Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
[linux-2.6] / net / mac80211 / wme.c
1 /*
2  * Copyright 2004, Instant802 Networks, Inc.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8
9 #include <linux/netdevice.h>
10 #include <linux/skbuff.h>
11 #include <linux/module.h>
12 #include <linux/if_arp.h>
13 #include <linux/types.h>
14 #include <net/ip.h>
15 #include <net/pkt_sched.h>
16
17 #include <net/mac80211.h>
18 #include "ieee80211_i.h"
19 #include "wme.h"
20
21 /* Default mapping in classifier to work with default
22  * queue setup.
23  */
24 const int ieee802_1d_to_ac[8] = { 2, 3, 3, 2, 1, 1, 0, 0 };
25
26 static const char llc_ip_hdr[8] = {0xAA, 0xAA, 0x3, 0, 0, 0, 0x08, 0};
27
28 /* Given a data frame determine the 802.1p/1d tag to use.  */
29 static unsigned int classify_1d(struct sk_buff *skb)
30 {
31         unsigned int dscp;
32
33         /* skb->priority values from 256->263 are magic values to
34          * directly indicate a specific 802.1d priority.  This is used
35          * to allow 802.1d priority to be passed directly in from VLAN
36          * tags, etc.
37          */
38         if (skb->priority >= 256 && skb->priority <= 263)
39                 return skb->priority - 256;
40
41         switch (skb->protocol) {
42         case htons(ETH_P_IP):
43                 dscp = ip_hdr(skb)->tos & 0xfc;
44                 break;
45
46         default:
47                 return 0;
48         }
49
50         return dscp >> 5;
51 }
52
53
54 static int wme_downgrade_ac(struct sk_buff *skb)
55 {
56         switch (skb->priority) {
57         case 6:
58         case 7:
59                 skb->priority = 5; /* VO -> VI */
60                 return 0;
61         case 4:
62         case 5:
63                 skb->priority = 3; /* VI -> BE */
64                 return 0;
65         case 0:
66         case 3:
67                 skb->priority = 2; /* BE -> BK */
68                 return 0;
69         default:
70                 return -1;
71         }
72 }
73
74
75 /* Indicate which queue to use.  */
76 static u16 classify80211(struct ieee80211_local *local, struct sk_buff *skb)
77 {
78         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
79
80         if (!ieee80211_is_data(hdr->frame_control)) {
81                 /* management frames go on AC_VO queue, but are sent
82                 * without QoS control fields */
83                 return 0;
84         }
85
86         if (0 /* injected */) {
87                 /* use AC from radiotap */
88         }
89
90         if (!ieee80211_is_data_qos(hdr->frame_control)) {
91                 skb->priority = 0; /* required for correct WPA/11i MIC */
92                 return ieee802_1d_to_ac[skb->priority];
93         }
94
95         /* use the data classifier to determine what 802.1d tag the
96          * data frame has */
97         skb->priority = classify_1d(skb);
98
99         /* in case we are a client verify acm is not set for this ac */
100         while (unlikely(local->wmm_acm & BIT(skb->priority))) {
101                 if (wme_downgrade_ac(skb)) {
102                         /* The old code would drop the packet in this
103                          * case.
104                          */
105                         return 0;
106                 }
107         }
108
109         /* look up which queue to use for frames with this 1d tag */
110         return ieee802_1d_to_ac[skb->priority];
111 }
112
113 u16 ieee80211_select_queue(struct net_device *dev, struct sk_buff *skb)
114 {
115         struct ieee80211_master_priv *mpriv = netdev_priv(dev);
116         struct ieee80211_local *local = mpriv->local;
117         struct ieee80211_hw *hw = &local->hw;
118         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
119         struct sta_info *sta;
120         u16 queue;
121         u8 tid;
122
123         queue = classify80211(local, skb);
124         if (unlikely(queue >= local->hw.queues))
125                 queue = local->hw.queues - 1;
126
127         if (skb->requeue) {
128                 if (!hw->ampdu_queues)
129                         return queue;
130
131                 rcu_read_lock();
132                 sta = sta_info_get(local, hdr->addr1);
133                 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
134                 if (sta) {
135                         int ampdu_queue = sta->tid_to_tx_q[tid];
136
137                         if ((ampdu_queue < ieee80211_num_queues(hw)) &&
138                             test_bit(ampdu_queue, local->queue_pool))
139                                 queue = ampdu_queue;
140                 }
141                 rcu_read_unlock();
142
143                 return queue;
144         }
145
146         /* Now we know the 1d priority, fill in the QoS header if
147          * there is one.
