xref: /openbmc/linux/net/mac80211/wme.c (revision 2640a82b)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2004, Instant802 Networks, Inc.
4  * Copyright 2013-2014  Intel Mobile Communications GmbH
5  * Copyright (C) 2022 Intel Corporation
6  */
7 
8 #include <linux/netdevice.h>
9 #include <linux/skbuff.h>
10 #include <linux/module.h>
11 #include <linux/if_arp.h>
12 #include <linux/types.h>
13 #include <net/ip.h>
14 #include <net/pkt_sched.h>
15 
16 #include <net/mac80211.h>
17 #include "ieee80211_i.h"
18 #include "wme.h"
19 
20 /* Default mapping in classifier to work with default
21  * queue setup.
22  */
23 const int ieee802_1d_to_ac[8] = {
24 	IEEE80211_AC_BE,
25 	IEEE80211_AC_BK,
26 	IEEE80211_AC_BK,
27 	IEEE80211_AC_BE,
28 	IEEE80211_AC_VI,
29 	IEEE80211_AC_VI,
30 	IEEE80211_AC_VO,
31 	IEEE80211_AC_VO
32 };
33 
34 static int wme_downgrade_ac(struct sk_buff *skb)
35 {
36 	switch (skb->priority) {
37 	case 6:
38 	case 7:
39 		skb->priority = 5; /* VO -> VI */
40 		return 0;
41 	case 4:
42 	case 5:
43 		skb->priority = 3; /* VI -> BE */
44 		return 0;
45 	case 0:
46 	case 3:
47 		skb->priority = 2; /* BE -> BK */
48 		return 0;
49 	default:
50 		return -1;
51 	}
52 }
53 
54 /**
55  * ieee80211_fix_reserved_tid - return the TID to use if this one is reserved
56  * @tid: the assumed-reserved TID
57  *
58  * Returns: the alternative TID to use, or 0 on error
59  */
60 static inline u8 ieee80211_fix_reserved_tid(u8 tid)
61 {
62 	switch (tid) {
63 	case 0:
64 		return 3;
65 	case 1:
66 		return 2;
67 	case 2:
68 		return 1;
69 	case 3:
70 		return 0;
71 	case 4:
72 		return 5;
73 	case 5:
74 		return 4;
75 	case 6:
76 		return 7;
77 	case 7:
78 		return 6;
79 	}
80 
81 	return 0;
82 }
83 
84 static u16 ieee80211_downgrade_queue(struct ieee80211_sub_if_data *sdata,
85 				     struct sta_info *sta, struct sk_buff *skb)
86 {
87 	struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
88 
89 	/* in case we are a client verify acm is not set for this ac */
90 	while (sdata->wmm_acm & BIT(skb->priority)) {
91 		int ac = ieee802_1d_to_ac[skb->priority];
92 
93 		if (ifmgd->tx_tspec[ac].admitted_time &&
94 		    skb->priority == ifmgd->tx_tspec[ac].up)
95 			return ac;
96 
97 		if (wme_downgrade_ac(skb)) {
98 			/*
99 			 * This should not really happen. The AP has marked all
100 			 * lower ACs to require admission control which is not
101 			 * a reasonable configuration. Allow the frame to be
102 			 * transmitted using AC_BK as a workaround.
