summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--net/wireless/reg.c225
1 files changed, 221 insertions, 4 deletions
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 77d0bb6f6e7a..a5c2d3a6cbb2 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -485,6 +485,178 @@ static bool freq_in_rule_band(const struct ieee80211_freq_range *freq_range,
}
/*
+ * Some APs may send a country IE triplet for each channel they
+ * support and while this is completely overkill and silly we still
+ * need to support it. We avoid making a single rule for each channel
+ * though and to help us with this we use this helper to find the
+ * actual subband end channel. These type of country IE triplet
+ * scenerios are handled then, all yielding two regulaotry rules from
+ * parsing a country IE:
+ *
+ * [1]
+ * [2]
+ * [36]
+ * [40]
+ *
+ * [1]
+ * [2-4]
+ * [5-12]
+ * [36]
+ * [40-44]
+ *
+ * [1-4]
+ * [5-7]
+ * [36-44]
+ * [48-64]
+ *
+ * [36-36]
+ * [40-40]
+ * [44-44]
+ * [48-48]
+ * [52-52]
+ * [56-56]
+ * [60-60]
+ * [64-64]
+ * [100-100]
+ * [104-104]
+ * [108-108]
+ * [112-112]
+ * [116-116]
+ * [120-120]
+ * [124-124]
+ * [128-128]
+ * [132-132]
+ * [136-136]
+ * [140-140]
+ *
+ * Returns 0 if the IE has been found to be invalid in the middle
+ * somewhere.
+ */
+static int max_subband_chan(int orig_cur_chan,
+ int orig_end_channel,
+ s8 orig_max_power,
+ u8 **country_ie,
+ u8 *country_ie_len)
+{
+ u8 *triplets_start = *country_ie;
+ u8 len_at_triplet = *country_ie_len;
+ int end_subband_chan = orig_end_channel;
+ enum ieee80211_band band;
+
+ /*
+ * We'll deal with padding for the caller unless
+ * its not immediate and we don't process any channels
+ */
+ if (*country_ie_len == 1) {
+ *country_ie += 1;
+ *country_ie_len -= 1;
+ return orig_end_channel;
+ }
+
+ /* Move to the next triplet and then start search */
+ *country_ie += 3;
+ *country_ie_len -= 3;
+
+ if (orig_cur_chan <= 14)
+ band = IEEE80211_BAND_2GHZ;
+ else
+ band = IEEE80211_BAND_5GHZ;
+
+ while (*country_ie_len >= 3) {
+ int end_channel = 0;
+ struct ieee80211_country_ie_triplet *triplet =
+ (struct ieee80211_country_ie_triplet *) *country_ie;
+ int cur_channel = 0, next_expected_chan;
+ enum ieee80211_band next_band = IEEE80211_BAND_2GHZ;
+
+ /* means last triplet is completely unrelated to this one */
+ if (triplet->ext.reg_extension_id >=
+ IEEE80211_COUNTRY_EXTENSION_ID) {
+ *country_ie -= 3;
+ *country_ie_len += 3;
+ break;
+ }
+
+ if (triplet->chans.first_channel == 0) {
+ *country_ie += 1;
+ *country_ie_len -= 1;
+ if (*country_ie_len != 0)
+ return 0;
+ break;
+ }
+
+ /* Monitonically increasing channel order */
+ if (triplet->chans.first_channel <= end_subband_chan)
+ return 0;
+
+ /* 2 GHz */
+ if (triplet->chans.first_channel <= 14) {
+ end_channel = triplet->chans.first_channel +
+ triplet->chans.num_channels - 1;
+ }
+ else {
+ end_channel = triplet->chans.first_channel +
+ (4 * (triplet->chans.num_channels - 1));
+ next_band = IEEE80211_BAND_5GHZ;
+ }
+
+ if (band != next_band) {
+ *country_ie -= 3;
+ *country_ie_len += 3;
+ break;
+ }
+
+ if (orig_max_power != triplet->chans.max_power) {
+ *country_ie -= 3;
+ *country_ie_len += 3;
+ break;
+ }
+
+ cur_channel = triplet->chans.first_channel;
+
+ /* The key is finding the right next expected channel */
+ if (band == IEEE80211_BAND_2GHZ)
+ next_expected_chan = end_subband_chan + 1;
+ else
+ next_expected_chan = end_subband_chan + 4;
+
+ if (cur_channel != next_expected_chan) {
+ *country_ie -= 3;
+ *country_ie_len += 3;
+ break;
+ }
+
+ end_subband_chan = end_channel;
+
+ /* Move to the next one */
+ *country_ie += 3;
+ *country_ie_len -= 3;
+
+ /*
+ * Padding needs to be dealt with if we processed
+ * some channels.
