cfg80211: read wmm rules from regulatory database

ETSI EN 301 893 v2.1.1 (2017-05) standard defines a new channel access
mechanism that all devices (WLAN and LAA) need to comply with.
The regulatory database can now be loaded into the kernel and also
has the option to load optional data.
In order to be able to comply with ETSI standard, we add wmm_rule into
regulatory rule and add the option to read its value from the regulatory
database.
Signed-off-by: Haim Dreyfuss <haim.dreyfuss@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
[johannes: fix memory leak in error path]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/regulatory.h

@@ -4,6 +4,7 @@
  * regulatory support structures
  *
  * Copyright 2008-2009	Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
+ * Copyright (C) 2018 Intel Corporation
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -188,9 +189,35 @@ struct ieee80211_power_rule {
 	u32 max_eirp;
 };
 
+/**
+ * struct ieee80211_wmm_ac - used to store per ac wmm regulatory limitation
+ *
+ * The information provided in this structure is required for QoS
+ * transmit queue configuration. Cf. IEEE 802.11 7.3.2.29.
+ *
+ * @cw_min: minimum contention window [a value of the form
+ *      2^n-1 in the range 1..32767]
+ * @cw_max: maximum contention window [like @cw_min]
+ * @cot: maximum burst time in units of 32 usecs, 0 meaning disabled
+ * @aifsn: arbitration interframe space [0..255]
+ *
+ */
+struct ieee80211_wmm_ac {
+	u16 cw_min;
+	u16 cw_max;
+	u16 cot;
+	u8 aifsn;
+};
+
+struct ieee80211_wmm_rule {
+	struct ieee80211_wmm_ac client[IEEE80211_NUM_ACS];
+	struct ieee80211_wmm_ac ap[IEEE80211_NUM_ACS];
+};
+
 struct ieee80211_reg_rule {
 	struct ieee80211_freq_range freq_range;
 	struct ieee80211_power_rule power_rule;
+	struct ieee80211_wmm_rule *wmm_rule;
 	u32 flags;
 	u32 dfs_cac_ms;
 };
@@ -198,6 +225,7 @@ struct ieee80211_reg_rule {
 struct ieee80211_regdomain {
 	struct rcu_head rcu_head;
 	u32 n_reg_rules;
+	u32 n_wmm_rules;
 	char alpha2[3];
 	enum nl80211_dfs_regions dfs_region;
 	struct ieee80211_reg_rule reg_rules[];

net/wireless/reg.c

@@ -5,6 +5,7 @@
  * Copyright 2008-2011	Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
  * Copyright 2013-2014  Intel Mobile Communications GmbH
  * Copyright      2017  Intel Deutschland GmbH
+ * Copyright (C) 2018 Intel Corporation
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -424,23 +425,36 @@ static const struct ieee80211_regdomain *
 reg_copy_regd(const struct ieee80211_regdomain *src_regd)
 {
 	struct ieee80211_regdomain *regd;
-	int size_of_regd;
+	int size_of_regd, size_of_wmms;
 	unsigned int i;
+	struct ieee80211_wmm_rule *d_wmm, *s_wmm;
 
 	size_of_regd =
 		sizeof(struct ieee80211_regdomain) +
 		src_regd->n_reg_rules * sizeof(struct ieee80211_reg_rule);
+	size_of_wmms = src_regd->n_wmm_rules *
+		sizeof(struct ieee80211_wmm_rule);
 
-	regd = kzalloc(size_of_regd, GFP_KERNEL);
+	regd = kzalloc(size_of_regd + size_of_wmms, GFP_KERNEL);
 	if (!regd)
 		return ERR_PTR(-ENOMEM);
 
 	memcpy(regd, src_regd, sizeof(struct ieee80211_regdomain));
 
-	for (i = 0; i < src_regd->n_reg_rules; i++)
+	d_wmm = (struct ieee80211_wmm_rule *)((u8 *)regd + size_of_regd);
+	s_wmm = (struct ieee80211_wmm_rule *)((u8 *)src_regd + size_of_regd);
+	memcpy(d_wmm, s_wmm, size_of_wmms);
+
+	for (i = 0; i < src_regd->n_reg_rules; i++) {
 		memcpy(&regd->reg_rules[i], &src_regd->reg_rules[i],
 		       sizeof(struct ieee80211_reg_rule));
+		if (!src_regd->reg_rules[i].wmm_rule)
+			continue;
 
