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 __constant_htons(ETH_P_IP):
  43                 dscp = ip_hdr(skb)->tos & 0xfc;
  44                 break;
  45
  46         default:
  47                 return 0;
  48         }
  49
  50         if (dscp & 0x1c)
  51                 return 0;
  52         return dscp >> 5;
  53 }
  54
  55
  56 static int wme_downgrade_ac(struct sk_buff *skb)
  57 {
  58         switch (skb->priority) {
  59         case 6:
  60         case 7:
  61                 skb->priority = 5; /* VO -> VI */
  62                 return 0;
  63         case 4:
  64         case 5:
  65                 skb->priority = 3; /* VI -> BE */
  66                 return 0;
  67         case 0:
  68         case 3:
  69                 skb->priority = 2; /* BE -> BK */
  70                 return 0;
  71         default:
  72                 return -1;
  73         }
  74 }
  75
  76
  77 /* Indicate which queue to use.  */
  78 static u16 classify80211(struct sk_buff *skb, struct net_device *dev)
  79 {
  80         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
  81         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
  82
  83         if (!ieee80211_is_data(hdr->frame_control)) {
  84                 /* management frames go on AC_VO queue, but are sent
  85                 * without QoS control fields */
  86                 return 0;
  87         }
  88
  89         if (0 /* injected */) {
  90                 /* use AC from radiotap */
  91         }
  92
  93         if (!ieee80211_is_data_qos(hdr->frame_control)) {
  94                 skb->priority = 0; /* required for correct WPA/11i MIC */
  95                 return ieee802_1d_to_ac[skb->priority];
  96         }
  97
  98         /* use the data classifier to determine what 802.1d tag the
  99          * data frame has */
 100         skb->priority = classify_1d(skb);
 101
 102         /* in case we are a client verify acm is not set for this ac */
 103         while (unlikely(local->wmm_acm & BIT(skb->priority))) {
 104                 if (wme_downgrade_ac(skb)) {
 105                         /* The old code would drop the packet in this
 106                          * case.
 107                          */
 108                         return 0;
 109                 }
 110         }
 111
 112         /* look up which queue to use for frames with this 1d tag */
 113         return ieee802_1d_to_ac[skb->priority];
 114 }
 115
 116 u16 ieee80211_select_queue(struct net_device *dev, struct sk_buff *skb)
 117 {
 118         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 119         struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
 120         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 121         struct sta_info *sta;
 122         u16 queue;
 123         u8 tid;
 124
 125         queue = classify80211(skb, dev);
 126         if (unlikely(queue >= local->hw.queues))
 127                 queue = local->hw.queues - 1;
 128
 129         if (info->flags & IEEE80211_TX_CTL_REQUEUE) {
 130                 rcu_read_lock();
 131                 sta = sta_info_get(local, hdr->addr1);
 132                 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
 133                 if (sta) {
 134                         struct ieee80211_hw *hw = &local->hw;
 135                         int ampdu_queue = sta->tid_to_tx_q[tid];
 136
 137                         if ((ampdu_queue < ieee80211_num_queues(hw)) &&
 138                             test_bit(ampdu_queue, local->queue_pool)) {
 139                                 queue = ampdu_queue;
 140                                 info->flags |= IEEE80211_TX_CTL_AMPDU;
 141                         } else {
 142                                 info->flags &= ~IEEE80211_TX_CTL_AMPDU;
 143                         }
 144                 }
 145                 rcu_read_unlock();
 146
 147                 return queue;
 148         }
 149
 150         /* Now we know the 1d priority, fill in the QoS header if
 151          * there is one.
