/*
* 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"
/* maximum number of hardware queues we support. */
#define TC_80211_MAX_QUEUES 8
struct ieee80211_sched_data
{
struct tcf_proto *filter_list;
struct Qdisc *queues[TC_80211_MAX_QUEUES];
struct sk_buff_head requeued[TC_80211_MAX_QUEUES];
};
/* given a data frame determine the 802.1p/1d tag to use */
static inline unsigned classify_1d(struct sk_buff *skb, struct Qdisc *qd)
{
struct iphdr *ip;
int dscp;
int offset;
struct ieee80211_sched_data *q = qdisc_priv(qd);
struct tcf_result res = { -1, 0 };
/* if there is a user set filter list, call out to that */
if (q->filter_list) {
tc_classify(skb, q->filter_list, &res);
if (res.class != -1)
return res.class;
}
/* 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;
/* check there is a valid IP header present */
offset = ieee80211_get_hdrlen_from_skb(skb) + 8 /* LLC + proto */;
if (skb->protocol != __constant_htons(ETH_P_IP) ||
skb->len < offset + sizeof(*ip))
return 0;
ip = (struct iphdr *) (skb->data + offset);
dscp = ip->tos & 0xfc;
if (dscp & 0x1c)
return 0;
return dscp >> 5;
}
static inline 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;
}
}
/* positive return value indicates which queue to use
* negative return value indicates to drop the frame */
static inline int classify80211(struct sk_buff *skb, struct Qdisc *qd)
{
struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
struct ieee80211_tx_packet_data *pkt_data =
(struct ieee80211_tx_packet_data *) skb->cb;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
unsigned short fc = le16_to_cpu(hdr->frame_control);
int qos;
const int ieee802_1d_to_ac[8] = { 2, 3, 3, 2, 1, 1, 0, 0 };
/* see if frame is data or non data frame */
if (unlikely((fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA)) {
/* management frames go on AC_VO queue, but are sent
* without QoS control fields */
return IEEE80211_TX_QUEUE_DATA0;
}
if (unlikely(pkt_data->flags & IEEE80211_TXPD_MGMT_IFACE)) {
/* Data frames from hostapd (mainly, EAPOL) use AC_VO
* and they will include QoS control fields if
* the target STA is using WME. */
skb->priority = 7;
return ieee802_1d_to_ac[skb->priority];
}
/* is this a QoS frame? */
qos = fc & IEEE80211_STYPE_QOS_DATA;
if (!qos) {
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, qd);
/* 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)) {
/* No AC with lower priority has acm=0, drop packet. */
return -1;
}
}
/* look up which queue to use for frames with this 1d tag */
return ieee802_1d_to_ac[skb->priority];
}
static int wme_qdiscop_enqueue(struct sk_buff *skb, struct Qdisc* qd)
{
struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
struct ieee80211_sched_data *q = qdisc_priv(qd);
struct ieee80211_tx_packet_data *pkt_data =
(struct ieee80211_tx_packet_data *) skb->cb;
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
unsigned short fc = le16_to_cpu(hdr->frame_control);
struct Qdisc *qdisc;
int err, queue;
if (pkt_data->flags & IEEE80211_TXPD_REQUEUE) {
skb_queue_tail(&q->requeued[pkt_data->queue], skb);
qd->q.qlen++;
return 0;
}
queue = classify80211(skb, qd);
/* now we know the 1d priority, fill in the QoS header if there is one
*/
if (WLAN_FC_IS_QOS_DATA(fc)) {
u8 *p = skb->data + ieee80211_get_hdrlen(fc) - 2;
u8 qos_hdr = skb->priority & QOS_CONTROL_TAG1D_MASK;