+		regd->reg_rules[i].wmm_rule = d_wmm +
+			(src_regd->reg_rules[i].wmm_rule - s_wmm) /
+			sizeof(struct ieee80211_wmm_rule);
+	}
 	return regd;
 }
 
@@ -595,6 +609,17 @@ enum fwdb_flags {
 	FWDB_FLAG_AUTO_BW	= BIT(4),
 };
 
+struct fwdb_wmm_ac {
+	u8 ecw;
+	u8 aifsn;
+	__be16 cot;
+} __packed;
+
+struct fwdb_wmm_rule {
+	struct fwdb_wmm_ac client[IEEE80211_NUM_ACS];
+	struct fwdb_wmm_ac ap[IEEE80211_NUM_ACS];
+} __packed;
+
 struct fwdb_rule {
 	u8 len;
 	u8 flags;
@@ -602,6 +627,7 @@ struct fwdb_rule {
 	__be32 start, end, max_bw;
 	/* start of optional data */
 	__be16 cac_timeout;
+	__be16 wmm_ptr;
 } __packed __aligned(4);
 
 #define FWDB_MAGIC 0x52474442
@@ -613,6 +639,31 @@ struct fwdb_header {
 	struct fwdb_country country[];
 } __packed __aligned(4);
 
+static int ecw2cw(int ecw)
+{
+	return (1 << ecw) - 1;
+}
+
+static bool valid_wmm(struct fwdb_wmm_rule *rule)
+{
+	struct fwdb_wmm_ac *ac = (struct fwdb_wmm_ac *)rule;
+	int i;
+
+	for (i = 0; i < IEEE80211_NUM_ACS * 2; i++) {
+		u16 cw_min = ecw2cw((ac[i].ecw & 0xf0) >> 4);
+		u16 cw_max = ecw2cw(ac[i].ecw & 0x0f);
+		u8 aifsn = ac[i].aifsn;
+
+		if (cw_min >= cw_max)
+			return false;
+
+		if (aifsn < 1)
+			return false;
+	}
+
+	return true;
+}
+
 static bool valid_rule(const u8 *data, unsigned int size, u16 rule_ptr)
 {
 	struct fwdb_rule *rule = (void *)(data + (rule_ptr << 2));
@@ -623,7 +674,18 @@ static bool valid_rule(const u8 *data, unsigned int size, u16 rule_ptr)
 	/* mandatory fields */
 	if (rule->len < offsetofend(struct fwdb_rule, max_bw))
 		return false;
+	if (rule->len >= offsetofend(struct fwdb_rule, wmm_ptr)) {
+		u32 wmm_ptr = be16_to_cpu(rule->wmm_ptr) << 2;
+		struct fwdb_wmm_rule *wmm;
 
+		if (wmm_ptr + sizeof(struct fwdb_wmm_rule) > size)
+			return false;
+
+		wmm = (void *)(data + wmm_ptr);
+
+		if (!valid_wmm(wmm))
+			return false;
+	}
 	return true;
 }
 
@@ -798,23 +860,64 @@ static bool valid_regdb(const u8 *data, unsigned int size)
 	return true;
 }
 
