nl80211: Add FILS discovery support

FILS discovery attribute, NL80211_ATTR_FILS_DISCOVERY, is nested which
supports following parameters as given in IEEE Std 802.11ai-2016,
Annex C.3 MIB detail:
(1) NL80211_FILS_DISCOVERY_ATTR_INT_MIN - Minimum packet interval
(2) NL80211_FILS_DISCOVERY_ATTR_INT_MAX - Maximum packet interval
(3) NL80211_FILS_DISCOVERY_ATTR_TMPL - Template data
Signed-off-by: Aloka Dixit <alokad@codeaurora.org>
Link: https://lore.kernel.org/r/20200805011838.28166-2-alokad@codeaurora.org
[fix attribute and other names, use NLA_RANGE(), use policy only once]
Link: https://lore.kernel.org/r/010101747a7b38a8-306f06b2-9061-4baf-81c1-054a42a18e22-000000@us-west-2.amazonses.comSigned-off-by: Johannes Berg <johannes.berg@intel.com>

include/net/cfg80211.h

@@ -1082,6 +1082,23 @@ struct cfg80211_acl_data {
 	struct mac_address mac_addrs[];
 };
 
+/**
+ * struct cfg80211_fils_discovery - FILS discovery parameters from
+ * IEEE Std 802.11ai-2016, Annex C.3 MIB detail.
+ *
+ * @min_interval: Minimum packet interval in TUs (0 - 10000)
+ * @max_interval: Maximum packet interval in TUs (0 - 10000)
+ * @tmpl_len: Template length
+ * @tmpl: Template data for FILS discovery frame including the action
+ *	frame headers.
+ */
+struct cfg80211_fils_discovery {
+	u32 min_interval;
+	u32 max_interval;
+	size_t tmpl_len;
+	const u8 *tmpl;
+};
+
 /**
  * enum cfg80211_ap_settings_flags - AP settings flags
  *
@@ -1129,6 +1146,7 @@ enum cfg80211_ap_settings_flags {
  * @he_obss_pd: OBSS Packet Detection settings
  * @he_bss_color: BSS Color settings
  * @he_oper: HE operation IE (or %NULL if HE isn't enabled)
+ * @fils_discovery: FILS discovery transmission parameters
  */
 struct cfg80211_ap_settings {
 	struct cfg80211_chan_def chandef;
@@ -1159,6 +1177,7 @@ struct cfg80211_ap_settings {
 	u32 flags;
 	struct ieee80211_he_obss_pd he_obss_pd;
 	struct cfg80211_he_bss_color he_bss_color;
+	struct cfg80211_fils_discovery fils_discovery;
 };
 
 /**

include/uapi/linux/nl80211.h

@@ -2513,6 +2513,10 @@ enum nl80211_commands {
  * @NL80211_ATTR_HE_6GHZ_CAPABILITY: HE 6 GHz Band Capability element (from
  *	association request when used with NL80211_CMD_NEW_STATION).
  *
+ * @NL80211_ATTR_FILS_DISCOVERY: Optional parameter to configure FILS
+ *	discovery. It is a nested attribute, see
+ *	&enum nl80211_fils_discovery_attributes.
+ *
  * @NUM_NL80211_ATTR: total number of nl80211_attrs available
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
@@ -2995,6 +2999,8 @@ enum nl80211_attrs {
 
 	NL80211_ATTR_HE_6GHZ_CAPABILITY,
 
+	NL80211_ATTR_FILS_DISCOVERY,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,
@@ -5867,6 +5873,9 @@ enum nl80211_feature_flags {
  * @NL80211_EXT_FEATURE_SAE_OFFLOAD_AP: Device wants to do SAE authentication
  *	in AP mode (SAE password is passed as part of the start AP command).
  *
+ * @NL80211_EXT_FEATURE_FILS_DISCOVERY: Driver/device supports FILS discovery
+ *	frames transmission
+ *
  * @NUM_NL80211_EXT_FEATURES: number of extended features.
  * @MAX_NL80211_EXT_FEATURES: highest extended feature index.
  */
@@ -5925,6 +5934,7 @@ enum nl80211_ext_feature_index {
 	NL80211_EXT_FEATURE_OPERATING_CHANNEL_VALIDATION,
 	NL80211_EXT_FEATURE_4WAY_HANDSHAKE_AP_PSK,
 	NL80211_EXT_FEATURE_SAE_OFFLOAD_AP,
+	NL80211_EXT_FEATURE_FILS_DISCOVERY,
 
 	/* add new features before the definition below */
 	NUM_NL80211_EXT_FEATURES,
@@ -7019,4 +7029,38 @@ enum nl80211_iftype_akm_attributes {
 	NL80211_IFTYPE_AKM_ATTR_MAX = __NL80211_IFTYPE_AKM_ATTR_LAST - 1,
 };
 
