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 int wme_downgrade_ac(struct sk_buff *skb)
  27 {
  28         switch (skb->priority) {
  29         case 6:
  30         case 7:
  31                 skb->priority = 5; /* VO -> VI */
  32                 return 0;
  33         case 4:
  34         case 5:
  35                 skb->priority = 3; /* VI -> BE */
  36                 return 0;
  37         case 0:
  38         case 3:
  39                 skb->priority = 2; /* BE -> BK */
  40                 return 0;
  41         default:
  42                 return -1;
  43         }
  44 }
  45
  46
  47 /* Indicate which queue to use. */
  48 u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
  49                            struct sk_buff *skb)
  50 {
  51         struct ieee80211_local *local = sdata->local;
  52         struct sta_info *sta = NULL;
  53         u32 sta_flags = 0;
  54         const u8 *ra = NULL;
  55         bool qos = false;
  56
  57         if (local->hw.queues < 4 || skb->len < 6) {
  58                 skb->priority = 0; /* required for correct WPA/11i MIC */
  59                 return min_t(u16, local->hw.queues - 1,
  60                              ieee802_1d_to_ac[skb->priority]);
  61         }
  62
  63         rcu_read_lock();
  64         switch (sdata->vif.type) {
  65         case NL80211_IFTYPE_AP_VLAN:
  66         case NL80211_IFTYPE_AP:
  67                 ra = skb->data;
  68                 break;
  69         case NL80211_IFTYPE_WDS:
  70                 ra = sdata->u.wds.remote_addr;
  71                 break;
  72 #ifdef CONFIG_MAC80211_MESH
  73         case NL80211_IFTYPE_MESH_POINT:
  74                 /*
  75                  * XXX: This is clearly broken ... but already was before,
  76                  * because ieee80211_fill_mesh_addresses() would clear A1
  77                  * except for multicast addresses.
  78                  */
  79                 break;
  80 #endif
  81         case NL80211_IFTYPE_STATION:
  82                 ra = sdata->u.mgd.bssid;
  83                 break;
  84         case NL80211_IFTYPE_ADHOC:
  85                 ra = skb->data;
  86                 break;
  87         default:
  88                 break;
  89         }
  90
  91         if (!sta && ra && !is_multicast_ether_addr(ra)) {
  92                 sta = sta_info_get(local, ra);
  93                 if (sta)
  94                         sta_flags = get_sta_flags(sta);
  95         }
  96
  97         if (sta_flags & WLAN_STA_WME)
  98                 qos = true;
  99
 100         rcu_read_unlock();
 101
 102         if (!qos) {
 103                 skb->priority = 0; /* required for correct WPA/11i MIC */
 104                 return ieee802_1d_to_ac[skb->priority];
 105         }
 106
 107         /* use the data classifier to determine what 802.1d tag the
 108          * data frame has */
 109         skb->priority = cfg80211_classify8021d(skb);
 110
 111         return ieee80211_downgrade_queue(local, skb);
 112 }
 113
 114 u16 ieee80211_downgrade_queue(struct ieee80211_local *local,
 115                               struct sk_buff *skb)
 116 {
 117         /* in case we are a client verify acm is not set for this ac */
 118         while (unlikely(local->wmm_acm & BIT(skb->priority))) {
 119                 if (wme_downgrade_ac(skb)) {
 120                         /*
 121                          * This should not really happen. The AP has marked all
 122                          * lower ACs to require admission control which is not
 123                          * a reasonable configuration. Allow the frame to be
 124                          * transmitted using AC_BK as a workaround.
 125                          */
 126                         break;
 127                 }
 128         }
 129
 130         /* look up which queue to use for frames with this 1d tag */
 131         return ieee802_1d_to_ac[skb->priority];
 132 }
 133
 134 void ieee80211_set_qos_hdr(struct ieee80211_local *local, struct sk_buff *skb)
 135 {
 136         struct ieee80211_hdr *hdr = (void *)skb->data;
 137
 138         /* Fill in the QoS header if there is one. */
 139         if (ieee80211_is_data_qos(hdr->frame_control)) {
 140                 u8 *p = ieee80211_get_qos_ctl(hdr);
 141                 u8 ack_policy = 0, tid;
 142
 143                 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
 144
 145                 if (unlikely(local->wifi_wme_noack_test))
 146                         ack_policy |= QOS_CONTROL_ACK_POLICY_NOACK <<
 147                                         QOS_CONTROL_ACK_POLICY_SHIFT;
 148                 /* qos header is 2 bytes, second reserved */
 149                 *p++ = ack_policy | tid;
 150                 *p = 0;
 151         }
 152 }