if (local->wifi_wme_noack_test)
qos_hdr |= QOS_CONTROL_ACK_POLICY_NOACK <<
QOS_CONTROL_ACK_POLICY_SHIFT;
/* qos header is 2 bytes, second reserved */
*p = qos_hdr;
p++;
*p = 0;
}
if (unlikely(queue >= local->hw.queues)) {
#if 0
if (net_ratelimit()) {
printk(KERN_DEBUG "%s - queue=%d (hw does not "
"support) -> %d\n",
__func__, queue, local->hw.queues - 1);
}
#endif
queue = local->hw.queues - 1;
}
if (unlikely(queue < 0)) {
kfree_skb(skb);
err = NET_XMIT_DROP;
} else {
pkt_data->queue = (unsigned int) queue;
qdisc = q->queues[queue];
err = qdisc->enqueue(skb, qdisc);
if (err == NET_XMIT_SUCCESS) {
qd->q.qlen++;
qd->bstats.bytes += skb->len;
qd->bstats.packets++;
return NET_XMIT_SUCCESS;
}
}
qd->qstats.drops++;
return err;
}
/* TODO: clean up the cases where master_hard_start_xmit
* returns non 0 - it shouldn't ever do that. Once done we
* can remove this function */
static int wme_qdiscop_requeue(struct sk_buff *skb, struct Qdisc* qd)
{
struct ieee80211_sched_data *q = qdisc_priv(qd);
struct ieee80211_tx_packet_data *pkt_data =
(struct ieee80211_tx_packet_data *) skb->cb;
struct Qdisc *qdisc;
int err;
/* we recorded which queue to use earlier! */
qdisc = q->queues[pkt_data->queue];
if ((err = qdisc->ops->requeue(skb, qdisc)) == 0) {
qd->q.qlen++;
return 0;
}
qd->qstats.drops++;
return err;
}
static struct sk_buff *wme_qdiscop_dequeue(struct Qdisc* qd)
{
struct ieee80211_sched_data *q = qdisc_priv(qd);
struct net_device *dev = qd->dev;
struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
struct ieee80211_hw *hw = &local->hw;
struct sk_buff *skb;
struct Qdisc *qdisc;
int queue;
/* check all the h/w queues in numeric/priority order */
for (queue = 0; queue < hw->queues; queue++) {
/* see if there is room in this hardware queue */
if (test_bit(IEEE80211_LINK_STATE_XOFF,
&local->state[queue]) ||
test_bit(IEEE80211_LINK_STATE_PENDING,
&local->state[queue]))
continue;
/* there is space - try and get a frame */
skb = skb_dequeue(&q->requeued[queue]);
if (skb) {
qd->q.qlen--;
return skb;
}
qdisc = q->queues[queue];
skb = qdisc->dequeue(qdisc);
if (skb) {
qd->q.qlen--;
return skb;
}
}
/* returning a NULL here when all the h/w queues are full means we
* never need to call netif_stop_queue in the driver */
return NULL;
}
static void wme_qdiscop_reset(struct Qdisc* qd)
{
struct ieee80211_sched_data *q = qdisc_priv(qd);
struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
struct ieee80211_hw *hw = &local->hw;
int queue;
/* QUESTION: should we have some hardware flush functionality here? */
for (queue = 0; queue < hw->queues; queue++) {
skb_queue_purge(&q->requeued[queue]);
qdisc_reset(q->queues[queue]);
}
qd->q.qlen = 0;
}
static void wme_qdiscop_destroy(struct Qdisc* qd)
{
struct ieee80211_sched_data *q = qdisc_priv(qd);
struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
struct ieee80211_hw *hw = &local->hw;
int queue;
tcf_destroy_chain(q->filter_list);
q->filter_list = NULL;
for (queue=0; queue < hw->queues; queue++) {
skb_queue_purge(&q->requeued[queue]);
qdisc_destroy(q->queues[queue]);
q->queues[queue] = &noop_qdisc;
}
}
/* called whenever parameters are updated on existing qdisc */
static int wme_qdiscop_tune(struct Qdisc *qd, struct rtattr *opt)
{
/* struct ieee80211_sched_data *q = qdisc_priv(qd);
*/
/* check our options block is the right size */
/* copy any options to our local structure */