+/**
+ * enum nl80211_fils_discovery_attributes - FILS discovery configuration
+ * from IEEE Std 802.11ai-2016, Annex C.3 MIB detail.
+ *
+ * @__NL80211_FILS_DISCOVERY_ATTR_INVALID: Invalid
+ *
+ * @NL80211_FILS_DISCOVERY_ATTR_INT_MIN: Minimum packet interval (u32, TU).
+ *	Allowed range: 0..10000 (TU = Time Unit)
+ * @NL80211_FILS_DISCOVERY_ATTR_INT_MAX: Maximum packet interval (u32, TU).
+ *	Allowed range: 0..10000 (TU = Time Unit)
+ * @NL80211_FILS_DISCOVERY_ATTR_TMPL: Template data for FILS discovery action
+ *	frame including the headers.
+ *
+ * @__NL80211_FILS_DISCOVERY_ATTR_LAST: Internal
+ * @NL80211_FILS_DISCOVERY_ATTR_MAX: highest attribute
+ */
+enum nl80211_fils_discovery_attributes {
+	__NL80211_FILS_DISCOVERY_ATTR_INVALID,
+
+	NL80211_FILS_DISCOVERY_ATTR_INT_MIN,
+	NL80211_FILS_DISCOVERY_ATTR_INT_MAX,
+	NL80211_FILS_DISCOVERY_ATTR_TMPL,
+
+	/* keep last */
+	__NL80211_FILS_DISCOVERY_ATTR_LAST,
+	NL80211_FILS_DISCOVERY_ATTR_MAX = __NL80211_FILS_DISCOVERY_ATTR_LAST - 1
+};
+
+/*
+ * FILS discovery template minimum length with action frame headers and
+ * mandatory fields.
+ */
+#define NL80211_FILS_DISCOVERY_TMPL_MIN_LEN 42
+
 #endif /* __LINUX_NL80211_H */

net/wireless/nl80211.c

@@ -376,6 +376,15 @@ nl80211_tid_config_attr_policy[NL80211_TID_CONFIG_ATTR_MAX + 1] = {
 			NLA_POLICY_NESTED(nl80211_txattr_policy),
 };
 
+static const struct nla_policy
+nl80211_fils_discovery_policy[NL80211_FILS_DISCOVERY_ATTR_MAX + 1] = {
+	[NL80211_FILS_DISCOVERY_ATTR_INT_MIN] = NLA_POLICY_MAX(NLA_U32, 10000),
+	[NL80211_FILS_DISCOVERY_ATTR_INT_MAX] = NLA_POLICY_MAX(NLA_U32, 10000),
+	NLA_POLICY_RANGE(NLA_BINARY,
+			 NL80211_FILS_DISCOVERY_TMPL_MIN_LEN,
+			 IEEE80211_MAX_DATA_LEN),
+};
+
 static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 	[0] = { .strict_start_type = NL80211_ATTR_HE_OBSS_PD },
 	[NL80211_ATTR_WIPHY] = { .type = NLA_U32 },
@@ -684,6 +693,8 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 	[NL80211_ATTR_SCAN_FREQ_KHZ] = { .type = NLA_NESTED },
 	[NL80211_ATTR_HE_6GHZ_CAPABILITY] =
 		NLA_POLICY_EXACT_LEN(sizeof(struct ieee80211_he_6ghz_capa)),
+	[NL80211_ATTR_FILS_DISCOVERY] =
+		NLA_POLICY_NESTED(nl80211_fils_discovery_policy),
 };
 
 /* policy for the key attributes */
@@ -4874,6 +4885,36 @@ static int nl80211_parse_he_bss_color(struct nlattr *attrs,
 	return 0;
 }
 
+static int nl80211_parse_fils_discovery(struct cfg80211_registered_device *rdev,
+					struct nlattr *attrs,
+					struct cfg80211_ap_settings *params)
+{
+	struct nlattr *tb[NL80211_FILS_DISCOVERY_ATTR_MAX + 1];
+	int ret;
+	struct cfg80211_fils_discovery *fd = &params->fils_discovery;
+
+	if (!wiphy_ext_feature_isset(&rdev->wiphy,
+				     NL80211_EXT_FEATURE_FILS_DISCOVERY))
+		return -EINVAL;
+
+	ret = nla_parse_nested(tb, NL80211_FILS_DISCOVERY_ATTR_MAX, attrs,
+			       NULL, NULL);
+	if (ret)
+		return ret;
+
+	if (!tb[NL80211_FILS_DISCOVERY_ATTR_INT_MIN] ||
+	    !tb[NL80211_FILS_DISCOVERY_ATTR_INT_MAX] ||
+	    !tb[NL80211_FILS_DISCOVERY_ATTR_TMPL])
+		return -EINVAL;
+
+	fd->tmpl_len = nla_len(tb[NL80211_FILS_DISCOVERY_ATTR_TMPL]);
+	fd->tmpl = nla_data(tb[NL80211_FILS_DISCOVERY_ATTR_TMPL]);
+	fd->min_interval = nla_get_u32(tb[NL80211_FILS_DISCOVERY_ATTR_INT_MIN]);
+	fd->max_interval = nla_get_u32(tb[NL80211_FILS_DISCOVERY_ATTR_INT_MAX]);
+
+	return 0;
+}
+
 static void nl80211_check_ap_rate_selectors(struct cfg80211_ap_settings *params,
 					    const u8 *rates)
 {
@@ -5182,6 +5223,14 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 			goto out;
 	}
 
+	if (info->attrs[NL80211_ATTR_FILS_DISCOVERY]) {
+		err = nl80211_parse_fils_discovery(rdev,
+						   info->attrs[NL80211_ATTR_FILS_DISCOVERY],
+						   &params);
+		if (err)
+			goto out;
+	}
+
 	nl80211_calculate_ap_params(&params);
 
 	if (info->attrs[NL80211_ATTR_EXTERNAL_AUTH_SUPPORT])