[PATCH RESEND wireless-next 12/18] wifi: nl80211: Define attributes to pack SMD BSS Transition context

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

Define nl80211 attributes and policies required to pack SMD BSS Transition
context along with NL80211_CMD_FRAME to be sent to userspace, and to set
and get the context during roaming via current AP MLD and roaming via
target AP MLD. Without these, userspace will not be able to transport the
context to the target AP MLD, program the context on the target AP MLD TX
and RX queues, nor fetch the context on behalf of the target AP MLD if
the ST Execution frame is sent directly to the target.

Suggested-by: Jouni Malinen <jouni.malinen@oss.qualcomm.com>
Signed-off-by: Pooventhiran G <pooventhiran.g@oss.qualcomm.com>
---
 include/uapi/linux/nl80211.h | 163 +++++++++++++++++++++++++++++++++++++++++++
 net/wireless/nl80211.c       |  44 ++++++++++++
 2 files changed, 207 insertions(+)

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 65c7eefe9db5..f41266181bf1 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -1427,6 +1427,18 @@
  * @NL80211_CMD_STOP_PD: Stop the PD operation, identified by
  *	its %NL80211_ATTR_WDEV interface.
  *
+ * @NL80211_CMD_SET_SMD_CTX: Set the SMD BSS Transition dynamic context for a
+ *	non-AP MLD sent from the current AP MLD on the target AP MLD managed by
+ *	an SMD-ME. This command carries %NL80211_ATTR_MLD_ADDR,
+ *	%NL80211_ATTR_SMD_CTX_TYPE and %NL80211_ATTR_SMD_CTX.
+ * @NL80211_CMD_GET_SMD_CTX: Get the SMD BSS Transition dynamic context for a
+ *	non-AP MLD associated to an AP MLD managed by an SMD-ME. This command
+ *	carries %NL80211_ATTR_MLD_ADDR and %NL80211_ATTR_SMD_CTX_TYPE.
+ * @NL80211_CMD_SMD_CTX_EVENT: Event reporting the collected SMD context
+ *	(requested via %NL80211_CMD_GET_SMD_CTX) to userspace. It carries
+ *	%NL80211_ATTR_MLD_ADDR, %NL80211_ATTR_SMD_CTX_TYPE, and
+ *	%NL80211_ATTR_SMD_CTX.
+ *
  * @NL80211_CMD_MAX: highest used command number
  * @__NL80211_CMD_AFTER_LAST: internal use
  */
@@ -1705,6 +1717,10 @@ enum nl80211_commands {
 	NL80211_CMD_START_PD,
 	NL80211_CMD_STOP_PD,
 
+	NL80211_CMD_SET_SMD_CTX,
+	NL80211_CMD_GET_SMD_CTX,
+	NL80211_CMD_SMD_CTX_EVENT,
+
 	/* add new commands above here */
 
 	/* used to define NL80211_CMD_MAX below */
@@ -3207,6 +3223,13 @@ enum nl80211_commands {
  *	IEEE P802.11bn/D2.0, Aug 2026, subclause 37.16.6).
  *	This flag is carried in %NL80211_CMD_NEW_STATION.
  *
+ * @NL80211_ATTR_SMD_CTX: Nested attribute associated with UHR SMD BSS
+ *	Transition data. Used with %NL80211_CMD_SET_SMD_CTX and
+ *	%NL80211_CMD_SMD_CTX_EVENT. See &enum nl80211_smd_ctx.
+ * @NL80211_ATTR_SMD_CTX_TYPE: u8 attribute specifying the type of SMD context.
+ *	Used along with %NL80211_CMD_SET_SMD_CTX, %NL80211_CMD_GET_SMD_CTX,
+ *	and %NL80211_CMD_SMD_CTX_EVENT.
+ *
  * @NUM_NL80211_ATTR: total number of nl80211_attrs available
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
@@ -3815,6 +3838,9 @@ enum nl80211_attrs {
 
 	NL80211_ATTR_SMD_ROAM_STA,
 
+	NL80211_ATTR_SMD_CTX,
+	NL80211_ATTR_SMD_CTX_TYPE,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,
@@ -9247,4 +9273,141 @@ enum nl80211_smd_params_attrs {
 	NL80211_SMD_PARAMS_ATTR_MAX = __NL80211_SMD_PARAMS_ATTR_LAST - 1
 };
 
