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
wme_downgrade_ac(struct sk_buff * skb)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
56 /* Indicate which queue to use. */
ieee80211_select_queue(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)57 u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
58 struct sk_buff *skb)
59 {
60 struct ieee80211_local *local = sdata->local;
61 struct sta_info *sta = NULL;
62 const u8 *ra = NULL;
63 bool qos = false;
64
65 if (local->hw.queues < 4 || skb->len < 6) {
66 skb->priority = 0; /* required for correct WPA/11i MIC */
67 return min_t(u16, local->hw.queues - 1, IEEE80211_AC_BE);
68 }
69
70 rcu_read_lock();
71 switch (sdata->vif.type) {
72 case NL80211_IFTYPE_AP_VLAN:
73 sta = rcu_dereference(sdata->u.vlan.sta);
74 if (sta) {
75 qos = get_sta_flags(sta) & WLAN_STA_WME;
76 break;
77 }
78 case NL80211_IFTYPE_AP:
79 ra = skb->data;
80 break;
81 case NL80211_IFTYPE_WDS:
82 ra = sdata->u.wds.remote_addr;
83 break;
84 #ifdef CONFIG_MAC80211_MESH
85 case NL80211_IFTYPE_MESH_POINT:
86 /*
87 * XXX: This is clearly broken ... but already was before,
88 * because ieee80211_fill_mesh_addresses() would clear A1
89 * except for multicast addresses.
90 */
91 break;
92 #endif
93 case NL80211_IFTYPE_STATION:
94 ra = sdata->u.mgd.bssid;
95 break;
96 case NL80211_IFTYPE_ADHOC:
97 ra = skb->data;
98 break;
99 default:
100 break;
101 }
102
103 if (!sta && ra && !is_multicast_ether_addr(ra)) {
104 sta = sta_info_get(sdata, ra);
105 if (sta)
106 qos = get_sta_flags(sta) & WLAN_STA_WME;
107 }
108 rcu_read_unlock();
109
110 if (!qos) {
111 skb->priority = 0; /* required for correct WPA/11i MIC */
112 return IEEE80211_AC_BE;
113 }
114
115 /* use the data classifier to determine what 802.1d tag the
116 * data frame has */
117 skb->priority = cfg80211_classify8021d(skb);
118
119 return ieee80211_downgrade_queue(local, skb);
120 }
121
ieee80211_downgrade_queue(struct ieee80211_local * local,struct sk_buff * skb)122 u16 ieee80211_downgrade_queue(struct ieee80211_local *local,
123 struct sk_buff *skb)
124 {
125 /* in case we are a client verify acm is not set for this ac */
126 while (unlikely(local->wmm_acm & BIT(skb->priority))) {
127 if (wme_downgrade_ac(skb)) {
128 /*
129 * This should not really happen. The AP has marked all
130 * lower ACs to require admission control which is not
131 * a reasonable configuration. Allow the frame to be
132 * transmitted using AC_BK as a workaround.
133 */
134 break;
135 }
136 }
137
138 /* look up which queue to use for frames with this 1d tag */
139 return ieee802_1d_to_ac[skb->priority];
140 }
141
ieee80211_set_qos_hdr(struct ieee80211_local * local,struct sk_buff * skb)142 void ieee80211_set_qos_hdr(struct ieee80211_local *local, struct sk_buff *skb)
143 {
144 struct ieee80211_hdr *hdr = (void *)skb->data;
145
146 /* Fill in the QoS header if there is one. */
147 if (ieee80211_is_data_qos(hdr->frame_control)) {
148 u8 *p = ieee80211_get_qos_ctl(hdr);
149 u8 ack_policy = 0, tid;
150
151 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
152
153 if (unlikely(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 }
161