cfg80211: fix NAN bands definition

The nl80211_nan_dual_band_conf enumeration doesn't make much sense.
The default value is assigned to a bit, which makes it weird if the
default bit and other bits are set at the same time.

To improve this, get rid of NL80211_NAN_BAND_DEFAULT and add a wiphy
configuration to let the drivers define which bands are supported.
This is exposed to the userspace, which then can make a decision on
which band(s) to use.  Additionally, rename all "dual_band" elements
to "bands", to make things clearer.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

3 files changed, 37 insertions, 17 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 903fc419217a..e55e05bc4805 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -626,7 +626,8 @@ int wiphy_register(struct wiphy *wiphy)
 
 	if (WARN_ON((wiphy->interface_modes & BIT(NL80211_IFTYPE_NAN)) &&
 		    (!rdev->ops->start_nan || !rdev->ops->stop_nan ||
-		     !rdev->ops->add_nan_func || !rdev->ops->del_nan_func)))
+		     !rdev->ops->add_nan_func || !rdev->ops->del_nan_func ||
+		     !(wiphy->nan_supported_bands & BIT(NL80211_BAND_2GHZ)))))
 		return -EINVAL;
 
 #ifndef CONFIG_WIRELESS_WDS
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 9d738f75bd4e..b5f755b3ac5d 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -398,7 +398,7 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 	},
 	[NL80211_ATTR_MU_MIMO_FOLLOW_MAC_ADDR] = { .len = ETH_ALEN },
 	[NL80211_ATTR_NAN_MASTER_PREF] = { .type = NLA_U8 },
-	[NL80211_ATTR_NAN_DUAL] = { .type = NLA_U8 },
+	[NL80211_ATTR_BANDS] = { .type = NLA_U32 },
 	[NL80211_ATTR_NAN_FUNC] = { .type = NLA_NESTED },
 	[NL80211_ATTR_FILS_KEK] = { .type = NLA_BINARY,
 				    .len = FILS_MAX_KEK_LEN },
@@ -1886,6 +1886,10 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev,
 			}
 		}
 
+		if (nla_put_u32(msg, NL80211_ATTR_BANDS,
+				rdev->wiphy.nan_supported_bands))
+			goto nla_put_failure;
+
 		/* done */
 		state->split_start = 0;
 		break;
@@ -10777,15 +10781,22 @@ static int nl80211_start_nan(struct sk_buff *skb, struct genl_info *info)
 	if (!info->attrs[NL80211_ATTR_NAN_MASTER_PREF])
 		return -EINVAL;
 
-	if (!info->attrs[NL80211_ATTR_NAN_DUAL])
-		return -EINVAL;
-
 	conf.master_pref =
 		nla_get_u8(info->attrs[NL80211_ATTR_NAN_MASTER_PREF]);
 	if (!conf.master_pref)
 		return -EINVAL;
 
-	conf.dual = nla_get_u8(info->attrs[NL80211_ATTR_NAN_DUAL]);
+	if (info->attrs[NL80211_ATTR_BANDS]) {
+		u32 bands = nla_get_u32(info->attrs[NL80211_ATTR_BANDS]);
+
+		if (bands & ~(u32)wdev->wiphy->nan_supported_bands)
+			return -EOPNOTSUPP;
+
+		if (bands && !(bands & BIT(NL80211_BAND_2GHZ)))
+			return -EINVAL;
+
+		conf.bands = bands;
+	}
 
 	err = rdev_start_nan(rdev, wdev, &conf);
 	if (err)
@@ -11150,9 +11161,17 @@ static int nl80211_nan_change_config(struct sk_buff *skb,
 		changed |= CFG80211_NAN_CONF_CHANGED_PREF;
 	}
 
-	if (info->attrs[NL80211_ATTR_NAN_DUAL]) {
-		conf.dual = nla_get_u8(info->attrs[NL80211_ATTR_NAN_DUAL]);
-		changed |= CFG80211_NAN_CONF_CHANGED_DUAL;
+	if (info->attrs[NL80211_ATTR_BANDS]) {
+		u32 bands = nla_get_u32(info->attrs[NL80211_ATTR_BANDS]);
+
+		if (bands & ~(u32)wdev->wiphy->nan_supported_bands)
+			return -EOPNOTSUPP;
+
+		if (bands && !(bands & BIT(NL80211_BAND_2GHZ)))
+			return -EINVAL;
+
+		conf.bands = bands;
+		changed |= CFG80211_NAN_CONF_CHANGED_BANDS;
 	}
 
 	if (!changed)
diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index 2419c390f150..776e80cef9b4 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -1915,18 +1915,18 @@ TRACE_EVENT(rdev_start_nan,
 		WIPHY_ENTRY
 		WDEV_ENTRY
 		__field(u8, master_pref)
-		__field(u8, dual);
+		__field(u8, bands);
 	),
 	TP_fast_assign(
 		WIPHY_ASSIGN;
 		WDEV_ASSIGN;
 		__entry->master_pref = conf->master_pref;
-		__entry->dual = conf->dual;
+		__entry->bands = conf->bands;
 	),
 	TP_printk(WIPHY_PR_FMT ", " WDEV_PR_FMT
-		  ", master preference: %u, dual: %d",
+		  ", master preference: %u, bands: 0x%0x",
 		  WIPHY_PR_ARG, WDEV_PR_ARG, __entry->master_pref,
-		  __entry->dual)
+		  __entry->bands)
 );
 
 TRACE_EVENT(rdev_nan_change_conf,
@@ -1937,20 +1937,20 @@ TRACE_EVENT(rdev_nan_change_conf,
 		WIPHY_ENTRY
 		WDEV_ENTRY
 		__field(u8, master_pref)
-		__field(u8, dual);
+		__field(u8, bands);
 		__field(u32, changes);
 	),
 	TP_fast_assign(
 		WIPHY_ASSIGN;
 		WDEV_ASSIGN;
 		__entry->master_pref = conf->master_pref;
-		__entry->dual = conf->dual;
+		__entry->bands = conf->bands;
 		__entry->changes = changes;
 	),
 	TP_printk(WIPHY_PR_FMT ", " WDEV_PR_FMT
-		  ", master preference: %u, dual: %d, changes: %x",
+		  ", master preference: %u, bands: 0x%0x, changes: %x",
 		  WIPHY_PR_ARG, WDEV_PR_ARG, __entry->master_pref,
-		  __entry->dual, __entry->changes)
+		  __entry->bands, __entry->changes)
 );
 
 DEFINE_EVENT(wiphy_wdev_evt, rdev_stop_nan,