Commit | Line | Data |
---|---|---|
59bbb6f7 JB |
1 | /* |
2 | * This file contains helper code to handle channel | |
3 | * settings and keeping track of what is possible at | |
4 | * any point in time. | |
5 | * | |
6 | * Copyright 2009 Johannes Berg <johannes@sipsolutions.net> | |
7 | */ | |
8 | ||
9 | #include <net/cfg80211.h> | |
10 | #include "core.h" | |
11 | ||
9588bbd5 JM |
12 | struct ieee80211_channel * |
13 | rdev_freq_to_chan(struct cfg80211_registered_device *rdev, | |
59bbb6f7 JB |
14 | int freq, enum nl80211_channel_type channel_type) |
15 | { | |
16 | struct ieee80211_channel *chan; | |
17 | struct ieee80211_sta_ht_cap *ht_cap; | |
59bbb6f7 JB |
18 | |
19 | chan = ieee80211_get_channel(&rdev->wiphy, freq); | |
20 | ||
21 | /* Primary channel not allowed */ | |
22 | if (!chan || chan->flags & IEEE80211_CHAN_DISABLED) | |
9588bbd5 | 23 | return NULL; |
59bbb6f7 JB |
24 | |
25 | if (channel_type == NL80211_CHAN_HT40MINUS && | |
26 | chan->flags & IEEE80211_CHAN_NO_HT40MINUS) | |
9588bbd5 | 27 | return NULL; |
59bbb6f7 JB |
28 | else if (channel_type == NL80211_CHAN_HT40PLUS && |
29 | chan->flags & IEEE80211_CHAN_NO_HT40PLUS) | |
9588bbd5 | 30 | return NULL; |
59bbb6f7 JB |
31 | |
32 | ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap; | |
33 | ||
34 | if (channel_type != NL80211_CHAN_NO_HT) { | |
35 | if (!ht_cap->ht_supported) | |
9588bbd5 | 36 | return NULL; |
59bbb6f7 | 37 | |
aed8e1f9 HS |
38 | if (channel_type != NL80211_CHAN_HT20 && |
39 | (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) || | |
40 | ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)) | |
9588bbd5 | 41 | return NULL; |
59bbb6f7 JB |
42 | } |
43 | ||
9588bbd5 JM |
44 | return chan; |
45 | } | |
46 | ||
9236d838 LR |
47 | static bool can_beacon_sec_chan(struct wiphy *wiphy, |
48 | struct ieee80211_channel *chan, | |
49 | enum nl80211_channel_type channel_type) | |
50 | { | |
51 | struct ieee80211_channel *sec_chan; | |
52 | int diff; | |
53 | ||
54 | switch (channel_type) { | |
55 | case NL80211_CHAN_HT40PLUS: | |
56 | diff = 20; | |
09a02fdb | 57 | break; |
9236d838 LR |
58 | case NL80211_CHAN_HT40MINUS: |
59 | diff = -20; | |
09a02fdb | 60 | break; |
9236d838 LR |
61 | default: |
62 | return false; | |
63 | } | |
64 | ||
65 | sec_chan = ieee80211_get_channel(wiphy, chan->center_freq + diff); | |
66 | if (!sec_chan) | |
67 | return false; | |
68 | ||
69 | /* we'll need a DFS capability later */ | |
70 | if (sec_chan->flags & (IEEE80211_CHAN_DISABLED | | |
71 | IEEE80211_CHAN_PASSIVE_SCAN | | |
72 | IEEE80211_CHAN_NO_IBSS | | |
73 | IEEE80211_CHAN_RADAR)) | |
74 | return false; | |
75 | ||
76 | return true; | |
77 | } | |
78 | ||
f444de05 JB |
79 | int cfg80211_set_freq(struct cfg80211_registered_device *rdev, |
80 | struct wireless_dev *wdev, int freq, | |
81 | enum nl80211_channel_type channel_type) | |
9588bbd5 JM |
82 | { |
83 | struct ieee80211_channel *chan; | |
84 | int result; | |
85 | ||
9fbc630c | 86 | if (wdev && wdev->iftype == NL80211_IFTYPE_MONITOR) |
f444de05 JB |
87 | wdev = NULL; |
88 | ||
89 | if (wdev) { | |
90 | ASSERT_WDEV_LOCK(wdev); | |
91 | ||
92 | if (!netif_running(wdev->netdev)) | |
93 | return -ENETDOWN; | |
94 | } | |
9588bbd5 JM |
95 | |
96 | if (!rdev->ops->set_channel) | |
97 | return -EOPNOTSUPP; | |
98 | ||
99 | chan = rdev_freq_to_chan(rdev, freq, channel_type); | |
100 | if (!chan) | |
101 | return -EINVAL; | |
102 | ||
9236d838 LR |
103 | /* Both channels should be able to initiate communication */ |
104 | if (wdev && (wdev->iftype == NL80211_IFTYPE_ADHOC || | |
105 | wdev->iftype == NL80211_IFTYPE_AP || | |
106 | wdev->iftype == NL80211_IFTYPE_AP_VLAN || | |
107 | wdev->iftype == NL80211_IFTYPE_MESH_POINT || | |
108 | wdev->iftype == NL80211_IFTYPE_P2P_GO)) { | |
109 | switch (channel_type) { | |
110 | case NL80211_CHAN_HT40PLUS: | |
111 | case NL80211_CHAN_HT40MINUS: | |
112 | if (!can_beacon_sec_chan(&rdev->wiphy, chan, | |
113 | channel_type)) { | |
114 | printk(KERN_DEBUG | |
115 | "cfg80211: Secondary channel not " | |
116 | "allowed to initiate communication\n"); | |
117 | return -EINVAL; | |
118 | } | |
119 | break; | |
120 | default: | |
121 | break; | |
122 | } | |
123 | } | |
124 | ||
f444de05 JB |
125 | result = rdev->ops->set_channel(&rdev->wiphy, |
126 | wdev ? wdev->netdev : NULL, | |
127 | chan, channel_type); | |
59bbb6f7 JB |
128 | if (result) |
129 | return result; | |
130 | ||
f444de05 JB |
131 | if (wdev) |
132 | wdev->channel = chan; | |
59bbb6f7 JB |
133 | |
134 | return 0; | |
135 | } |