linux/net/mac80211/wme.c
Johannes Berg d3707d9918 mac80211: make noack test available
There's this internal wifi_wme_noack_test variable that
we use to set the QoS control if set. For one, it is
unlikely that it is set. Secondly, if set it needs to
influence the IEEE80211_TX_CTL_NO_ACK TX control flag,
and finally we should also be able to set it at all, so
make it available in debugfs.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-05-13 15:44:53 -04:00

146 lines
3.6 KiB
C

/*
* 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)) {
/*
* This should not really happen. The AP has marked all
* lower ACs to require admission control which is not
* a reasonable configuration. Allow the frame to be
* transmitted using AC_BK as a workaround.
*/
break;
}
}
/* 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;
u16 queue;
u8 tid;
queue = classify80211(local, skb);
if (unlikely(queue >= local->hw.queues))
queue = local->hw.queues - 1;
/*
* Now we know the 1d priority, fill in the QoS header if
* there is one (and we haven't done this before).
*/
if (!skb->requeue && 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 (unlikely(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;
}
return queue;
}