[PATCH wireless-next v3 02/21] wifi: nl80211/cfg80211: define interfaces for SMD setup and STA update

[Pooventhiran G <pooventhiran.g@oss.qualcomm.com>]

From: Aditya Sathish <asathish@qti.qualcomm.com>

Define nl80211 and cfg80211 interfaces to support SMD setup for an AP
MLD and the non-AP STA MLD creation upon SMD negotiation.

Allow only APs affiliated to an AP MLD to enable SMD while starting.
STA creation can happen in two ways: typical 802.11 association with SMD
negotiated or via SMD BSS Transition Preparation on the target AP MLD;
the latter should be marked explicitly to inform drivers so that they
can handle ST Execution and datapath switch once the ST procedure is
completed.

Signed-off-by: Aditya Sathish <asathish@qti.qualcomm.com>
Co-developed-by: Rohan Dutta <drohan@qti.qualcomm.com>
Signed-off-by: Rohan Dutta <drohan@qti.qualcomm.com>
Co-developed-by: Sidhanta Sahu <sidhanta.sahu@oss.qualcomm.com>
Signed-off-by: Sidhanta Sahu <sidhanta.sahu@oss.qualcomm.com>
Signed-off-by: Pooventhiran G <pooventhiran.g@oss.qualcomm.com>
---
 include/net/cfg80211.h       | 15 ++++++++++
 include/uapi/linux/nl80211.h | 10 +++++++
 net/wireless/nl80211.c       | 68 +++++++++++++++++++++++++++++++++++++++-----
 3 files changed, 86 insertions(+), 7 deletions(-)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index b4f384ade47a..54d549afd8e3 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1624,6 +1624,7 @@ struct cfg80211_s1g_short_beacon {
  * @mbssid_config: AP settings for multiple bssid
  * @s1g_long_beacon_period: S1G long beacon period
  * @s1g_short_beacon: S1G short beacon data
+ * @smd: Seamless Mobility Domain (SMD) enabled
  */
 struct cfg80211_ap_settings {
 	struct cfg80211_chan_def chandef;
@@ -1656,6 +1657,7 @@ struct cfg80211_ap_settings {
 	struct cfg80211_mbssid_config mbssid_config;
 	u8 s1g_long_beacon_period;
 	struct cfg80211_s1g_short_beacon s1g_short_beacon;
+	bool smd;
 };
 
 
@@ -1880,6 +1882,17 @@ struct cfg80211_ttlm_params {
 	u16 ulink[8];
 };
 
+/**
+ * struct cfg80211_sta_smd_params - SMD parameters for an added station
+ *
+ * @smd_sta: SMD-negotiated STA
+ * @roam_sta: station was created via SMD BSS Transition procedure
+ */
+struct cfg80211_sta_smd_params {
+	bool smd_sta;
+	bool roam_sta;
+};
+
 /**
  * struct station_parameters - station parameters
  *
@@ -1920,6 +1933,7 @@ struct cfg80211_ttlm_params {
  * @link_sta_params: link related params.
  * @epp_peer: EPP peer indication
  * @nmi_mac: MAC address of the NMI station of the NAN peer
+ * @smd_params: SMD params for this station
  */
 struct station_parameters {
 	struct net_device *vlan;
@@ -1948,6 +1962,7 @@ struct station_parameters {
 	struct link_station_parameters link_sta_params;
 	bool epp_peer;
 	const u8 *nmi_mac;
+	struct cfg80211_sta_smd_params smd_params;
 };
 
 /**
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 3e71564ce87c..cfc1bcad13f0 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -361,6 +361,11 @@
  *	SMD capability in %NL80211_CMD_GET_WIPHY.
  *	%NL80211_CMD_START_AP carries %NL80211_ATTR_SMD_SUPPORT to indicate that
  *	the AP affiliated to an AP MLD is part of an SMD.
+ *	%NL80211_CMD_NEW_STATION carries %NL80211_ATTR_SMD_SUPPORT to indicate
+ *	that the non-AP MLD getting added has successfully negotiated SMD with
+ *	the AP MLD. %NL80211_ATTR_SMD_ROAM_STA is also set on the target AP MLD
+ *	to indicate that it is part of ST Preparation; drivers must keep these
+ *	links in powersave at this point until successful ST Execution.
  */
 
