net/mac80211/wme.c

   1 /*
   2  * Copyright 2004, Instant802 Networks, Inc.
   3  * Copyright 2013-2014  Intel Mobile Communications GmbH
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  */
   9
  10 #include <linux/netdevice.h>
  11 #include <linux/skbuff.h>
  12 #include <linux/module.h>
  13 #include <linux/if_arp.h>
  14 #include <linux/types.h>
  15 #include <net/ip.h>
  16 #include <net/pkt_sched.h>
  17
  18 #include <net/mac80211.h>
  19 #include "ieee80211_i.h"
  20 #include "wme.h"
  21
  22 /* Default mapping in classifier to work with default
  23  * queue setup.
  24  */
  25 const int ieee802_1d_to_ac[8] = {
  26         IEEE80211_AC_BE,
  27         IEEE80211_AC_BK,
  28         IEEE80211_AC_BK,
  29         IEEE80211_AC_BE,
  30         IEEE80211_AC_VI,
  31         IEEE80211_AC_VI,
  32         IEEE80211_AC_VO,
  33         IEEE80211_AC_VO
  34 };
  35
  36 static int wme_downgrade_ac(struct sk_buff *skb)
  37 {
  38         switch (skb->priority) {
  39         case 6:
  40         case 7:
  41                 skb->priority = 5; /* VO -> VI */
  42                 return 0;
  43         case 4:
  44         case 5:
  45                 skb->priority = 3; /* VI -> BE */
  46                 return 0;
  47         case 0:
  48         case 3:
  49                 skb->priority = 2; /* BE -> BK */
  50                 return 0;
  51         default:
  52                 return -1;
  53         }
  54 }
  55
  56 static u16 ieee80211_downgrade_queue(struct ieee80211_sub_if_data *sdata,
  57                                      struct sk_buff *skb)
  58 {
  59         /* in case we are a client verify acm is not set for this ac */
  60         while (unlikely(sdata->wmm_acm & BIT(skb->priority))) {
  61                 if (wme_downgrade_ac(skb)) {
  62                         /*
  63                          * This should not really happen. The AP has marked all
  64                          * lower ACs to require admission control which is not
  65                          * a reasonable configuration. Allow the frame to be
  66                          * transmitted using AC_BK as a workaround.
  67                          */
  68                         break;
  69                 }
  70         }
  71
  72         /* look up which queue to use for frames with this 1d tag */
  73         return ieee802_1d_to_ac[skb->priority];
  74 }
  75
  76 /* Indicate which queue to use for this fully formed 802.11 frame */
  77 u16 ieee80211_select_queue_80211(struct ieee80211_sub_if_data *sdata,
  78                                  struct sk_buff *skb,
  79                                  struct ieee80211_hdr *hdr)
  80 {
  81         struct ieee80211_local *local = sdata->local;
  82         u8 *p;
  83
  84         if (local->hw.queues < IEEE80211_NUM_ACS)
  85                 return 0;
  86
  87         if (!ieee80211_is_data(hdr->frame_control)) {
  88                 skb->priority = 7;
  89                 return ieee802_1d_to_ac[skb->priority];
  90         }
  91         if (!ieee80211_is_data_qos(hdr->frame_control)) {
  92                 skb->priority = 0;
  93                 return ieee802_1d_to_ac[skb->priority];
  94         }
  95
  96         p = ieee80211_get_qos_ctl(hdr);
  97         skb->priority = *p & IEEE80211_QOS_CTL_TAG1D_MASK;
  98
  99         return ieee80211_downgrade_queue(sdata, skb);
 100 }
 101
 102 /* Indicate which queue to use. */
 103 u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
 104                            struct sk_buff *skb)
 105 {
 106         struct ieee80211_local *local = sdata->local;
 107         struct sta_info *sta = NULL;
 108         const u8 *ra = NULL;
 109         bool qos = false;
 110         struct mac80211_qos_map *qos_map;
 111
 112         if (local->hw.queues < IEEE80211_NUM_ACS || skb->len < 6) {