103 			 */
104 			break;
105 		}
106 	}
107 
108 	/* Check to see if this is a reserved TID */
109 	if (sta && sta->reserved_tid == skb->priority)
110 		skb->priority = ieee80211_fix_reserved_tid(skb->priority);
111 
112 	/* look up which queue to use for frames with this 1d tag */
113 	return ieee802_1d_to_ac[skb->priority];
114 }
115 
116 /* Indicate which queue to use for this fully formed 802.11 frame */
117 u16 ieee80211_select_queue_80211(struct ieee80211_sub_if_data *sdata,
118 				 struct sk_buff *skb,
119 				 struct ieee80211_hdr *hdr)
120 {
121 	struct ieee80211_local *local = sdata->local;
122 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
123 	u8 *p;
124 
125 	/* Ensure hash is set prior to potential SW encryption */
126 	skb_get_hash(skb);
127 
128 	if ((info->control.flags & IEEE80211_TX_CTRL_DONT_REORDER) ||
129 	    local->hw.queues < IEEE80211_NUM_ACS)
130 		return 0;
131 
132 	if (!ieee80211_is_data(hdr->frame_control)) {
133 		skb->priority = 7;
134 		return ieee802_1d_to_ac[skb->priority];
135 	}
136 	if (!ieee80211_is_data_qos(hdr->frame_control)) {
137 		skb->priority = 0;
138 		return ieee802_1d_to_ac[skb->priority];
139 	}
140 
141 	p = ieee80211_get_qos_ctl(hdr);
142 	skb->priority = *p & IEEE80211_QOS_CTL_TAG1D_MASK;
143 
144 	return ieee80211_downgrade_queue(sdata, NULL, skb);
145 }
146 
147 u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
148 			   struct sta_info *sta, struct sk_buff *skb)
149 {
150 	struct mac80211_qos_map *qos_map;
151 	bool qos;
152 
153 	/* Ensure hash is set prior to potential SW encryption */
154 	skb_get_hash(skb);
155 
156 	/* all mesh/ocb stations are required to support WME */
157 	if (sta && (sdata->vif.type == NL80211_IFTYPE_MESH_POINT ||
158 		    sdata->vif.type == NL80211_IFTYPE_OCB))
159 		qos = true;
160 	else if (sta)
161 		qos = sta->sta.wme;
162 	else
163 		qos = false;
164 
165 	if (!qos) {
166 		skb->priority = 0; /* required for correct WPA/11i MIC */
167 		return IEEE80211_AC_BE;
168 	}
169 
170 	if (skb->protocol == sdata->control_port_protocol) {
171 		skb->priority = 7;
172 		goto downgrade;
173 	}
174 
175 	/* use the data classifier to determine what 802.1d tag the
176 	 * data frame has */
177 	qos_map = rcu_dereference(sdata->qos_map);
178 	skb->priority = cfg80211_classify8021d(skb, qos_map ?
179 					       &qos_map->qos_map : NULL);
180 
181  downgrade:
182 	return ieee80211_downgrade_queue(sdata, sta, skb);
183 }
184 
185 /**
186  * ieee80211_set_qos_hdr - Fill in the QoS header if there is one.
187  *
188  * @sdata: local subif
189  * @skb: packet to be updated
190  */
191 void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata,
192 			   struct sk_buff *skb)
193 {
194 	struct ieee80211_hdr *hdr = (void *)skb->data;
195 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
196 	u8 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
197 	u8 flags;
198 	u8 *p;
199 
200 	if (!ieee80211_is_data_qos(hdr->frame_control))
201 		return;
202 
203 	p = ieee80211_get_qos_ctl(hdr);
204 
205 	/* don't overwrite the QoS field of injected frames */
206 	if (info->flags & IEEE80211_TX_CTL_INJECTED) {
207 		/* do take into account Ack policy of injected frames */
208 		if (*p & IEEE80211_QOS_CTL_ACK_POLICY_NOACK)
209 			info->flags |= IEEE80211_TX_CTL_NO_ACK;
210 		return;
211 	}
212 
213 	/* set up the first byte */
214 
215 	/*
216 	 * preserve everything but the TID and ACK policy
217 	 * (which we both write here)
218 	 */
219 	flags = *p & ~(IEEE80211_QOS_CTL_TID_MASK |
220 		       IEEE80211_QOS_CTL_ACK_POLICY_MASK);
221 
222 	if (is_multicast_ether_addr(hdr->addr1) ||
223 	    sdata->noack_map & BIT(tid)) {
224 		flags |= IEEE80211_QOS_CTL_ACK_POLICY_NOACK;
225 		info->flags |= IEEE80211_TX_CTL_NO_ACK;
226 	}
227 
228 	*p = flags | tid;
229 
230 	/* set up the second byte */
231 	p++;
232 
233 	if (ieee80211_vif_is_mesh(&sdata->vif)) {
234 		/* preserve RSPI and Mesh PS Level bit */
235 		*p &= ((IEEE80211_QOS_CTL_RSPI |
236 			IEEE80211_QOS_CTL_MESH_PS_LEVEL) >> 8);
237 
238 		/* Nulls don't have a mesh header (frame body) */
239 		if (!ieee80211_is_qos_nullfunc(hdr->frame_control))
240 			*p |= (IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8);
241 	} else {
242 		*p = 0;
243 	}
244 }
245