[PATCH v5] cfg80211: Provision to allow the support for different beacon intervals

[PATCH v5] cfg80211: Provision to allow the support for different beacon intervals

[Purushottam Kushwaha]

This commit provides a mechanism for the host drivers to advertise the
support for different beacon intervals among the respective interface
combinations in a group, through diff_beacon_int_gcd (u32).

The configured BI for a specific interface must be a multiple of this
value and also the active beaconing interfaces (along with the current
one) must match with the interface combinations in a group that advertise
the support for different beacon interval.

Signed-off-by: Purushottam Kushwaha <pkushwah@qti.qualcomm.com>
---
 include/net/cfg80211.h       |  4 ++++
 include/uapi/linux/nl80211.h |  8 ++++++--
 net/wireless/core.h          |  2 +-
 net/wireless/nl80211.c       | 13 ++++++++++---
 net/wireless/util.c          | 39 +++++++++++++++++++++++++++++++++++++--
 5 files changed, 58 insertions(+), 8 deletions(-)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 9c23f4d3..a0c635a 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -2939,6 +2939,8 @@ struct ieee80211_iface_limit {
  *	only in special cases.
  * @radar_detect_widths: bitmap of channel widths supported for radar detection
  * @radar_detect_regions: bitmap of regions supported for radar detection
+ * @diff_beacon_int_gcd: This interface combination supports different beacon
+ *	intervals in multiple of GCD value.
  *
  * With this structure the driver can describe which interface
  * combinations it supports concurrently.
@@ -2970,6 +2972,7 @@ struct ieee80211_iface_limit {
  *	.n_limits = ARRAY_SIZE(limits2),
  *	.max_interfaces = 8,
  *	.num_different_channels = 1,
+ *	.diff_beacon_int_gcd = 100,
  *  };
  *
  *
@@ -2997,6 +3000,7 @@ struct ieee80211_iface_combination {
 	bool beacon_int_infra_match;
 	u8 radar_detect_widths;
 	u8 radar_detect_regions;
+	u32 diff_beacon_int_gcd;
 };
 
 struct ieee80211_txrx_stypes {
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 2206941..369e403 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -4203,6 +4203,9 @@ enum nl80211_iface_limit_attrs {
  *	of supported channel widths for radar detection.
  * @NL80211_IFACE_COMB_RADAR_DETECT_REGIONS: u32 attribute containing the bitmap
  *	of supported regulatory regions for radar detection.
+ * @NL80211_IFACE_COMB_DIFF_BI_GCD: u32 attribute specifying the GCD of
+ *	different beacon intervals supported by all the interface combinations
+ *	in this group (not present if all beacon interval must match).
  * @NUM_NL80211_IFACE_COMB: number of attributes
  * @MAX_NL80211_IFACE_COMB: highest attribute number
  *
@@ -4210,8 +4213,8 @@ enum nl80211_iface_limit_attrs {
  *	limits = [ #{STA} <= 1, #{AP} <= 1 ], matching BI, channels = 1, max = 2
  *	=> allows an AP and a STA that must match BIs
  *
- *	numbers = [ #{AP, P2P-GO} <= 8 ], channels = 1, max = 8
- *	=> allows 8 of AP/GO
+ *	numbers = [ #{AP, P2P-GO} <= 8 ], diff BI gcd, channels = 1, max = 8,
+ *	=> allows 8 of AP/GO that can beacon at multiple of gcd intervals
  *
  *	numbers = [ #{STA} <= 2 ], channels = 2, max = 2
  *	=> allows two STAs on different channels
@@ -4237,6 +4240,7 @@ enum nl80211_if_combination_attrs {
 	NL80211_IFACE_COMB_NUM_CHANNELS,
 	NL80211_IFACE_COMB_RADAR_DETECT_WIDTHS,
 	NL80211_IFACE_COMB_RADAR_DETECT_REGIONS,
+	NL80211_IFACE_COMB_DIFF_BI_GCD,
 
 	/* keep last */
 	NUM_NL80211_IFACE_COMB,
diff --git a/net/wireless/core.h b/net/wireless/core.h
index eee9144..5fffe58 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -475,7 +475,7 @@ int ieee80211_get_ratemask(struct ieee80211_supported_band *sband,
 			   u32 *mask);
 
 int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
-				 u32 beacon_int);
+				 enum nl80211_iftype iftype, u32 beacon_int);
 
 void cfg80211_update_iface_num(struct cfg80211_registered_device *rdev,
 			       enum nl80211_iftype iftype, int num);
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index ddb1469..d3b757d 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1020,6 +1020,10 @@ static int nl80211_put_iface_combinations(struct wiphy *wiphy,
 		     nla_put_u32(msg, NL80211_IFACE_COMB_RADAR_DETECT_REGIONS,
 				c->radar_detect_regions)))
 			goto nla_put_failure;
+		if (c->diff_beacon_int_gcd &&
+		    nla_put_u32(msg, NL80211_IFACE_COMB_DIFF_BI_GCD,
+				c->diff_beacon_int_gcd))
+			goto nla_put_failure;
 
 		nla_nest_end(msg, nl_combi);
 	}
@@ -3454,7 +3458,8 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 	params.dtim_period =
 		nla_get_u32(info->attrs[NL80211_ATTR_DTIM_PERIOD]);
 
