diff options
Diffstat (limited to 'net/wireless/reg.c')
| -rw-r--r-- | net/wireless/reg.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/net/wireless/reg.c b/net/wireless/reg.c new file mode 100644 index 00000000000..2b63c96dcf1 --- /dev/null +++ b/net/wireless/reg.c @@ -0,0 +1,153 @@ +/* + * 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 ®dom_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); +} |