cfg80211: regulatory: allow getting DFS CAC time from userspace

Introduce DFS CAC time as a regd param, configured per REG_RULE and
set per channel in cfg80211. DFS CAC time is close connected with
regulatory database configuration. Instead of using hardcoded values,
get DFS CAC time form regulatory database. Pass DFS CAC time to user
mode (mainly for iw reg get, iw list, iw info). Allow setting DFS CAC
time via CRDA. Add support for internal regulatory database.

Signed-off-by: Janusz Dziedzic <janusz.dziedzic@tieto.com>
[rewrap commit log]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 8c9ba44..bfa9a0c 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -151,6 +151,7 @@
  * @dfs_state: current state of this channel. Only relevant if radar is required
  *	on this channel.
  * @dfs_state_entered: timestamp (jiffies) when the dfs state was entered.
+ * @dfs_cac_ms: DFS CAC time in milliseconds, this is valid for DFS channels.
  */
 struct ieee80211_channel {
 	enum ieee80211_band band;
@@ -165,6 +166,7 @@
 	int orig_mag, orig_mpwr;
 	enum nl80211_dfs_state dfs_state;
 	unsigned long dfs_state_entered;
+	unsigned int dfs_cac_ms;
 };
 
 /**
diff --git a/include/net/regulatory.h b/include/net/regulatory.h
index b07cdc9..75fc1f5 100644
--- a/include/net/regulatory.h
+++ b/include/net/regulatory.h
@@ -155,6 +155,7 @@
 	struct ieee80211_freq_range freq_range;
 	struct ieee80211_power_rule power_rule;
 	u32 flags;
+	u32 dfs_cac_ms;
 };
 
 struct ieee80211_regdomain {
@@ -172,14 +173,18 @@
 #define DBM_TO_MBM(gain) ((gain) * 100)
 #define MBM_TO_DBM(gain) ((gain) / 100)
 
-#define REG_RULE(start, end, bw, gain, eirp, reg_flags) \
-{							\
-	.freq_range.start_freq_khz = MHZ_TO_KHZ(start),	\
-	.freq_range.end_freq_khz = MHZ_TO_KHZ(end),	\
-	.freq_range.max_bandwidth_khz = MHZ_TO_KHZ(bw),	\
-	.power_rule.max_antenna_gain = DBI_TO_MBI(gain),\
-	.power_rule.max_eirp = DBM_TO_MBM(eirp),	\
-	.flags = reg_flags,				\
+#define REG_RULE_EXT(start, end, bw, gain, eirp, dfs_cac, reg_flags)	\
+{									\
+	.freq_range.start_freq_khz = MHZ_TO_KHZ(start),			\
+	.freq_range.end_freq_khz = MHZ_TO_KHZ(end),			\
+	.freq_range.max_bandwidth_khz = MHZ_TO_KHZ(bw),			\
+	.power_rule.max_antenna_gain = DBI_TO_MBI(gain),		\
+	.power_rule.max_eirp = DBM_TO_MBM(eirp),			\
+	.flags = reg_flags,						\
+	.dfs_cac_ms = dfs_cac,						\
 }
 
+#define REG_RULE(start, end, bw, gain, eirp, reg_flags) \
+	REG_RULE_EXT(start, end, bw, gain, eirp, 0, reg_flags)
+
 #endif
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index ff72cab..1ba9d62 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -2335,6 +2335,7 @@
  * @NL80211_FREQUENCY_ATTR_NO_160MHZ: any 160 MHz (but not 80+80) channel
  *	using this channel as the primary or any of the secondary channels
  *	isn't possible
+ * @NL80211_FREQUENCY_ATTR_DFS_CAC_TIME: DFS CAC time in milliseconds.
  * @NL80211_FREQUENCY_ATTR_MAX: highest frequency attribute number
  *	currently defined
  * @__NL80211_FREQUENCY_ATTR_AFTER_LAST: internal use
@@ -2353,6 +2354,7 @@
 	NL80211_FREQUENCY_ATTR_NO_HT40_PLUS,
 	NL80211_FREQUENCY_ATTR_NO_80MHZ,
 	NL80211_FREQUENCY_ATTR_NO_160MHZ,
+	NL80211_FREQUENCY_ATTR_DFS_CAC_TIME,
 
