wme.c

  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 */
 23const 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
 34static 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 */
 60static 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
 84static 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 */
117u16 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
147u16 ieee80211_select_queue(struct ieee80211_sub_if_data *sdata,
148			   struct sta_info *sta, struct sk_buff *skb)
149{
150	const struct ethhdr *eth = (void *)skb->data;
151	struct mac80211_qos_map *qos_map;
152	bool qos;
153
154	/* Ensure hash is set prior to potential SW encryption */
155	skb_get_hash(skb);
156
157	/* all mesh/ocb stations are required to support WME */
158	if ((sdata->vif.type == NL80211_IFTYPE_MESH_POINT &&
159	    !is_multicast_ether_addr(eth->h_dest)) ||
160	    (sdata->vif.type == NL80211_IFTYPE_OCB && sta))
161		qos = true;
162	else if (sta)
163		qos = sta->sta.wme;
164	else
165		qos = false;
166
167	if (!qos) {
168		skb->priority = 0; /* required for correct WPA/11i MIC */
169		return IEEE80211_AC_BE;
170	}
171
172	if (skb->protocol == sdata->control_port_protocol) {
173		skb->priority = 7;
174		goto downgrade;
175	}
176
177	/* use the data classifier to determine what 802.1d tag the
178	 * data frame has */
179	qos_map = rcu_dereference(sdata->qos_map);
180	skb->priority = cfg80211_classify8021d(skb, qos_map ?
181					       &qos_map->qos_map : NULL);
182
183 downgrade:
184	return ieee80211_downgrade_queue(sdata, sta, skb);
185}
186
187/**
188 * ieee80211_set_qos_hdr - Fill in the QoS header if there is one.
189 *
190 * @sdata: local subif
191 * @skb: packet to be updated
192 */
193void ieee80211_set_qos_hdr(struct ieee80211_sub_if_data *sdata,
194			   struct sk_buff *skb)
195{
196	struct ieee80211_hdr *hdr = (void *)skb->data;
197	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
198	u8 tid = skb->priority & IEEE80211_QOS_CTL_TAG1D_MASK;
199	u8 flags;
200	u8 *p;
201
202	if (!ieee80211_is_data_qos(hdr->frame_control))
203		return;
204
205	p = ieee80211_get_qos_ctl(hdr);
206
207	/* don't overwrite the QoS field of injected frames */
208	if (info->flags & IEEE80211_TX_CTL_INJECTED) {
209		/* do take into account Ack policy of injected frames */
210		if (*p & IEEE80211_QOS_CTL_ACK_POLICY_NOACK)
211			info->flags |= IEEE80211_TX_CTL_NO_ACK;
212		return;
213	}
214
215	/* set up the first byte */
216
217	/*
218	 * preserve everything but the TID and ACK policy
219	 * (which we both write here)
220	 */
221	flags = *p & ~(IEEE80211_QOS_CTL_TID_MASK |
222		       IEEE80211_QOS_CTL_ACK_POLICY_MASK);
223
224	if (is_multicast_ether_addr(hdr->addr1) ||
225	    sdata->noack_map & BIT(tid)) {
226		flags |= IEEE80211_QOS_CTL_ACK_POLICY_NOACK;
227		info->flags |= IEEE80211_TX_CTL_NO_ACK;
228	}
229
230	*p = flags | tid;
231
232	/* set up the second byte */
233	p++;
234
235	if (ieee80211_vif_is_mesh(&sdata->vif)) {
236		/* preserve RSPI and Mesh PS Level bit */
237		*p &= ((IEEE80211_QOS_CTL_RSPI |
238			IEEE80211_QOS_CTL_MESH_PS_LEVEL) >> 8);
239
240		/* Nulls don't have a mesh header (frame body) */
241		if (!ieee80211_is_qos_nullfunc(hdr->frame_control))
242			*p |= (IEEE80211_QOS_CTL_MESH_CONTROL_PRESENT >> 8);
243	} else {
244		*p = 0;
245	}
246}