-	err = cfg80211_validate_beacon_int(rdev, params.beacon_interval);
+	err = cfg80211_validate_beacon_int(rdev, dev->ieee80211_ptr->iftype,
+					   params.beacon_interval);
 	if (err)
 		return err;
 
@@ -7780,7 +7785,8 @@ static int nl80211_join_ibss(struct sk_buff *skb, struct genl_info *info)
 			return -EINVAL;
 	}
 
-	err = cfg80211_validate_beacon_int(rdev, ibss.beacon_interval);
+	err = cfg80211_validate_beacon_int(rdev, NL80211_IFTYPE_ADHOC,
+					   ibss.beacon_interval);
 	if (err)
 		return err;
 
@@ -9260,7 +9266,8 @@ static int nl80211_join_mesh(struct sk_buff *skb, struct genl_info *info)
 		    setup.beacon_interval > 10000)
 			return -EINVAL;
 
-		err = cfg80211_validate_beacon_int(rdev, setup.beacon_interval);
+		err = cfg80211_validate_beacon_int(rdev, NL80211_IFTYPE_MESH_POINT,
+						   setup.beacon_interval);
 		if (err)
 			return err;
 	}
diff --git a/net/wireless/util.c b/net/wireless/util.c
index b7d1592..ff9a9cb 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -1553,10 +1553,36 @@ bool ieee80211_chandef_to_operating_class(struct cfg80211_chan_def *chandef,
 }
 EXPORT_SYMBOL(ieee80211_chandef_to_operating_class);
 
+static bool diff_beacon_interval_supported(struct wiphy *wiphy, u16 types,
+					   u32 beacon_int)
+{
+	const struct ieee80211_iface_combination *c;
+	u16 all_types;
+	int i, j;
+
+	for (i = 0; i < wiphy->n_iface_combinations; i++) {
+		c = &wiphy->iface_combinations[i];
+
+		if (!c->diff_beacon_int_gcd ||
+		    (beacon_int % c->diff_beacon_int_gcd))
+			continue;
+
+		all_types = 0;
+		for (j = 0; j < c->n_limits; j++)
+			all_types |= c->limits[j].types;
+
+		if (all_types & types)
+			return true;
+	}
+
+	return false;
+}
+
 int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
-				 u32 beacon_int)
+				 enum nl80211_iftype iftype, u32 beacon_int)
 {
 	struct wireless_dev *wdev;
+	u16 types = 0;
 	int res = 0;
 
 	if (!beacon_int)
@@ -1565,7 +1591,16 @@ int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
 	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
 		if (!wdev->beacon_interval)
 			continue;
-		if (wdev->beacon_interval != beacon_int) {
+		types |= BIT(wdev->iftype);
+	}
+	types |= BIT(iftype);
+
+	list_for_each_entry(wdev, &rdev->wiphy.wdev_list, list) {
+		if (!wdev->beacon_interval)
+			continue;
+		if (wdev->beacon_interval != beacon_int &&
+		    !diff_beacon_interval_supported(&rdev->wiphy, types,
+						    beacon_int)) {
 			res = -EINVAL;
 			break;
 		}
-- 
1.9.1

Re: [PATCH v5] cfg80211: Provision to allow the support for different beacon intervals

[Johannes Berg]

> +static bool diff_beacon_interval_supported(struct wiphy *wiphy, u16
> types,
> +					   u32 beacon_int)
> +{
> +	const struct ieee80211_iface_combination *c;
> +	u16 all_types;
> +	int i, j;
> +
> +	for (i = 0; i < wiphy->n_iface_combinations; i++) {
> +		c = &wiphy->iface_combinations[i];
> +
> +		if (!c->diff_beacon_int_gcd ||
> +		    (beacon_int % c->diff_beacon_int_gcd))
> +			continue;
> +
> +		all_types = 0;
> +		for (j = 0; j < c->n_limits; j++)
> +			all_types |= c->limits[j].types;
> +
> +		if (all_types & types)
> +			return true;
> +	}
> +
> +	return false;
> +}

This seems odd. Shouldn't it use cfg80211_iter_combinations()? Might
need some additional helper to understand which interface types are
used right now - seems we mostly moved that to mac80211, but for this
case it should probably stay in cfg80211? Or should it?

johannes

RE: [PATCH v5] cfg80211: Provision to allow the support for different beacon intervals

[Undekari, Sunil Dutt]

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