cfg80211: regulatory introduce maximum bandwidth calculation

In case we will get regulatory request with rule
where max_bandwidth_khz is set to 0 handle this
case as a special one.

If max_bandwidth_khz == 0 we should calculate maximum
available bandwidth base on all frequency contiguous rules.
In case we need auto calculation we just have to set:

country PL: DFS-ETSI
        (2402 - 2482 @ 40), (N/A, 20)
        (5170 - 5250 @ AUTO), (N/A, 20)
        (5250 - 5330 @ AUTO), (N/A, 20), DFS
        (5490 - 5710 @ 80), (N/A, 27), DFS

This mean we will calculate maximum bw for rules where
AUTO (N/A) were set, 160MHz (5330 - 5170) in example above.
So we will get:
        (5170 - 5250 @ 160), (N/A, 20)
        (5250 - 5330 @ 160), (N/A, 20), DFS

In other case:
country FR: DFS-ETSI
        (2402 - 2482 @ 40), (N/A, 20)
        (5170 - 5250 @ AUTO), (N/A, 20)
        (5250 - 5330 @ 80), (N/A, 20), DFS
        (5490 - 5710 @ 80), (N/A, 27), DFS

We will get 80MHz (5250 - 5170):
        (5170 - 5250 @ 80), (N/A, 20)
        (5250 - 5330 @ 80), (N/A, 20), DFS

Base on this calculations we will set correct channel
bandwidth flags (eg. IEEE80211_CHAN_NO_80MHZ).

We don't need any changes in CRDA or internal regulatory.

Signed-off-by: Janusz Dziedzic <janusz.dziedzic@tieto.com>
[extend nl80211 description a bit, fix typo]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 474ce32e07974e19f96adfa18adc42e81dae073c..a12e6cae5132569815271c352508c48001c1b51e 100644 (file)
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -2437,7 +2437,10 @@ enum nl80211_reg_type {
  *     in KHz. This is not a center a frequency but an actual regulatory
  *     band edge.
  * @NL80211_ATTR_FREQ_RANGE_MAX_BW: maximum allowed bandwidth for this
- *     frequency range, in KHz.
+ *     frequency range, in KHz. If not present or 0, maximum available
+ *     bandwidth should be calculated base on contiguous rules and wider
+ *     channels will be allowed to cross multiple contiguous/overlapping
+ *     frequency ranges.
  * @NL80211_ATTR_POWER_RULE_MAX_ANT_GAIN: the maximum allowed antenna gain
  *     for a given frequency range. The value is in mBi (100 * dBi).
  *     If you don't have one then don't send this.

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index be091ddd43a4e23cefaa72296f923e9cc80c59b9..ebea1a197afb368faadfc90d1f97f2ffa6e1bcff 100644 (file)
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -4626,8 +4626,6 @@ static int parse_reg_rule(struct nlattr *tb[],
                return -EINVAL;
        if (!tb[NL80211_ATTR_FREQ_RANGE_END])
                return -EINVAL;
-       if (!tb[NL80211_ATTR_FREQ_RANGE_MAX_BW])
-               return -EINVAL;
        if (!tb[NL80211_ATTR_POWER_RULE_MAX_EIRP])
                return -EINVAL;
 
@@ -4637,8 +4635,9 @@ static int parse_reg_rule(struct nlattr *tb[],
                nla_get_u32(tb[NL80211_ATTR_FREQ_RANGE_START]);
        freq_range->end_freq_khz =
                nla_get_u32(tb[NL80211_ATTR_FREQ_RANGE_END]);
-       freq_range->max_bandwidth_khz =
-               nla_get_u32(tb[NL80211_ATTR_FREQ_RANGE_MAX_BW]);
+       if (tb[NL80211_ATTR_FREQ_RANGE_MAX_BW])
+               freq_range->max_bandwidth_khz =
+                       nla_get_u32(tb[NL80211_ATTR_FREQ_RANGE_MAX_BW]);
 
        power_rule->max_eirp =
                nla_get_u32(tb[NL80211_ATTR_POWER_RULE_MAX_EIRP]);
@@ -5108,6 +5107,7 @@ static int nl80211_get_reg(struct sk_buff *skb, struct genl_info *info)
                const struct ieee80211_reg_rule *reg_rule;
                const struct ieee80211_freq_range *freq_range;
                const struct ieee80211_power_rule *power_rule;
+               unsigned int max_bandwidth_khz;
 
                reg_rule = &regdom->reg_rules[i];
                freq_range = &reg_rule->freq_range;
@@ -5117,6 +5117,11 @@ static int nl80211_get_reg(struct sk_buff *skb, struct genl_info *info)
                if (!nl_reg_rule)
                        goto nla_put_failure_rcu;
 
