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-rw-r--r--net/wireless/reg.c128
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, &reg_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);
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-21 05:32:55 +0000