diff options
Diffstat (limited to 'net/wireless')
| -rw-r--r-- | net/wireless/reg.c | 128 |
1 files changed, 117 insertions, 11 deletions
diff --git a/net/wireless/reg.c b/net/wireless/reg.c index 4f877535e66..bc494cef210 100644 --- a/net/wireless/reg.c +++ b/net/wireless/reg.c @@ -421,6 +421,31 @@ static u32 freq_max_bandwidth(const struct ieee80211_freq_range *freq_range, return 0; } +/** + * freq_in_rule_band - tells us if a frequency is in a frequency band + * @freq_range: frequency rule we want to query + * @freq_khz: frequency we are inquiring about + * + * This lets us know if a specific frequency rule is or is not relevant to + * a specific frequency's band. Bands are device specific and artificial + * definitions (the "2.4 GHz band" and the "5 GHz band"), however it is + * safe for now to assume that a frequency rule should not be part of a + * frequency's band if the start freq or end freq are off by more than 2 GHz. + * This resolution can be lowered and should be considered as we add + * regulatory rule support for other "bands". + **/ +static bool freq_in_rule_band(const struct ieee80211_freq_range *freq_range, + u32 freq_khz) +{ +#define ONE_GHZ_IN_KHZ 1000000 + if (abs(freq_khz - freq_range->start_freq_khz) <= (2 * ONE_GHZ_IN_KHZ)) + return true; + if (abs(freq_khz - freq_range->end_freq_khz) <= (2 * ONE_GHZ_IN_KHZ)) + return true; + return false; +#undef ONE_GHZ_IN_KHZ +} + /* Converts a country IE to a regulatory domain. A regulatory domain * structure has a lot of information which the IE doesn't yet have, * so for the other values we use upper max values as we will intersect @@ -538,6 +563,7 @@ static struct ieee80211_regdomain *country_ie_2_rd( /* This time around we fill in the rd */ while (country_ie_len >= 3) { + int end_channel = 0; struct ieee80211_country_ie_triplet *triplet = (struct ieee80211_country_ie_triplet *) country_ie; struct ieee80211_reg_rule *reg_rule = NULL; @@ -559,6 +585,23 @@ static struct ieee80211_regdomain *country_ie_2_rd( reg_rule->flags = flags; + /* 2 GHz */ + if (triplet->chans.first_channel <= 14) + end_channel = triplet->chans.first_channel + + triplet->chans.num_channels; + else + /* + * 5 GHz -- For example in country IEs if the first + * channel given is 36 and the number of channels is 4 + * then the individual channel numbers defined for the + * 5 GHz PHY by these parameters are: 36, 40, 44, and 48 + * and not 36, 37, 38, 39. + * + * See: http://tinyurl.com/11d-clarification + */ + end_channel = triplet->chans.first_channel + + (4 * (triplet->chans.num_channels - 1)); + /* The +10 is since the regulatory domain expects * the actual band edge, not the center of freq for * its start and end freqs, assuming 20 MHz bandwidth on @@ -568,8 +611,7 @@ static struct ieee80211_regdomain *country_ie_2_rd( triplet->chans.first_channel) - 10); freq_range->end_freq_khz = MHZ_TO_KHZ(ieee80211_channel_to_frequency( - triplet->chans.first_channel + - triplet->chans.num_channels) + 10); + end_channel) + 10); /* Large arbitrary values, we intersect later */ /* Increment this if we ever support >= 40 MHz channels @@ -748,12 +790,23 @@ static u32 map_regdom_flags(u32 rd_flags) * this value to the maximum allowed bandwidth. * @reg_rule: the regulatory rule which we have for this frequency * - * Use this function to get the regulatory rule for a specific frequency. + * Use this function to get the regulatory rule for a specific frequency on + * a given wireless device. If the device has a specific regulatory domain + * it wants to follow we respect that unless a country IE has been received + * and processed already. + * + * Returns 0 if it was able to find a valid regulatory rule which does + * apply to the given center_freq otherwise it returns non-zero. It will + * also return -ERANGE if we determine the given center_freq does not even have + * a