xref: /openbmc/linux/net/mac80211/wme.c (revision e9088629)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2004, Instant802 Networks, Inc.
4  * Copyright 2013-2014  Intel Mobile Communications GmbH
5  */
6 
7 #include <linux/netdevice.h>
8 #include <linux/skbuff.h>
9 #include <linux/module.h>
10 #include <linux/if_arp.h>
11 #include <linux/types.h>
12 #include <net/ip.h>
13 #include <net/pkt_sched.h>
14 
15 #include <net/mac80211.h>
16 #include "ieee80211_i.h"
17 #include "wme.h"
18 
19 /* Default mapping in classifier to work with default
20  * queue setup.
21  */
22 const int ieee802_1d_to_ac[8] = {
23 	IEEE80211_AC_BE,
24 	IEEE80211_AC_BK,
25 	IEEE80211_AC_BK,
26 	IEEE80211_AC_BE,
27 	IEEE80211_AC_VI,
28 	IEEE80211_AC_VI,
29 	IEEE80211_AC_VO,
30 	IEEE80211_AC_VO
31 };
32 
33 static int wme_downgrade_ac(struct sk_buff *skb)
34 {
35 	switch (skb->priority) {
36 	case 6:
37 	case 7:
38 		skb->priority = 5; /* VO -> VI */
39 		return 0;
40 	case 4:
41 	case 5:
42 		skb->priority = 3; /* VI -> BE */
43 		return 0;
44 	case 0:
45 	case 3:
46 		skb->priority = 2; /* BE -> BK */
47 		return 0;
48 	default:
49 		return -1;
50 	}
51 }
52 
53 /**
54  * ieee80211_fix_reserved_tid - return the TID to use if this one is reserved
55  * @tid: the assumed-reserved TID
56  *
57  * Returns: the alternative TID to use, or 0 on error
58  */
59 static inline u8 ieee80211_fix_reserved_tid(u8 tid)
60 {
61 	switch (tid) {
62 	case 0:
63 		return 3;
64 	case 1:
65 		return 2;
66 	case 2:
67 		return 1;
68 	case 3:
69 		return 0;
70 	case 4:
71 		return 5;
72 	case 5:
73 		return 4;
74 	case 6:
75 		return 7;
76 	case 7:
77 		return 6;
78 	}
79 
80 	return 0;
81 }
82 
83 static u16 ieee80211_downgrade_queue(struct ieee80211_sub_if_data *sdata,
84 				     struct sta_info *sta, struct sk_buff *skb)
85 {
86 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
87 
88 	/* in case we are a client verify acm is not set for this ac */
89 	while (sdata->wmm_acm & BIT(skb->priority)) {
90 		int ac = ieee802_1d_to_ac[skb->priority];
91 
92 		if (ifmgd->tx_tspec[ac].admitted_time &&
93 		    skb->priority == ifmgd->tx_tspec[ac].up)
94 			return ac;
95 
96 		if (wme_downgrade_ac(skb)) {
97 			/*
98 			 * This should not really happen. The AP has marked all
99 			 * lower ACs to require admission control which is not
100 			 * a reasonable configuration. Allow the frame to be
101 			 * transmitted using AC_BK as a workaround.
102 			 */
103 			break;
104 		}
105 	}
106 
107 	/* Check to see if this is a reserved TID */
108 	if (sta && sta->reserved_tid == skb->priority)
109 		skb->priority = ieee80211_fix_reserved_tid(skb->priority);
110 
111 	/* look up which queue to use for frames with this 1d tag */
112 	return ieee802_1d_to_ac[skb->priority];
113 }
114 
115 /* Indicate which queue to use for this fully formed 802.11 frame */
116 u16 ieee80211_select_queue_80211(struct ieee80211_sub_if_data *sdata,
117 				 struct sk_buff *skb,
118 				 struct ieee80211_hdr *hdr)
119 {
120 	struct ieee80211_local *local = sdata->local;
121 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
122 	u8 *p;
123 
124 	if ((info->control.flags & IEEE80211_TX_CTRL_DONT_REORDER) ||
125 	    local->hw.queues < IEEE80211_NUM_ACS)
126 		return 0;
127 
128 	if (!ieee80211_is_data(hdr->frame_control)) {
129 		skb->priority = 7;
130 		return ieee802_1d_to_ac[skb->priority];
131 	}
132 	if (!ieee80211_is_data_qos(hdr->frame_control)) {
133 		skb->priority = 0;
134 		return ieee802_1d_to_ac[skb->priority];
135 	}
136 
137 	p = ieee80211_get_qos_ctl(hdr);
138 	skb->priority = *p & IEEE80211_QOS_CTL_TAG1D_MASK;
139 
140 	return ieee80211_downgrade_queue(sdata, NULL, skb);
141 }
142 
143 u16 __ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
144 			     struct sta_info *sta, struct sk_buff *skb)
145 {
146 	struct mac80211_qos_map *qos_map;
147 	bool qos;
148 
149 	/* all mesh/ocb stations are required to support WME */
150 	if (sta && (sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
151 		    sdata->vif.type == NL80211_IFTYPE_OCB))
152 		qos = true;
153 	else if (sta)
154 		qos = sta->sta.wme;
155 	else
156 		qos = false;
157 
158 	if (!qos) {
159 		skb->priority = 0; /* required for correct WPA/11i MIC */
160 		return IEEE80211_AC_BE;
161 	}
162 
163 	if (skb->protocol == sdata->control_port_protocol) {
164 		skb->priority = 7;
165 		goto downgrade;
166 	}
167 
168 	/* use the data classifier to determine what 802.1d tag the
169 	 * data frame has */
170 	qos_map = rcu_dereference(sdata->qos_map);
171 	skb->priority = cfg80211_classify8021d(skb, qos_map ?
