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From:   Aloka Dixit <alokad@codeaurora.org>
To:     johannes@sipsolutions.net
Cc:     linux-wireless@vger.kernel.org, Aloka Dixit <alokad@codeaurora.org>
Subject: [PATCH v4 1/2] nl80211: Unsolicited broadcast probe response support
Date:   Tue, 11 Aug 2020 18:22:25 -0700
Message-Id: <20200812012226.11347-2-alokad@codeaurora.org>
In-Reply-To: <20200812012226.11347-1-alokad@codeaurora.org>
References: <20200812012226.11347-1-alokad@codeaurora.org>
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This patch adds new attributes to support unsolicited broadcast
probe response transmission used for in-band
discovery in 6GHz band (IEEE P802.11ax/D6.0 26.17.2.3.2, AP behavior for
fast passive scanning).
The new attribute, NL80211_ATTR_UNSOL_BCAST_PROBE_RESP, is nested which
supports following parameters:
(1) NL80211_UNSOL_BCAST_PROBE_RESP_INT - Packet interval
(2) NL80211_UNSOL_BCAST_PROBE_RESP_TMPL - Template data

Signed-off-by: Aloka Dixit <alokad@codeaurora.org>
---
v4: Addressed comments

 include/net/cfg80211.h       | 23 ++++++++++++++++++++
 include/uapi/linux/nl80211.h | 32 ++++++++++++++++++++++++++++
 net/wireless/nl80211.c       | 41 ++++++++++++++++++++++++++++++++++++
 3 files changed, 96 insertions(+)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index fc7e8807838d..e6f11c55f6bd 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1047,6 +1047,22 @@ struct cfg80211_acl_data {
 	struct mac_address mac_addrs[];
 };
 
+/**
+ * struct cfg80211_unsol_bcast_probe_resp - Unsolicited broadcast probe
+ *	response parameters in 6GHz.
+ *
+ * @interval: Packet interval in TUs. Maximum allowed is 20 TU, as mentioned
+ *	in IEEE P802.11ax/D6.0 26.17.2.3.2 - AP behavior for fast passive
+ *	scanning
+ * @tmpl_len: Template length
+ * @tmpl: Template data for probe response
+ */
+struct cfg80211_unsol_bcast_probe_resp {
+	u32 interval;
+	size_t tmpl_len;
+	const u8 *tmpl;
+};
+
 /**
  * enum cfg80211_ap_settings_flags - AP settings flags
  *
@@ -1094,6 +1110,7 @@ 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)
+ * @unsol_bcast_probe_resp: Unsolicited broadcast probe response parameters
  */
 struct cfg80211_ap_settings {
 	struct cfg80211_chan_def chandef;
@@ -1124,6 +1141,7 @@ struct cfg80211_ap_settings {
 	u32 flags;
 	struct ieee80211_he_obss_pd he_obss_pd;
 	struct cfg80211_he_bss_color he_bss_color;
+	struct cfg80211_unsol_bcast_probe_resp unsol_bcast_probe_resp;
 };
 
 /**
@@ -4737,6 +4755,9 @@ struct wiphy_iftype_akm_suites {
  *	HE AP, in order to avoid compatibility issues.
  *	@support_mbssid must be set for this to have any effect.
  *
+ * @support_unsol_bcast_probe_resp: can HW support unsolicited broadcast
+ *	probe response transmission
+ *
  * @pmsr_capa: peer measurement capabilities
  *
  * @tid_config_support: describes the per-TID config support that the
@@ -4880,6 +4901,8 @@ struct wiphy {
 	u8 support_mbssid:1,
 	   support_only_he_mbssid:1;
 
+	u8 support_unsol_bcast_probe_resp:1;
+
 	const struct cfg80211_pmsr_capabilities *pmsr_capa;
 
 	struct {
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 4e6339ab1fce..91d0b6bd3671 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -2505,6 +2505,10 @@ 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_UNSOL_BCAST_PROBE_RESP: Optional parameter to configure
+ *	unsolicited broadcast probe response. It is a nested attribute, see
+ *	&enum nl80211_unsol_bcast_probe_resp_attributes.
+ *
  * @NUM_NL80211_ATTR: total number of nl80211_attrs available
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
@@ -2987,6 +2991,8 @@ enum nl80211_attrs {
 
 	NL80211_ATTR_HE_6GHZ_CAPABILITY,
 
+	NL80211_ATTR_UNSOL_BCAST_PROBE_RESP,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,
@@ -6922,4 +6928,30 @@ enum nl80211_iftype_akm_attributes {
 	NL80211_IFTYPE_AKM_ATTR_MAX = __NL80211_IFTYPE_AKM_ATTR_LAST - 1,
 };
 
