xref: /openbmc/linux/net/mac80211/wme.c (revision 609e478b)
1 /*
2  * Copyright 2004, Instant802 Networks, Inc.
3  * Copyright 2013-2014  Intel Mobile Communications GmbH
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9 
10 #include <linux/netdevice.h>
11 #include <linux/skbuff.h>
12 #include <linux/module.h>
13 #include <linux/if_arp.h>
14 #include <linux/types.h>
15 #include <net/ip.h>
16 #include <net/pkt_sched.h>
17 
18 #include <net/mac80211.h>
19 #include "ieee80211_i.h"
20 #include "wme.h"
21 
22 /* Default mapping in classifier to work with default
23  * queue setup.
24  */
25 const int ieee802_1d_to_ac[8] = {
26 	IEEE80211_AC_BE,
27 	IEEE80211_AC_BK,
28 	IEEE80211_AC_BK,
29 	IEEE80211_AC_BE,
30 	IEEE80211_AC_VI,
31 	IEEE80211_AC_VI,
32 	IEEE80211_AC_VO,
33 	IEEE80211_AC_VO
34 };
35 
36 static int wme_downgrade_ac(struct sk_buff *skb)
37 {
38 	switch (skb->priority) {
39 	case 6:
40 	case 7:
41 		skb->priority = 5; /* VO -> VI */
42 		return 0;
43 	case 4:
44 	case 5:
45 		skb->priority = 3; /* VI -> BE */
46 		return 0;
47 	case 0:
48 	case 3:
49 		skb->priority = 2; /* BE -> BK */
50 		return 0;
51 	default:
52 		return -1;
53 	}
54 }
55 
56 static u16 ieee80211_downgrade_queue(struct ieee80211_sub_if_data *sdata,
57 				     struct sk_buff *skb)
58 {
59 	/* in case we are a client verify acm is not set for this ac */
60 	while (unlikely(sdata->wmm_acm & BIT(skb->priority))) {
61 		if (wme_downgrade_ac(skb)) {
62 			/*
63 			 * This should not really happen. The AP has marked all
64 			 * lower ACs to require admission control which is not
65 			 * a reasonable configuration. Allow the frame to be
66 			 * transmitted using AC_BK as a workaround.
67 			 */
68 			break;
69 		}
70 	}
71 
72 	/* look up which queue to use for frames with this 1d tag */
73 	return ieee802_1d_to_ac[skb->priority];
74 }
75 
76 /* Indicate which queue to use for this fully formed 802.11 frame */
77 u16 ieee80211_select_queue_80211(struct ieee80211_sub_if_data *sdata,
78 				 struct sk_buff *skb,
79 				 struct ieee80211_hdr *hdr)
80 {
81 	struct ieee80211_local *local = sdata->local;
82 	u8 *p;
83 
84 	if (local->hw.queues < IEEE80211_NUM_ACS)
85 		return 0;
86 
87 	if (!ieee80211_is_data(hdr->frame_control)) {
88 		skb->priority = 7;
89 		return ieee802_1d_to_ac[skb->priority];
90 	}
91 	if (!ieee80211_is_data_qos(hdr->frame_control)) {
92 		skb->priority = 0;
93 		return ieee802_1d_to_ac[skb->priority];
94 	}
95 
96 	p = ieee80211_get_qos_ctl(hdr);
97 	skb->priority = *p & IEEE80211_QOS_CTL_TAG1D_MASK;
98 
99 	return ieee80211_downgrade_queue(sdata, skb);
100 }
101 
102 /* Indicate which queue to use. */
103 u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
104 			   struct sk_buff *skb)
105 {
106 	struct ieee80211_local *local = sdata->local;
107 	struct sta_info *sta = NULL;
108 	const u8 *ra = NULL;
109 	bool qos = false;
110 	struct mac80211_qos_map *qos_map;
111 