 	/* keep last */
 	__NL80211_FREQUENCY_ATTR_AFTER_LAST,
@@ -2449,6 +2451,8 @@
  * 	If you don't have one then don't send this.
  * @NL80211_ATTR_POWER_RULE_MAX_EIRP: the maximum allowed EIRP for
  * 	a given frequency range. The value is in mBm (100 * dBm).
+ * @NL80211_ATTR_DFS_CAC_TIME: DFS CAC time in milliseconds.
+ *	If not present or 0 default CAC time will be used.
  * @NL80211_REG_RULE_ATTR_MAX: highest regulatory rule attribute number
  *	currently defined
  * @__NL80211_REG_RULE_ATTR_AFTER_LAST: internal use
@@ -2464,6 +2468,8 @@
 	NL80211_ATTR_POWER_RULE_MAX_ANT_GAIN,
 	NL80211_ATTR_POWER_RULE_MAX_EIRP,
 
+	NL80211_ATTR_DFS_CAC_TIME,
+
 	/* keep last */
 	__NL80211_REG_RULE_ATTR_AFTER_LAST,
 	NL80211_REG_RULE_ATTR_MAX = __NL80211_REG_RULE_ATTR_AFTER_LAST - 1
diff --git a/net/wireless/genregdb.awk b/net/wireless/genregdb.awk
index fdfd3f0..b35da8d 100644
--- a/net/wireless/genregdb.awk
+++ b/net/wireless/genregdb.awk
@@ -66,6 +66,7 @@
 	units = $8
 	sub(/\)/, "", units)
 	sub(/,/, "", units)
+	dfs_cac = $9
 	if (units == "mW") {
 		if (power == 100) {
 			power = 20
@@ -78,7 +79,12 @@
 		} else {
 			print "Unknown power value in database!"
 		}
+	} else {
+		dfs_cac = $8
 	}
+	sub(/,/, "", dfs_cac)
+	sub(/\(/, "", dfs_cac)
+	sub(/\)/, "", dfs_cac)
 	flagstr = ""
 	for (i=8; i<=NF; i++)
 		flagstr = flagstr $i
@@ -111,7 +117,7 @@
 
 	}
 	flags = flags "0"
-	printf "\t\tREG_RULE(%d, %d, %d, %d, %d, %s),\n", start, end, bw, gain, power, flags
+	printf "\t\tREG_RULE_EXT(%d, %d, %d, %d, %d, %d, %s),\n", start, end, bw, gain, power, dfs_cac, flags
 	rules++
 }
 
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 2c38b28..9f7ebf9 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -593,6 +593,10 @@
 			if (nla_put_u32(msg, NL80211_FREQUENCY_ATTR_DFS_TIME,
 					time))
 				goto nla_put_failure;
+			if (nla_put_u32(msg,
+					NL80211_FREQUENCY_ATTR_DFS_CAC_TIME,
+					chan->dfs_cac_ms))
+				goto nla_put_failure;
 		}
 	}
 
@@ -4614,6 +4618,7 @@
 	[NL80211_ATTR_FREQ_RANGE_MAX_BW]	= { .type = NLA_U32 },
 	[NL80211_ATTR_POWER_RULE_MAX_ANT_GAIN]	= { .type = NLA_U32 },
 	[NL80211_ATTR_POWER_RULE_MAX_EIRP]	= { .type = NLA_U32 },
+	[NL80211_ATTR_DFS_CAC_TIME]		= { .type = NLA_U32 },
 };
 
 static int parse_reg_rule(struct nlattr *tb[],
@@ -4649,6 +4654,10 @@
 		power_rule->max_antenna_gain =
 			nla_get_u32(tb[NL80211_ATTR_POWER_RULE_MAX_ANT_GAIN]);
 