+/**
+ * enum nl80211_unsol_bcast_probe_resp_attributes - Unsolicited broadcast probe
+ *	response configuration. Applicable only in 6GHz.
+ *
+ * @__NL80211_UNSOL_BCAST_PROBE_RESP_INVALID: Invalid
+ *
+ * @NL80211_UNSOL_BCAST_PROBE_RESP_INT: Maximum packet interval (u32, TU).
+ *	Allowed range: 0..20 (TU = Time Unit). IEEE P802.11ax/D6.0
+ *	26.17.2.3.2 (AP behavior for fast passive scanning).
+ * @NL80211_UNSOL_BCAST_PROBE_RESP_TMPL: Unsolicited broadcast probe response
+ *	frame template (binary).
+ *
+ * @__NL80211_UNSOL_BCAST_PROBE_RESP_LAST: Internal
+ * @NL80211_UNSOL_BCAST_PROBE_RESP_MAX: highest attribute
+ */
+enum nl80211_unsol_bcast_probe_resp_attributes {
+	__NL80211_UNSOL_BCAST_PROBE_RESP_INVALID,
+
+	NL80211_UNSOL_BCAST_PROBE_RESP_INT,
+	NL80211_UNSOL_BCAST_PROBE_RESP_TMPL,
+
+	/* keep last */
+	__NL80211_UNSOL_BCAST_PROBE_RESP_LAST,
+	NL80211_UNSOL_BCAST_PROBE_RESP_MAX =
+		__NL80211_UNSOL_BCAST_PROBE_RESP_LAST - 1
+};
 #endif /* __LINUX_NL80211_H */
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 263ae395ad44..0193c40b2caa 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -360,6 +360,13 @@ nl80211_tid_config_attr_policy[NL80211_TID_CONFIG_ATTR_MAX + 1] = {
 			NLA_POLICY_NESTED(nl80211_txattr_policy),
 };
 
+static const struct nla_policy
+unsol_bcast_probe_resp_policy[NL80211_UNSOL_BCAST_PROBE_RESP_MAX + 1] = {
+	[NL80211_UNSOL_BCAST_PROBE_RESP_INT] = NLA_POLICY_MAX(NLA_U32, 20),
+	[NL80211_UNSOL_BCAST_PROBE_RESP_TMPL] = { .type = NLA_BINARY,
+						  .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 },
@@ -658,6 +665,8 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 		.type = NLA_EXACT_LEN,
 		.len = sizeof(struct ieee80211_he_6ghz_capa),
 	},
+	[NL80211_ATTR_UNSOL_BCAST_PROBE_RESP] =
+		NLA_POLICY_NESTED(unsol_bcast_probe_resp_policy),
 };
 
 /* policy for the key attributes */
@@ -4721,6 +4730,30 @@ static int nl80211_parse_he_bss_color(struct nlattr *attrs,
 	return 0;
 }
 
+static int
+nl80211_parse_unsol_bcast_probe_resp(struct nlattr *attrs,
+				     struct cfg80211_ap_settings *params)
+{
+	struct nlattr *tb[NL80211_UNSOL_BCAST_PROBE_RESP_MAX + 1];
+	int ret;
+	struct cfg80211_unsol_bcast_probe_resp *presp =
+					&params->unsol_bcast_probe_resp;
+
+	ret = nla_parse_nested(tb, NL80211_UNSOL_BCAST_PROBE_RESP_MAX, attrs,
+			       unsol_bcast_probe_resp_policy, NULL);
+	if (ret)
+		return ret;
+
+	if (!tb[NL80211_UNSOL_BCAST_PROBE_RESP_INT] ||
+	    !tb[NL80211_UNSOL_BCAST_PROBE_RESP_TMPL])
+		return -EINVAL;
+
+	presp->tmpl = nla_data(tb[NL80211_UNSOL_BCAST_PROBE_RESP_TMPL]);
+	presp->tmpl_len = nla_len(tb[NL80211_UNSOL_BCAST_PROBE_RESP_TMPL]);
+	presp->interval = nla_get_u32(tb[NL80211_UNSOL_BCAST_PROBE_RESP_INT]);
+	return 0;
+}
+
 static void nl80211_check_ap_rate_selectors(struct cfg80211_ap_settings *params,
 					    const u8 *rates)
 {
@@ -5027,6 +5060,14 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 			return err;
 	}
 
+	if (info->attrs[NL80211_ATTR_UNSOL_BCAST_PROBE_RESP]) {
+		err = nl80211_parse_unsol_bcast_probe_resp(
+			info->attrs[NL80211_ATTR_UNSOL_BCAST_PROBE_RESP],
+			&params);
+		if (err)
+			return err;
+	}
+
 	nl80211_calculate_ap_params(&params);
 
 	if (info->attrs[NL80211_ATTR_EXTERNAL_AUTH_SUPPORT])
-- 
2.25.0