);
 600                        continue;
 601                }
 602
 603                /* set up RTS protection if desired */
 604                if (rts)
 605                        info->control.rates[i].flags |=
 606                                IEEE80211_TX_RC_USE_RTS_CTS;
 607
 608                /* RC is busted */
 609                if (WARN_ON_ONCE(info->control.rates[i].idx >=
 610                                 sband->n_bitrates)) {
 611                        info->control.rates[i].idx = -1;
 612                        continue;
 613                }
 614
 615                rate = &sband->bitrates[info->control.rates[i].idx];
 616
 617                /* set up short preamble */
 618                if (short_preamble &&
 619                    rate->flags & IEEE80211_RATE_SHORT_PREAMBLE)
 620                        info->control.rates[i].flags |=
 621                                IEEE80211_TX_RC_USE_SHORT_PREAMBLE;
 622
 623                /* set up G protection */
 624                if (!rts && tx->sdata->vif.bss_conf.use_cts_prot &&
 625                    rate->flags & IEEE80211_RATE_ERP_G)
 626                        info->control.rates[i].flags |=
 627                                IEEE80211_TX_RC_USE_CTS_PROTECT;
 628        }
 629
 630        return TX_CONTINUE;
 631}
 632
 633static ieee80211_tx_result debug_noinline
 634ieee80211_tx_h_misc(struct ieee80211_tx_data *tx)
 635{
 636        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
 637
 638        if (tx->sta)
 639                info->control.sta = &tx->sta->sta;
 640
 641        return TX_CONTINUE;
 642}
 643
 644static ieee80211_tx_result debug_noinline
 645ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
 646{
 647        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
 648        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
 649        u16 *seq;
 650        u8 *qc;
 651        int tid;
 652
 653        /*
 654         * Packet injection may want to control the sequence
 655         * number, if we have no matching interface then we
 656         * neither assign one ourselves nor ask the driver to.
 657         */
 658        if (unlikely(!info->control.vif))
 659                return TX_CONTINUE;
 660
 661        if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
 662                return TX_CONTINUE;
 663
 664        if (ieee80211_hdrlen(hdr->frame_control) < 24)
 665                return TX_CONTINUE;
 666
 667        /*
 668         * Anything but QoS data that has a sequence number field
 669         * (is long enough) gets a sequence number from the global
 670         * counter.
 671         */
 672        if (!ieee80211_is_data_qos(hdr->frame_control)) {
 673                /* driver should assign sequence number */
 674                info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
 675                /* for pure STA mode without beacons, we can do it */
 676                hdr->seq_ctrl = cpu_to_le16(tx->sdata->sequence_number);
 677                tx->sdata->sequence_number += 0x10;
 678                tx->sdata->sequence_number &= IEEE80211_SCTL_SEQ;
 679                return TX_CONTINUE;
 680        }
 681
 682        /*
 683         * This should be true for injected/management frames only, for
 684         * management frames we have set the IEEE80211_TX_CTL_ASSIGN_SEQ
 685         * above since they are not QoS-data frames.
 686         */
 687        if (!tx->sta)
 688                return TX_CONTINUE;
 689
 690        /* include per-STA, per-TID sequence counter */
 691
 692        qc = ieee80211_get_qos_ctl(hdr);
 693        tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
 694        seq = &tx->sta->tid_seq[tid];
 695
 696        hdr->seq_ctrl = cpu_to_le16(*seq);
 697
 698        /* Increase the sequence number. */
 699        *seq = (*seq + 0x10) & IEEE80211_SCTL_SEQ;
 700
 701        return TX_CONTINUE;
 702}
 703
 704static int ieee80211_fragment(struct ieee80211_local *local,
 705                              struct sk_buff *skb, int hdrlen,
 706                              int frag_threshold)
 707{
 708        struct sk_buff *tail = skb, *tmp;
 709        int per_fragm = frag_threshold - hdrlen - FCS_LEN;
 710        int pos = hdrlen + per_fragm;
 711        int rem = skb->len - hdrlen - per_fragm;
 712
 713        if (WARN_ON(rem < 0))
 714                return -EINVAL;
 715
 716        while (rem) {
 717                int fraglen = per_fragm;
 718
 719                if (fraglen > rem)
 720                        fraglen = rem;
 721                rem -= fraglen;
 722                tmp = dev_alloc_skb(local->tx_headroom +
 723                                    frag_threshold +
 724                                    IEEE80211_ENCRYPT_HEADROOM +
 725                                    IEEE80211_ENCRYPT_TAILROOM);
 726                if (!tmp)
 727                        return -ENOMEM;
 728                tail->next = tmp;
 729                tail = tmp;
 730                skb_reserve(tmp, local->tx_headroom +
 731                                 IEEE80211_ENCRYPT_HEADROOM);
 732                /* copy control information */
 733                memcpy(tmp->cb, skb->cb, sizeof(tmp->cb));
 734                skb_copy_queue_mapping(tmp, skb);
 735                tmp->priority = skb->priority;
 736                tmp->do_not_encrypt = skb->do_not_encrypt;
 737                tmp->dev = skb->dev;
 738                tmp->iif = skb->iif;
 739
 740                /* copy header and data */
 741                memcpy(skb_put(tmp, hdrlen), skb->data, hdrlen);
 742                memcpy(skb_put(tmp, fraglen), skb->data + pos, fraglen);
 743
 744                pos += fraglen;
 745        }
 746
 747        skb->len = hdrlen + per_fragm;
 748        return 0;
 749}
 750
 751static ieee80211_tx_result debug_noinline
 752ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
 753{
 754        struct sk_buff *skb = tx->skb;
 755        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 756        struct ieee80211_hdr *hdr = (void *)skb->data;
 757        int frag_threshold = tx->local->fragmentation_threshold;
 758        int hdrlen;
 759        int fragnum;
 760
 761        if (!(tx->flags & IEEE80211_TX_FRAGMENTED))
 762                return TX_CONTINUE;
 763
 764        /*
 765         * Warn when submitting a fragmented A-MPDU frame and drop it.
 766         * This scenario is handled in __ieee80211_tx_prepare but extra
 767         * caution taken here as fragmented ampdu may cause Tx stop.
 768         */
 769        if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
 770                return TX_DROP;
 771
 772        hdrlen = ieee80211_hdrlen(hdr->frame_control);
 773
 774        /* internal error, why is TX_FRAGMENTED set? */
 775        if (WARN_ON(skb->len + FCS_LEN <= frag_threshold))
 776                return TX_DROP;
 777
 778        /*
 779         * Now fragment the frame. This will allocate all the fragments and
 780         * chain them (using skb as the first fragment) to skb->next.
 781         * During transmission, we will remove the successfully transmitted
 782         * fragments from this list. When the low-level driver rejects one
 783         * of the fragments then we will simply pretend to accept the skb
 784         * but store it away as pending.
 785         */
 786        if (ieee80211_fragment(tx->local, skb, hdrlen, frag_threshold))
 787                return TX_DROP;
 788
 789        /* update duration/seq/flags of fragments */
 790        fragnum = 0;
 791        do {
 792                int next_len;
 793                const __le16 morefrags = cpu_to_le16(IEEE80211_FCTL_MOREFRAGS);
 794
 795                hdr = (void *)skb->data;
 796                info = IEEE80211_SKB_CB(skb);
 797
 798                if (skb->next) {
 799                        hdr->frame_control |= morefrags;
 800                        next_len = skb->next->len;
 801                        /*
 802                         * No multi-rate retries for fragmented frames, that
 803                         * would completely throw off the NAV at other STAs.
