xref: /linux/net/mac80211/wme.c (revision 26b0d14106954ae46d2f4f7eec3481828a210f7d)
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] = {
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 
35 static 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 
55 static u16 ieee80211_downgrade_queue(struct ieee80211_local *local,
56 				     struct sk_buff *skb)
57 {
58 	/* in case we are a client verify acm is not set for this ac */
59 	while (unlikely(local->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 */
76 u16 ieee80211_select_queue_80211(struct ieee80211_local *local,
77 				 struct sk_buff *skb,
78 				 struct ieee80211_hdr *hdr)
79 {
80 	u8 *p;
81 
82 	if (local->hw.queues < IEEE80211_NUM_ACS)
83 		return 0;
84 
85 	if (!ieee80211_is_data(hdr->frame_control)) {
86 		skb->priority = 7;
87 		return ieee802_1d_to_ac[skb->priority];
88 	}
89 	if (!ieee80211_is_data_qos(hdr->frame_control)) {
90 		skb->priority = 0;
91 		return ieee802_1d_to_ac[skb->priority];
92 	}
93 
94 	p = ieee80211_get_qos_ctl(hdr);
95 	skb->priority = *p & IEEE80211_QOS_CTL_TAG1D_MASK;
96 
97 	return ieee80211_downgrade_queue(local, skb);
98 }
99 
100 /* Indicate which queue to use. */
101 u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
102 			   struct sk_buff *skb)
103 {
104 	struct ieee80211_local *local = sdata->local;
105 	struct sta_info *sta = NULL;
106 	const u8 *ra = NULL;
107 	bool qos = false;
108 
109 	if (local->hw.queues < IEEE80211_NUM_ACS || skb->len < 6) {
110 		skb->priority = 0; /* required for correct WPA/11i MIC */
111 		return 0;
112 	}
113 
114 	rcu_read_lock();
115 	switch (sdata->vif.type) {
116 	case NL80211_IFTYPE_AP_VLAN:
117 		sta = rcu_dereference(sdata->u.vlan.sta);
118 		if (sta) {
119 			qos = test_sta_flag(sta, WLAN_STA_WME);
120 			break;
121 		}
122 	case NL80211_IFTYPE_AP:
123 		ra = skb->data;
124 		break;
125 	case NL80211_IFTYPE_WDS:
126 		ra = sdata->u.wds.remote_addr;
127 		break;
128 #ifdef CONFIG_MAC80211_MESH
129 	case NL80211_IFTYPE_MESH_POINT:
130 		qos = true;
131 		break;
132 #endif
133 	case NL80211_IFTYPE_STATION:
134 		ra = sdata->u.mgd.bssid;
135 		break;
136 	case NL80211_IFTYPE_ADHOC:
137 		ra = skb->data;
138 		break;
139 	default:
140 		break;
141 	}
142 
143 	if (!sta && ra && !is_multicast_ether_addr(ra)) {
144 		sta = sta_info_get(sdata, ra);
145 		if (sta)
146 			qos = test_sta_flag(sta, WLAN_STA_WME);
147 	}
148 	rcu_read_unlock();
149 
150 	if (!qos) {
151 		skb->priority = 0; /* required for correct WPA/11i MIC */
152 		return IEEE80211_AC_BE;
153 	}
154 
155 	/* use the data classifier to determine what 802.1d tag the
156 	 * data frame has */
157 	skb->priority = cfg80211_classify8021d(skb);
158 
159 	return ieee80211_downgrade_queue(local, skb);
160 }
161 
162 void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata,
163 			   struct sk_buff *skb)
164 {
165 	struct ieee80211_hdr *hdr = (void *)skb->data;
166 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
167 
168 	/* Fill in the QoS header if there is one. */
169 	if (ieee80211_is_data_qos(hdr->frame_control)) {
170 		u8 *p = ieee80211_get_qos_ctl(hdr);
171 		u8 ack_policy, tid;
172 
173 		tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
174 
175 		/* preserve EOSP bit */
176 		ack_policy = *p & IEEE80211_QOS_CTL_EOSP;
177 
178 		if (is_multicast_ether_addr(hdr->addr1) ||
179 		    sdata->noack_map & BIT(tid)) {
180 			ack_policy |= IEEE80211_QOS_CTL_ACK_POLICY_NOACK;
181 			info->flags |= IEEE80211_TX_CTL_NO_ACK;
182 		}
183 
184 		/* qos header is 2 bytes */
185 		*p++ = ack_policy | tid;
186 		*p = ieee80211_vif_is_mesh(&sdata->vif) ?
187 			(IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8) : 0;
188 	}
189 }
190