172 					       &qos_map->qos_map : NULL);
173 
174  downgrade:
175 	return ieee80211_downgrade_queue(sdata, sta, skb);
176 }
177 
178 
179 /* Indicate which queue to use. */
180 u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
181 			   struct sk_buff *skb)
182 {
183 	struct ieee80211_local *local = sdata->local;
184 	struct sta_info *sta = NULL;
185 	const u8 *ra = NULL;
186 	u16 ret;
187 
188 	/* when using iTXQ, we can do this later */
189 	if (local->ops->wake_tx_queue)
190 		return 0;
191 
192 	if (local->hw.queues < IEEE80211_NUM_ACS || skb->len < 6) {
193 		skb->priority = 0; /* required for correct WPA/11i MIC */
194 		return 0;
195 	}
196 
197 	rcu_read_lock();
198 	switch (sdata->vif.type) {
199 	case NL80211_IFTYPE_AP_VLAN:
200 		sta = rcu_dereference(sdata->u.vlan.sta);
201 		if (sta)
202 			break;
203 		fallthrough;
204 	case NL80211_IFTYPE_AP:
205 		ra = skb->data;
206 		break;
207 	case NL80211_IFTYPE_STATION:
208 		/* might be a TDLS station */
209 		sta = sta_info_get(sdata, skb->data);
210 		if (sta)
211 			break;
212 
213 		ra = sdata->u.mgd.bssid;
214 		break;
215 	case NL80211_IFTYPE_ADHOC:
216 		ra = skb->data;
217 		break;
218 	default:
219 		break;
220 	}
221 
222 	if (!sta && ra && !is_multicast_ether_addr(ra))
223 		sta = sta_info_get(sdata, ra);
224 
225 	ret = __ieee80211_select_queue(sdata, sta, skb);
226 
227 	rcu_read_unlock();
228 	return ret;
229 }
230 
231 /**
232  * ieee80211_set_qos_hdr - Fill in the QoS header if there is one.
233  *
234  * @sdata: local subif
235  * @skb: packet to be updated
236  */
237 void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata,
238 			   struct sk_buff *skb)
239 {
240 	struct ieee80211_hdr *hdr = (void *)skb->data;
241 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
242 	u8 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
243 	u8 flags;
244 	u8 *p;
245 
246 	if (!ieee80211_is_data_qos(hdr->frame_control))
247 		return;
248 
249 	p = ieee80211_get_qos_ctl(hdr);
250 
251 	/* don't overwrite the QoS field of injected frames */
252 	if (info->flags & IEEE80211_TX_CTL_INJECTED) {
253 		/* do take into account Ack policy of injected frames */
254 		if (*p & IEEE80211_QOS_CTL_ACK_POLICY_NOACK)
255 			info->flags |= IEEE80211_TX_CTL_NO_ACK;
256 		return;
257 	}
258 
259 	/* set up the first byte */
260 
261 	/*
262 	 * preserve everything but the TID and ACK policy
263 	 * (which we both write here)
264 	 */
265 	flags = *p & ~(IEEE80211_QOS_CTL_TID_MASK |
266 		       IEEE80211_QOS_CTL_ACK_POLICY_MASK);
267 
268 	if (is_multicast_ether_addr(hdr->addr1) ||
269 	    sdata->noack_map & BIT(tid)) {
270 		flags |= IEEE80211_QOS_CTL_ACK_POLICY_NOACK;
271 		info->flags |= IEEE80211_TX_CTL_NO_ACK;
272 	}
273 
274 	*p = flags | tid;
275 
276 	/* set up the second byte */
277 	p++;
278 
279 	if (ieee80211_vif_is_mesh(&sdata->vif)) {
280 		/* preserve RSPI and Mesh PS Level bit */
281 		*p &= ((IEEE80211_QOS_CTL_RSPI |
282 			IEEE80211_QOS_CTL_MESH_PS_LEVEL) >> 8);
283 
284 		/* Nulls don't have a mesh header (frame body) */
285 		if (!ieee80211_is_qos_nullfunc(hdr->frame_control))
286 			*p |= (IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8);
287 	} else {
288 		*p = 0;
289 	}
290 }
291