 804                         */
 805                        info->control.rates[1].idx = -1;
 806                        info->control.rates[2].idx = -1;
 807                        info->control.rates[3].idx = -1;
 808                        info->control.rates[4].idx = -1;
 809                        BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5);
 810                        info->flags &= ~IEEE80211_TX_CTL_RATE_CTRL_PROBE;
 811                } else {
 812                        hdr->frame_control &= ~morefrags;
 813                        next_len = 0;
 814                }
 815                hdr->duration_id = ieee80211_duration(tx, 0, next_len);
 816                hdr->seq_ctrl |= cpu_to_le16(fragnum & IEEE80211_SCTL_FRAG);
 817                fragnum++;
 818        } while ((skb = skb->next));
 819
 820        return TX_CONTINUE;
 821}
 822
 823static ieee80211_tx_result debug_noinline
 824ieee80211_tx_h_encrypt(struct ieee80211_tx_data *tx)
 825{
 826        if (!tx->key)
 827                return TX_CONTINUE;
 828
 829        switch (tx->key->conf.alg) {
 830        case ALG_WEP:
 831                return ieee80211_crypto_wep_encrypt(tx);
 832        case ALG_TKIP:
 833                return ieee80211_crypto_tkip_encrypt(tx);
 834        case ALG_CCMP:
 835                return ieee80211_crypto_ccmp_encrypt(tx);
 836        case ALG_AES_CMAC:
 837                return ieee80211_crypto_aes_cmac_encrypt(tx);
 838        }
 839
 840        /* not reached */
 841        WARN_ON(1);
 842        return TX_DROP;
 843}
 844
 845static ieee80211_tx_result debug_noinline
 846ieee80211_tx_h_calculate_duration(struct ieee80211_tx_data *tx)
 847{
 848        struct sk_buff *skb = tx->skb;
 849        struct ieee80211_hdr *hdr;
 850        int next_len;
 851        bool group_addr;
 852
 853        do {
 854                hdr = (void *) skb->data;
 855                next_len = skb->next ? skb->next->len : 0;
 856                group_addr = is_multicast_ether_addr(hdr->addr1);
 857
 858                hdr->duration_id =
 859                        ieee80211_duration(tx, group_addr, next_len);
 860        } while ((skb = skb->next));
 861
 862        return TX_CONTINUE;
 863}
 864
 865static ieee80211_tx_result debug_noinline
 866ieee80211_tx_h_stats(struct ieee80211_tx_data *tx)
 867{
 868        struct sk_buff *skb = tx->skb;
 869
 870        if (!tx->sta)
 871                return TX_CONTINUE;
 872
 873        tx->sta->tx_packets++;
 874        do {
 875                tx->sta->tx_fragments++;
 876                tx->sta->tx_bytes += skb->len;
 877        } while ((skb = skb->next));
 878
 879        return TX_CONTINUE;
 880}
 881
 882/* actual transmit path */
 883
 884/*
 885 * deal with packet injection down monitor interface
 886 * with Radiotap Header -- only called for monitor mode interface
 887 */
 888static ieee80211_tx_result
 889__ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
 890                              struct sk_buff *skb)
 891{
 892        /*
 893         * this is the moment to interpret and discard the radiotap header that
 894         * must be at the start of the packet injected in Monitor mode
 895         *
 896         * Need to take some care with endian-ness since radiotap
 897         * args are little-endian
 898         */
 899
 900        struct ieee80211_radiotap_iterator iterator;
 901        struct ieee80211_radiotap_header *rthdr =
 902                (struct ieee80211_radiotap_header *) skb->data;
 903        struct ieee80211_supported_band *sband;
 904        int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len);
 905
 906        sband = tx->local->hw.wiphy->bands[tx->channel->band];
 907
 908        skb->do_not_encrypt = 1;
 909        tx->flags &= ~IEEE80211_TX_FRAGMENTED;
 910
 911        /*
 912         * for every radiotap entry that is present
 913         * (ieee80211_radiotap_iterator_next returns -ENOENT when no more
 914         * entries present, or -EINVAL on error)
 915         */
 916
 917        while (!ret) {
 918                ret = ieee80211_radiotap_iterator_next(&iterator);
 919
 920                if (ret)
 921                        continue;
 922
 923                /* see if this argument is something we can use */
 924                switch (iterator.this_arg_index) {
 925                /*
 926                 * You must take care when dereferencing iterator.this_arg
 927                 * for multibyte types... the pointer is not aligned.  Use
 928                 * get_unaligned((type *)iterator.this_arg) to dereference
 929                 * iterator.this_arg for type "type" safely on all arches.
 930                */
 931                case IEEE80211_RADIOTAP_FLAGS:
 932                        if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FCS) {
 933                                /*
 934                                 * this indicates that the skb we have been
 935                                 * handed has the 32-bit FCS CRC at the end...
 936                                 * we should react to that by snipping it off
 937                                 * because it will be recomputed and added
 938                                 * on transmission
 939                                 */
 940                                if (skb->len < (iterator.max_length + FCS_LEN))
 941                                        return TX_DROP;
 942
 943                                skb_trim(skb, skb->len - FCS_LEN);
 944                        }
 945                        if (*iterator.this_arg & IEEE80211_RADIOTAP_F_WEP)
 946                                tx->skb->do_not_encrypt = 0;
 947                        if (*iterator.this_arg & IEEE80211_RADIOTAP_F_FRAG)
 948                                tx->flags |= IEEE80211_TX_FRAGMENTED;
 949                        break;
 950
 951                /*
 952                 * Please update the file
 953                 * Documentation/networking/mac80211-injection.txt
 954                 * when parsing new fields here.
 955                 */
 956
 957                default:
 958                        break;
 959                }
 960        }
 961
 962        if (ret != -ENOENT) /* ie, if we didn't simply run out of fields */
 963                return TX_DROP;
 964
 965        /*
 966         * remove the radiotap header
 967         * iterator->max_length was sanity-checked against
 968         * skb->len by iterator init
 969         */
 970        skb_pull(skb, iterator.max_length);
 971
 972        return TX_CONTINUE;
 973}
 974
 975/*
 976 * initialises @tx
 977 */
 978static ieee80211_tx_result
 979__ieee80211_tx_prepare(struct ieee80211_tx_data *tx,
 980                       struct sk_buff *skb,
 981                       struct net_device *dev)
 982{
 983        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 984        struct ieee80211_hdr *hdr;
 985        struct ieee80211_sub_if_data *sdata;
 986        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 987        int hdrlen, tid;
 988        u8 *qc, *state;
 989        bool queued = false;
 990
 991        memset(tx, 0, sizeof(*tx));
 992        tx->skb = skb;
 993        tx->dev = dev; /* use original interface */
 994        tx->local = local;
 995        tx->sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 996        tx->channel = local->hw.conf.channel;
 997        /*
 998         * Set this flag (used below to indicate "automatic fragmentation"),
 999         * it will be cleared/left by radiotap as desired.
1000         */
1001        tx->flags |= IEEE80211_TX_FRAGMENTED;
1002
1003        /* process and remove the injection radiotap header */
1004        sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1005        if (unlikely(info->flags & IEEE80211_TX_CTL_INJECTED)) {
1006                if (__ieee80211_parse_tx_radiotap(tx, skb) == TX_DROP)
1007                        return TX_DROP;
1008
1009                /*
1010                 * __ieee80211_parse_tx_radiotap has now removed
1011                 * the radiotap header that was present and pre-filled
1012                 * 'tx' with tx control information.
1013                 */
1014        }
1015
1016        /*
1017         * If this flag is set to true anywhere, and we get here,
1018         * we are doing the needed processing, so remove the flag
1019         * now.
1020         */
1021        info->flags &= ~IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1022
1023        hdr = (struct ieee80211_hdr *) skb->data;
1024
1025        tx->sta = sta_info_get(local, hdr->addr1);
1026
1027        if (tx->sta && ieee80211_is_data_qos(hdr->frame_control) &&
1028            (local->hw.flags & IEEE80211_HW_AMPDU_AGGREGATION)) {
1029                unsigned long flags;
1030                struct tid_ampdu_tx *tid_tx;
1031
1032                qc = ieee80211_get_qos_ctl(hdr);
1033                tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
1034
1035                spin_lock_irqsave(&tx->sta->lock, flags);
1036                /*
1037                 * XXX: This spinlock could be fairly expensive, but see the
1038                 *      comment in agg-tx.c:ieee80211_agg_tx_operational().