/* Ignore options block for now - always use static mapping
struct tc_ieee80211_qopt *qopt = RTA_DATA(opt);
if (opt->rta_len < RTA_LENGTH(sizeof(*qopt)))
return -EINVAL;
memcpy(q->tag2queue, qopt->tag2queue, sizeof(qopt->tag2queue));
*/
return 0;
}
/* called during initial creation of qdisc on device */
static int wme_qdiscop_init(struct Qdisc *qd, struct rtattr *opt)
{
struct ieee80211_sched_data *q = qdisc_priv(qd);
struct net_device *dev = qd->dev;
struct ieee80211_local *local;
int queues;
int err = 0, i;
/* check that device is a mac80211 device */
if (!dev->ieee80211_ptr ||
dev->ieee80211_ptr->wiphy->privid != mac80211_wiphy_privid)
return -EINVAL;
/* check this device is an ieee80211 master type device */
if (dev->type != ARPHRD_IEEE80211)
return -EINVAL;
/* check that there is no qdisc currently attached to device
* this ensures that we will be the root qdisc. (I can't find a better
* way to test this explicitly) */
if (dev->qdisc_sleeping != &noop_qdisc)
return -EINVAL;
if (qd->flags & TCQ_F_INGRESS)
return -EINVAL;
local = wdev_priv(dev->ieee80211_ptr);
queues = local->hw.queues;
/* if options were passed in, set them */
if (opt) {
err = wme_qdiscop_tune(qd, opt);
}
/* create child queues */
for (i = 0; i < queues; i++) {
skb_queue_head_init(&q->requeued[i]);
q->queues[i] = qdisc_create_dflt(qd->dev, &pfifo_qdisc_ops,
qd->handle);
if (!q->queues[i]) {
q->queues[i] = &noop_qdisc;
printk(KERN_ERR "%s child qdisc %i creation failed", dev->name, i);
}
}
return err;
}
static int wme_qdiscop_dump(struct Qdisc *qd, struct sk_buff *skb)
{
/* struct ieee80211_sched_data *q = qdisc_priv(qd);
unsigned char *p = skb->tail;
struct tc_ieee80211_qopt opt;
memcpy(&opt.tag2queue, q->tag2queue, TC_80211_MAX_TAG + 1);
RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
*/ return skb->len;
/*
rtattr_failure:
skb_trim(skb, p - skb->data);*/
return -1;
}
static int wme_classop_graft(struct Qdisc *qd, unsigned long arg,
struct Qdisc *new, struct Qdisc **old)
{
struct ieee80211_sched_data *q = qdisc_priv(qd);
struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
struct ieee80211_hw *hw = &local->hw;
unsigned long queue = arg - 1;
if (queue >= hw->queues)
return -EINVAL;
if (!new)
new = &noop_qdisc;
sch_tree_lock(qd);
*old = q->queues[queue];
q->queues[queue] = new;
qdisc_reset(*old);
sch_tree_unlock(qd);
return 0;
}
static struct Qdisc *
wme_classop_leaf(struct Qdisc *qd, unsigned long arg)
{
struct ieee80211_sched_data *q = qdisc_priv(qd);
struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
struct ieee80211_hw *hw = &local->hw;
unsigned long queue = arg - 1;
if (queue >= hw->queues)
return NULL;
return q->queues[queue];
}
static unsigned long wme_classop_get(struct Qdisc *qd, u32 classid)
{
struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
struct ieee80211_hw *hw = &local->hw;
unsigned long queue = TC_H_MIN(classid);
if (queue - 1 >= hw->queues)
return 0;
return queue;
}
static unsigned long wme_classop_bind(struct Qdisc *qd, unsigned long parent,
u32 classid)
{
return wme_classop_get(qd, classid);
}
static void wme_classop_put(struct Qdisc *q, unsigned long cl)
{
}
static int wme_classop_change(struct Qdisc *qd, u32 handle, u32 parent,
struct rtattr **tca, unsigned long *arg)
{
unsigned long cl = *arg;
struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