148          */
149         if (ieee80211_is_data_qos(hdr->frame_control)) {
150                 u8 *p = ieee80211_get_qos_ctl(hdr);
151                 u8 ack_policy = 0;
152                 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
153                 if (local->wifi_wme_noack_test)
154                         ack_policy |= QOS_CONTROL_ACK_POLICY_NOACK <<
155                                         QOS_CONTROL_ACK_POLICY_SHIFT;
156                 /* qos header is 2 bytes, second reserved */
157                 *p++ = ack_policy | tid;
158                 *p = 0;
159
160                 if (!hw->ampdu_queues)
161                         return queue;
162
163                 rcu_read_lock();
164
165                 sta = sta_info_get(local, hdr->addr1);
166                 if (sta) {
167                         int ampdu_queue = sta->tid_to_tx_q[tid];
168
169                         if ((ampdu_queue < ieee80211_num_queues(hw)) &&
170                             test_bit(ampdu_queue, local->queue_pool))
171                                 queue = ampdu_queue;
172                 }
173
174                 rcu_read_unlock();
175         }
176
177         return queue;
178 }
179
180 int ieee80211_ht_agg_queue_add(struct ieee80211_local *local,
181                                struct sta_info *sta, u16 tid)
182 {
183         int i;
184
185         /* XXX: currently broken due to cb/requeue use */
186         return -EPERM;
187
188         /* prepare the filter and save it for the SW queue
189          * matching the received HW queue */
190
191         if (!local->hw.ampdu_queues)
192                 return -EPERM;
193
194         /* try to get a Qdisc from the pool */
195         for (i = local->hw.queues; i < ieee80211_num_queues(&local->hw); i++)
196                 if (!test_and_set_bit(i, local->queue_pool)) {
197                         ieee80211_stop_queue(local_to_hw(local), i);
198                         sta->tid_to_tx_q[tid] = i;
199
200                         /* IF there are already pending packets
201                          * on this tid first we need to drain them
202                          * on the previous queue
203                          * since HT is strict in order */
204 #ifdef CONFIG_MAC80211_HT_DEBUG
205                         if (net_ratelimit())
206                                 printk(KERN_DEBUG "allocated aggregation queue"
207                                         " %d tid %d addr %pM pool=0x%lX\n",
208                                         i, tid, sta->sta.addr,
209                                         local->queue_pool[0]);
210 #endif /* CONFIG_MAC80211_HT_DEBUG */
211                         return 0;
212                 }
213
214         return -EAGAIN;
215 }
216
217 /**
218  * the caller needs to hold netdev_get_tx_queue(local->mdev, X)->lock
219  */
220 void ieee80211_ht_agg_queue_remove(struct ieee80211_local *local,
221                                    struct sta_info *sta, u16 tid,
222                                    u8 requeue)
223 {
224         int agg_queue = sta->tid_to_tx_q[tid];
225         struct ieee80211_hw *hw = &local->hw;
226
227         /* return the qdisc to the pool */
228         clear_bit(agg_queue, local->queue_pool);
229         sta->tid_to_tx_q[tid] = ieee80211_num_queues(hw);
230
231         if (requeue) {
232                 ieee80211_requeue(local, agg_queue);
233         } else {
234                 struct netdev_queue *txq;
235                 spinlock_t *root_lock;
236                 struct Qdisc *q;
237
238                 txq = netdev_get_tx_queue(local->mdev, agg_queue);
239                 q = rcu_dereference(txq->qdisc);
240                 root_lock = qdisc_lock(q);
241
242                 spin_lock_bh(root_lock);
243                 qdisc_reset(q);
244                 spin_unlock_bh(root_lock);
245         }
246 }
247
248 void ieee80211_requeue(struct ieee80211_local *local, int queue)
249 {
250         struct netdev_queue *txq = netdev_get_tx_queue(local->mdev, queue);
251         struct sk_buff_head list;
252         spinlock_t *root_lock;
253         struct Qdisc *qdisc;
254         u32 len;
255
256         rcu_read_lock_bh();
257
258         qdisc = rcu_dereference(txq->qdisc);
259         if (!qdisc || !qdisc->dequeue)
260                 goto out_unlock;
261
262         skb_queue_head_init(&list);
263
264         root_lock = qdisc_root_lock(qdisc);
265         spin_lock(root_lock);
266         for (len = qdisc->q.qlen; len > 0; len--) {
267                 struct sk_buff *skb = qdisc->dequeue(qdisc);
268
269                 if (skb)
270                         __skb_queue_tail(&list, skb);
271         }
272         spin_unlock(root_lock);
273
274         for (len = list.qlen; len > 0; len--) {
275                 struct sk_buff *skb = __skb_dequeue(&list);
276                 u16 new_queue;
277
278                 BUG_ON(!skb);
279                 new_queue = ieee80211_select_queue(local->mdev, skb);
280                 skb_set_queue_mapping(skb, new_queue);
281
282                 txq = netdev_get_tx_queue(local->mdev, new_queue);
283
284
285                 qdisc = rcu_dereference(txq->qdisc);
286                 root_lock = qdisc_root_lock(qdisc);
287
288                 spin_lock(root_lock);
289                 qdisc_enqueue_root(skb, qdisc);
290                 spin_unlock(root_lock);
291         }
292
293 out_unlock:
294         rcu_read_unlock_bh();
295 }