+static void set_wmm_rule(struct ieee80211_wmm_rule *rule,
+			 struct fwdb_wmm_rule *wmm)
+{
+	unsigned int i;
+
+	for (i = 0; i < IEEE80211_NUM_ACS; i++) {
+		rule->client[i].cw_min =
+			ecw2cw((wmm->client[i].ecw & 0xf0) >> 4);
+		rule->client[i].cw_max = ecw2cw(wmm->client[i].ecw & 0x0f);
+		rule->client[i].aifsn =  wmm->client[i].aifsn;
+		rule->client[i].cot = 1000 * be16_to_cpu(wmm->client[i].cot);
+		rule->ap[i].cw_min = ecw2cw((wmm->ap[i].ecw & 0xf0) >> 4);
+		rule->ap[i].cw_max = ecw2cw(wmm->ap[i].ecw & 0x0f);
+		rule->ap[i].aifsn = wmm->ap[i].aifsn;
+		rule->ap[i].cot = 1000 * be16_to_cpu(wmm->ap[i].cot);
+	}
+}
+
+struct wmm_ptrs {
+	struct ieee80211_wmm_rule *rule;
+	u32 ptr;
+};
+
+static struct ieee80211_wmm_rule *find_wmm_ptr(struct wmm_ptrs *wmm_ptrs,
+					       u32 wmm_ptr, int n_wmms)
+{
+	int i;
+
+	for (i = 0; i < n_wmms; i++) {
+		if (wmm_ptrs[i].ptr == wmm_ptr)
+			return wmm_ptrs[i].rule;
+	}
+	return NULL;
+}
+
 static int regdb_query_country(const struct fwdb_header *db,
 			       const struct fwdb_country *country)
 {
 	unsigned int ptr = be16_to_cpu(country->coll_ptr) << 2;
 	struct fwdb_collection *coll = (void *)((u8 *)db + ptr);
 	struct ieee80211_regdomain *regdom;
-	unsigned int size_of_regd;
-	unsigned int i;
+	struct ieee80211_regdomain *tmp_rd;
+	unsigned int size_of_regd, i, n_wmms = 0;
+	struct wmm_ptrs *wmm_ptrs;
 
-	size_of_regd =
-		sizeof(struct ieee80211_regdomain) +
+	size_of_regd = sizeof(struct ieee80211_regdomain) +
 		coll->n_rules * sizeof(struct ieee80211_reg_rule);
 
 	regdom = kzalloc(size_of_regd, GFP_KERNEL);
 	if (!regdom)
 		return -ENOMEM;
 
+	wmm_ptrs = kcalloc(coll->n_rules, sizeof(*wmm_ptrs), GFP_KERNEL);
+	if (!wmm_ptrs) {
+		kfree(regdom);
+		return -ENOMEM;
+	}
+
 	regdom->n_reg_rules = coll->n_rules;
 	regdom->alpha2[0] = country->alpha2[0];
 	regdom->alpha2[1] = country->alpha2[1];
@@ -851,7 +954,38 @@ static int regdb_query_country(const struct fwdb_header *db,
 		if (rule->len >= offsetofend(struct fwdb_rule, cac_timeout))
 			rrule->dfs_cac_ms =
 				1000 * be16_to_cpu(rule->cac_timeout);
+		if (rule->len >= offsetofend(struct fwdb_rule, wmm_ptr)) {
+			u32 wmm_ptr = be16_to_cpu(rule->wmm_ptr) << 2;
+			struct ieee80211_wmm_rule *wmm_pos =
+				find_wmm_ptr(wmm_ptrs, wmm_ptr, n_wmms);
+			struct fwdb_wmm_rule *wmm;
+			struct ieee80211_wmm_rule *wmm_rule;
+
+			if (wmm_pos) {
+				rrule->wmm_rule = wmm_pos;
+				continue;
+			}
+			wmm = (void *)((u8 *)db + wmm_ptr);
+			tmp_rd = krealloc(regdom, size_of_regd + (n_wmms + 1) *
+					  sizeof(struct ieee80211_wmm_rule),
+					  GFP_KERNEL);
+
+			if (!tmp_rd) {
+				kfree(regdom);
+				return -ENOMEM;
+			}
+			regdom = tmp_rd;
+
+			wmm_rule = (struct ieee80211_wmm_rule *)
+				((u8 *)regdom + size_of_regd + n_wmms *
+				sizeof(struct ieee80211_wmm_rule));
+
+			set_wmm_rule(wmm_rule, wmm);
+			wmm_ptrs[n_wmms].ptr = wmm_ptr;
+			wmm_ptrs[n_wmms++].rule = wmm_rule;
+		}
 	}
+	kfree(wmm_ptrs);
 
 	return reg_schedule_apply(regdom);
 }