 152          */
 153         if (ieee80211_is_data_qos(hdr->frame_control)) {
 154                 u8 *p = ieee80211_get_qos_ctl(hdr);
 155                 u8 ack_policy = 0;
 156                 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
 157                 if (local->wifi_wme_noack_test)
 158                         ack_policy |= QOS_CONTROL_ACK_POLICY_NOACK <<
 159                                         QOS_CONTROL_ACK_POLICY_SHIFT;
 160                 /* qos header is 2 bytes, second reserved */
 161                 *p++ = ack_policy | tid;
 162                 *p = 0;
 163
 164                 rcu_read_lock();
 165
 166                 sta = sta_info_get(local, hdr->addr1);
 167                 if (sta) {
 168                         int ampdu_queue = sta->tid_to_tx_q[tid];
 169                         struct ieee80211_hw *hw = &local->hw;
 170
 171                         if ((ampdu_queue < ieee80211_num_queues(hw)) &&
 172                             test_bit(ampdu_queue, local->queue_pool)) {
 173                                 queue = ampdu_queue;
 174                                 info->flags |= IEEE80211_TX_CTL_AMPDU;
 175                         } else {
 176                                 info->flags &= ~IEEE80211_TX_CTL_AMPDU;
 177                         }
 178                 }
 179
 180                 rcu_read_unlock();
 181         }
 182
 183         return queue;
 184 }
 185
 186 int ieee80211_ht_agg_queue_add(struct ieee80211_local *local,
 187                                struct sta_info *sta, u16 tid)
 188 {
 189         int i;
 190
 191         /* XXX: currently broken due to cb/requeue use */
 192         return -EPERM;
 193
 194         /* prepare the filter and save it for the SW queue
 195          * matching the received HW queue */
 196
 197         if (!local->hw.ampdu_queues)
 198                 return -EPERM;
 199
 200         /* try to get a Qdisc from the pool */
 201         for (i = local->hw.queues; i < ieee80211_num_queues(&local->hw); i++)
 202                 if (!test_and_set_bit(i, local->queue_pool)) {
 203                         ieee80211_stop_queue(local_to_hw(local), i);
 204                         sta->tid_to_tx_q[tid] = i;
 205
 206                         /* IF there are already pending packets
 207                          * on this tid first we need to drain them
 208                          * on the previous queue
 209                          * since HT is strict in order */
 210 #ifdef CONFIG_MAC80211_HT_DEBUG
 211                         if (net_ratelimit()) {
 212                                 DECLARE_MAC_BUF(mac);
 213                                 printk(KERN_DEBUG "allocated aggregation queue"
 214                                         " %d tid %d addr %s pool=0x%lX\n",
 215                                         i, tid, print_mac(mac, sta->addr),
 216                                         local->queue_pool[0]);
 217                         }
 218 #endif /* CONFIG_MAC80211_HT_DEBUG */
 219                         return 0;
 220                 }
 221
 222         return -EAGAIN;
 223 }
 224
 225 /**
 226  * the caller needs to hold netdev_get_tx_queue(local->mdev, X)->lock
 227  */
 228 void ieee80211_ht_agg_queue_remove(struct ieee80211_local *local,
 229                                    struct sta_info *sta, u16 tid,
 230                                    u8 requeue)
 231 {
 232         int agg_queue = sta->tid_to_tx_q[tid];
 233         struct ieee80211_hw *hw = &local->hw;
 234
 235         /* return the qdisc to the pool */
 236         clear_bit(agg_queue, local->queue_pool);
 237         sta->tid_to_tx_q[tid] = ieee80211_num_queues(hw);
 238
 239         if (requeue) {
 240                 ieee80211_requeue(local, agg_queue);
 241         } else {
 242                 struct netdev_queue *txq;
 243                 spinlock_t *root_lock;
 244
 245                 txq = netdev_get_tx_queue(local->mdev, agg_queue);
 246                 root_lock = qdisc_root_lock(txq->qdisc);
 247
 248                 spin_lock_bh(root_lock);
 249                 qdisc_reset(txq->qdisc);
 250                 spin_unlock_bh(root_lock);
 251         }
 252 }
 253
 254 void ieee80211_requeue(struct ieee80211_local *local, int queue)
 255 {
 256         struct netdev_queue *txq = netdev_get_tx_queue(local->mdev, queue);
 257         struct sk_buff_head list;
 258         spinlock_t *root_lock;
 259         struct Qdisc *qdisc;
 260         u32 len;
 261
 262         rcu_read_lock_bh();
 263
 264         qdisc = rcu_dereference(txq->qdisc);
 265         if (!qdisc || !qdisc->dequeue)
 266                 goto out_unlock;
 267
 268         skb_queue_head_init(&list);
 269
 270         root_lock = qdisc_root_lock(qdisc);
 271         spin_lock(root_lock);
 272         for (len = qdisc->q.qlen; len > 0; len--) {
 273                 struct sk_buff *skb = qdisc->dequeue(qdisc);
 274
 275                 if (skb)
 276                         __skb_queue_tail(&list, skb);
 277         }
 278         spin_unlock(root_lock);
 279
 280         for (len = list.qlen; len > 0; len--) {
 281                 struct sk_buff *skb = __skb_dequeue(&list);
 282                 u16 new_queue;
 283
 284                 BUG_ON(!skb);
 285                 new_queue = ieee80211_select_queue(local->mdev, skb);
 286                 skb_set_queue_mapping(skb, new_queue);
 287
 288                 txq = netdev_get_tx_queue(local->mdev, new_queue);
 289
 290
 291                 qdisc = rcu_dereference(txq->qdisc);
 292                 root_lock = qdisc_root_lock(qdisc);
 293
 294                 spin_lock(root_lock);
 295                 qdisc_enqueue_root(skb, qdisc);
 296                 spin_unlock(root_lock);
 297         }
 298
 299 out_unlock:
 300         rcu_read_unlock_bh();
 301 }