1039                 *      One way to solve this would be to do something RCU-like
1040                 *      for managing the tid_tx struct and using atomic bitops
1041                 *      for the actual state -- by introducing an actual
1042                 *      'operational' bit that would be possible. It would
1043                 *      require changing ieee80211_agg_tx_operational() to
1044                 *      set that bit, and changing the way tid_tx is managed
1045                 *      everywhere, including races between that bit and
1046                 *      tid_tx going away (tid_tx being added can be easily
1047                 *      committed to memory before the 'operational' bit).
1048                 */
1049                tid_tx = tx->sta->ampdu_mlme.tid_tx[tid];
1050                state = &tx->sta->ampdu_mlme.tid_state_tx[tid];
1051                if (*state == HT_AGG_STATE_OPERATIONAL) {
1052                        info->flags |= IEEE80211_TX_CTL_AMPDU;
1053                } else if (*state != HT_AGG_STATE_IDLE) {
1054                        /* in progress */
1055                        queued = true;
1056                        info->flags |= IEEE80211_TX_INTFL_NEED_TXPROCESSING;
1057                        __skb_queue_tail(&tid_tx->pending, skb);
1058                }
1059                spin_unlock_irqrestore(&tx->sta->lock, flags);
1060
1061                if (unlikely(queued))
1062                        return TX_QUEUED;
1063        }
1064
1065        if (is_multicast_ether_addr(hdr->addr1)) {
1066                tx->flags &= ~IEEE80211_TX_UNICAST;
1067                info->flags |= IEEE80211_TX_CTL_NO_ACK;
1068        } else {
1069                tx->flags |= IEEE80211_TX_UNICAST;
1070                info->flags &= ~IEEE80211_TX_CTL_NO_ACK;
1071        }
1072
1073        if (tx->flags & IEEE80211_TX_FRAGMENTED) {
1074                if ((tx->flags & IEEE80211_TX_UNICAST) &&
1075                    skb->len + FCS_LEN > local->fragmentation_threshold &&
1076                    !(info->flags & IEEE80211_TX_CTL_AMPDU))
1077                        tx->flags |= IEEE80211_TX_FRAGMENTED;
1078                else
1079                        tx->flags &= ~IEEE80211_TX_FRAGMENTED;
1080        }
1081
1082        if (!tx->sta)
1083                info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1084        else if (test_and_clear_sta_flags(tx->sta, WLAN_STA_CLEAR_PS_FILT))
1085                info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
1086
1087        hdrlen = ieee80211_hdrlen(hdr->frame_control);
1088        if (skb->len > hdrlen + sizeof(rfc1042_header) + 2) {
1089                u8 *pos = &skb->data[hdrlen + sizeof(rfc1042_header)];
1090                tx->ethertype = (pos[0] << 8) | pos[1];
1091        }
1092        info->flags |= IEEE80211_TX_CTL_FIRST_FRAGMENT;
1093
1094        return TX_CONTINUE;
1095}
1096
1097/*
1098 * NB: @tx is uninitialised when passed in here
1099 */
1100static int ieee80211_tx_prepare(struct ieee80211_local *local,
1101                                struct ieee80211_tx_data *tx,
1102                                struct sk_buff *skb)
1103{
1104        struct net_device *dev;
1105
1106        dev = dev_get_by_index(&init_net, skb->iif);
1107        if (unlikely(dev && !is_ieee80211_device(local, dev))) {
1108                dev_put(dev);
1109                dev = NULL;
1110        }
1111        if (unlikely(!dev))
1112                return -ENODEV;
1113        /*
1114         * initialises tx with control
1115         *
1116         * return value is safe to ignore here because this function
1117         * can only be invoked for multicast frames
1118         *
1119         * XXX: clean up
1120         */
1121        __ieee80211_tx_prepare(tx, skb, dev);
1122        dev_put(dev);
1123        return 0;
1124}
1125
1126static int __ieee80211_tx(struct ieee80211_local *local,
1127                          struct sk_buff **skbp,
1128                          struct sta_info *sta)
1129{
1130        struct sk_buff *skb = *skbp, *next;
1131        struct ieee80211_tx_info *info;
1132        int ret, len;
1133        bool fragm = false;
1134
1135        local->mdev->trans_start = jiffies;
1136
1137        while (skb) {
1138                if (ieee80211_queue_stopped(&local->hw,
1139                                            skb_get_queue_mapping(skb)))
1140                        return IEEE80211_TX_PENDING;
1141
1142                info = IEEE80211_SKB_CB(skb);
1143
1144                if (fragm)
1145                        info->flags &= ~(IEEE80211_TX_CTL_CLEAR_PS_FILT |
1146                                         IEEE80211_TX_CTL_FIRST_FRAGMENT);
1147
1148                next = skb->next;
1149                len = skb->len;
1150                ret = local->ops->tx(local_to_hw(local), skb);
1151                if (WARN_ON(ret != NETDEV_TX_OK && skb->len != len)) {
1152                        dev_kfree_skb(skb);
1153                        ret = NETDEV_TX_OK;
1154                }
1155                if (ret != NETDEV_TX_OK)
1156                        return IEEE80211_TX_AGAIN;
1157                *skbp = skb = next;
1158                ieee80211_led_tx(local, 1);
1159                fragm = true;
1160        }
1161
1162        return IEEE80211_TX_OK;
1163}
1164
1165/*
1166 * Invoke TX handlers, return 0 on success and non-zero if the
1167 * frame was dropped or queued.
1168 */
1169static int invoke_tx_handlers(struct ieee80211_tx_data *tx)
1170{
1171        struct sk_buff *skb = tx->skb;
1172        ieee80211_tx_result res = TX_DROP;
1173
1174#define CALL_TXH(txh)           \
1175        res = txh(tx);          \
1176        if (res != TX_CONTINUE) \
1177                goto txh_done;
1178
1179        CALL_TXH(ieee80211_tx_h_check_assoc)
1180        CALL_TXH(ieee80211_tx_h_ps_buf)
1181        CALL_TXH(ieee80211_tx_h_select_key)
1182        CALL_TXH(ieee80211_tx_h_michael_mic_add)
1183        CALL_TXH(ieee80211_tx_h_rate_ctrl)
1184        CALL_TXH(ieee80211_tx_h_misc)
1185        CALL_TXH(ieee80211_tx_h_sequence)
1186        CALL_TXH(ieee80211_tx_h_fragment)
1187        /* handlers after fragment must be aware of tx info fragmentation! */
1188        CALL_TXH(ieee80211_tx_h_encrypt)
1189        CALL_TXH(ieee80211_tx_h_calculate_duration)
1190        CALL_TXH(ieee80211_tx_h_stats)
1191#undef CALL_TXH
1192
1193 txh_done:
1194        if (unlikely(res == TX_DROP)) {
1195                I802_DEBUG_INC(tx->local->tx_handlers_drop);
1196                while (skb) {
1197                        struct sk_buff *next;
1198
1199                        next = skb->next;
1200                        dev_kfree_skb(skb);
1201                        skb = next;
1202                }
1203                return -1;
1204        } else if (unlikely(res == TX_QUEUED)) {
1205                I802_DEBUG_INC(tx->local->tx_handlers_queued);
1206                return -1;
1207        }
1208
1209        return 0;
1210}
1211
1212static void ieee80211_tx(struct net_device *dev, struct sk_buff *skb,
1213                         bool txpending)
1214{
1215        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1216        struct sta_info *sta;
1217        struct ieee80211_tx_data tx;
1218        ieee80211_tx_result res_prepare;
1219        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1220        struct sk_buff *next;
1221        unsigned long flags;
1222        int ret, retries;
1223        u16 queue;
1224
1225        queue = skb_get_queue_mapping(skb);
1226
1227        WARN_ON(!txpending && !skb_queue_empty(&local->pending[queue]));
1228
1229        if (unlikely(skb->len < 10)) {
1230                dev_kfree_skb(skb);
1231                return;
1232        }
1233
1234        rcu_read_lock();
1235
1236        /* initialises tx */
1237        res_prepare = __ieee80211_tx_prepare(&tx, skb, dev);
1238
1239        if (unlikely(res_prepare == TX_DROP)) {
1240                dev_kfree_skb(skb);
1241                rcu_read_unlock();
1242                return;
1243        } else if (unlikely(res_prepare == TX_QUEUED)) {
1244                rcu_read_unlock();
1245                return;
1246        }
1247
1248        sta = tx.sta;
1249        tx.channel = local->hw.conf.channel;
1250        info->band = tx.channel->band;
1251
1252        if (invoke_tx_handlers(&tx))
1253                goto out;
1254
1255        retries = 0;
1256 retry:
1257        ret = __ieee80211_tx(local, &tx.skb, tx.sta);
1258        switch (ret) {
1259        case IEEE80211_TX_OK:
1260                break;
1261        case IEEE80211_TX_AGAIN:
1262                /*
1263                 * Since there are no fragmented frames on A-MPDU
1264                 * queues, there's no reason for a driver to reject
1265                 * a frame there, warn and drop it.
