net/mac80211/wme.c

   1 /*
   2  * Copyright 2004, Instant802 Networks, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/netdevice.h>
  10 #include <linux/skbuff.h>
  11 #include <linux/module.h>
  12 #include <linux/if_arp.h>
  13 #include <linux/types.h>
  14 #include <net/ip.h>
  15 #include <net/pkt_sched.h>
  16
  17 #include <net/mac80211.h>
  18 #include "ieee80211_i.h"
  19 #include "wme.h"
  20
  21 /* Default mapping in classifier to work with default
  22  * queue setup.
  23  */
  24 const int ieee802_1d_to_ac[8] = { 2, 3, 3, 2, 1, 1, 0, 0 };
  25
  26 static const char llc_ip_hdr[8] = {0xAA, 0xAA, 0x3, 0, 0, 0, 0x08, 0};
  27
  28 /* Given a data frame determine the 802.1p/1d tag to use.  */
  29 static unsigned int classify_1d(struct sk_buff *skb)
  30 {
  31         unsigned int dscp;
  32
  33         /* skb->priority values from 256->263 are magic values to
  34          * directly indicate a specific 802.1d priority.  This is used
  35          * to allow 802.1d priority to be passed directly in from VLAN
  36          * tags, etc.
  37          */
  38         if (skb->priority >= 256 && skb->priority <= 263)
  39                 return skb->priority - 256;
  40
  41         switch (skb->protocol) {
  42         case htons(ETH_P_IP):
  43                 dscp = ip_hdr(skb)->tos & 0xfc;
  44                 break;
  45
  46         default:
  47                 return 0;
  48         }
  49
  50         return dscp >> 5;
  51 }
  52
  53
  54 static int wme_downgrade_ac(struct sk_buff *skb)
  55 {
  56         switch (skb->priority) {
  57         case 6:
  58         case 7:
  59                 skb->priority = 5; /* VO -> VI */
  60                 return 0;
  61         case 4:
  62         case 5:
  63                 skb->priority = 3; /* VI -> BE */
  64                 return 0;
  65         case 0:
  66         case 3:
  67                 skb->priority = 2; /* BE -> BK */
  68                 return 0;
  69         default:
  70                 return -1;
  71         }
  72 }
  73
  74
  75 /* Indicate which queue to use.  */
  76 static u16 classify80211(struct ieee80211_local *local, struct sk_buff *skb)
  77 {
  78         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
  79
  80         if (!ieee80211_is_data(hdr->frame_control)) {
  81                 /* management frames go on AC_VO queue, but are sent
  82                 * without QoS control fields */
  83                 return 0;
  84         }
  85
  86         if (0 /* injected */) {
  87                 /* use AC from radiotap */
  88         }
  89
  90         if (!ieee80211_is_data_qos(hdr->frame_control)) {
  91                 skb->priority = 0; /* required for correct WPA/11i MIC */
  92                 return ieee802_1d_to_ac[skb->priority];
  93         }
  94
  95         /* use the data classifier to determine what 802.1d tag the
  96          * data frame has */
  97         skb->priority = classify_1d(skb);
  98
  99         /* in case we are a client verify acm is not set for this ac */
 100         while (unlikely(local->wmm_acm & BIT(skb->priority))) {
 101                 if (wme_downgrade_ac(skb)) {
 102                         /* The old code would drop the packet in this
 103                          * case.
 104                          */
 105                         return 0;
 106                 }
 107         }
 108
 109         /* look up which queue to use for frames with this 1d tag */
 110         return ieee802_1d_to_ac[skb->priority];
 111 }
 112
 113 u16 ieee80211_select_queue(struct net_device *dev, struct sk_buff *skb)
 114 {
 115         struct ieee80211_master_priv *mpriv = netdev_priv(dev);
 116         struct ieee80211_local *local = mpriv->local;
 117         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 118         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 119         struct sta_info *sta;
 120         u16 queue;
 121         u8 tid;
 122
 123         queue = classify80211(local, skb);
 124         if (unlikely(queue >= local->hw.queues))
 125                 queue = local->hw.queues - 1;
 126
 127         if (info->flags & IEEE80211_TX_CTL_REQUEUE) {
 128                 rcu_read_lock();
 129                 sta = sta_info_get(local, hdr->addr1);
 130                 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
 131                 if (sta) {
 132                         struct ieee80211_hw *hw = &local->hw;
 133                         int ampdu_queue = sta->tid_to_tx_q[tid];
 134
 135                         if ((ampdu_queue < ieee80211_num_queues(hw)) &&
 136                             test_bit(ampdu_queue, local->queue_pool)) {
 137                                 queue = ampdu_queue;
 138                                 info->flags |= IEEE80211_TX_CTL_AMPDU;
 139                         } else {
 140                                 info->flags &= ~IEEE80211_TX_CTL_AMPDU;
 141                         }
 142                 }
 143                 rcu_read_unlock();
 144
 145                 return queue;
 146         }
 147
 148         /* Now we know the 1d priority, fill in the QoS header if
 149          * there is one.
