xref: /linux/net/mac80211/wme.c (revision f884ab15afdc5514e88105c92a4e2e1e6539869a)
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_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 */
76 u16 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. */
102 u16 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  */
169 void 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 	if (ieee80211_vif_is_mesh(&sdata->vif)) {
195 		/* preserve RSPI and Mesh PS Level bit */
196 		*p &= ((IEEE80211_QOS_CTL_RSPI |
197 			IEEE80211_QOS_CTL_MESH_PS_LEVEL) >> 8);
198 
199 		/* Nulls don't have a mesh header (frame body) */
200 		if (!ieee80211_is_qos_nullfunc(hdr->frame_control))
201 			*p |= (IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8);
202 	} else {
203 		*p = 0;
204 	}
205 }
206