1266                 */
1267                if (WARN_ON(info->flags & IEEE80211_TX_CTL_AMPDU))
1268                        goto drop;
1269                /* fall through */
1270        case IEEE80211_TX_PENDING:
1271                skb = tx.skb;
1272
1273                spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1274
1275                if (__netif_subqueue_stopped(local->mdev, queue)) {
1276                        do {
1277                                next = skb->next;
1278                                skb->next = NULL;
1279                                if (unlikely(txpending))
1280                                        skb_queue_head(&local->pending[queue],
1281                                                       skb);
1282                                else
1283                                        skb_queue_tail(&local->pending[queue],
1284                                                       skb);
1285                        } while ((skb = next));
1286
1287                        /*
1288                         * Make sure nobody will enable the queue on us
1289                         * (without going through the tasklet) nor disable the
1290                         * netdev queue underneath the pending handling code.
1291                         */
1292                        __set_bit(IEEE80211_QUEUE_STOP_REASON_PENDING,
1293                                  &local->queue_stop_reasons[queue]);
1294
1295                        spin_unlock_irqrestore(&local->queue_stop_reason_lock,
1296                                               flags);
1297                } else {
1298                        spin_unlock_irqrestore(&local->queue_stop_reason_lock,
1299                                               flags);
1300
1301                        retries++;
1302                        if (WARN(retries > 10, "tx refused but queue active"))
1303                                goto drop;
1304                        goto retry;
1305                }
1306        }
1307 out:
1308        rcu_read_unlock();
1309        return;
1310
1311 drop:
1312        rcu_read_unlock();
1313
1314        skb = tx.skb;
1315        while (skb) {
1316                next = skb->next;
1317                dev_kfree_skb(skb);
1318                skb = next;
1319        }
1320}
1321
1322/* device xmit handlers */
1323
1324static int ieee80211_skb_resize(struct ieee80211_local *local,
1325                                struct sk_buff *skb,
1326                                int head_need, bool may_encrypt)
1327{
1328        int tail_need = 0;
1329
1330        /*
1331         * This could be optimised, devices that do full hardware
1332         * crypto (including TKIP MMIC) need no tailroom... But we
1333         * have no drivers for such devices currently.
1334         */
1335        if (may_encrypt) {
1336                tail_need = IEEE80211_ENCRYPT_TAILROOM;
1337                tail_need -= skb_tailroom(skb);
1338                tail_need = max_t(int, tail_need, 0);
1339        }
1340
1341        if (head_need || tail_need) {
1342                /* Sorry. Can't account for this any more */
1343                skb_orphan(skb);
1344        }
1345
1346        if (skb_header_cloned(skb))
1347                I802_DEBUG_INC(local->tx_expand_skb_head_cloned);
1348        else
1349                I802_DEBUG_INC(local->tx_expand_skb_head);
1350
1351        if (pskb_expand_head(skb, head_need, tail_need, GFP_ATOMIC)) {
1352                printk(KERN_DEBUG "%s: failed to reallocate TX buffer\n",
1353                       wiphy_name(local->hw.wiphy));
1354                return -ENOMEM;
1355        }
1356
1357        /* update truesize too */
1358        skb->truesize += head_need + tail_need;
1359
1360        return 0;
1361}
1362
1363int ieee80211_master_start_xmit(struct sk_buff *skb, struct net_device *dev)
1364{
1365        struct ieee80211_master_priv *mpriv = netdev_priv(dev);
1366        struct ieee80211_local *local = mpriv->local;
1367        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1368        struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
1369        struct net_device *odev = NULL;
1370        struct ieee80211_sub_if_data *osdata;
1371        int headroom;
1372        bool may_encrypt;
1373        enum {
1374                NOT_MONITOR,
1375                FOUND_SDATA,
1376                UNKNOWN_ADDRESS,
1377        } monitor_iface = NOT_MONITOR;
1378
1379        if (skb->iif)
1380                odev = dev_get_by_index(&init_net, skb->iif);
1381        if (unlikely(odev && !is_ieee80211_device(local, odev))) {
1382                dev_put(odev);
1383                odev = NULL;
1384        }
1385        if (unlikely(!odev)) {
1386#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1387                printk(KERN_DEBUG "%s: Discarded packet with nonexistent "
1388                       "originating device\n", dev->name);
1389#endif
1390                dev_kfree_skb(skb);
1391                return NETDEV_TX_OK;
1392        }
1393
1394        if ((local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK) &&
1395            local->hw.conf.dynamic_ps_timeout > 0) {
1396                if (local->hw.conf.flags & IEEE80211_CONF_PS) {
1397                        ieee80211_stop_queues_by_reason(&local->hw,
1398                                        IEEE80211_QUEUE_STOP_REASON_PS);
1399                        queue_work(local->hw.workqueue,
1400                                        &local->dynamic_ps_disable_work);
1401                }
1402
1403                mod_timer(&local->dynamic_ps_timer, jiffies +
1404                        msecs_to_jiffies(local->hw.conf.dynamic_ps_timeout));
1405        }
1406
1407        memset(info, 0, sizeof(*info));
1408
1409        info->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
1410
1411        osdata = IEEE80211_DEV_TO_SUB_IF(odev);
1412
1413        if (ieee80211_vif_is_mesh(&osdata->vif) &&
1414            ieee80211_is_data(hdr->frame_control)) {
1415                if (is_multicast_ether_addr(hdr->addr3))
1416                        memcpy(hdr->addr1, hdr->addr3, ETH_ALEN);
1417                else
1418                        if (mesh_nexthop_lookup(skb, osdata)) {
1419                                dev_put(odev);
1420                                return NETDEV_TX_OK;
1421                        }
1422                if (memcmp(odev->dev_addr, hdr->addr4, ETH_ALEN) != 0)
1423                        IEEE80211_IFSTA_MESH_CTR_INC(&osdata->u.mesh,
1424                                                            fwded_frames);
1425        } else if (unlikely(osdata->vif.type == NL80211_IFTYPE_MONITOR)) {
1426                struct ieee80211_sub_if_data *sdata;
1427                int hdrlen;
1428                u16 len_rthdr;
1429
1430                info->flags |= IEEE80211_TX_CTL_INJECTED;
1431                monitor_iface = UNKNOWN_ADDRESS;
1432
1433                len_rthdr = ieee80211_get_radiotap_len(skb->data);
1434                hdr = (struct ieee80211_hdr *)skb->data + len_rthdr;
1435                hdrlen = ieee80211_hdrlen(hdr->frame_control);
1436
1437                /* check the header is complete in the frame */
1438                if (likely(skb->len >= len_rthdr + hdrlen)) {
1439                        /*
1440                         * We process outgoing injected frames that have a
1441                         * local address we handle as though they are our
1442                         * own frames.
1443                         * This code here isn't entirely correct, the local
1444                         * MAC address is not necessarily enough to find
1445                         * the interface to use; for that proper VLAN/WDS
1446                         * support we will need a different mechanism.