 /**
@@ -3265,6 +3270,8 @@ enum nl80211_commands {
  *
  * @NL80211_ATTR_SMD_SUPPORT: Flag attribute to indicate SMD support. Used with
  *	multiple commands to indicate appropriate SMD support (refer DOC).
+ * @NL80211_ATTR_SMD_ROAM_STA: Flag attribute to indicate that the station is
+ *	created as part of SMD BSS Transition and not by typical association.
  *
  * @NUM_NL80211_ATTR: total number of nl80211_attrs available
  * @NL80211_ATTR_MAX: highest attribute number currently defined
@@ -3874,6 +3881,7 @@ enum nl80211_attrs {
 	NL80211_ATTR_ASSOC_PROTECTED_TWT,
 
 	NL80211_ATTR_SMD_SUPPORT,
+	NL80211_ATTR_SMD_ROAM_STA,
 
 	/* add attributes here, update the policy in nl80211.c */
 
@@ -4026,6 +4034,7 @@ enum nl80211_iftype {
  *	previously added station into associated state
  * @NL80211_STA_FLAG_SPP_AMSDU: station supports SPP A-MSDUs
  * @NL80211_STA_FLAG_CIP: station has Control Integrity Protocol (CIP) enabled
+ * @NL80211_STA_FLAG_SMD: station has negotiated SMD.
  * @NL80211_STA_FLAG_MAX: highest station flag number currently defined
  * @__NL80211_STA_FLAG_AFTER_LAST: internal use
  */
@@ -4040,6 +4049,7 @@ enum nl80211_sta_flags {
 	NL80211_STA_FLAG_ASSOCIATED,
 	NL80211_STA_FLAG_SPP_AMSDU,
 	NL80211_STA_FLAG_CIP,
+	NL80211_STA_FLAG_SMD,
 
 	/* keep last */
 	__NL80211_STA_FLAG_AFTER_LAST,
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 16d00ebed10a..b06772ec8ac5 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1202,6 +1202,7 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 	[NL80211_ATTR_CIP_CAPABILITIES] = { .type = NLA_U8 },
 	[NL80211_ATTR_ASSOC_PROTECTED_TWT] = { .type = NLA_FLAG },
 	[NL80211_ATTR_SMD_SUPPORT] = { .type = NLA_FLAG },
+	[NL80211_ATTR_SMD_ROAM_STA] = { .type = NLA_FLAG },
 };
 
 /* policy for the key attributes */
@@ -7379,6 +7380,28 @@ static int nl80211_check_npca(struct cfg80211_registered_device *rdev,
 	return -EINVAL;
 }
 
+static int nl80211_validate_smd(struct genl_info *info,
+				struct cfg80211_ap_settings *params)
+{
+	struct cfg80211_registered_device *rdev = info->user_ptr[0];
+	struct net_device *dev = info->user_ptr[1];
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+
+	if (!(rdev->wiphy.flags & WIPHY_FLAG_SUPPORTS_SMD)) {
+		GENL_SET_ERR_MSG(info, "SMD is not supported");
+		return -EOPNOTSUPP;
+	}
+
+	if (!wdev->valid_links) {
+		GENL_SET_ERR_MSG(info, "SMD is not allowed without MLO");
+		return -EINVAL;
+	}
+
+	params->smd = true;
+
+	return 0;
+}
+
 static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 {
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
@@ -7661,6 +7684,12 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 
 	/* FIXME: validate MLO/link-id against driver capabilities */
 
+	if (info->attrs[NL80211_ATTR_SMD_SUPPORT]) {
+		err = nl80211_validate_smd(info, params);
+		if (err)
+			goto out;
+	}
+
 	err = rdev_start_ap(rdev, dev, params);
 	if (!err) {
 		wdev->links[link_id].ap.beacon_interval = params->beacon_interval;
@@ -7995,6 +8024,7 @@ static const struct nla_policy sta_flags_policy[NL80211_STA_FLAG_MAX + 1] = {
 	[NL80211_STA_FLAG_MFP] = { .type = NLA_FLAG },
 	[NL80211_STA_FLAG_AUTHENTICATED] = { .type = NLA_FLAG },
 	[NL80211_STA_FLAG_TDLS_PEER] = { .type = NLA_FLAG },
+	[NL80211_STA_FLAG_SMD] = { .type = NLA_FLAG },
 };
 