 150          */
 151         if (ieee80211_is_data_qos(hdr->frame_control)) {
 152                 u8 *p = ieee80211_get_qos_ctl(hdr);
 153                 u8 ack_policy = 0;
 154                 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
 155                 if (local->wifi_wme_noack_test)
 156                         ack_policy |= QOS_CONTROL_ACK_POLICY_NOACK <<
 157                                         QOS_CONTROL_ACK_POLICY_SHIFT;
 158                 /* qos header is 2 bytes, second reserved */
 159                 *p++ = ack_policy | tid;
 160                 *p = 0;
 161
 162                 rcu_read_lock();
 163
 164                 sta = sta_info_get(local, hdr->addr1);
 165                 if (sta) {
 166                         int ampdu_queue = sta->tid_to_tx_q[tid];
 167                         struct ieee80211_hw *hw = &local->hw;
 168
 169                         if ((ampdu_queue < ieee80211_num_queues(hw)) &&
 170                             test_bit(ampdu_queue, local->queue_pool)) {
 171                                 queue = ampdu_queue;
 172                                 info->flags |= IEEE80211_TX_CTL_AMPDU;
 173                         } else {
 174                                 info->flags &= ~IEEE80211_TX_CTL_AMPDU;
 175                         }
 176                 }
 177
 178                 rcu_read_unlock();
 179         }
 180
 181         return queue;
 182 }
 183
 184 int ieee80211_ht_agg_queue_add(struct ieee80211_local *local,
 185                                struct sta_info *sta, u16 tid)
 186 {
 187         int i;
 188
 189         /* XXX: currently broken due to cb/requeue use */
 190         return -EPERM;
 191
 192         /* prepare the filter and save it for the SW queue
 193          * matching the received HW queue */
 194
 195         if (!local->hw.ampdu_queues)
 196                 return -EPERM;
 197
 198         /* try to get a Qdisc from the pool */
 199         for (i = local->hw.queues; i < ieee80211_num_queues(&local->hw); i++)
 200                 if (!test_and_set_bit(i, local->queue_pool)) {
 201                         ieee80211_stop_queue(local_to_hw(local), i);
 202                         sta->tid_to_tx_q[tid] = i;
 203
 204                         /* IF there are already pending packets
 205                          * on this tid first we need to drain them
 206                          * on the previous queue
 207                          * since HT is strict in order */
 208 #ifdef CONFIG_MAC80211_HT_DEBUG
 209                         if (net_ratelimit())
 210                                 printk(KERN_DEBUG "allocated aggregation queue"
 211                                         " %d tid %d addr %pM pool=0x%lX\n",
 212                                         i, tid, sta->sta.addr,
 213                                         local->queue_pool[0]);
 214 #endif /* CONFIG_MAC80211_HT_DEBUG */
 215                         return 0;
 216                 }
 217
 218         return -EAGAIN;
 219 }
 220
 221 /**
 222  * the caller needs to hold netdev_get_tx_queue(local->mdev, X)->lock
 223  */
 224 void ieee80211_ht_agg_queue_remove(struct ieee80211_local *local,
 225                                    struct sta_info *sta, u16 tid,
 226                                    u8 requeue)
 227 {
 228         int agg_queue = sta->tid_to_tx_q[tid];
 229         struct ieee80211_hw *hw = &local->hw;
 230
 231         /* return the qdisc to the pool */
 232         clear_bit(agg_queue, local->queue_pool);
 233         sta->tid_to_tx_q[tid] = ieee80211_num_queues(hw);
 234
 235         if (requeue) {
 236                 ieee80211_requeue(local, agg_queue);
 237         } else {
 238                 struct netdev_queue *txq;
 239                 spinlock_t *root_lock;
 240                 struct Qdisc *q;
 241
 242                 txq = netdev_get_tx_queue(local->mdev, agg_queue);
 243                 q = rcu_dereference(txq->qdisc);
 244                 root_lock = qdisc_lock(q);
 245
 246                 spin_lock_bh(root_lock);
 247                 qdisc_reset(q);
 248                 spin_unlock_bh(root_lock);
 249         }
 250 }
 251
 252 void ieee80211_requeue(struct ieee80211_local *local, int queue)
 253 {
 254         struct netdev_queue *txq = netdev_get_tx_queue(local->mdev, queue);
 255         struct sk_buff_head list;
 256         spinlock_t *root_lock;
 257         struct Qdisc *qdisc;
 258         u32 len;
 259
 260         rcu_read_lock_bh();
 261
 262         qdisc = rcu_dereference(txq->qdisc);
 263         if (!qdisc || !qdisc->dequeue)
 264                 goto out_unlock;
 265
 266         skb_queue_head_init(&list);
 267
 268         root_lock = qdisc_root_lock(qdisc);
 269         spin_lock(root_lock);
 270         for (len = qdisc->q.qlen; len > 0; len--) {
 271                 struct sk_buff *skb = qdisc->dequeue(qdisc);
 272
 273                 if (skb)
 274                         __skb_queue_tail(&list, skb);
 275         }
 276         spin_unlock(root_lock);
 277
 278         for (len = list.qlen; len > 0; len--) {
 279                 struct sk_buff *skb = __skb_dequeue(&list);
 280                 u16 new_queue;
 281
 282                 BUG_ON(!skb);
 283                 new_queue = ieee80211_select_queue(local->mdev, skb);
 284                 skb_set_queue_mapping(skb, new_queue);
 285
 286                 txq = netdev_get_tx_queue(local->mdev, new_queue);
 287
 288
 289                 qdisc = rcu_dereference(txq->qdisc);
 290                 root_lock = qdisc_root_lock(qdisc);
 291
 292                 spin_lock(root_lock);
 293                 qdisc_enqueue_root(skb, qdisc);
 294                 spin_unlock(root_lock);
 295         }
 296
 297 out_unlock:
 298         rcu_read_unlock_bh();
 299 }