cfg80211: make wmm_rule part of the reg_rule structure

Make wmm_rule be part of the reg_rule structure. This simplifies the
code a lot at the cost of having bigger memory usage. However in most
cases we have only few reg_rule's and when we do have many like in
iwlwifi we do not save memory as it allocates a separate wmm_rule for
each channel anyway.

This also fixes a bug reported in various places where somewhere the
pointers were corrupted and we ended up doing a null-dereference.

Fixes: 230ebaa189af ("cfg80211: read wmm rules from regulatory database")
Signed-off-by: Stanislaw Gruszka <[e-mail]>
[rephrase commit message slightly]
Signed-off-by: Johannes Berg <[e-mail]>

drivers/net/wireless/intel/iwlwifi/iwl-nvm-parse.c

···
 	const u8 *nvm_chan = cfg->nvm_type == IWL_NVM_EXT ?
 			     iwl_ext_nvm_channels : iwl_nvm_channels;
 	struct ieee80211_regdomain *regd, *copy_rd;
-	int size_of_regd, regd_to_copy, wmms_to_copy;
-	int size_of_wmms = 0;
+	int size_of_regd, regd_to_copy;
 	struct ieee80211_reg_rule *rule;
-	struct ieee80211_wmm_rule *wmm_rule, *d_wmm, *s_wmm;
 	struct regdb_ptrs *regdb_ptrs;
 	enum nl80211_band band;
 	int center_freq, prev_center_freq = 0;
-	int valid_rules = 0, n_wmms = 0;
-	int i;
+	int valid_rules = 0;
 	bool new_rule;
 	int max_num_ch = cfg->nvm_type == IWL_NVM_EXT ?
 			 IWL_NVM_NUM_CHANNELS_EXT : IWL_NVM_NUM_CHANNELS;
···
 		sizeof(struct ieee80211_regdomain) +
 		num_of_ch * sizeof(struct ieee80211_reg_rule);
 
-	if (geo_info & GEO_WMM_ETSI_5GHZ_INFO)
-		size_of_wmms =
-			num_of_ch * sizeof(struct ieee80211_wmm_rule);
-
-	regd = kzalloc(size_of_regd + size_of_wmms, GFP_KERNEL);
+	regd = kzalloc(size_of_regd, GFP_KERNEL);
 	if (!regd)
 		return ERR_PTR(-ENOMEM);
 
···
 	/* set alpha2 from FW. */
 	regd->alpha2[0] = fw_mcc >> 8;
 	regd->alpha2[1] = fw_mcc & 0xff;
-
-	wmm_rule = (struct ieee80211_wmm_rule *)((u8 *)regd + size_of_regd);
 
 	for (ch_idx = 0; ch_idx < num_of_ch; ch_idx++) {
 		ch_flags = (u16)__le32_to_cpup(channels + ch_idx);
···
 		    band == NL80211_BAND_2GHZ)
 			continue;
 
-		if (!reg_query_regdb_wmm(regd->alpha2, center_freq,
-					 &regdb_ptrs[n_wmms].token, wmm_rule)) {
-			/* Add only new rules */
-			for (i = 0; i < n_wmms; i++) {
-				if (regdb_ptrs[i].token ==
-				    regdb_ptrs[n_wmms].token) {
-					rule->wmm_rule = regdb_ptrs[i].rule;
-					break;
-				}
-			}
-			if (i == n_wmms) {
-				rule->wmm_rule = wmm_rule;
-				regdb_ptrs[n_wmms++].rule = wmm_rule;
-				wmm_rule++;
-			}
-		}
+		reg_query_regdb_wmm(regd->alpha2, center_freq, rule);
 	}
 
 	regd->n_reg_rules = valid_rules;
-	regd->n_wmm_rules = n_wmms;
 
 	/*
 	 * Narrow down regdom for unused regulatory rules to prevent hole
···
 	regd_to_copy = sizeof(struct ieee80211_regdomain) +
 		valid_rules * sizeof(struct ieee80211_reg_rule);
 