1447                         */
1448
1449                        rcu_read_lock();
1450                        list_for_each_entry_rcu(sdata, &local->interfaces,
1451                                                list) {
1452                                if (!netif_running(sdata->dev))
1453                                        continue;
1454                                if (sdata->vif.type != NL80211_IFTYPE_AP)
1455                                        continue;
1456                                if (compare_ether_addr(sdata->dev->dev_addr,
1457                                                       hdr->addr2)) {
1458                                        dev_hold(sdata->dev);
1459                                        dev_put(odev);
1460                                        osdata = sdata;
1461                                        odev = osdata->dev;
1462                                        skb->iif = sdata->dev->ifindex;
1463                                        monitor_iface = FOUND_SDATA;
1464                                        break;
1465                                }
1466                        }
1467                        rcu_read_unlock();
1468                }
1469        }
1470
1471        may_encrypt = !skb->do_not_encrypt;
1472
1473        headroom = osdata->local->tx_headroom;
1474        if (may_encrypt)
1475                headroom += IEEE80211_ENCRYPT_HEADROOM;
1476        headroom -= skb_headroom(skb);
1477        headroom = max_t(int, 0, headroom);
1478
1479        if (ieee80211_skb_resize(osdata->local, skb, headroom, may_encrypt)) {
1480                dev_kfree_skb(skb);
1481                dev_put(odev);
1482                return NETDEV_TX_OK;
1483        }
1484
1485        if (osdata->vif.type == NL80211_IFTYPE_AP_VLAN)
1486                osdata = container_of(osdata->bss,
1487                                      struct ieee80211_sub_if_data,
1488                                      u.ap);
1489        if (likely(monitor_iface != UNKNOWN_ADDRESS))
1490                info->control.vif = &osdata->vif;
1491
1492        ieee80211_tx(odev, skb, false);
1493        dev_put(odev);
1494
1495        return NETDEV_TX_OK;
1496}
1497
1498int ieee80211_monitor_start_xmit(struct sk_buff *skb,
1499                                 struct net_device *dev)
1500{
1501        struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
1502        struct ieee80211_channel *chan = local->hw.conf.channel;
1503        struct ieee80211_radiotap_header *prthdr =
1504                (struct ieee80211_radiotap_header *)skb->data;
1505        u16 len_rthdr;
1506
1507        /*
1508         * Frame injection is not allowed if beaconing is not allowed
1509         * or if we need radar detection. Beaconing is usually not allowed when
1510         * the mode or operation (Adhoc, AP, Mesh) does not support DFS.
1511         * Passive scan is also used in world regulatory domains where
1512         * your country is not known and as such it should be treated as
1513         * NO TX unless the channel is explicitly allowed in which case
1514         * your current regulatory domain would not have the passive scan
1515         * flag.
1516         *
1517         * Since AP mode uses monitor interfaces to inject/TX management
1518         * frames we can make AP mode the exception to this rule once it
1519         * supports radar detection as its implementation can deal with
1520         * radar detection by itself. We can do that later by adding a
1521         * monitor flag interfaces used for AP support.
1522         */
1523        if ((chan->flags & (IEEE80211_CHAN_NO_IBSS | IEEE80211_CHAN_RADAR |
1524             IEEE80211_CHAN_PASSIVE_SCAN)))
1525                goto fail;
1526
1527        /* check for not even having the fixed radiotap header part */
1528        if (unlikely(skb->len < sizeof(struct ieee80211_radiotap_header)))
1529                goto fail; /* too short to be possibly valid */
1530
1531        /* is it a header version we can trust to find length from? */
1532        if (unlikely(prthdr->it_version))
1533                goto fail; /* only version 0 is supported */
1534
1535        /* then there must be a radiotap header with a length we can use */
1536        len_rthdr = ieee80211_get_radiotap_len(skb->data);
1537
1538        /* does the skb contain enough to deliver on the alleged length? */
1539        if (unlikely(skb->len < len_rthdr))
1540                goto fail; /* skb too short for claimed rt header extent */
1541
1542        skb->dev = local->mdev;
1543
1544        /* needed because we set skb device to master */
1545        skb->iif = dev->ifindex;
1546
1547        /* sometimes we do encrypt injected frames, will be fixed
1548         * up in radiotap parser if not wanted */
1549        skb->do_not_encrypt = 0;
1550
1551        /*
1552         * fix up the pointers accounting for the radiotap
1553         * header still being in there.  We are being given
1554         * a precooked IEEE80211 header so no need for
1555         * normal processing
1556         */
1557        skb_set_mac_header(skb, len_rthdr);
1558        /*
1559         * these are just fixed to the end of the rt area since we
1560         * don't have any better information and at this point, nobody cares
1561         */
1562        skb_set_network_header(skb, len_rthdr);
1563        skb_set_transport_header(skb, len_rthdr);
1564
1565        /* pass the radiotap header up to the next stage intact */
1566        dev_queue_xmit(skb);
1567        return NETDEV_TX_OK;
1568
1569fail:
1570        dev_kfree_skb(skb);
1571        return NETDEV_TX_OK; /* meaning, we dealt with the skb */
1572}
1573
1574/**
1575 * ieee80211_subif_start_xmit - netif start_xmit function for Ethernet-type
1576 * subinterfaces (wlan#, WDS, and VLAN interfaces)
1577 * @skb: packet to be sent
1578 * @dev: incoming interface
1579 *
1580 * Returns: 0 on success (and frees skb in this case) or 1 on failure (skb will
1581 * not be freed, and caller is responsible for either retrying later or freeing
1582 * skb).
1583 *
1584 * This function takes in an Ethernet header and encapsulates it with suitable
1585 * IEEE 802.11 header based on which interface the packet is coming in. The
1586 * encapsulated packet will then be passed to master interface, wlan#.11, for
1587 * transmission (through low-level driver).