+               max_bandwidth_khz = freq_range->max_bandwidth_khz;
+               if (!max_bandwidth_khz)
+                       max_bandwidth_khz = reg_get_max_bandwidth(regdom,
+                                                                 reg_rule);
+
                if (nla_put_u32(msg, NL80211_ATTR_REG_RULE_FLAGS,
                                reg_rule->flags) ||
                    nla_put_u32(msg, NL80211_ATTR_FREQ_RANGE_START,
@@ -5124,7 +5129,7 @@ static int nl80211_get_reg(struct sk_buff *skb, struct genl_info *info)
                    nla_put_u32(msg, NL80211_ATTR_FREQ_RANGE_END,
                                freq_range->end_freq_khz) ||
                    nla_put_u32(msg, NL80211_ATTR_FREQ_RANGE_MAX_BW,
-                               freq_range->max_bandwidth_khz) ||
+                               max_bandwidth_khz) ||
                    nla_put_u32(msg, NL80211_ATTR_POWER_RULE_MAX_ANT_GAIN,
                                power_rule->max_antenna_gain) ||
                    nla_put_u32(msg, NL80211_ATTR_POWER_RULE_MAX_EIRP,

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 27807bf0cdfc532433c03c1fa4e4e96727117933..27c5253e7a610b706ac99402727eda9bc66de755 100644 (file)
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -538,6 +538,61 @@ static const struct ieee80211_regdomain *reg_get_regdomain(struct wiphy *wiphy)
        return get_cfg80211_regdom();
 }
 
+unsigned int reg_get_max_bandwidth(const struct ieee80211_regdomain *rd,
+                                  const struct ieee80211_reg_rule *rule)
+{
+       const struct ieee80211_freq_range *freq_range = &rule->freq_range;
+       const struct ieee80211_freq_range *freq_range_tmp;
+       const struct ieee80211_reg_rule *tmp;
+       u32 start_freq, end_freq, idx, no;
+
+       for (idx = 0; idx < rd->n_reg_rules; idx++)
+               if (rule == &rd->reg_rules[idx])
+                       break;
+
+       if (idx == rd->n_reg_rules)
+               return 0;
+
+       /* get start_freq */
+       no = idx;
+
+       while (no) {
+               tmp = &rd->reg_rules[--no];
+               freq_range_tmp = &tmp->freq_range;
+
+               if (freq_range_tmp->end_freq_khz < freq_range->start_freq_khz)
+                       break;
+
+               if (freq_range_tmp->max_bandwidth_khz)
+                       break;
+
+               freq_range = freq_range_tmp;
+       }
+
+       start_freq = freq_range->start_freq_khz;
+
+       /* get end_freq */
+       freq_range = &rule->freq_range;
+       no = idx;
+
+       while (no < rd->n_reg_rules - 1) {
+               tmp = &rd->reg_rules[++no];
+               freq_range_tmp = &tmp->freq_range;
+
+               if (freq_range_tmp->start_freq_khz > freq_range->end_freq_khz)
+                       break;
+
+               if (freq_range_tmp->max_bandwidth_khz)
+                       break;
+
+               freq_range = freq_range_tmp;
+       }
+
+       end_freq = freq_range->end_freq_khz;
+
+       return end_freq - start_freq;
+}
+
 /* Sanity check on a regulatory rule */
 static bool is_valid_reg_rule(const struct ieee80211_reg_rule *rule)
 {
@@ -646,7 +701,9 @@ reg_intersect_dfs_region(const enum nl80211_dfs_regions dfs_region1,
  * Helper for regdom_intersect(), this does the real
  * mathematical intersection fun
  */
-static int reg_rules_intersect(const struct ieee80211_reg_rule *rule1,
+static int reg_rules_intersect(const struct ieee80211_regdomain *rd1,
+                              const struct ieee80211_regdomain *rd2,
+                              const struct ieee80211_reg_rule *rule1,
                               const struct ieee80211_reg_rule *rule2,
                               struct ieee80211_reg_rule *intersected_rule)
 {
@@ -654,7 +711,7 @@ static int reg_rules_intersect(const struct ieee80211_reg_rule *rule1,
        struct ieee80211_freq_range *freq_range;
        const struct ieee80211_power_rule *power_rule1, *power_rule2;
        struct ieee80211_power_rule *power_rule;
-       u32 freq_diff;
+       u32 freq_diff, max_bandwidth1, max_bandwidth2;
 