+/**
+ * enum nl80211_smd_ctx_type - SMD Request Type values
+ *
+ * Used with %NL80211_ATTR_SMD_CTX_TYPE.
+ *
+ * @NL80211_SMD_CTX_TYPE_PREP: SMD BSS Transition (ST) Preparation.
+ * @NL80211_SMD_CTX_TYPE_EXEC: ST Execution.
+ * @NUM_SMD_CTX_TYPES: internal.
+ * @NL80211_SMD_CTX_TYPE_MAX: Max type of ST context.
+ */
+enum nl80211_smd_ctx_type {
+	NL80211_SMD_CTX_TYPE_PREP,
+	NL80211_SMD_CTX_TYPE_EXEC,
+
+	NUM_SMD_CTX_TYPES,
+	NL80211_SMD_CTX_TYPE_MAX = NUM_SMD_CTX_TYPES - 1,
+};
+
+/**
+ * enum nl80211_smd_ctx_ba_param - SMD Block Ack Context attributes
+ *
+ * @__NL80211_SMD_CTX_BA_ATTR_INVALID: Invalid attribute.
+ * @NL80211_SMD_CTX_BA_ATTR_BUFF_SIZE: Required (u16) BA buffer size.
+ * @NL80211_SMD_CTX_BA_ATTR_POLICY: Required (u8) BA policy.
+ * @NL80211_SMD_CTX_BA_ATTR_AMSDU_SUPPORT: Flag attribute to indicate
+ *	AMSDU support.
+ * @NL80211_SMD_CTX_BA_ATTR_TIMEOUT: Required (u16) Block Ack timeout.
+ * @NL80211_SMD_CTX_BA_ATTR_EXT_NO_FRAG: Flag attribute to indicate
+ *	fragmentation support.
+ * @NL80211_SMD_CTX_BA_ATTR_EXT_FRAG_LEVEL: Required (u8) HE fragmentation
+ *	level.
+ * @NL80211_SMD_CTX_BA_ATTR_EXT_BUFF_SIZE: Required (u16) extended buffer size.
+ * @__NL80211_SMD_CTX_BA_ATTR_LAST: Last attribute, used internally.
+ * @NL80211_SMD_CTX_BA_ATTR_MAX: Max attribute.
+ *
+ * Used with %NL80211_SMD_CTX_DL_ATTR_BA_PARAMS and
+ * %NL80211_SMD_CTX_UL_ATTR_BA_PARAMS.
+ */
+enum nl80211_smd_ctx_ba_param {
+	__NL80211_SMD_CTX_BA_ATTR_INVALID,
+	NL80211_SMD_CTX_BA_ATTR_BUFF_SIZE,
+	NL80211_SMD_CTX_BA_ATTR_POLICY,
+	NL80211_SMD_CTX_BA_ATTR_AMSDU_SUPPORT,
+	NL80211_SMD_CTX_BA_ATTR_TIMEOUT,
+	NL80211_SMD_CTX_BA_ATTR_EXT_NO_FRAG,
+	NL80211_SMD_CTX_BA_ATTR_EXT_FRAG_LEVEL,
+	NL80211_SMD_CTX_BA_ATTR_EXT_BUFF_SIZE,
+
+	__NL80211_SMD_CTX_BA_ATTR_LAST,
+	NL80211_SMD_CTX_BA_ATTR_MAX = __NL80211_SMD_CTX_BA_ATTR_LAST - 1
+};
+
+/**
+ * enum nl80211_smd_ctx_dl - SMD Dynamic Context - DL direction
+ *
+ * @__NL80211_SMD_CTX_DL_ATTR_INVALID: Invalid attribute.
+ * @NL80211_SMD_CTX_DL_ATTR_VALID_TID_BITMAP: Optional (u8) TIDs included.
+ * @NL80211_SMD_CTX_DL_ATTR_SN: Optional (nested) next SN (u16) per TID to
+ *	be assigned to DL individually addressed frames.
+ * @NL80211_SMD_CTX_DL_ATTR_PN: Optional (binary) starting PN (max 16 bytes) for
+ *	DL individually addressed frames.
+ * @NL80211_SMD_CTX_DL_ATTR_BA_PARAMS: Optional (nested) Block Ack parameters,
+ *	nested array of TIDs (uses &enum nl80211_smd_ctx_ba_param).
+ * @__NL80211_SMD_CTX_DL_ATTR_LAST: Last attribute, used internally.
+ * @NL80211_SMD_CTX_DL_ATTR_MAX: Max attribute.
+ *
+ * Used with %NL80211_SMD_CTX_ATTR_DL.
+ */
+enum nl80211_smd_ctx_dl {
+	__NL80211_SMD_CTX_DL_ATTR_INVALID,
+	NL80211_SMD_CTX_DL_ATTR_VALID_TID_BITMAP,
+	NL80211_SMD_CTX_DL_ATTR_SN,
+	NL80211_SMD_CTX_DL_ATTR_PN,
+	NL80211_SMD_CTX_DL_ATTR_BA_PARAMS,
+
+	__NL80211_SMD_CTX_DL_ATTR_LAST,
+	NL80211_SMD_CTX_DL_ATTR_MAX = __NL80211_SMD_CTX_DL_ATTR_LAST - 1
+};
+
+/**