regulatory rule for a frequency range in the center_freq's band. See + * freq_in_rule_band() for our current definition of a band -- this is purely + * subjective and right now its 802.11 specific. */ static int freq_reg_info(u32 center_freq, u32 *bandwidth, const struct ieee80211_reg_rule **reg_rule) { int i; + bool band_rule_found = false; u32 max_bandwidth = 0; if (!cfg80211_regdomain) @@ -767,7 +820,15 @@ static int freq_reg_info(u32 center_freq, u32 *bandwidth, rr = &cfg80211_regdomain->reg_rules[i]; fr = &rr->freq_range; pr = &rr->power_rule; + + /* We only need to know if one frequency rule was + * was in center_freq's band, that's enough, so lets + * not overwrite it once found */ + if (!band_rule_found) + band_rule_found = freq_in_rule_band(fr, center_freq); + max_bandwidth = freq_max_bandwidth(fr, center_freq); + if (max_bandwidth && *bandwidth <= max_bandwidth) { *reg_rule = rr; *bandwidth = max_bandwidth; @@ -775,23 +836,64 @@ static int freq_reg_info(u32 center_freq, u32 *bandwidth, } } + if (!band_rule_found) + return -ERANGE; + return !max_bandwidth; } -static void handle_channel(struct ieee80211_channel *chan) +static void handle_channel(struct wiphy *wiphy, enum ieee80211_band band, + unsigned int chan_idx) { int r; - u32 flags = chan->orig_flags; + u32 flags; u32 max_bandwidth = 0; const struct ieee80211_reg_rule *reg_rule = NULL; const struct ieee80211_power_rule *power_rule = NULL; + struct ieee80211_supported_band *sband; + struct ieee80211_channel *chan; + + sband = wiphy->bands[band]; + BUG_ON(chan_idx >= sband->n_channels); + chan = &sband->channels[chan_idx]; + + flags = chan->orig_flags; r = freq_reg_info(MHZ_TO_KHZ(chan->center_freq), &max_bandwidth, ®_rule); if (r) { - flags |= IEEE80211_CHAN_DISABLED; - chan->flags = flags; + /* This means no regulatory rule was found in the country IE + * with a frequency range on the center_freq's band, since + * IEEE-802.11 allows for a country IE to have a subset of the + * regulatory information provided in a country we ignore + * disabling the channel unless at least one reg rule was + * found on the center_freq's band. For details see this + * clarification: + * + * http://tinyurl.com/11d-clarification + */ + if (r == -ERANGE && + last_request->initiator == REGDOM_SET_BY_COUNTRY_IE) { +#ifdef CONFIG_CFG80211_REG_DEBUG + printk(KERN_DEBUG "cfg80211: Leaving channel %d MHz " + "intact on %s - no rule found in band on " + "Country IE\n", + chan->center_freq, wiphy_name(wiphy)); +#endif + } else { + /* In this case we know the country IE has at least one reg rule + * for the band so we respect its band definitions */ +#ifdef CONFIG_CFG80211_REG_DEBUG + if (last_request->initiator == REGDOM_SET_BY_COUNTRY_IE) + printk(KERN_DEBUG "cfg80211: Disabling " + "channel %d MHz on %s due to " + "Country IE\n", + chan->center_freq, wiphy_name(wiphy)); +#endif + flags |= IEEE80211_CHAN_DISABLED; + chan->flags = flags; + } return; } @@ -808,12 +910,16 @@ static void handle_channel(struct ieee80211_channel *chan) chan->max_power = (int) MBM_TO_DBM(power_rule->max_eirp); } -static void handle_band(struct ieee80211_supported_band *sband) +static void handle_band(struct wiphy *wiphy, enum ieee80211_band band) { - int i; + unsigned int i; + struct ieee80211_supported_band *sband; + + BUG_ON(!wiphy->bands[band]); + sband = wiphy->bands[band]; for (i = 0; i < sband->n_channels; i++) - handle_channel(&sband->channels[i]); + handle_channel(wiphy, band, i); } static bool ignore_reg_update(struct wiphy *wiphy, enum reg_set_by setby) @@ -840,7 +946,7 @@ void wiphy_update_regulatory(struct wiphy *wiphy, enum reg_set_by setby) enum ieee80211_band band; for (band = 0; band < IEEE80211_NUM_BANDS; band++) { if (wiphy->bands[band]) - handle_band(wiphy->bands[band]); + handle_band(wiphy, band); if (wiphy->reg_notifier) wiphy->reg_notifier(wiphy, setby); } |