[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 000000000000..89ce81529694
--- /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 */