112 	if (local->hw.queues < IEEE80211_NUM_ACS || skb->len < 6) {
113 		skb->priority = 0; /* required for correct WPA/11i MIC */
114 		return 0;
115 	}
116 
117 	rcu_read_lock();
118 	switch (sdata->vif.type) {
119 	case NL80211_IFTYPE_AP_VLAN:
120 		sta = rcu_dereference(sdata->u.vlan.sta);
121 		if (sta) {
122 			qos = sta->sta.wme;
123 			break;
124 		}
125 	case NL80211_IFTYPE_AP:
126 		ra = skb->data;
127 		break;
128 	case NL80211_IFTYPE_WDS:
129 		ra = sdata->u.wds.remote_addr;
130 		break;
131 #ifdef CONFIG_MAC80211_MESH
132 	case NL80211_IFTYPE_MESH_POINT:
133 		qos = true;
134 		break;
135 #endif
136 	case NL80211_IFTYPE_STATION:
137 		ra = sdata->u.mgd.bssid;
138 		break;
139 	case NL80211_IFTYPE_ADHOC:
140 		ra = skb->data;
141 		break;
142 	default:
143 		break;
144 	}
145 
146 	if (!sta && ra && !is_multicast_ether_addr(ra)) {
147 		sta = sta_info_get(sdata, ra);
148 		if (sta)
149 			qos = sta->sta.wme;
150 	}
151 	rcu_read_unlock();
152 
153 	if (!qos) {
154 		skb->priority = 0; /* required for correct WPA/11i MIC */
155 		return IEEE80211_AC_BE;
156 	}
157 
158 	if (skb->protocol == sdata->control_port_protocol) {
159 		skb->priority = 7;
160 		return ieee80211_downgrade_queue(sdata, skb);
161 	}
162 
163 	/* use the data classifier to determine what 802.1d tag the
164 	 * data frame has */
165 	rcu_read_lock();
166 	qos_map = rcu_dereference(sdata->qos_map);
167 	skb->priority = cfg80211_classify8021d(skb, qos_map ?
168 					       &qos_map->qos_map : NULL);
169 	rcu_read_unlock();
170 
171 	return ieee80211_downgrade_queue(sdata, skb);
172 }
173 
174 /**
175  * ieee80211_set_qos_hdr - Fill in the QoS header if there is one.
176  *
177  * @sdata: local subif
178  * @skb: packet to be updated
179  */
180 void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata,
181 			   struct sk_buff *skb)
182 {
183 	struct ieee80211_hdr *hdr = (void *)skb->data;
184 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
185 	u8 *p;
186 	u8 ack_policy, tid;
187 
188 	if (!ieee80211_is_data_qos(hdr->frame_control))
189 		return;
190 
191 	p = ieee80211_get_qos_ctl(hdr);
192 	tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
193 
194 	/* preserve EOSP bit */
195 	ack_policy = *p & IEEE80211_QOS_CTL_EOSP;
196 
197 	if (is_multicast_ether_addr(hdr->addr1) ||
198 	    sdata->noack_map & BIT(tid)) {
199 		ack_policy |= IEEE80211_QOS_CTL_ACK_POLICY_NOACK;
200 		info->flags |= IEEE80211_TX_CTL_NO_ACK;
201 	}
202 
203 	/* qos header is 2 bytes */
204 	*p++ = ack_policy | tid;
205 	if (ieee80211_vif_is_mesh(&sdata->vif)) {
206 		/* preserve RSPI and Mesh PS Level bit */
207 		*p &= ((IEEE80211_QOS_CTL_RSPI |
208 			IEEE80211_QOS_CTL_MESH_PS_LEVEL) >> 8);
209 
210 		/* Nulls don't have a mesh header (frame body) */
211 		if (!ieee80211_is_qos_nullfunc(hdr->frame_control))
212 			*p |= (IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8);
213 	} else {
214 		*p = 0;
215 	}
216 }
217