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Johannes Bergf444de02010-05-05 15:25:02 +02001/*
2 * mac80211 - channel management
3 */
4
Johannes Berg0aaffa92010-05-05 15:28:27 +02005#include <linux/nl80211.h>
Paul Stewart3117bbdb2012-03-13 07:46:18 -07006#include <net/cfg80211.h>
Johannes Bergf444de02010-05-05 15:25:02 +02007#include "ieee80211_i.h"
8
Johannes Berg368a07d2010-05-28 14:26:23 +02009static enum ieee80211_chan_mode
Johannes Bergf444de02010-05-05 15:25:02 +020010__ieee80211_get_channel_mode(struct ieee80211_local *local,
11 struct ieee80211_sub_if_data *ignore)
12{
13 struct ieee80211_sub_if_data *sdata;
14
Johannes Berg46a5eba2010-09-15 13:28:15 +020015 lockdep_assert_held(&local->iflist_mtx);
Johannes Bergf444de02010-05-05 15:25:02 +020016
17 list_for_each_entry(sdata, &local->interfaces, list) {
18 if (sdata == ignore)
19 continue;
20
21 if (!ieee80211_sdata_running(sdata))
22 continue;
23
Johannes Berge9980e62012-01-09 13:57:36 +010024 switch (sdata->vif.type) {
25 case NL80211_IFTYPE_MONITOR:
Johannes Bergf444de02010-05-05 15:25:02 +020026 continue;
Johannes Berge9980e62012-01-09 13:57:36 +010027 case NL80211_IFTYPE_STATION:
28 if (!sdata->u.mgd.associated)
29 continue;
30 break;
31 case NL80211_IFTYPE_ADHOC:
Johannes Bergf444de02010-05-05 15:25:02 +020032 if (!sdata->u.ibss.ssid_len)
33 continue;
34 if (!sdata->u.ibss.fixed_channel)
35 return CHAN_MODE_HOPPING;
Johannes Berge9980e62012-01-09 13:57:36 +010036 break;
37 case NL80211_IFTYPE_AP_VLAN:
38 /* will also have _AP interface */
Johannes Bergf444de02010-05-05 15:25:02 +020039 continue;
Johannes Berge9980e62012-01-09 13:57:36 +010040 case NL80211_IFTYPE_AP:
41 if (!sdata->u.ap.beacon)
42 continue;
43 break;
44 default:
45 break;
46 }
Johannes Bergf444de02010-05-05 15:25:02 +020047
48 return CHAN_MODE_FIXED;
49 }
50
51 return CHAN_MODE_UNDEFINED;
52}
53
54enum ieee80211_chan_mode
55ieee80211_get_channel_mode(struct ieee80211_local *local,
56 struct ieee80211_sub_if_data *ignore)
57{
58 enum ieee80211_chan_mode mode;
59
60 mutex_lock(&local->iflist_mtx);
61 mode = __ieee80211_get_channel_mode(local, ignore);
62 mutex_unlock(&local->iflist_mtx);
63
64 return mode;
65}
Johannes Berg0aaffa92010-05-05 15:28:27 +020066
67bool ieee80211_set_channel_type(struct ieee80211_local *local,
68 struct ieee80211_sub_if_data *sdata,
69 enum nl80211_channel_type chantype)
70{
71 struct ieee80211_sub_if_data *tmp;
72 enum nl80211_channel_type superchan = NL80211_CHAN_NO_HT;
73 bool result;
74
75 mutex_lock(&local->iflist_mtx);
76
77 list_for_each_entry(tmp, &local->interfaces, list) {
78 if (tmp == sdata)
79 continue;
80
81 if (!ieee80211_sdata_running(tmp))
82 continue;
83
84 switch (tmp->vif.bss_conf.channel_type) {
85 case NL80211_CHAN_NO_HT:
86 case NL80211_CHAN_HT20:
Felix Fietkau9db372f2011-03-11 21:45:51 +010087 if (superchan > tmp->vif.bss_conf.channel_type)
88 break;
89
Johannes Berg0aaffa92010-05-05 15:28:27 +020090 superchan = tmp->vif.bss_conf.channel_type;
91 break;
92 case NL80211_CHAN_HT40PLUS:
93 WARN_ON(superchan == NL80211_CHAN_HT40MINUS);
94 superchan = NL80211_CHAN_HT40PLUS;
95 break;
96 case NL80211_CHAN_HT40MINUS:
97 WARN_ON(superchan == NL80211_CHAN_HT40PLUS);
98 superchan = NL80211_CHAN_HT40MINUS;
99 break;
100 }
101 }
102
103 switch (superchan) {
104 case NL80211_CHAN_NO_HT:
105 case NL80211_CHAN_HT20:
106 /*
107 * allow any change that doesn't go to no-HT
108 * (if it already is no-HT no change is needed)
109 */
110 if (chantype == NL80211_CHAN_NO_HT)
111 break;
112 superchan = chantype;
113 break;
114 case NL80211_CHAN_HT40PLUS:
115 case NL80211_CHAN_HT40MINUS:
116 /* allow smaller bandwidth and same */
117 if (chantype == NL80211_CHAN_NO_HT)
118 break;
119 if (chantype == NL80211_CHAN_HT20)
120 break;
121 if (superchan == chantype)
122 break;
123 result = false;
124 goto out;
125 }
126
127 local->_oper_channel_type = superchan;
128
129 if (sdata)
130 sdata->vif.bss_conf.channel_type = chantype;
131
132 result = true;
133 out:
134 mutex_unlock(&local->iflist_mtx);
135
136 return result;
137}
Paul Stewart3117bbdb2012-03-13 07:46:18 -0700138
139/*
140 * ieee80211_get_tx_channel_type returns the channel type we should
141 * use for packet transmission, given the channel capability and
142 * whatever regulatory flags we have been given.
143 */
144enum nl80211_channel_type ieee80211_get_tx_channel_type(
145 struct ieee80211_local *local,
146 enum nl80211_channel_type channel_type)
147{
148 switch (channel_type) {
149 case NL80211_CHAN_HT40PLUS:
150 if (local->hw.conf.channel->flags &
151 IEEE80211_CHAN_NO_HT40PLUS)
152 return NL80211_CHAN_HT20;
153 break;
154 case NL80211_CHAN_HT40MINUS:
155 if (local->hw.conf.channel->flags &
156 IEEE80211_CHAN_NO_HT40MINUS)
157 return NL80211_CHAN_HT20;
158 break;
159 default:
160 break;
161 }
162 return channel_type;
163}