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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 
wme_downgrade_ac(struct sk_buff * skb)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  */
ieee80211_fix_reserved_tid(u8 tid)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 
ieee80211_downgrade_queue(struct ieee80211_sub_if_data * sdata,struct sta_info * sta,struct sk_buff * skb)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 */
ieee80211_select_queue_80211(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb,struct ieee80211_hdr * hdr)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 	u8 *p;
122 
123 	if (local->hw.queues < IEEE80211_NUM_ACS)
124 		return 0;
125 
126 	if (!ieee80211_is_data(hdr->frame_control)) {
127 		skb->priority = 7;
128 		return ieee802_1d_to_ac[skb->priority];
129 	}
130 	if (!ieee80211_is_data_qos(hdr->frame_control)) {
131 		skb->priority = 0;
132 		return ieee802_1d_to_ac[skb->priority];
133 	}
134 
135 	p = ieee80211_get_qos_ctl(hdr);
136 	skb->priority = *p & IEEE80211_QOS_CTL_TAG1D_MASK;
137 
138 	return ieee80211_downgrade_queue(sdata, NULL, skb);
139 }
140 
__ieee80211_select_queue(struct ieee80211_sub_if_data * sdata,struct sta_info * sta,struct sk_buff * skb)141 u16 __ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
142 			     struct sta_info *sta, struct sk_buff *skb)
143 {
144 	const struct ethhdr *eth = (void *)skb->data;
145 	struct mac80211_qos_map *qos_map;
146 	bool qos;
147 
148 	/* all mesh/ocb stations are required to support WME */
149 	if ((sdata->vif.type == NL80211_IFTYPE_MESH_POINT &&
150 	    !is_multicast_ether_addr(eth->h_dest)) ||
151 	    (sdata->vif.type == NL80211_IFTYPE_OCB && sta))
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. */
ieee80211_select_queue(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)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 		/* fall through */
204 	case NL80211_IFTYPE_AP:
205 		ra = skb->data;
206 		break;
207 	case NL80211_IFTYPE_WDS:
208 		ra = sdata->u.wds.remote_addr;
209 		break;
210 	case NL80211_IFTYPE_STATION:
211 		/* might be a TDLS station */
212 		sta = sta_info_get(sdata, skb->data);
213 		if (sta)
214 			break;
215 
216 		ra = sdata->u.mgd.bssid;
217 		break;
218 	case NL80211_IFTYPE_ADHOC:
219 		ra = skb->data;
220 		break;
221 	default:
222 		break;
223 	}
224 
225 	if (!sta && ra && !is_multicast_ether_addr(ra))
226 		sta = sta_info_get(sdata, ra);
227 
228 	ret = __ieee80211_select_queue(sdata, sta, skb);
229 
230 	rcu_read_unlock();
231 	return ret;
232 }
233 
234 /**
235  * ieee80211_set_qos_hdr - Fill in the QoS header if there is one.
236  *
237  * @sdata: local subif
238  * @skb: packet to be updated
239  */
ieee80211_set_qos_hdr(struct ieee80211_sub_if_data * sdata,struct sk_buff * skb)240 void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata,
241 			   struct sk_buff *skb)
242 {
243 	struct ieee80211_hdr *hdr = (void *)skb->data;
244 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
245 	u8 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
246 	u8 flags;
247 	u8 *p;
248 
249 	if (!ieee80211_is_data_qos(hdr->frame_control))
250 		return;
251 
252 	p = ieee80211_get_qos_ctl(hdr);
253 
254 	/* set up the first byte */
255 
256 	/*
257 	 * preserve everything but the TID and ACK policy
258 	 * (which we both write here)
259 	 */
260 	flags = *p & ~(IEEE80211_QOS_CTL_TID_MASK |
261 		       IEEE80211_QOS_CTL_ACK_POLICY_MASK);
262 
263 	if (is_multicast_ether_addr(hdr->addr1) ||
264 	    sdata->noack_map & BIT(tid)) {
265 		flags |= IEEE80211_QOS_CTL_ACK_POLICY_NOACK;
266 		info->flags |= IEEE80211_TX_CTL_NO_ACK;
267 	}
268 
269 	*p = flags | tid;
270 
271 	/* set up the second byte */
272 	p++;
273 
274 	if (ieee80211_vif_is_mesh(&sdata->vif)) {
275 		/* preserve RSPI and Mesh PS Level bit */
276 		*p &= ((IEEE80211_QOS_CTL_RSPI |
277 			IEEE80211_QOS_CTL_MESH_PS_LEVEL) >> 8);
278 
279 		/* Nulls don't have a mesh header (frame body) */
280 		if (!ieee80211_is_qos_nullfunc(hdr->frame_control))
281 			*p |= (IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8);
282 	} else {
283 		*p = 0;
284 	}
285 }
286