cfg80211: Add API to allow querying regdb for wmm_rule

In general regulatory self managed devices maintain their own
regulatory profiles thus it doesn't have to query the regulatory database
on country change.

ETSI has recently introduced a new channel access mechanism for 5GHz
that all wlan devices need to comply with.
These values are stored in the regulatory database.
There are self managed devices which can't maintain these
values on their own. Add API to allow self managed regulatory devices
to query the regulatory database for high band wmm rule.

Signed-off-by: Haim Dreyfuss <haim.dreyfuss@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
[johannes: fix documentation]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 54 insertions, 0 deletions

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index e352a0d1c438..16c7e4ef5820 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -878,6 +878,60 @@ static void set_wmm_rule(struct ieee80211_wmm_rule *rule,
 	}
 }
 
+static int __regdb_query_wmm(const struct fwdb_header *db,
+			     const struct fwdb_country *country, int freq,
+			     u32 *dbptr, struct ieee80211_wmm_rule *rule)
+{
+	unsigned int ptr = be16_to_cpu(country->coll_ptr) << 2;
+	struct fwdb_collection *coll = (void *)((u8 *)db + ptr);
+	int i;
+
+	for (i = 0; i < coll->n_rules; i++) {
+		__be16 *rules_ptr = (void *)((u8 *)coll + ALIGN(coll->len, 2));
+		unsigned int rule_ptr = be16_to_cpu(rules_ptr[i]) << 2;
+		struct fwdb_rule *rrule = (void *)((u8 *)db + rule_ptr);
+		struct fwdb_wmm_rule *wmm;
+		unsigned int wmm_ptr;
+
+		if (rrule->len < offsetofend(struct fwdb_rule, wmm_ptr))
+			continue;
+
+		if (freq >= KHZ_TO_MHZ(be32_to_cpu(rrule->start)) &&
+		    freq <= KHZ_TO_MHZ(be32_to_cpu(rrule->end))) {
+			wmm_ptr = be16_to_cpu(rrule->wmm_ptr) << 2;
+			wmm = (void *)((u8 *)db + wmm_ptr);
+			set_wmm_rule(rule, wmm);
+			if (dbptr)
+				*dbptr = wmm_ptr;
+			return 0;
+		}
+	}
+
+	return -ENODATA;
+}
+
+int reg_query_regdb_wmm(char *alpha2, int freq, u32 *dbptr,
+			struct ieee80211_wmm_rule *rule)
+{
+	const struct fwdb_header *hdr = regdb;
+	const struct fwdb_country *country;
+
+	if (IS_ERR(regdb))
+		return PTR_ERR(regdb);
+
+	country = &hdr->country[0];
+	while (country->coll_ptr) {
+		if (alpha2_equal(alpha2, country->alpha2))
+			return __regdb_query_wmm(regdb, country, freq, dbptr,
+						 rule);
+
+		country++;
+	}
+
+	return -ENODATA;
+}
+EXPORT_SYMBOL(reg_query_regdb_wmm);
+
 struct wmm_ptrs {
 	struct ieee80211_wmm_rule *rule;
 	u32 ptr;