+ */
+ if (*country_ie_len == 1) {
+ *country_ie += 1;
+ *country_ie_len -= 1;
+ break;
+ }
+
+ /* If seen, the IE is invalid */
+ if (*country_ie_len == 2)
+ return 0;
+ }
+
+ if (end_subband_chan == orig_end_channel) {
+ *country_ie = triplets_start;
+ *country_ie_len = len_at_triplet;
+ return orig_end_channel;
+ }
+
+ return end_subband_chan;
+}
+
+/*
* 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
@@ -552,6 +724,19 @@ static struct ieee80211_regdomain *country_ie_2_rd(
continue;
}
+ /*
+ * APs can add padding to make length divisible
+ * by two, required by the spec.
+ */
+ if (triplet->chans.first_channel == 0) {
+ country_ie++;
+ country_ie_len--;
+ /* This is expected to be at the very end only */
+ if (country_ie_len != 0)
+ return NULL;
+ break;
+ }
+
/* 2 GHz */
if (triplet->chans.first_channel <= 14)
end_channel = triplet->chans.first_channel +
@@ -570,6 +755,20 @@ static struct ieee80211_regdomain *country_ie_2_rd(
(4 * (triplet->chans.num_channels - 1));
cur_channel = triplet->chans.first_channel;
+
+ /*
+ * Enhancement for APs that send a triplet for every channel
+ * or for whatever reason sends triplets with multiple channels
+ * separated when in fact they should be together.
+ */
+ end_channel = max_subband_chan(cur_channel,
+ end_channel,
+ triplet->chans.max_power,
+ &country_ie,
+ &country_ie_len);
+ if (!end_channel)
+ return NULL;
+
cur_sub_max_channel = end_channel;
/* Basic sanity check */
@@ -600,10 +799,13 @@ static struct ieee80211_regdomain *country_ie_2_rd(
last_sub_max_channel = cur_sub_max_channel;
- country_ie += 3;
- country_ie_len -= 3;
num_rules++;
+ if (country_ie_len >= 3) {
+ country_ie += 3;
+ country_ie_len -= 3;
+ }
+
/*
* Note: this is not a IEEE requirement but
* simply a memory requirement
@@ -646,6 +848,12 @@ static struct ieee80211_regdomain *country_ie_2_rd(
continue;
}
+ if (triplet->chans.first_channel == 0) {
+ country_ie++;
+ country_ie_len--;
+ break;
+ }
+
reg_rule = &rd->reg_rules[i];
freq_range = &reg_rule->freq_range;
power_rule = &reg_rule->power_rule;
@@ -660,6 +868,12 @@ static struct ieee80211_regdomain *country_ie_2_rd(
end_channel = triplet->chans.first_channel +
(4 * (triplet->chans.num_channels - 1));
+ end_channel = max_subband_chan(triplet->chans.first_channel,
+ end_channel,
+ triplet->chans.max_power,
+ &country_ie,
+ &country_ie_len);
+
/*
* The +10 is since the regulatory domain expects
* the actual band edge, not the center of freq for
@@ -682,10 +896,13 @@ static struct ieee80211_regdomain *country_ie_2_rd(
power_rule->max_antenna_gain = DBI_TO_MBI(100);
power_rule->max_eirp = DBM_TO_MBM(triplet->chans.max_power);
- country_ie += 3;
- country_ie_len -= 3;
i++;
+ if (country_ie_len >= 3) {
+ country_ie += 3;
+ country_ie_len -= 3;
+ }
+
BUG_ON(i > NL80211_MAX_SUPP_REG_RULES);
}