-	wmms_to_copy = sizeof(struct ieee80211_wmm_rule) * n_wmms;
-
-	copy_rd = kzalloc(regd_to_copy + wmms_to_copy, GFP_KERNEL);
+	copy_rd = kzalloc(regd_to_copy, GFP_KERNEL);
 	if (!copy_rd) {
 		copy_rd = ERR_PTR(-ENOMEM);
 		goto out;
 	}
 
 	memcpy(copy_rd, regd, regd_to_copy);
-	memcpy((u8 *)copy_rd + regd_to_copy, (u8 *)regd + size_of_regd,
-	       wmms_to_copy);
-
-	d_wmm = (struct ieee80211_wmm_rule *)((u8 *)copy_rd + regd_to_copy);
-	s_wmm = (struct ieee80211_wmm_rule *)((u8 *)regd + size_of_regd);
-
-	for (i = 0; i < regd->n_reg_rules; i++) {
-		if (!regd->reg_rules[i].wmm_rule)
-			continue;
-
-		copy_rd->reg_rules[i].wmm_rule = d_wmm +
-			(regd->reg_rules[i].wmm_rule - s_wmm);
-	}
 
 out:
 	kfree(regdb_ptrs);

include/net/cfg80211.h

···
  *
  * Return: 0 on success. -ENODATA.
  */
-int reg_query_regdb_wmm(char *alpha2, int freq, u32 *ptr,
-			struct ieee80211_wmm_rule *rule);
+int reg_query_regdb_wmm(char *alpha2, int freq,
+			struct ieee80211_reg_rule *rule);
 
 /*
  * callbacks for asynchronous cfg80211 methods, notification

include/net/regulatory.h

···
 struct ieee80211_reg_rule {
 	struct ieee80211_freq_range freq_range;
 	struct ieee80211_power_rule power_rule;
-	struct ieee80211_wmm_rule *wmm_rule;
+	struct ieee80211_wmm_rule wmm_rule;
 	u32 flags;
 	u32 dfs_cac_ms;
+	bool has_wmm;
 };
 
 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/mac80211/util.c

···
 {
 	struct ieee80211_chanctx_conf *chanctx_conf;
 	const struct ieee80211_reg_rule *rrule;
-	struct ieee80211_wmm_ac *wmm_ac;
+	const struct ieee80211_wmm_ac *wmm_ac;
 	u16 center_freq = 0;
 
 	if (sdata->vif.type != NL80211_IFTYPE_AP &&
···
 
 	rrule = freq_reg_info(sdata->wdev.wiphy, MHZ_TO_KHZ(center_freq));
 
-	if (IS_ERR_OR_NULL(rrule) || !rrule->wmm_rule) {
+	if (IS_ERR_OR_NULL(rrule) || !rrule->has_wmm) {
 		rcu_read_unlock();
 		return;
 	}
 
 	if (sdata->vif.type == NL80211_IFTYPE_AP)
-		wmm_ac = &rrule->wmm_rule->ap[ac];
+		wmm_ac = &rrule->wmm_rule.ap[ac];
 	else
-		wmm_ac = &rrule->wmm_rule->client[ac];
+		wmm_ac = &rrule->wmm_rule.client[ac];
 	qparam->cw_min = max_t(u16, qparam->cw_min, wmm_ac->cw_min);
 	qparam->cw_max = max_t(u16, qparam->cw_max, wmm_ac->cw_max);
 	qparam->aifs = max_t(u8, qparam->aifs, wmm_ac->aifsn);

net/wireless/nl80211.c

···
 			goto nla_put_failure;
 
