[MAC80211]: Add mac80211 wireless stack.

Add mac80211, the IEEE 802.11 software MAC layer.

Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 678 insertions, 0 deletions

diff --git a/net/mac80211/wme.c b/net/mac80211/wme.c
new file mode 100644
index 00000000000..89ce8152969
--- /dev/null
+++ b/net/mac80211/wme.c
@@ -0,0 +1,678 @@
+/*
+ * 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"
+
+static inline int WLAN_FC_IS_QOS_DATA(u16 fc)
+{
+	return (fc & 0x8C) == 0x88;
+}
+
+
+ieee80211_txrx_result
+ieee80211_rx_h_parse_qos(struct ieee80211_txrx_data *rx)
+{
+	u8 *data = rx->skb->data;
+	int tid;
+
+	/* does the frame have a qos control field? */
+	if (WLAN_FC_IS_QOS_DATA(rx->fc)) {
+		u8 *qc = data + ieee80211_get_hdrlen(rx->fc) - QOS_CONTROL_LEN;
+		/* frame has qos control */
+		tid = qc[0] & QOS_CONTROL_TID_MASK;
+	} else {
+		if (unlikely((rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_MGMT)) {
+			/* Separate TID for management frames */
+			tid = NUM_RX_DATA_QUEUES - 1;
+		} else {
+			/* no qos control present */
+			tid = 0; /* 802.1d - Best Effort */
+		}
+	}
+#ifdef CONFIG_MAC80211_DEBUG_COUNTERS
+	I802_DEBUG_INC(rx->local->wme_rx_queue[tid]);
+	if (rx->sta) {
+		I802_DEBUG_INC(rx->sta->wme_rx_queue[tid]);
+	}
+#endif /* CONFIG_MAC80211_DEBUG_COUNTERS */
+
+	rx->u.rx.queue = tid;
+	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
+	 * For now, set skb->priority to 0 for other cases. */
+	rx->skb->priority = (tid > 7) ? 0 : tid;
+
+	return TXRX_CONTINUE;
+}
+
+
+ieee80211_txrx_result
+ieee80211_rx_h_remove_qos_control(struct ieee80211_txrx_data *rx)
+{
+	u16 fc = rx->fc;
+	u8 *data = rx->skb->data;
+	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) data;
+
+	if (!WLAN_FC_IS_QOS_DATA(fc))
+		return TXRX_CONTINUE;
+
+	/* remove the qos control field, update frame type and meta-data */
+	memmove(data + 2, data, ieee80211_get_hdrlen(fc) - 2);
+	hdr = (struct ieee80211_hdr *) skb_pull(rx->skb, 2);
+	/* change frame type to non QOS */
+	rx->fc = fc &= ~IEEE80211_STYPE_QOS_DATA;
+	hdr->frame_control = cpu_to_le16(fc);
+
+	return TXRX_CONTINUE;
+}
+
+
+#ifdef CONFIG_NET_SCHED
+/* 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->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);
+
+	/* incase 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->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] == 0) {
+			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);
+}
+#endif /* CONFIG_NET_SCHED */