1588 */
1589int ieee80211_subif_start_xmit(struct sk_buff *skb,
1590                               struct net_device *dev)
1591{
1592        struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1593        struct ieee80211_local *local = sdata->local;
1594        int ret = 1, head_need;
1595        u16 ethertype, hdrlen,  meshhdrlen = 0;
1596        __le16 fc;
1597        struct ieee80211_hdr hdr;
1598        struct ieee80211s_hdr mesh_hdr;
1599        const u8 *encaps_data;
1600        int encaps_len, skip_header_bytes;
1601        int nh_pos, h_pos;
1602        struct sta_info *sta;
1603        u32 sta_flags = 0;
1604
1605        if (unlikely(skb->len < ETH_HLEN)) {
1606                ret = 0;
1607                goto fail;
1608        }
1609
1610        nh_pos = skb_network_header(skb) - skb->data;
1611        h_pos = skb_transport_header(skb) - skb->data;
1612
1613        /* convert Ethernet header to proper 802.11 header (based on
1614         * operation mode) */
1615        ethertype = (skb->data[12] << 8) | skb->data[13];
1616        fc = cpu_to_le16(IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA);
1617
1618        switch (sdata->vif.type) {
1619        case NL80211_IFTYPE_AP:
1620        case NL80211_IFTYPE_AP_VLAN:
1621                fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS);
1622                /* DA BSSID SA */
1623                memcpy(hdr.addr1, skb->data, ETH_ALEN);
1624                memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
1625                memcpy(hdr.addr3, skb->data + ETH_ALEN, ETH_ALEN);
1626                hdrlen = 24;
1627                break;
1628        case NL80211_IFTYPE_WDS:
1629                fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1630                /* RA TA DA SA */
1631                memcpy(hdr.addr1, sdata->u.wds.remote_addr, ETH_ALEN);
1632                memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
1633                memcpy(hdr.addr3, skb->data, ETH_ALEN);
1634                memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1635                hdrlen = 30;
1636                break;
1637#ifdef CONFIG_MAC80211_MESH
1638        case NL80211_IFTYPE_MESH_POINT:
1639                fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS);
1640                if (!sdata->u.mesh.mshcfg.dot11MeshTTL) {
1641                        /* Do not send frames with mesh_ttl == 0 */
1642                        sdata->u.mesh.mshstats.dropped_frames_ttl++;
1643                        ret = 0;
1644                        goto fail;
1645                }
1646                memset(&mesh_hdr, 0, sizeof(mesh_hdr));
1647
1648                if (compare_ether_addr(dev->dev_addr,
1649                                          skb->data + ETH_ALEN) == 0) {
1650                        /* RA TA DA SA */
1651                        memset(hdr.addr1, 0, ETH_ALEN);
1652                        memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
1653                        memcpy(hdr.addr3, skb->data, ETH_ALEN);
1654                        memcpy(hdr.addr4, skb->data + ETH_ALEN, ETH_ALEN);
1655                        meshhdrlen = ieee80211_new_mesh_header(&mesh_hdr, sdata);
1656                } else {
1657                        /* packet from other interface */
1658                        struct mesh_path *mppath;
1659
1660                        memset(hdr.addr1, 0, ETH_ALEN);
1661                        memcpy(hdr.addr2, dev->dev_addr, ETH_ALEN);
1662                        memcpy(hdr.addr4, dev->dev_addr, ETH_ALEN);
1663
1664                        if (is_multicast_ether_addr(skb->data))
1665                                memcpy(hdr.addr3, skb->data, ETH_ALEN);
1666                        else {
1667                                rcu_read_lock();
1668                                mppath = mpp_path_lookup(skb->data, sdata);
1669                                if (mppath)
1670                                        memcpy(hdr.addr3, mppath->mpp, ETH_ALEN);
1671                                else
1672                                        memset(hdr.addr3, 0xff, ETH_ALEN);
1673                                rcu_read_unlock();
1674                        }
1675
1676                        mesh_hdr.flags |= MESH_FLAGS_AE_A5_A6;
1677                        mesh_hdr.ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
1678                        put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &mesh_hdr.seqnum);
1679                        memcpy(mesh_hdr.eaddr1, skb->data, ETH_ALEN);
1680                        memcpy(mesh_hdr.eaddr2, skb->data + ETH_ALEN, ETH_ALEN);
1681                        sdata->u.mesh.mesh_seqnum++;
1682                        meshhdrlen = 18;
1683                }
1684                hdrlen = 30;
1685                break;
1686#endif
1687        case NL80211_IFTYPE_STATION:
1688                fc |= cpu_to_le16(IEEE80211_FCTL_TODS);
1689                /* BSSID SA DA */
1690                memcpy(hdr.addr1, sdata->u.mgd.bssid, ETH_ALEN);
1691                memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1692                memcpy(hdr.addr3, skb->data, ETH_ALEN);
1693                hdrlen = 24;
1694                break;
1695        case NL80211_IFTYPE_ADHOC:
1696                /* DA SA BSSID */
1697                memcpy(hdr.addr1, skb->data, ETH_ALEN);
1698                memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
1699                memcpy(hdr.addr3, sdata->u.ibss.bssid, ETH_ALEN);
1700                hdrlen = 24;
1701                break;
1702        default:
1703                ret = 0;
1704                goto fail;
1705        }
1706
1707        /*
1708         * There's no need to try to look up the destination
1709         * if it is a multicast address (which can only happen
1710         * in AP mode)
1711         */
1712        if (!is_multicast_ether_addr(hdr.addr1)) {
1713                rcu_read_lock();
1714                sta = sta_info_get(local, hdr.addr1);
1715                if (sta)
1716                        sta_flags = get_sta_flags(sta);
1717                rcu_read_unlock();
1718        }
1719
1720        /* receiver and we are QoS enabled, use a QoS type frame */
1721        if ((sta_flags & WLAN_STA_WME) && local->hw.queues >= 4) {
1722                fc |= cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1723                hdrlen += 2;
1724        }
1725
1726        /*
1727         * Drop unicast frames to unauthorised stations unless they are
1728         * EAPOL frames from the local station.
1729         */
1730        if (!ieee80211_vif_is_mesh(&sdata->vif) &&
1731                unlikely(!is_multicast_ether_addr(hdr.addr1) &&
1732                      !(sta_flags & WLAN_STA_AUTHORIZED) &&
1733                      !(ethertype == ETH_P_PAE &&
1734                       compare_ether_addr(dev->dev_addr,
1735                                          skb->data + ETH_ALEN) == 0))) {
1736#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
1737                if (net_ratelimit())
1738                        printk(KERN_DEBUG "%s: dropped frame to %pM"
1739                               " (unauthorized port)\n", dev->name,
1740                               hdr.addr1);
1741#endif
1742
1743                I802_DEBUG_INC(local->tx_handlers_drop_unauth_port);
1744
1745                ret = 0;
1746                goto fail;
1747        }
1748
1749        hdr.frame_control = fc;
1750        hdr.duration_id = 0;
1751        hdr.seq_ctrl = 0;
1752
1753        skip_header_bytes = ETH_HLEN;
1754        if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
1755                encaps_data = bridge_tunnel_header;
1756                encaps_len = sizeof(bridge_tunnel_header);
1757                skip_header_bytes -= 2;
1758        } else if (ethertype >= 0x600) {
1759                encaps_data = rfc1042_header;
1760                encaps_len = sizeof(rfc1042_header);
1761                skip_header_bytes -= 2;
1762        } else {
1763                encaps_data = NULL;
1764                encaps_len = 0;
1765        }
1766
1767        skb_pull(skb, skip_header_bytes);
1768        nh_pos -= skip_header_bytes;
1769        h_pos -= skip_header_bytes;
1770
1771        head_need = hdrlen + encaps_len + meshhdrlen - skb_headroom(skb);
1772
1773        /*
1774         * So we need to modify the skb header and hence need a copy of
1775         * that. The head_need variable above doesn't, so far, include
1776         * the needed header space that we don't need right away. If we
1777         * can, then we don't reallocate right now but only after the
1778         * frame arrives at the master device (if it does...)
1779         *
1780         * If we cannot, however, then we will reallocate to include all
1781         * the ever needed space. Also, if we need to reallocate it anyway,
1782         * make it big enough for everything we may ever need.
1783         */
1784
1785        if (head_need > 0 || skb_cloned(skb)) {
1786                head_need += IEEE80211_ENCRYPT_HEADROOM;
1787                head_need += local->tx_headroom;
1788                head_need = max_t(int, 0, head_need);
1789                if (ieee80211_skb_resize(local, skb, head_need, true))
1790                        goto fail;
1791        }
1792
1793        if (encaps_data) {
1794                memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
1795                nh_pos += encaps_len;
1796                h_pos += encaps_len;
1797        }
1798
1799        if (meshhdrlen > 0) {
1800                memcpy(skb_push(skb, meshhdrlen), &mesh_hdr, meshhdrlen);
1801                nh_pos += meshhdrlen;
1802                h_pos += meshhdrlen;
1803        }
1804
1805        if (ieee80211_is_data_qos(fc)) {
1806                __le16 *qos_control;
1807
1808                qos_control = (__le16*) skb_push(skb, 2);
1809                memcpy(skb_push(skb, hdrlen - 2), &hdr, hdrlen - 2);
1810                /*
1811                 * Maybe we could actually set some fields here, for now just
1812                 * initialise to zero to indicate no special operation.
1813                 */
1814                *qos_control = 0;
1815        } else
1816                memcpy(skb_push(skb, hdrlen), &hdr, hdrlen);
1817
1818        nh_pos += hdrlen;
1819        h_pos += hdrlen;
1820
1821        skb->iif = dev->ifindex;
1822
1823        skb->dev = local->mdev;
1824        dev->stats.tx_packets++;
1825        dev->stats.tx_bytes += skb->len;
1826
1827        /* Update skb pointers to various headers since this modified frame
1828         * is going to go through Linux networking code that may potentially
1829         * need things like pointer to IP header. */
1830        skb_set_mac_header(skb, 0);
1831        skb_set_network_header(skb, nh_pos);
1832        skb_set_transport_header(skb, h_pos);
1833
1834        dev->trans_start = jiffies;
1835        dev_queue_xmit(skb);
1836
1837        return 0;
1838
1839 fail:
1840        if (!ret)
1841                dev_kfree_skb(skb);
1842
1843        return ret;
1844}
1845
1846
1847/*
1848 * ieee80211_clear_tx_pending may not be called in a context where
1849 * it is possible that it packets could come in again.