 static int parse_station_flags(struct genl_info *info,
@@ -8061,11 +8091,13 @@ static int parse_station_flags(struct genl_info *info,
 	switch (iftype) {
 	case NL80211_IFTYPE_AP:
 	case NL80211_IFTYPE_AP_VLAN:
+		params->sta_flags_mask = BIT(NL80211_STA_FLAG_SMD);
+		fallthrough;
 	case NL80211_IFTYPE_P2P_GO:
-		params->sta_flags_mask = BIT(NL80211_STA_FLAG_AUTHORIZED) |
-					 BIT(NL80211_STA_FLAG_SHORT_PREAMBLE) |
-					 BIT(NL80211_STA_FLAG_WME) |
-					 BIT(NL80211_STA_FLAG_MFP);
+		params->sta_flags_mask |= BIT(NL80211_STA_FLAG_AUTHORIZED) |
+					  BIT(NL80211_STA_FLAG_SHORT_PREAMBLE) |
+					  BIT(NL80211_STA_FLAG_WME) |
+					  BIT(NL80211_STA_FLAG_MFP);
 		break;
 	case NL80211_IFTYPE_P2P_CLIENT:
 	case NL80211_IFTYPE_STATION:
@@ -9276,7 +9308,7 @@ int cfg80211_check_station_change(struct wiphy *wiphy,
 		return -EINVAL;
 
 	/* When you run into this, adjust the code below for the new flag */
-	BUILD_BUG_ON(NL80211_STA_FLAG_MAX != 9);
+	BUILD_BUG_ON(NL80211_STA_FLAG_MAX != 10);
 
 	switch (statype) {
 	case CFG80211_STA_MESH_PEER_KERNEL:
@@ -9371,7 +9403,8 @@ int cfg80211_check_station_change(struct wiphy *wiphy,
 				  BIT(NL80211_STA_FLAG_WME) |
 				  BIT(NL80211_STA_FLAG_MFP) |
 				  BIT(NL80211_STA_FLAG_SPP_AMSDU) |
-				  BIT(NL80211_STA_FLAG_CIP)))
+				  BIT(NL80211_STA_FLAG_CIP) |
+				  BIT(NL80211_STA_FLAG_SMD)))
 			return -EINVAL;
 
 		/* but authenticated/associated only if driver handles it */
@@ -9633,6 +9666,23 @@ static int nl80211_parse_sta_txpower_setting(struct genl_info *info,
 	return 0;
 }
 
+static int nl80211_parse_sta_smd(struct genl_info *info,
+				 struct station_parameters *params)
+{
+	params->smd_params.smd_sta =
+		!!info->attrs[NL80211_ATTR_SMD_SUPPORT];
+
+	if (!params->smd_params.smd_sta)
+		return 0;
+
+	if (!info->attrs[NL80211_ATTR_MLD_ADDR])
+		return -EINVAL;
+
+	params->smd_params.roam_sta = !!info->attrs[NL80211_ATTR_SMD_ROAM_STA];
+
+	return 0;
+}
+
 static int nl80211_set_station(struct sk_buff *skb, struct genl_info *info)
 {
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
@@ -10041,6 +10091,10 @@ static int nl80211_new_station(struct sk_buff *skb, struct genl_info *info)
 	if (parse_station_flags(info, wdev->iftype, &params))
 		return -EINVAL;
 
+	err = nl80211_parse_sta_smd(info, &params);
+	if (err)
+		return err;
+
 	/* HT/VHT requires QoS, but if we don't have that just ignore HT/VHT
 	 * as userspace might just pass through the capabilities from the IEs
 	 * directly, rather than enforcing this restriction and returning an
@@ -10074,7 +10128,7 @@ static int nl80211_new_station(struct sk_buff *skb, struct genl_info *info)
 		return -EINVAL;
 
 	/* When you run into this, adjust the code below for the new flag */
-	BUILD_BUG_ON(NL80211_STA_FLAG_MAX != 9);
+	BUILD_BUG_ON(NL80211_STA_FLAG_MAX != 10);
 
 	switch (wdev->iftype) {
 	case NL80211_IFTYPE_AP:

-- 
2.34.1