 		if (nla_put_u16(msg, NL80211_WMMR_CW_MIN,
-				rule->wmm_rule->client[j].cw_min) ||
+				rule->wmm_rule.client[j].cw_min) ||
 		    nla_put_u16(msg, NL80211_WMMR_CW_MAX,
-				rule->wmm_rule->client[j].cw_max) ||
+				rule->wmm_rule.client[j].cw_max) ||
 		    nla_put_u8(msg, NL80211_WMMR_AIFSN,
-			       rule->wmm_rule->client[j].aifsn) ||
+			       rule->wmm_rule.client[j].aifsn) ||
 		    nla_put_u8(msg, NL80211_WMMR_TXOP,
-			       rule->wmm_rule->client[j].cot))
+			       rule->wmm_rule.client[j].cot))
 			goto nla_put_failure;
 
 		nla_nest_end(msg, nl_wmm_rule);
···
 		const struct ieee80211_reg_rule *rule =
 			freq_reg_info(wiphy, chan->center_freq);
 
-		if (!IS_ERR(rule) && rule->wmm_rule) {
+		if (!IS_ERR_OR_NULL(rule) && rule->has_wmm) {
 			if (nl80211_msg_put_wmm_rules(msg, rule))
 				goto nla_put_failure;
 		}

net/wireless/reg.c

···
 reg_copy_regd(const struct ieee80211_regdomain *src_regd)
 {
 	struct ieee80211_regdomain *regd;
-	int size_of_regd, size_of_wmms;
+	int size_of_regd;
 	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 + size_of_wmms, GFP_KERNEL);
+	regd = kzalloc(size_of_regd, GFP_KERNEL);
 	if (!regd)
 		return ERR_PTR(-ENOMEM);
 
 	memcpy(regd, src_regd, sizeof(struct ieee80211_regdomain));
 
-	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++) {
+	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);
-	}
 	return regd;
 }
 
···
 	return true;
 }
 
-static void set_wmm_rule(struct ieee80211_wmm_rule *rule,
+static void set_wmm_rule(struct ieee80211_reg_rule *rrule,
 			 struct fwdb_wmm_rule *wmm)
 {
+	struct ieee80211_wmm_rule *rule = &rrule->wmm_rule;
 	unsigned int i;
 
 	for (i = 0; i < IEEE80211_NUM_ACS; i++) {
···
 		rule->ap[i].aifsn = wmm->ap[i].aifsn;
 		rule->ap[i].cot = 1000 * be16_to_cpu(wmm->ap[i].cot);
 	}
+
+	rrule->has_wmm = true;
 }
 
 static int __regdb_query_wmm(const struct fwdb_header *db,
 			     const struct fwdb_country *country, int freq,
-			     u32 *dbptr, struct ieee80211_wmm_rule *rule)
+			     struct ieee80211_reg_rule *rule)
 {
 	unsigned int ptr = be16_to_cpu(country->coll_ptr) << 2;
 	struct fwdb_collection *coll = (void *)((u8 *)db + ptr);
···
 			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)
+int reg_query_regdb_wmm(char *alpha2, int freq, struct ieee80211_reg_rule *rule)
 {
 	const struct fwdb_header *hdr = regdb;
 	const struct fwdb_country *country;
···
 	country = &hdr->country[0];
 	while (country->coll_ptr) {
 		if (alpha2_equal(alpha2, country->alpha2))
-			return __regdb_query_wmm(regdb, country, freq, dbptr,
-						 rule);
+			return __regdb_query_wmm(regdb, country, freq, rule);
 
 		country++;
 	}
···
 }
 EXPORT_SYMBOL(reg_query_regdb_wmm);
 
-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;
-	struct ieee80211_regdomain *tmp_rd;
-	unsigned int size_of_regd, i, n_wmms = 0;
-	struct wmm_ptrs *wmm_ptrs;
+	unsigned int size_of_regd, i;
 
 	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];
···
 				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;
+			struct fwdb_wmm_rule *wmm = (void *)((u8 *)db + wmm_ptr);
 
-			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);
-				kfree(wmm_ptrs);
-				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;
+			set_wmm_rule(rrule, wmm);
 		}
 	}
-	kfree(wmm_ptrs);
 
 	return reg_schedule_apply(regdom);
 }