struct ieee80211_hw *hw = &local->hw;
if (cl - 1 > hw->queues)
return -ENOENT;
/* TODO: put code to program hardware queue parameters here,
* to allow programming from tc command line */
return 0;
}
/* we don't support deleting hardware queues
* when we add WMM-SA support - TSPECs may be deleted here */
static int wme_classop_delete(struct Qdisc *qd, unsigned long cl)
{
struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
struct ieee80211_hw *hw = &local->hw;
if (cl - 1 > hw->queues)
return -ENOENT;
return 0;
}
static int wme_classop_dump_class(struct Qdisc *qd, unsigned long cl,
struct sk_buff *skb, struct tcmsg *tcm)
{
struct ieee80211_sched_data *q = qdisc_priv(qd);
struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
struct ieee80211_hw *hw = &local->hw;
if (cl - 1 > hw->queues)
return -ENOENT;
tcm->tcm_handle = TC_H_MIN(cl);
tcm->tcm_parent = qd->handle;
tcm->tcm_info = q->queues[cl-1]->handle; /* do we need this? */
return 0;
}
static void wme_classop_walk(struct Qdisc *qd, struct qdisc_walker *arg)
{
struct ieee80211_local *local = wdev_priv(qd->dev->ieee80211_ptr);
struct ieee80211_hw *hw = &local->hw;
int queue;
if (arg->stop)
return;
for (queue = 0; queue < hw->queues; queue++) {
if (arg->count < arg->skip) {
arg->count++;
continue;
}
/* we should return classids for our internal queues here
* as well as the external ones */
if (arg->fn(qd, queue+1, arg) < 0) {
arg->stop = 1;
break;
}
arg->count++;
}
}
static struct tcf_proto ** wme_classop_find_tcf(struct Qdisc *qd,
unsigned long cl)
{
struct ieee80211_sched_data *q = qdisc_priv(qd);
if (cl)
return NULL;
return &q->filter_list;
}
/* this qdisc is classful (i.e. has classes, some of which may have leaf qdiscs attached)
* - these are the operations on the classes */
static struct Qdisc_class_ops class_ops =
{
.graft = wme_classop_graft,
.leaf = wme_classop_leaf,
.get = wme_classop_get,
.put = wme_classop_put,
.change = wme_classop_change,
.delete = wme_classop_delete,
.walk = wme_classop_walk,
.tcf_chain = wme_classop_find_tcf,
.bind_tcf = wme_classop_bind,
.unbind_tcf = wme_classop_put,
.dump = wme_classop_dump_class,
};
/* queueing discipline operations */
static struct Qdisc_ops wme_qdisc_ops =
{
.next = NULL,
.cl_ops = &class_ops,
.id = "ieee80211",
.priv_size = sizeof(struct ieee80211_sched_data),
.enqueue = wme_qdiscop_enqueue,
.dequeue = wme_qdiscop_dequeue,
.requeue = wme_qdiscop_requeue,
.drop = NULL, /* drop not needed since we are always the root qdisc */
.init = wme_qdiscop_init,
.reset = wme_qdiscop_reset,
.destroy = wme_qdiscop_destroy,
.change = wme_qdiscop_tune,
.dump = wme_qdiscop_dump,
};
void ieee80211_install_qdisc(struct net_device *dev)
{
struct Qdisc *qdisc;
qdisc = qdisc_create_dflt(dev, &wme_qdisc_ops, TC_H_ROOT);
if (!qdisc) {
printk(KERN_ERR "%s: qdisc installation failed\n", dev->name);
return;
}
/* same handle as would be allocated by qdisc_alloc_handle() */
qdisc->handle = 0x80010000;
qdisc_lock_tree(dev);
list_add_tail(&qdisc->list, &dev->qdisc_list);
dev->qdisc_sleeping = qdisc;
qdisc_unlock_tree(dev);
}
int ieee80211_qdisc_installed(struct net_device *dev)
{
return dev->qdisc_sleeping->ops == &wme_qdisc_ops;
}
int ieee80211_wme_register(void)
{
return register_qdisc(&wme_qdisc_ops);
}
void ieee80211_wme_unregister(void)
{
unregister_qdisc(&wme_qdisc_ops);
}