1850 */
1851void ieee80211_clear_tx_pending(struct ieee80211_local *local)
1852{
1853        int i;
1854
1855        for (i = 0; i < local->hw.queues; i++)
1856                skb_queue_purge(&local->pending[i]);
1857}
1858
1859static bool ieee80211_tx_pending_skb(struct ieee80211_local *local,
1860                                     struct sk_buff *skb)
1861{
1862        struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
1863        struct ieee80211_sub_if_data *sdata;
1864        struct sta_info *sta;
1865        struct ieee80211_hdr *hdr;
1866        struct net_device *dev;
1867        int ret;
1868        bool result = true;
1869
1870        /* does interface still exist? */
1871        dev = dev_get_by_index(&init_net, skb->iif);
1872        if (!dev) {
1873                dev_kfree_skb(skb);
1874                return true;
1875        }
1876
1877        /* validate info->control.vif against skb->iif */
1878        sdata = IEEE80211_DEV_TO_SUB_IF(dev);
1879        if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
1880                sdata = container_of(sdata->bss,
1881                                     struct ieee80211_sub_if_data,
1882                                     u.ap);
1883
1884        if (unlikely(info->control.vif && info->control.vif != &sdata->vif)) {
1885                dev_kfree_skb(skb);
1886                result = true;
1887                goto out;
1888        }
1889
1890        if (info->flags & IEEE80211_TX_INTFL_NEED_TXPROCESSING) {
1891                ieee80211_tx(dev, skb, true);
1892        } else {
1893                hdr = (struct ieee80211_hdr *)skb->data;
1894                sta = sta_info_get(local, hdr->addr1);
1895
1896                ret = __ieee80211_tx(local, &skb, sta);
1897                if (ret != IEEE80211_TX_OK)
1898                        result = false;
1899        }
1900
1901 out:
1902        dev_put(dev);
1903
1904        return result;
1905}
1906
1907/*
1908 * Transmit all pending packets. Called from tasklet, locks master device
1909 * TX lock so that no new packets can come in.
1910 */
1911void ieee80211_tx_pending(unsigned long data)
1912{
1913        struct ieee80211_local *local = (struct ieee80211_local *)data;
1914        struct net_device *dev = local->mdev;
1915        unsigned long flags;
1916        int i;
1917        bool next;
1918
1919        rcu_read_lock();
1920        netif_tx_lock_bh(dev);
1921
1922        for (i = 0; i < local->hw.queues; i++) {
1923                /*
1924                 * If queue is stopped by something other than due to pending
1925                 * frames, or we have no pending frames, proceed to next queue.
1926                 */
1927                spin_lock_irqsave(&local->queue_stop_reason_lock, flags);
1928                next = false;
1929                if (local->queue_stop_reasons[i] !=
1930                        BIT(IEEE80211_QUEUE_STOP_REASON_PENDING) ||
1931                    skb_queue_empty(&local->pending[i]))
1932                        next = true;
1933                spin_unlock_irqrestore(&local->queue_stop_reason_lock, flags);
1934
1935                if (next)
1936                        continue;
1937
1938                /*
1939                 * start the queue now to allow processing our packets,
1940                 * we're under the tx lock here anyway so nothing will
1941                 * happen as a result of this
1942                 */
1943                netif_start_subqueue(local->mdev, i);
1944
1945                while (!skb_queue_empty(&local->pending[i])) {
1946                        struct sk_buff *skb = skb_dequeue(&local->pending[i]);
1947
1948                        if (!ieee80211_tx_pending_skb(local, skb)) {
1949                                skb_queue_head(&local->pending[i], skb);
1950                                break;
1951                        }
1952                }
1953
1954                /* Start regular packet processing again. */
1955                if (skb_queue_empty(&local->pending[i]))
1956                        ieee80211_wake_queue_by_reason(&local->hw, i,
1957                                        IEEE80211_QUEUE_STOP_REASON_PENDING);
1958        }
1959
1960        netif_tx_unlock_bh(dev);
1961        rcu_read_unlock();
1962}
1963
1964/* functions for drivers to get certain frames */
1965
1966static void ieee80211_beacon_add_tim(struct ieee80211_if_ap *bss,
1967                                     struct sk_buff *skb,
1968                                     struct beacon_data *beacon)
1969{
1970        u8 *pos, *tim;
1971        int aid0 = 0;
1972        int i, have_bits = 0, n1, n2;
1973
1974        /* Generate bitmap for TIM only if there are any STAs in power save
1975         * mode. */
1976        if (atomic_read(&bss->num_sta_ps) > 0)
1977                /* in the hope that this is faster than
1978                 * checking byte-for-byte */
1979                have_bits = !bitmap_empty((unsigned long*)bss->tim,
1980                                          IEEE80211_MAX_AID+1);
1981
1982        if (bss->dtim_count == 0)
1983                bss->dtim_count = beacon->dtim_period - 1;
1984        else
1985                bss->dtim_count--;
1986
1987        tim = pos = (u8 *) skb_put(skb, 6);
1988        *pos++ = WLAN_EID_TIM;
1989        *pos++ = 4;
1990        *pos++ = bss->dtim_count;
1991        *pos++ = beacon->dtim_period;
1992
1993        if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf))
1994                aid0 = 1;
1995
1996        if (have_bits) {
1997                /* Find largest even number N1 so that bits numbered 1 through
1998                 * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits
1999                 * (N2 + 1) x 8 through 2007 are 0. */
2000                n1 = 0;
2001                for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) {
2002                        if (bss->tim[i]) {
2003                                n1 = i & 0xfe;
2004                                break;
2005                        }
2006                }
2007                n2 = n1;
2008                for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) {
2009                        if (bss->tim[i]) {
2010                                n2 = i;
2011                                break;
2012                        }
2013                }
2014
2015                /* Bitmap control */
2016                *pos++ = n1 | aid0;
2017                /* Part Virt Bitmap */
2018                memcpy(pos, bss->tim + n1, n2 - n1 + 1);
2019
2020                tim[1] = n2 - n1 + 4;
2021                skb_put(skb, n2 - n1);
2022        } else {
2023                *pos++ = aid0; /* Bitmap control */
2024                *pos++ = 0; /* Part Virt Bitmap */
2025        }
2026}
2027
2028struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
2029                                     struct ieee80211_vif *vif)
2030{
2031        struct ieee80211_local *local = hw_to_local(hw);
2032        struct sk_buff *skb = NULL;
2033        struct ieee80211_tx_info *info;
2034        struct ieee80211_sub_if_data *sdata = NULL;
2035        struct ieee80211_if_ap *ap = NULL;
2036        struct beacon_data *beacon;
2037        struct ieee80211_supported_band *sband;
2038        enum ieee80211_band band = local->hw.conf.channel->band;
2039
2040        sband = local->hw.wiphy->bands[band];
2041
2042        rcu_read_lock();
2043
2044        sdata = vif_to_sdata(vif);
2045
2046        if (sdata->vif.type == NL80211_IFTYPE_AP) {
2047                ap = &sdata->u.ap;
2048                beacon = rcu_dereference(ap->beacon);
2049                if (ap && beacon) {
2050                        /*
2051                         * headroom, head length,
2052                         * tail length and maximum TIM length
2053                         */
2054                        skb = dev_alloc_skb(local->tx_headroom +
2055                                            beacon->head_len +
2056                                            beacon->tail_len + 256);
2057                        if (!skb)
2058                                goto out;
2059
2060                        skb_reserve(skb, local->tx_headroom);
2061                        memcpy(skb_put(skb, beacon->head_len), beacon->head,
2062                               beacon->head_len);
2063
2064                        /*
2065                         * Not very nice, but we want to allow the driver to call
2066                         * ieee80211_beacon_get() as a response to the set_tim()
2067                         * callback. That, however, is already invoked under the
2068                         * sta_lock to guarantee consistent and race-free update
2069                         * of the tim bitmap in mac80211 and the driver.