+	if (tb[NL80211_ATTR_DFS_CAC_TIME])
+		reg_rule->dfs_cac_ms =
+			nla_get_u32(tb[NL80211_ATTR_DFS_CAC_TIME]);
+
 	return 0;
 }
 
@@ -5136,7 +5145,9 @@
 		    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,
-				power_rule->max_eirp))
+				power_rule->max_eirp) ||
+		    nla_put_u32(msg, NL80211_ATTR_DFS_CAC_TIME,
+				reg_rule->dfs_cac_ms))
 			goto nla_put_failure_rcu;
 
 		nla_nest_end(msg, nl_reg_rule);
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 651404c..b95e9cf 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -756,6 +756,9 @@
 	power_rule->max_antenna_gain = min(power_rule1->max_antenna_gain,
 		power_rule2->max_antenna_gain);
 
+	intersected_rule->dfs_cac_ms = max(rule1->dfs_cac_ms,
+					   rule2->dfs_cac_ms);
+
 	if (!is_valid_reg_rule(intersected_rule))
 		return -EINVAL;
 
@@ -1078,6 +1081,14 @@
 		min_t(int, chan->orig_mag,
 		      MBI_TO_DBI(power_rule->max_antenna_gain));
 	chan->max_reg_power = (int) MBM_TO_DBM(power_rule->max_eirp);
+
+	if (chan->flags & IEEE80211_CHAN_RADAR) {
+		if (reg_rule->dfs_cac_ms)
+			chan->dfs_cac_ms = reg_rule->dfs_cac_ms;
+		else
+			chan->dfs_cac_ms = IEEE80211_DFS_MIN_CAC_TIME_MS;
+	}
+
 	if (chan->orig_mpwr) {
 		/*
 		 * Devices that use REGULATORY_COUNTRY_IE_FOLLOW_POWER
@@ -2256,9 +2267,9 @@
 	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];
+	char bw[32], cac_time[32];
 
-	pr_info("  (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)\n");
+	pr_info("  (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time)\n");
 
 	for (i = 0; i < rd->n_reg_rules; i++) {
 		reg_rule = &rd->reg_rules[i];
@@ -2273,23 +2284,32 @@
 			snprintf(bw, sizeof(bw), "%d KHz",
 				 freq_range->max_bandwidth_khz);
 
+		if (reg_rule->flags & NL80211_RRF_DFS)
+			scnprintf(cac_time, sizeof(cac_time), "%u s",
+				  reg_rule->dfs_cac_ms/1000);
+		else
+			scnprintf(cac_time, sizeof(cac_time), "N/A");
+
+
 		/*
 		 * There may not be documentation for max antenna gain
 		 * in certain regions
 		 */
 		if (power_rule->max_antenna_gain)
-			pr_info("  (%d KHz - %d KHz @ %s), (%d mBi, %d mBm)\n",
+			pr_info("  (%d KHz - %d KHz @ %s), (%d mBi, %d mBm), (%s)\n",
 				freq_range->start_freq_khz,
 				freq_range->end_freq_khz,
 				bw,
 				power_rule->max_antenna_gain,
-				power_rule->max_eirp);
+				power_rule->max_eirp,
+				cac_time);
 		else
-			pr_info("  (%d KHz - %d KHz @ %s), (N/A, %d mBm)\n",
+			pr_info("  (%d KHz - %d KHz @ %s), (N/A, %d mBm), (%s)\n",
 				freq_range->start_freq_khz,
 				freq_range->end_freq_khz,
 				bw,
-				power_rule->max_eirp);
+				power_rule->max_eirp,
+				cac_time);
 	}
 }