wme.c revision 40aefedc8b494d6a7006ceb9d051fbc58268c86e 
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 */
24const int ieee802_1d_to_ac[8] = {
25	IEEE80211_AC_BE,
26	IEEE80211_AC_BK,
27	IEEE80211_AC_BK,
28	IEEE80211_AC_BE,
29	IEEE80211_AC_VI,
30	IEEE80211_AC_VI,
31	IEEE80211_AC_VO,
32	IEEE80211_AC_VO
33};
34
35static int wme_downgrade_ac(struct sk_buff *skb)
36{
37	switch (skb->priority) {
38	case 6:
39	case 7:
40		skb->priority = 5; /* VO -> VI */
41		return 0;
42	case 4:
43	case 5:
44		skb->priority = 3; /* VI -> BE */
45		return 0;
46	case 0:
47	case 3:
48		skb->priority = 2; /* BE -> BK */
49		return 0;
50	default:
51		return -1;
52	}
53}
54
55static u16 ieee80211_downgrade_queue(struct ieee80211_sub_if_data *sdata,
56				     struct sk_buff *skb)
57{
58	/* in case we are a client verify acm is not set for this ac */
59	while (unlikely(sdata->wmm_acm & BIT(skb->priority))) {
60		if (wme_downgrade_ac(skb)) {
61			/*
62			 * This should not really happen. The AP has marked all
63			 * lower ACs to require admission control which is not
64			 * a reasonable configuration. Allow the frame to be
65			 * transmitted using AC_BK as a workaround.
66			 */
67			break;
68		}
69	}
70
71	/* look up which queue to use for frames with this 1d tag */
72	return ieee802_1d_to_ac[skb->priority];
73}
74
75/* Indicate which queue to use for this fully formed 802.11 frame */
76u16 ieee80211_select_queue_80211(struct ieee80211_sub_if_data *sdata,
77				 struct sk_buff *skb,
78				 struct ieee80211_hdr *hdr)
79{
80	struct ieee80211_local *local = sdata->local;
81	u8 *p;
82
83	if (local->hw.queues < IEEE80211_NUM_ACS)
84		return 0;
85
86	if (!ieee80211_is_data(hdr->frame_control)) {
87		skb->priority = 7;
88		return ieee802_1d_to_ac[skb->priority];
89	}
90	if (!ieee80211_is_data_qos(hdr->frame_control)) {
91		skb->priority = 0;
92		return ieee802_1d_to_ac[skb->priority];
93	}
94
95	p = ieee80211_get_qos_ctl(hdr);
96	skb->priority = *p & IEEE80211_QOS_CTL_TAG1D_MASK;
97
98	return ieee80211_downgrade_queue(sdata, skb);
99}
100
101/* Indicate which queue to use. */
102u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
103			   struct sk_buff *skb)
104{
105	struct ieee80211_local *local = sdata->local;
106	struct sta_info *sta = NULL;
107	const u8 *ra = NULL;
108	bool qos = false;
109
110	if (local->hw.queues < IEEE80211_NUM_ACS || skb->len < 6) {
111		skb->priority = 0; /* required for correct WPA/11i MIC */
112		return 0;
113	}
114
115	rcu_read_lock();
116	switch (sdata->vif.type) {
117	case NL80211_IFTYPE_AP_VLAN:
118		sta = rcu_dereference(sdata->u.vlan.sta);
119		if (sta) {
120			qos = test_sta_flag(sta, WLAN_STA_WME);
121			break;
122		}
123	case NL80211_IFTYPE_AP:
124		ra = skb->data;
125		break;
126	case NL80211_IFTYPE_WDS:
127		ra = sdata->u.wds.remote_addr;
128		break;
129#ifdef CONFIG_MAC80211_MESH
130	case NL80211_IFTYPE_MESH_POINT:
131		qos = true;
132		break;
133#endif
134	case NL80211_IFTYPE_STATION:
135		ra = sdata->u.mgd.bssid;
136		break;
137	case NL80211_IFTYPE_ADHOC:
138		ra = skb->data;
139		break;
140	default:
141		break;
142	}
143
144	if (!sta && ra && !is_multicast_ether_addr(ra)) {
145		sta = sta_info_get(sdata, ra);
146		if (sta)
147			qos = test_sta_flag(sta, WLAN_STA_WME);
148	}
149	rcu_read_unlock();
150
151	if (!qos) {
152		skb->priority = 0; /* required for correct WPA/11i MIC */
153		return IEEE80211_AC_BE;
154	}
155
156	/* use the data classifier to determine what 802.1d tag the
157	 * data frame has */
158	skb->priority = cfg80211_classify8021d(skb);
159
160	return ieee80211_downgrade_queue(sdata, skb);
161}
162
163/**
164 * ieee80211_set_qos_hdr - Fill in the QoS header if there is one.
165 *
166 * @sdata: local subif
167 * @skb: packet to be updated
168 */
169void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata,
170			   struct sk_buff *skb)
171{
172	struct ieee80211_hdr *hdr = (void *)skb->data;
173	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
174	u8 *p;
175	u8 ack_policy, tid;
176
177	if (!ieee80211_is_data_qos(hdr->frame_control))
178		return;
179
180	p = ieee80211_get_qos_ctl(hdr);
181	tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
182
183	/* preserve EOSP bit */
184	ack_policy = *p & IEEE80211_QOS_CTL_EOSP;
185
186	if (is_multicast_ether_addr(hdr->addr1) ||
187	    sdata->noack_map & BIT(tid)) {
188		ack_policy |= IEEE80211_QOS_CTL_ACK_POLICY_NOACK;
189		info->flags |= IEEE80211_TX_CTL_NO_ACK;
190	}
191
192	/* qos header is 2 bytes */
193	*p++ = ack_policy | tid;
194	*p = ieee80211_vif_is_mesh(&sdata->vif) ?
195		(IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8) : 0;
196}
197