 113                 skb->priority = 0; /* required for correct WPA/11i MIC */
 114                 return 0;
 115         }
 116
 117         rcu_read_lock();
 118         switch (sdata->vif.type) {
 119         case NL80211_IFTYPE_AP_VLAN:
 120                 sta = rcu_dereference(sdata->u.vlan.sta);
 121                 if (sta) {
 122                         qos = sta->sta.wme;
 123                         break;
 124                 }
 125         case NL80211_IFTYPE_AP:
 126                 ra = skb->data;
 127                 break;
 128         case NL80211_IFTYPE_WDS:
 129                 ra = sdata->u.wds.remote_addr;
 130                 break;
 131 #ifdef CONFIG_MAC80211_MESH
 132         case NL80211_IFTYPE_MESH_POINT:
 133                 qos = true;
 134                 break;
 135 #endif
 136         case NL80211_IFTYPE_STATION:
 137                 ra = sdata->u.mgd.bssid;
 138                 break;
 139         case NL80211_IFTYPE_ADHOC:
 140                 ra = skb->data;
 141                 break;
 142         default:
 143                 break;
 144         }
 145
 146         if (!sta && ra && !is_multicast_ether_addr(ra)) {
 147                 sta = sta_info_get(sdata, ra);
 148                 if (sta)
 149                         qos = sta->sta.wme;
 150         }
 151         rcu_read_unlock();
 152
 153         if (!qos) {
 154                 skb->priority = 0; /* required for correct WPA/11i MIC */
 155                 return IEEE80211_AC_BE;
 156         }
 157
 158         if (skb->protocol == sdata->control_port_protocol) {
 159                 skb->priority = 7;
 160                 return ieee80211_downgrade_queue(sdata, skb);
 161         }
 162
 163         /* use the data classifier to determine what 802.1d tag the
 164          * data frame has */
 165         rcu_read_lock();
 166         qos_map = rcu_dereference(sdata->qos_map);
 167         skb->priority = cfg80211_classify8021d(skb, qos_map ?
 168                                                &qos_map->qos_map : NULL);
 169         rcu_read_unlock();
 170
 171         return ieee80211_downgrade_queue(sdata, skb);
 172 }
 173
 174 /**
 175  * ieee80211_set_qos_hdr - Fill in the QoS header if there is one.
 176  *
 177  * @sdata: local subif
 178  * @skb: packet to be updated
 179  */
 180 void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata,
 181                            struct sk_buff *skb)
 182 {
 183         struct ieee80211_hdr *hdr = (void *)skb->data;
 184         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 185         u8 *p;
 186         u8 ack_policy, tid;
 187
 188         if (!ieee80211_is_data_qos(hdr->frame_control))
 189                 return;
 190
 191         p = ieee80211_get_qos_ctl(hdr);
 192         tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
 193
 194         /* preserve EOSP bit */
 195         ack_policy = *p & IEEE80211_QOS_CTL_EOSP;
 196
 197         if (is_multicast_ether_addr(hdr->addr1) ||
 198             sdata->noack_map & BIT(tid)) {
 199                 ack_policy |= IEEE80211_QOS_CTL_ACK_POLICY_NOACK;
 200                 info->flags |= IEEE80211_TX_CTL_NO_ACK;
 201         }
 202
 203         /* qos header is 2 bytes */
 204         *p++ = ack_policy | tid;
 205         if (ieee80211_vif_is_mesh(&sdata->vif)) {
 206                 /* preserve RSPI and Mesh PS Level bit */
 207                 *p &= ((IEEE80211_QOS_CTL_RSPI |
 208                         IEEE80211_QOS_CTL_MESH_PS_LEVEL) >> 8);
 209
 210                 /* Nulls don't have a mesh header (frame body) */
 211                 if (!ieee80211_is_qos_nullfunc(hdr->frame_control))
 212                         *p |= (IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8);
 213         } else {
 214                 *p = 0;
 215         }
 216 }