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DEFINITIONS
This source file includes following definitions.
- classify_1d
- wme_downgrade_ac
- classify80211
- ieee80211_select_queue
- ieee80211_ht_agg_queue_add
- ieee80211_ht_agg_queue_remove
- ieee80211_requeue
/*
* Copyright 2004, Instant802 Networks, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/module.h>
#include <linux/if_arp.h>
#include <linux/types.h>
#include <net/ip.h>
#include <net/pkt_sched.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "wme.h"
/* Default mapping in classifier to work with default
* queue setup.
*/
const int ieee802_1d_to_ac[8] = { 2, 3, 3, 2, 1, 1, 0, 0 };
static const char llc_ip_hdr[8] = {0xAA, 0xAA, 0x3, 0, 0, 0, 0x08, 0};
/* Given a data frame determine the 802.1p/1d tag to use. */
static unsigned int classify_1d(struct sk_buff *skb)
{
unsigned int dscp;
/* skb->priority values from 256->263 are magic values to
* directly indicate a specific 802.1d priority. This is used
* to allow 802.1d priority to be passed directly in from VLAN
* tags, etc.
*/
if (skb->priority >= 256 && skb->priority <= 263)
return skb->priority - 256;
switch (skb->protocol) {
case htons(ETH_P_IP):
dscp = ip_hdr(skb)->tos & 0xfc;
break;
default:
return 0;
}
return dscp >> 5;
}
static int wme_downgrade_ac(struct sk_buff *skb)
{
switch (skb->priority) {
case 6:
case 7:
skb->priority = 5; /* VO -> VI */
return 0;
case 4:
case 5:
skb->priority = 3; /* VI -> BE */
return 0;
case 0:
case 3:
skb->priority = 2; /* BE -> BK */
return 0;
default:
return -1;
}
}
/* Indicate which queue to use. */
static u16 classify80211(struct ieee80211_local *local, struct sk_buff *skb)
{
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
if (!ieee80211_is_data(hdr->frame_control)) {
/* management frames go on AC_VO queue, but are sent
* without QoS control fields */
return 0;
}
if (0 /* injected */) {
/* use AC from radiotap */
}
if (!ieee80211_is_data_qos(hdr->frame_control)) {
skb->priority = 0; /* required for correct WPA/11i MIC */
return ieee802_1d_to_ac[skb->priority];
}
/* use the data classifier to determine what 802.1d tag the
* data frame has */
skb->priority = classify_1d(skb);
/* in case we are a client verify acm is not set for this ac */
while (unlikely(local->wmm_acm & BIT(skb->priority))) {
if (wme_downgrade_ac(skb)) {
/* The old code would drop the packet in this
* case.
*/
return 0;
}
}
/* look up which queue to use for frames with this 1d tag */
return ieee802_1d_to_ac[skb->priority];
}
u16 ieee80211_select_queue(struct net_device *dev, struct sk_buff *skb)
{
struct ieee80211_master_priv *mpriv = netdev_priv(dev);
struct ieee80211_local *local = mpriv->local;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct sta_info *sta;
u16 queue;
u8 tid;
queue = classify80211(local, skb);
if (unlikely(queue >= local->hw.queues))
queue = local->hw.queues - 1;
if (info->flags & IEEE80211_TX_CTL_REQUEUE) {
rcu_read_lock();
sta = sta_info_get(local, hdr->addr1);
tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
if (sta) {
struct ieee80211_hw *hw = &local->hw;
int ampdu_queue = sta->tid_to_tx_q[tid];
if ((ampdu_queue < ieee80211_num_queues(hw)) &&
test_bit(ampdu_queue, local->queue_pool)) {
queue = ampdu_queue;
info->flags |= IEEE80211_TX_CTL_AMPDU;
} else {
info->flags &= ~IEEE80211_TX_CTL_AMPDU;
}
}
rcu_read_unlock();
return queue;
}
/* Now we know the 1d priority, fill in the QoS header if
* there is one.