2070                         */
2071                        if (local->tim_in_locked_section) {
2072                                ieee80211_beacon_add_tim(ap, skb, beacon);
2073                        } else {
2074                                unsigned long flags;
2075
2076                                spin_lock_irqsave(&local->sta_lock, flags);
2077                                ieee80211_beacon_add_tim(ap, skb, beacon);
2078                                spin_unlock_irqrestore(&local->sta_lock, flags);
2079                        }
2080
2081                        if (beacon->tail)
2082                                memcpy(skb_put(skb, beacon->tail_len),
2083                                       beacon->tail, beacon->tail_len);
2084                } else
2085                        goto out;
2086        } else if (sdata->vif.type == NL80211_IFTYPE_ADHOC) {
2087                struct ieee80211_if_ibss *ifibss = &sdata->u.ibss;
2088                struct ieee80211_hdr *hdr;
2089
2090                if (!ifibss->probe_resp)
2091                        goto out;
2092
2093                skb = skb_copy(ifibss->probe_resp, GFP_ATOMIC);
2094                if (!skb)
2095                        goto out;
2096
2097                hdr = (struct ieee80211_hdr *) skb->data;
2098                hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
2099                                                 IEEE80211_STYPE_BEACON);
2100
2101        } else if (ieee80211_vif_is_mesh(&sdata->vif)) {
2102                struct ieee80211_mgmt *mgmt;
2103                u8 *pos;
2104
2105                /* headroom, head length, tail length and maximum TIM length */
2106                skb = dev_alloc_skb(local->tx_headroom + 400);
2107                if (!skb)
2108                        goto out;
2109
2110                skb_reserve(skb, local->hw.extra_tx_headroom);
2111                mgmt = (struct ieee80211_mgmt *)
2112                        skb_put(skb, 24 + sizeof(mgmt->u.beacon));
2113                memset(mgmt, 0, 24 + sizeof(mgmt->u.beacon));
2114                mgmt->frame_control =
2115                    cpu_to_le16(IEEE80211_FTYPE_MGMT | IEEE80211_STYPE_BEACON);
2116                memset(mgmt->da, 0xff, ETH_ALEN);
2117                memcpy(mgmt->sa, sdata->dev->dev_addr, ETH_ALEN);
2118                /* BSSID is left zeroed, wildcard value */
2119                mgmt->u.beacon.beacon_int =
2120                        cpu_to_le16(local->hw.conf.beacon_int);
2121                mgmt->u.beacon.capab_info = 0x0; /* 0x0 for MPs */
2122
2123                pos = skb_put(skb, 2);
2124                *pos++ = WLAN_EID_SSID;
2125                *pos++ = 0x0;
2126
2127                mesh_mgmt_ies_add(skb, sdata);
2128        } else {
2129                WARN_ON(1);
2130                goto out;
2131        }
2132
2133        info = IEEE80211_SKB_CB(skb);
2134
2135        skb->do_not_encrypt = 1;
2136
2137        info->band = band;
2138        /*
2139         * XXX: For now, always use the lowest rate
2140         */
2141        info->control.rates[0].idx = 0;
2142        info->control.rates[0].count = 1;
2143        info->control.rates[1].idx = -1;
2144        info->control.rates[2].idx = -1;
2145        info->control.rates[3].idx = -1;
2146        info->control.rates[4].idx = -1;
2147        BUILD_BUG_ON(IEEE80211_TX_MAX_RATES != 5);
2148
2149        info->control.vif = vif;
2150
2151        info->flags |= IEEE80211_TX_CTL_NO_ACK;
2152        info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
2153        info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
2154 out:
2155        rcu_read_unlock();
2156        return skb;
2157}
2158EXPORT_SYMBOL(ieee80211_beacon_get);
2159
2160void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2161                       const void *frame, size_t frame_len,
2162                       const struct ieee80211_tx_info *frame_txctl,
2163                       struct ieee80211_rts *rts)
2164{
2165        const struct ieee80211_hdr *hdr = frame;
2166
2167        rts->frame_control =
2168            cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_RTS);
2169        rts->duration = ieee80211_rts_duration(hw, vif, frame_len,
2170                                               frame_txctl);
2171        memcpy(rts->ra, hdr->addr1, sizeof(rts->ra));
2172        memcpy(rts->ta, hdr->addr2, sizeof(rts->ta));
2173}
2174EXPORT_SYMBOL(ieee80211_rts_get);
2175
2176void ieee80211_ctstoself_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
2177                             const void *frame, size_t frame_len,
2178                             const struct ieee80211_tx_info *frame_txctl,
2179                             struct ieee80211_cts *cts)
2180{
2181        const struct ieee80211_hdr *hdr = frame;
2182
2183        cts->frame_control =
2184            cpu_to_le16(IEEE80211_FTYPE_CTL | IEEE80211_STYPE_CTS);
2185        cts->duration = ieee80211_ctstoself_duration(hw, vif,
2186                                                     frame_len, frame_txctl);
2187        memcpy(cts->ra, hdr->addr1, sizeof(cts->ra));
2188}
2189EXPORT_SYMBOL(ieee80211_ctstoself_get);
2190
2191struct sk_buff *
2192ieee80211_get_buffered_bc(struct ieee80211_hw *hw,
2193                          struct ieee80211_vif *vif)
2194{
2195        struct ieee80211_local *local = hw_to_local(hw);
2196        struct sk_buff *skb = NULL;
2197        struct sta_info *sta;
2198        struct ieee80211_tx_data tx;
2199        struct ieee80211_sub_if_data *sdata;
2200        struct ieee80211_if_ap *bss = NULL;
2201        struct beacon_data *beacon;
2202        struct ieee80211_tx_info *info;
2203
2204        sdata = vif_to_sdata(vif);
2205        bss = &sdata->u.ap;
2206
2207        if (!bss)
2208                return NULL;
2209
2210        rcu_read_lock();
2211        beacon = rcu_dereference(bss->beacon);
2212
2213        if (sdata->vif.type != NL80211_IFTYPE_AP || !beacon || !beacon->head)
2214                goto out;
2215
2216        if (bss->dtim_count != 0)
2217                goto out; /* send buffered bc/mc only after DTIM beacon */
2218
2219        while (1) {
2220                skb = skb_dequeue(&bss->ps_bc_buf);
2221                if (!skb)
2222                        goto out;
2223                local->total_ps_buffered--;
2224
2225                if (!skb_queue_empty(&bss->ps_bc_buf) && skb->len >= 2) {
2226                        struct ieee80211_hdr *hdr =
2227                                (struct ieee80211_hdr *) skb->data;
2228                        /* more buffered multicast/broadcast frames ==> set
2229                         * MoreData flag in IEEE 802.11 header to inform PS
2230                         * STAs */
2231                        hdr->frame_control |=
2232                                cpu_to_le16(IEEE80211_FCTL_MOREDATA);
2233                }
2234
2235                if (!ieee80211_tx_prepare(local, &tx, skb))
2236                        break;
2237                dev_kfree_skb_any(skb);
2238        }
2239
2240        info = IEEE80211_SKB_CB(skb);
2241
2242        sta = tx.sta;
2243        tx.flags |= IEEE80211_TX_PS_BUFFERED;
2244        tx.channel = local->hw.conf.channel;
2245        info->band = tx.channel->band;
2246
2247        if (invoke_tx_handlers(&tx))
2248                skb = NULL;
2249 out:
2250        rcu_read_unlock();
2251
2252        return skb;
2253}
2254EXPORT_SYMBOL(ieee80211_get_buffered_bc);
2255