        freq_range1 = &rule1->freq_range;
        freq_range2 = &rule2->freq_range;
@@ -668,8 +725,24 @@ static int reg_rules_intersect(const struct ieee80211_reg_rule *rule1,
                                         freq_range2->start_freq_khz);
        freq_range->end_freq_khz = min(freq_range1->end_freq_khz,
                                       freq_range2->end_freq_khz);
-       freq_range->max_bandwidth_khz = min(freq_range1->max_bandwidth_khz,
-                                           freq_range2->max_bandwidth_khz);
+
+       max_bandwidth1 = freq_range1->max_bandwidth_khz;
+       max_bandwidth2 = freq_range2->max_bandwidth_khz;
+
+       /*
+        * In case max_bandwidth1 == 0 and max_bandwith2 == 0 set
+        * output bandwidth as 0 (auto calculation). Next we will
+        * calculate this correctly in handle_channel function.
+        * In other case calculate output bandwidth here.
+        */
+       if (max_bandwidth1 || max_bandwidth2) {
+               if (!max_bandwidth1)
+                       max_bandwidth1 = reg_get_max_bandwidth(rd1, rule1);
+               if (!max_bandwidth2)
+                       max_bandwidth2 = reg_get_max_bandwidth(rd2, rule2);
+       }
+
+       freq_range->max_bandwidth_khz = min(max_bandwidth1, max_bandwidth2);
 
        freq_diff = freq_range->end_freq_khz - freq_range->start_freq_khz;
        if (freq_range->max_bandwidth_khz > freq_diff)
@@ -729,7 +802,8 @@ regdom_intersect(const struct ieee80211_regdomain *rd1,
                rule1 = &rd1->reg_rules[x];
                for (y = 0; y < rd2->n_reg_rules; y++) {
                        rule2 = &rd2->reg_rules[y];
-                       if (!reg_rules_intersect(rule1, rule2, &dummy_rule))
+                       if (!reg_rules_intersect(rd1, rd2, rule1, rule2,
+                                                &dummy_rule))
                                num_rules++;
                }
        }
@@ -754,7 +828,8 @@ regdom_intersect(const struct ieee80211_regdomain *rd1,
                         * a memcpy()
                         */
                        intersected_rule = &rd->reg_rules[rule_idx];
-                       r = reg_rules_intersect(rule1, rule2, intersected_rule);
+                       r = reg_rules_intersect(rd1, rd2, rule1, rule2,
+                                               intersected_rule);
                        /*
                         * No need to memset here the intersected rule here as
                         * we're not using the stack anymore
@@ -909,6 +984,8 @@ static void handle_channel(struct wiphy *wiphy,
        const struct ieee80211_freq_range *freq_range = NULL;
        struct wiphy *request_wiphy = NULL;
        struct regulatory_request *lr = get_last_request();
+       const struct ieee80211_regdomain *regd;
+       u32 max_bandwidth_khz;
 
        request_wiphy = wiphy_idx_to_wiphy(lr->wiphy_idx);
 
@@ -950,11 +1027,18 @@ static void handle_channel(struct wiphy *wiphy,
        power_rule = &reg_rule->power_rule;
        freq_range = &reg_rule->freq_range;
 
-       if (freq_range->max_bandwidth_khz < MHZ_TO_KHZ(40))
+       max_bandwidth_khz = freq_range->max_bandwidth_khz;
+       /* Check if auto calculation requested */
+       if (!max_bandwidth_khz) {
+               regd = reg_get_regdomain(wiphy);
+               max_bandwidth_khz = reg_get_max_bandwidth(regd, reg_rule);
+       }
+
+       if (max_bandwidth_khz < MHZ_TO_KHZ(40))
                bw_flags = IEEE80211_CHAN_NO_HT40;
-       if (freq_range->max_bandwidth_khz < MHZ_TO_KHZ(80))
+       if (max_bandwidth_khz < MHZ_TO_KHZ(80))
                bw_flags |= IEEE80211_CHAN_NO_80MHZ;
-       if (freq_range->max_bandwidth_khz < MHZ_TO_KHZ(160))
+       if (max_bandwidth_khz < MHZ_TO_KHZ(160))
                bw_flags |= IEEE80211_CHAN_NO_160MHZ;
 