*/
if (ieee80211_is_data_qos(hdr->frame_control)) {
u8 *p = ieee80211_get_qos_ctl(hdr);
u8 ack_policy = 0;
tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
if (local->wifi_wme_noack_test)
ack_policy |= QOS_CONTROL_ACK_POLICY_NOACK <<
QOS_CONTROL_ACK_POLICY_SHIFT;
/* qos header is 2 bytes, second reserved */
*p++ = ack_policy | tid;
*p = 0;
rcu_read_lock();
sta = sta_info_get(local, hdr->addr1);
if (sta) {
int ampdu_queue = sta->tid_to_tx_q[tid];
struct ieee80211_hw *hw = &local->hw;
if ((ampdu_queue < ieee80211_num_queues(hw)) &&
test_bit(ampdu_queue, local->queue_pool)) {
queue = ampdu_queue;
info->flags |= IEEE80211_TX_CTL_AMPDU;
} else {
info->flags &= ~IEEE80211_TX_CTL_AMPDU;
}
}
rcu_read_unlock();
}
return queue;
}
int ieee80211_ht_agg_queue_add(struct ieee80211_local *local,
struct sta_info *sta, u16 tid)
{
int i;
/* XXX: currently broken due to cb/requeue use */
return -EPERM;
/* prepare the filter and save it for the SW queue
* matching the received HW queue */
if (!local->hw.ampdu_queues)
return -EPERM;
/* try to get a Qdisc from the pool */
for (i = local->hw.queues; i < ieee80211_num_queues(&local->hw); i++)
if (!test_and_set_bit(i, local->queue_pool)) {
ieee80211_stop_queue(local_to_hw(local), i);
sta->tid_to_tx_q[tid] = i;
/* IF there are already pending packets
* on this tid first we need to drain them
* on the previous queue
* since HT is strict in order */
#ifdef CONFIG_MAC80211_HT_DEBUG
if (net_ratelimit()) {
DECLARE_MAC_BUF(mac);
printk(KERN_DEBUG "allocated aggregation queue"
" %d tid %d addr %s pool=0x%lX\n",
i, tid, print_mac(mac, sta->sta.addr),
local->queue_pool[0]);
}
#endif /* CONFIG_MAC80211_HT_DEBUG */
return 0;
}
return -EAGAIN;
}
/**
* the caller needs to hold netdev_get_tx_queue(local->mdev, X)->lock
*/
void ieee80211_ht_agg_queue_remove(struct ieee80211_local *local,
struct sta_info *sta, u16 tid,
u8 requeue)
{
int agg_queue = sta->tid_to_tx_q[tid];
struct ieee80211_hw *hw = &local->hw;
/* return the qdisc to the pool */
clear_bit(agg_queue, local->queue_pool);
sta->tid_to_tx_q[tid] = ieee80211_num_queues(hw);
if (requeue) {
ieee80211_requeue(local, agg_queue);
} else {
struct netdev_queue *txq;
spinlock_t *root_lock;
struct Qdisc *q;
txq = netdev_get_tx_queue(local->mdev, agg_queue);
q = rcu_dereference(txq->qdisc);
root_lock = qdisc_lock(q);
spin_lock_bh(root_lock);
qdisc_reset(q);
spin_unlock_bh(root_lock);
}
}
void ieee80211_requeue(struct ieee80211_local *local, int queue)
{
struct netdev_queue *txq = netdev_get_tx_queue(local->mdev, queue);
struct sk_buff_head list;
spinlock_t *root_lock;
struct Qdisc *qdisc;
u32 len;
rcu_read_lock_bh();
qdisc = rcu_dereference(txq->qdisc);
if (!qdisc || !qdisc->dequeue)
goto out_unlock;
skb_queue_head_init(&list);
root_lock = qdisc_root_lock(qdisc);
spin_lock(root_lock);
for (len = qdisc->q.qlen; len > 0; len--) {
struct sk_buff *skb = qdisc->dequeue(qdisc);
if (skb)
__skb_queue_tail(&list, skb);
}
spin_unlock(root_lock);
for (len = list.qlen; len > 0; len--) {
struct sk_buff *skb = __skb_dequeue(&list);
u16 new_queue;
BUG_ON(!skb);
new_queue = ieee80211_select_queue(local->mdev, skb);
skb_set_queue_mapping(skb, new_queue);
txq = netdev_get_tx_queue(local->mdev, new_queue);
qdisc = rcu_dereference(txq->qdisc);
root_lock = qdisc_root_lock(qdisc);
spin_lock(root_lock);
qdisc_enqueue_root(skb, qdisc);
spin_unlock(root_lock);
}
out_unlock:
rcu_read_unlock_bh();
}