net/mac80211/regdomain.c

   1 /*
   2  * Copyright 2002-2005, Instant802 Networks, Inc.
   3  * Copyright 2005-2006, Devicescape Software, Inc.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  */
   9
  10 /*
  11  * This regulatory domain control implementation is known to be incomplete
  12  * and confusing. mac80211 regulatory domain control will be significantly
  13  * reworked in the not-too-distant future.
  14  *
  15  * For now, drivers wishing to control which channels are and aren't available
  16  * are advised as follows:
  17  *  - set the IEEE80211_HW_DEFAULT_REG_DOMAIN_CONFIGURED flag
  18  *  - continue to include *ALL* possible channels in the modes registered
  19  *    through ieee80211_register_hwmode()
  20  *  - for each allowable ieee80211_channel structure registered in the above
  21  *    call, set the flag member to some meaningful value such as
  22  *    IEEE80211_CHAN_W_SCAN | IEEE80211_CHAN_W_ACTIVE_SCAN |
  23  *    IEEE80211_CHAN_W_IBSS.
  24  *  - leave flag as 0 for non-allowable channels
  25  *
  26  * The usual implementation is for a driver to read a device EEPROM to
  27  * determine which regulatory domain it should be operating under, then
  28  * looking up the allowable channels in a driver-local table, then performing
  29  * the above.
  30  */
  31
  32 #include <linux/module.h>
  33 #include <linux/netdevice.h>
  34 #include <net/mac80211.h>
  35 #include "ieee80211_i.h"
  36
  37 static int ieee80211_regdom = 0x10; /* FCC */
  38 module_param(ieee80211_regdom, int, 0444);
  39 MODULE_PARM_DESC(ieee80211_regdom, "IEEE 802.11 regulatory domain; 64=MKK");
  40
  41 /*
  42  * If firmware is upgraded by the vendor, additional channels can be used based
  43  * on the new Japanese regulatory rules. This is indicated by setting
  44  * ieee80211_japan_5ghz module parameter to one when loading the 80211 kernel
  45  * module.
  46  */
  47 static int ieee80211_japan_5ghz /* = 0 */;
  48 module_param(ieee80211_japan_5ghz, int, 0444);
  49 MODULE_PARM_DESC(ieee80211_japan_5ghz, "Vendor-updated firmware for 5 GHz");
  50
  51
  52 struct ieee80211_channel_range {
  53         short start_freq;
  54         short end_freq;
  55         unsigned char power_level;
  56         unsigned char antenna_max;
  57 };
  58
  59 static const struct ieee80211_channel_range ieee80211_fcc_channels[] = {
  60         { 2412, 2462, 27, 6 } /* IEEE 802.11b/g, channels 1..11 */,
  61         { 5180, 5240, 17, 6 } /* IEEE 802.11a, channels 36..48 */,
  62         { 5260, 5320, 23, 6 } /* IEEE 802.11a, channels 52..64 */,
  63         { 5745, 5825, 30, 6 } /* IEEE 802.11a, channels 149..165, outdoor */,
  64         { 0 }
  65 };
  66
  67 static const struct ieee80211_channel_range ieee80211_mkk_channels[] = {
  68         { 2412, 2472, 20, 6 } /* IEEE 802.11b/g, channels 1..13 */,
  69         { 5170, 5240, 20, 6 } /* IEEE 802.11a, channels 34..48 */,
  70         { 5260, 5320, 20, 6 } /* IEEE 802.11a, channels 52..64 */,
  71         { 0 }
  72 };
  73
  74
  75 static const struct ieee80211_channel_range *channel_range =
  76         ieee80211_fcc_channels;
  77
  78
  79 static void ieee80211_unmask_channel(int mode, struct ieee80211_channel *chan)
  80 {
  81         int i;
  82
  83         chan->flag = 0;
  84
  85         if (ieee80211_regdom == 64 &&
  86             (mode == MODE_ATHEROS_TURBO || mode == MODE_ATHEROS_TURBOG)) {
  87                 /* Do not allow Turbo modes in Japan. */
  88                 return;
  89         }
  90
  91         for (i = 0; channel_range[i].start_freq; i++) {
  92                 const struct ieee80211_channel_range *r = &channel_range[i];
  93                 if (r->start_freq <= chan->freq && r->end_freq >= chan->freq) {
  94                         if (ieee80211_regdom == 64 && !ieee80211_japan_5ghz &&
  95                             chan->freq >= 5260 && chan->freq <= 5320) {
  96                                 /*
  97                                  * Skip new channels in Japan since the
  98                                  * firmware was not marked having been upgraded
  99                                  * by the vendor.
 100                                  */
 101                                 continue;
 102                         }
 103
 104                         if (ieee80211_regdom == 0x10 &&
 105                             (chan->freq == 5190 || chan->freq == 5210 ||
 106                              chan->freq == 5230)) {
 107                                     /* Skip MKK channels when in FCC domain. */
 108                                     continue;
 109                         }
 110
 111                         chan->flag |= IEEE80211_CHAN_W_SCAN |
 112                                 IEEE80211_CHAN_W_ACTIVE_SCAN |
 113                                 IEEE80211_CHAN_W_IBSS;
 114                         chan->power_level = r->power_level;
 115                         chan->antenna_max = r->antenna_max;
 116
 117                         if (ieee80211_regdom == 64 &&
 118                             (chan->freq == 5170 || chan->freq == 5190 ||
 119                              chan->freq == 5210 || chan->freq == 5230)) {
 120                                 /*
 121                                  * New regulatory rules in Japan have backwards
 122                                  * compatibility with old channels in 5.15-5.25
 123                                  * GHz band, but the station is not allowed to
 124                                  * use active scan on these old channels.
 125                                  */
 126                                 chan->flag &= ~IEEE80211_CHAN_W_ACTIVE_SCAN;
 127                         }
 128
 129                         if (ieee80211_regdom == 64 &&
 130                             (chan->freq == 5260 || chan->freq == 5280 ||
 131                              chan->freq == 5300 || chan->freq == 5320)) {
 132                                 /*
 133                                  * IBSS is not allowed on 5.25-5.35 GHz band
 134                                  * due to radar detection requirements.
 135                                  */
 136                                 chan->flag &= ~IEEE80211_CHAN_W_IBSS;
 137                         }
 138
 139                         break;
 140                 }
 141         }
 142 }
 143
 144
 145 void ieee80211_set_default_regdomain(struct ieee80211_hw_mode *mode)
 146 {
 147         int c;
 148         for (c = 0; c < mode->num_channels; c++)
 149                 ieee80211_unmask_channel(mode->mode, &mode->channels[c]);
 150 }
 151
 152
 153 void ieee80211_regdomain_init(void)
 154 {
 155         if (ieee80211_regdom == 0x40)
 156                 channel_range = ieee80211_mkk_channels;
 157 }
 158