1 /* 2 * Copyright 2002-2005, Instant802 Networks, Inc. 3 * Copyright 2005-2006, Devicescape Software, Inc. 4 * Copyright 2007 Johannes Berg <johannes@sipsolutions.net> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 11 /* 12 * This regulatory domain control implementation is highly incomplete, it 13 * only exists for the purpose of not regressing mac80211. 14 * 15 * For now, drivers can restrict the set of allowed channels by either 16 * not registering those channels or setting the IEEE80211_CHAN_DISABLED 17 * flag; that flag will only be *set* by this code, never *cleared. 18 * 19 * The usual implementation is for a driver to read a device EEPROM to 20 * determine which regulatory domain it should be operating under, then 21 * looking up the allowable channels in a driver-local table and finally 22 * registering those channels in the wiphy structure. 23 * 24 * Alternatively, drivers that trust the regulatory domain control here 25 * will register a complete set of capabilities and the control code 26 * will restrict the set by setting the IEEE80211_CHAN_* flags. 27 */ 28 #include <linux/kernel.h> 29 #include <net/wireless.h> 30 #include "core.h" 31 32 static char *ieee80211_regdom = "US"; 33 module_param(ieee80211_regdom, charp, 0444); 34 MODULE_PARM_DESC(ieee80211_regdom, "IEEE 802.11 regulatory domain code"); 35 36 struct ieee80211_channel_range { 37 short start_freq; 38 short end_freq; 39 int max_power; 40 int max_antenna_gain; 41 u32 flags; 42 }; 43 44 struct ieee80211_regdomain { 45 const char *code; 46 const struct ieee80211_channel_range *ranges; 47 int n_ranges; 48 }; 49 50 #define RANGE_PWR(_start, _end, _pwr, _ag, _flags) \ 51 { _start, _end, _pwr, _ag, _flags } 52 53 54 /* 55 * Ideally, in the future, these definitions will be loaded from a 56 * userspace table via some daemon. 57 */ 58 static const struct ieee80211_channel_range ieee80211_US_channels[] = { 59 /* IEEE 802.11b/g, channels 1..11 */ 60 RANGE_PWR(2412, 2462, 27, 6, 0), 61 /* IEEE 802.11a, channel 36*/ 62 RANGE_PWR(5180, 5180, 23, 6, 0), 63 /* IEEE 802.11a, channel 40*/ 64 RANGE_PWR(5200, 5200, 23, 6, 0), 65 /* IEEE 802.11a, channel 44*/ 66 RANGE_PWR(5220, 5220, 23, 6, 0), 67 /* IEEE 802.11a, channels 48..64 */ 68 RANGE_PWR(5240, 5320, 23, 6, 0), 69 /* IEEE 802.11a, channels 149..165, outdoor */ 70 RANGE_PWR(5745, 5825, 30, 6, 0), 71 }; 72 73 static const struct ieee80211_channel_range ieee80211_JP_channels[] = { 74 /* IEEE 802.11b/g, channels 1..14 */ 75 RANGE_PWR(2412, 2484, 20, 6, 0), 76 /* IEEE 802.11a, channels 34..48 */ 77 RANGE_PWR(5170, 5240, 20, 6, IEEE80211_CHAN_PASSIVE_SCAN), 78 /* IEEE 802.11a, channels 52..64 */ 79 RANGE_PWR(5260, 5320, 20, 6, IEEE80211_CHAN_NO_IBSS | 80 IEEE80211_CHAN_RADAR), 81 }; 82 83 #define REGDOM(_code) \ 84 { \ 85 .code = __stringify(_code), \ 86 .ranges = ieee80211_ ##_code## _channels, \ 87 .n_ranges = ARRAY_SIZE(ieee80211_ ##_code## _channels), \ 88 } 89 90 static const struct ieee80211_regdomain ieee80211_regdoms[] = { 91 REGDOM(US), 92 REGDOM(JP), 93 }; 94 95 96 static const struct ieee80211_regdomain *get_regdom(void) 97 { 98 static const struct ieee80211_channel_range 99 ieee80211_world_channels[] = { 100 /* IEEE 802.11b/g, channels 1..11 */ 101 RANGE_PWR(2412, 2462, 27, 6, 0), 102 }; 103 static const struct ieee80211_regdomain regdom_world = REGDOM(world); 104 int i; 105 106 for (i = 0; i < ARRAY_SIZE(ieee80211_regdoms); i++) 107 if (strcmp(ieee80211_regdom, ieee80211_regdoms[i].code) == 0) 108 return &ieee80211_regdoms[i]; 109 110 return ®dom_world; 111 } 112 113 114 static void handle_channel(struct ieee80211_channel *chan, 115 const struct ieee80211_regdomain *rd) 116 { 117 int i; 118 u32 flags = chan->orig_flags; 119 const struct ieee80211_channel_range *rg = NULL; 120 121 for (i = 0; i < rd->n_ranges; i++) { 122 if (rd->ranges[i].start_freq <= chan->center_freq && 123 chan->center_freq <= rd->ranges[i].end_freq) { 124 rg = &rd->ranges[i]; 125 break; 126 } 127 } 128 129 if (!rg) { 130 /* not found */ 131 flags |= IEEE80211_CHAN_DISABLED; 132 chan->flags = flags; 133 return; 134 } 135 136 chan->flags = flags; 137 chan->max_antenna_gain = min(chan->orig_mag, 138 rg->max_antenna_gain); 139 if (chan->orig_mpwr) 140 chan->max_power = min(chan->orig_mpwr, rg->max_power); 141 else 142 chan->max_power = rg->max_power; 143 } 144 145 static void handle_band(struct ieee80211_supported_band *sband, 146 const struct ieee80211_regdomain *rd) 147 { 148 int i; 149 150 for (i = 0; i < sband->n_channels; i++) 151 handle_channel(&sband->channels[i], rd); 152 } 153 154 void wiphy_update_regulatory(struct wiphy *wiphy) 155 { 156 enum ieee80211_band band; 157 const struct ieee80211_regdomain *rd = get_regdom(); 158 159 for (band = 0; band < IEEE80211_NUM_BANDS; band++) 160 if (wiphy->bands[band]) 161 handle_band(wiphy->bands[band], rd); 162 } 163