aboutsummaryrefslogtreecommitdiff
path: root/net/wireless/reg.c
blob: 2b63c96dcf199a2e22a8c23f80ba0f240bd5f234 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

/*
 * This regulatory domain control implementation is highly incomplete, it
 * only exists for the purpose of not regressing mac80211.
 *
 * For now, drivers can restrict the set of allowed channels by either
 * not registering those channels or setting the IEEE80211_CHAN_DISABLED
 * flag; that flag will only be *set* by this code, never *cleared.
 *
 * The usual implementation is for a driver to read a device EEPROM to
 * determine which regulatory domain it should be operating under, then
 * looking up the allowable channels in a driver-local table and finally
 * registering those channels in the wiphy structure.
 *
 * Alternatively, drivers that trust the regulatory domain control here
 * will register a complete set of capabilities and the control code
 * will restrict the set by setting the IEEE80211_CHAN_* flags.
 */
#include <linux/kernel.h>
#include <net/wireless.h>
#include "core.h"

static char *ieee80211_regdom = "US";
module_param(ieee80211_regdom, charp, 0444);
MODULE_PARM_DESC(ieee80211_regdom, "IEEE 802.11 regulatory domain code");

struct ieee80211_channel_range {
	short start_freq;
	short end_freq;
	int max_power;
	int max_antenna_gain;
	u32 flags;
};

struct ieee80211_regdomain {
	const char *code;
	const struct ieee80211_channel_range *ranges;
	int n_ranges;
};

#define RANGE_PWR(_start, _end, _pwr, _ag, _flags)	\
	{ _start, _end, _pwr, _ag, _flags }


/*
 * Ideally, in the future, these definitions will be loaded from a
 * userspace table via some daemon.
 */
static const struct ieee80211_channel_range ieee80211_US_channels[] = {
	/* IEEE 802.11b/g, channels 1..11 */
	RANGE_PWR(2412, 2462, 27, 6, 0),
	/* IEEE 802.11a, channels 52..64 */
	RANGE_PWR(5260, 5320, 23, 6, 0),
	/* IEEE 802.11a, channels 149..165, outdoor */
	RANGE_PWR(5745, 5825, 30, 6, 0),
};

static const struct ieee80211_channel_range ieee80211_JP_channels[] = {
	/* IEEE 802.11b/g, channels 1..14 */
	RANGE_PWR(2412, 2484, 20, 6, 0),
	/* IEEE 802.11a, channels 34..48 */
	RANGE_PWR(5170, 5240, 20, 6, IEEE80211_CHAN_PASSIVE_SCAN),
	/* IEEE 802.11a, channels 52..64 */
	RANGE_PWR(5260, 5320, 20, 6, IEEE80211_CHAN_NO_IBSS |
				     IEEE80211_CHAN_RADAR),
};

#define REGDOM(_code)							\
	{								\
		.code = __stringify(_code),				\
		.ranges = ieee80211_ ##_code## _channels,		\
		.n_ranges = ARRAY_SIZE(ieee80211_ ##_code## _channels),	\
	}

static const struct ieee80211_regdomain ieee80211_regdoms[] = {
	REGDOM(US),
	REGDOM(JP),
};


static const struct ieee80211_regdomain *get_regdom(void)
{
	static const struct ieee80211_channel_range
	ieee80211_world_channels[] = {
		/* IEEE 802.11b/g, channels 1..11 */
		RANGE_PWR(2412, 2462, 27, 6, 0),
	};
	static const struct ieee80211_regdomain regdom_world = REGDOM(world);
	int i;

	for (i = 0; i < ARRAY_SIZE(ieee80211_regdoms); i++)
		if (strcmp(ieee80211_regdom, ieee80211_regdoms[i].code) == 0)
			return &ieee80211_regdoms[i];

	return &regdom_world;
}


static void handle_channel(struct ieee80211_channel *chan,
			   const struct ieee80211_regdomain *rd)
{
	int i;
	u32 flags = chan->orig_flags;
	const struct ieee80211_channel_range *rg = NULL;

	for (i = 0; i < rd->n_ranges; i++) {
		if (rd->ranges[i].start_freq <= chan->center_freq &&
		    chan->center_freq <= rd->ranges[i].end_freq) {
			rg = &rd->ranges[i];
			break;
		}
	}

	if (!rg) {
		/* not found */
		flags |= IEEE80211_CHAN_DISABLED;
		chan->flags = flags;
		return;
	}

	chan->flags = flags;
	chan->max_antenna_gain = min(chan->orig_mag,
					 rg->max_antenna_gain);
	chan->max_power = min(chan->orig_mpwr, rg->max_power);
}

static void handle_band(struct ieee80211_supported_band *sband,
			const struct ieee80211_regdomain *rd)
{
	int i;

	for (i = 0; i < sband->n_channels; i++)
		handle_channel(&sband->channels[i], rd);
}

void wiphy_update_regulatory(struct wiphy *wiphy)
{
	enum ieee80211_band band;
	const struct ieee80211_regdomain *rd = get_regdom();

	for (band = 0; band < IEEE80211_NUM_BANDS; band++)
		if (wiphy->bands[band])
			handle_band(wiphy->bands[band], rd);
}