        if (lr->initiator == NL80211_REGDOM_SET_BY_DRIVER &&
@@ -1340,6 +1424,7 @@ static void handle_channel_custom(struct wiphy *wiphy,
        const struct ieee80211_reg_rule *reg_rule = NULL;
        const struct ieee80211_power_rule *power_rule = NULL;
        const struct ieee80211_freq_range *freq_range = NULL;
+       u32 max_bandwidth_khz;
 
        reg_rule = freq_reg_info_regd(wiphy, MHZ_TO_KHZ(chan->center_freq),
                                      regd);
@@ -1357,11 +1442,16 @@ static void handle_channel_custom(struct wiphy *wiphy,
        power_rule = &reg_rule->power_rule;
        freq_range = &reg_rule->freq_range;
 
-       if (freq_range->max_bandwidth_khz < MHZ_TO_KHZ(40))
+       max_bandwidth_khz = freq_range->max_bandwidth_khz;
+       /* Check if auto calculation requested */
+       if (!max_bandwidth_khz)
+               max_bandwidth_khz = reg_get_max_bandwidth(regd, reg_rule);
+
+       if (max_bandwidth_khz < MHZ_TO_KHZ(40))
                bw_flags = IEEE80211_CHAN_NO_HT40;
-       if (freq_range->max_bandwidth_khz < MHZ_TO_KHZ(80))
+       if (max_bandwidth_khz < MHZ_TO_KHZ(80))
                bw_flags |= IEEE80211_CHAN_NO_80MHZ;
-       if (freq_range->max_bandwidth_khz < MHZ_TO_KHZ(160))
+       if (max_bandwidth_khz < MHZ_TO_KHZ(160))
                bw_flags |= IEEE80211_CHAN_NO_160MHZ;
 
        chan->flags |= map_regdom_flags(reg_rule->flags) | bw_flags;
@@ -2155,6 +2245,7 @@ static void print_rd_rules(const struct ieee80211_regdomain *rd)
        const struct ieee80211_reg_rule *reg_rule = NULL;
        const struct ieee80211_freq_range *freq_range = NULL;
        const struct ieee80211_power_rule *power_rule = NULL;
+       char bw[32];
 
        pr_info("  (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)\n");
 
@@ -2163,22 +2254,29 @@ static void print_rd_rules(const struct ieee80211_regdomain *rd)
                freq_range = &reg_rule->freq_range;
                power_rule = &reg_rule->power_rule;
 
+               if (!freq_range->max_bandwidth_khz)
+                       snprintf(bw, 32, "%d KHz, AUTO",
+                                reg_get_max_bandwidth(rd, reg_rule));
+               else
+                       snprintf(bw, 32, "%d KHz",
+                                freq_range->max_bandwidth_khz);
+
                /*
                 * There may not be documentation for max antenna gain
                 * in certain regions
                 */
                if (power_rule->max_antenna_gain)
-                       pr_info("  (%d KHz - %d KHz @ %d KHz), (%d mBi, %d mBm)\n",
+                       pr_info("  (%d KHz - %d KHz @ %s), (%d mBi, %d mBm)\n",
                                freq_range->start_freq_khz,
                                freq_range->end_freq_khz,
-                               freq_range->max_bandwidth_khz,
+                               bw,
                                power_rule->max_antenna_gain,
                                power_rule->max_eirp);
                else
-                       pr_info("  (%d KHz - %d KHz @ %d KHz), (N/A, %d mBm)\n",
+                       pr_info("  (%d KHz - %d KHz @ %s), (N/A, %d mBm)\n",
                                freq_range->start_freq_khz,
                                freq_range->end_freq_khz,
-                               freq_range->max_bandwidth_khz,
+                               bw,
                                power_rule->max_eirp);
        }
 }

diff --git a/net/wireless/reg.h b/net/wireless/reg.h
index 02bd8f4b0921dafca98c4e1bc23b729045b036db..18524617ab62642d5b8cbd59644d7e2be2e4fede 100644 (file)
--- a/net/wireless/reg.h
+++ b/net/wireless/reg.h
@@ -34,6 +34,8 @@ int __init regulatory_init(void);
 void regulatory_exit(void);
 
 int set_regdom(const struct ieee80211_regdomain *rd);
+unsigned int reg_get_max_bandwidth(const struct ieee80211_regdomain *rd,
+                                  const struct ieee80211_reg_rule *rule);
 
 bool reg_last_request_cell_base(void);