nl80211: Add wmm rule attribute to NL80211_CMD_GET_WIPHY dump command

This will serve userspace entity to maintain its regulatory limitation.
More specifcally APs can use this data to calculate the WMM IE when
building: beacons, probe responses, assoc responses etc...
Signed-off-by: Haim Dreyfuss <haim.dreyfuss@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

include/uapi/linux/nl80211.h

@@ -11,6 +11,7 @@
  * Copyright 2008 Jouni Malinen <jouni.malinen@atheros.com>
  * Copyright 2008 Colin McCabe <colin@cozybit.com>
  * Copyright 2015-2017	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
@@ -3141,6 +3142,29 @@ enum nl80211_band_attr {
 
 #define NL80211_BAND_ATTR_HT_CAPA NL80211_BAND_ATTR_HT_CAPA
 
+/**
+ * enum nl80211_wmm_rule - regulatory wmm rule
+ *
+ * @__NL80211_WMMR_INVALID: attribute number 0 is reserved
+ * @NL80211_WMMR_CW_MIN: Minimum contention window slot.
+ * @NL80211_WMMR_CW_MAX: Maximum contention window slot.
+ * @NL80211_WMMR_AIFSN: Arbitration Inter Frame Space.
+ * @NL80211_WMMR_TXOP: Maximum allowed tx operation time.
+ * @nl80211_WMMR_MAX: highest possible wmm rule.
+ * @__NL80211_WMMR_LAST: Internal use.
+ */
+enum nl80211_wmm_rule {
+	__NL80211_WMMR_INVALID,
+	NL80211_WMMR_CW_MIN,
+	NL80211_WMMR_CW_MAX,
+	NL80211_WMMR_AIFSN,
+	NL80211_WMMR_TXOP,
+
+	/* keep last */
+	__NL80211_WMMR_LAST,
+	NL80211_WMMR_MAX = __NL80211_WMMR_LAST - 1
+};
+
 /**
  * enum nl80211_frequency_attr - frequency attributes
  * @__NL80211_FREQUENCY_ATTR_INVALID: attribute number 0 is reserved
@@ -3190,6 +3214,9 @@ enum nl80211_band_attr {
  *	on this channel in current regulatory domain.
  * @NL80211_FREQUENCY_ATTR_NO_10MHZ: 10 MHz operation is not allowed
  *	on this channel in current regulatory domain.
+ * @NL80211_FREQUENCY_ATTR_WMM: this channel has wmm limitations.
+ *	This is a nested attribute that contains the wmm limitation per AC.
+ *	(see &enum nl80211_wmm_rule)
  * @NL80211_FREQUENCY_ATTR_MAX: highest frequency attribute number
  *	currently defined
  * @__NL80211_FREQUENCY_ATTR_AFTER_LAST: internal use
@@ -3218,6 +3245,7 @@ enum nl80211_frequency_attr {
 	NL80211_FREQUENCY_ATTR_IR_CONCURRENT,
 	NL80211_FREQUENCY_ATTR_NO_20MHZ,
 	NL80211_FREQUENCY_ATTR_NO_10MHZ,
+	NL80211_FREQUENCY_ATTR_WMM,
 
 	/* keep last */
 	__NL80211_FREQUENCY_ATTR_AFTER_LAST,

net/wireless/nl80211.c

@@ -4,6 +4,7 @@
  * Copyright 2006-2010	Johannes Berg <johannes@sipsolutions.net>
  * Copyright 2013-2014  Intel Mobile Communications GmbH
  * Copyright 2015-2017	Intel Deutschland GmbH
+ * Copyright (C) 2018 Intel Corporation
  */
 
 #include <linux/if.h>
@@ -645,7 +646,43 @@ static inline void *nl80211hdr_put(struct sk_buff *skb, u32 portid, u32 seq,
 	return genlmsg_put(skb, portid, seq, &nl80211_fam, flags, cmd);
 }
 
-static int nl80211_msg_put_channel(struct sk_buff *msg,
+static int nl80211_msg_put_wmm_rules(struct sk_buff *msg,
+				     const struct ieee80211_reg_rule *rule)
+{
+	int j;
+	struct nlattr *nl_wmm_rules =
+		nla_nest_start(msg, NL80211_FREQUENCY_ATTR_WMM);
+
+	if (!nl_wmm_rules)
+		goto nla_put_failure;
+
+	for (j = 0; j < IEEE80211_NUM_ACS; j++) {
+		struct nlattr *nl_wmm_rule = nla_nest_start(msg, j);
+
+		if (!nl_wmm_rule)
+			goto nla_put_failure;
+
+		if (nla_put_u16(msg, NL80211_WMMR_CW_MIN,
+				rule->wmm_rule->client[j].cw_min) ||
+		    nla_put_u16(msg, NL80211_WMMR_CW_MAX,
+				rule->wmm_rule->client[j].cw_max) ||
+		    nla_put_u8(msg, NL80211_WMMR_AIFSN,
+			       rule->wmm_rule->client[j].aifsn) ||
+		    nla_put_u8(msg, NL80211_WMMR_TXOP,
+			       rule->wmm_rule->client[j].cot))
+			goto nla_put_failure;
+
+		nla_nest_end(msg, nl_wmm_rule);
+	}
+	nla_nest_end(msg, nl_wmm_rules);
+
+	return 0;
+
+nla_put_failure:
+	return -ENOBUFS;
+}
+
+static int nl80211_msg_put_channel(struct sk_buff *msg, struct wiphy *wiphy,
 				   struct ieee80211_channel *chan,
 				   bool large)
 {
@@ -721,6 +758,16 @@ static int nl80211_msg_put_channel(struct sk_buff *msg,
 			DBM_TO_MBM(chan->max_power)))
 		goto nla_put_failure;
 
+	if (large) {
+		const struct ieee80211_reg_rule *rule =
+			freq_reg_info(wiphy, chan->center_freq);
+
+		if (!IS_ERR(rule) && rule->wmm_rule) {
+			if (nl80211_msg_put_wmm_rules(msg, rule))
+				goto nla_put_failure;
+		}
+	}
+
 	return 0;
 
  nla_put_failure:
@@ -1631,7 +1678,7 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev,
 					chan = &sband->channels[i];
 
 					if (nl80211_msg_put_channel(
-							msg, chan,
+							msg, &rdev->wiphy, chan,
 							state->split))
 						goto nla_put_failure;
 
@@ -14320,7 +14367,8 @@ void nl80211_send_beacon_hint_event(struct wiphy *wiphy,
 	nl_freq = nla_nest_start(msg, NL80211_ATTR_FREQ_BEFORE);
 	if (!nl_freq)
 		goto nla_put_failure;
-	if (nl80211_msg_put_channel(msg, channel_before, false))
+
+	if (nl80211_msg_put_channel(msg, wiphy, channel_before, false))
 		goto nla_put_failure;
 	nla_nest_end(msg, nl_freq);
 
@@ -14328,7 +14376,8 @@ void nl80211_send_beacon_hint_event(struct wiphy *wiphy,
 	nl_freq = nla_nest_start(msg, NL80211_ATTR_FREQ_AFTER);
 	if (!nl_freq)
 		goto nla_put_failure;
-	if (nl80211_msg_put_channel(msg, channel_after, false))
+
+	if (nl80211_msg_put_channel(msg, wiphy, channel_after, false))
 		goto nla_put_failure;
 	nla_nest_end(msg, nl_freq);