/* * 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]; }; 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 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); if (skb->len < offset + sizeof(llc_ip_hdr) + sizeof(*ip) || memcmp(skb->data + offset, llc_ip_hdr, sizeof(llc_ip_hdr))) return 0; ip = (struct iphdr *) (skb->data + offset + sizeof(llc_ip_hdr)); 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_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 (0 /* injected */) { /* use AC from radiotap */ } /* 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 nlattr *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 = nla_data(opt); if (opt->nla_len < nla_attr_size(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 nlattr *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); NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt); */ return skb->len; /* nla_put_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 nlattr **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 const 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 __read_mostly = { .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); }