+ * enum nl80211_smd_ctx_ul - SMD Dynamic Context - UL direction
+ *
+ * @__NL80211_SMD_CTX_UL_ATTR_INVALID: Invalid attribute.
+ * @NL80211_SMD_CTX_UL_ATTR_VALID_TID_BITMAP: Optional (u8) TIDs included.
+ * @NL80211_SMD_CTX_UL_ATTR_SN: Optional (nested) last SN received per TID
+ *	for UL individually addressed frames.
+ * @NL80211_SMD_CTX_UL_ATTR_PN: Optional (nested) last PN received per TID
+ *	for UL individually addressed frames.
+ * @NL80211_SMD_CTX_UL_ATTR_BA_PARAMS: Optional (nested) Block Ack parameters
+ *	(uses &enum nl80211_smd_ctx_ba_param).
+ * @__NL80211_SMD_CTX_UL_ATTR_LAST: Last attribute, used internally.
+ * @NL80211_SMD_CTX_UL_ATTR_MAX: Max attribute.
+ *
+ * Used with %NL80211_SMD_CTX_ATTR_UL.
+ */
+enum nl80211_smd_ctx_ul {
+	__NL80211_SMD_CTX_UL_ATTR_INVALID,
+	NL80211_SMD_CTX_UL_ATTR_VALID_TID_BITMAP,
+	NL80211_SMD_CTX_UL_ATTR_SN,
+	NL80211_SMD_CTX_UL_ATTR_PN,
+	NL80211_SMD_CTX_UL_ATTR_BA_PARAMS,
+
+	__NL80211_SMD_CTX_UL_ATTR_LAST,
+	NL80211_SMD_CTX_UL_ATTR_MAX = __NL80211_SMD_CTX_UL_ATTR_LAST - 1
+};
+
+/**
+ * enum nl80211_smd_ctx - SMD Context information
+ *
+ * Top-level container for SMD BSS Transition dynamic context.  Carried in
+ * %NL80211_ATTR_SMD_CTX with %NL80211_CMD_SET_SMD_CTX (target AP MLD) or
+ * with %NL80211_CMD_FRAME (current AP MLD reporting context to userspace)
+ * and %NL80211_CMD_SMD_CTX_EVENT (current AP MLD reporting the requested
+ * context on behalf of the target AP MLD).
+ *
+ * @__NL80211_SMD_CTX_ATTR_INVALID: Invalid attribute.
+ * @NL80211_SMD_CTX_ATTR_DL: Optional (nested) DL parameters.
+ *	See &enum nl80211_smd_ctx_dl.
+ * @NL80211_SMD_CTX_ATTR_UL: Optional (nested) UL parameters.
+ *	See &enum nl80211_smd_ctx_ul.
+ * @NL80211_SMD_CTX_ATTR_DRV_DATA: Optional (binary) driver-specific blob.
+ *	Passed through nl80211 as a blob; parsed only at the driver layer of
+ *	the current AP MLD and target AP MLD. First 3 bytes shall be driver OUI
+ *	for the driver to parse as required.
+ * @__NL80211_SMD_CTX_ATTR_LAST: Last attribute, used internally.
+ * @NL80211_SMD_CTX_ATTR_MAX: Max attribute.
+ */
+enum nl80211_smd_ctx {
+	__NL80211_SMD_CTX_ATTR_INVALID,
+	NL80211_SMD_CTX_ATTR_DL,
+	NL80211_SMD_CTX_ATTR_UL,
+	NL80211_SMD_CTX_ATTR_DRV_DATA,
+
+	__NL80211_SMD_CTX_ATTR_LAST,
+	NL80211_SMD_CTX_ATTR_MAX = __NL80211_SMD_CTX_ATTR_LAST - 1
+};
+
 #endif /* __LINUX_NL80211_H */
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 282d3c82dce8..d59f0eb40493 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -704,6 +704,47 @@ nl80211_smd_params_policy[NL80211_SMD_PARAMS_ATTR_MAX + 1] = {
 	[NL80211_SMD_PARAMS_ATTR_NEIGHBOR_PROBING] = { .type = NLA_FLAG },
 };
 
+static const struct nla_policy
+nl80211_smd_ctx_ba_policy[NL80211_SMD_CTX_BA_ATTR_MAX + 1] = {
+	[NL80211_SMD_CTX_BA_ATTR_BUFF_SIZE] = { .type = NLA_U16 },
+	[NL80211_SMD_CTX_BA_ATTR_POLICY] = { .type = NLA_U8 },
+	[NL80211_SMD_CTX_BA_ATTR_AMSDU_SUPPORT] = { .type = NLA_FLAG },
+	[NL80211_SMD_CTX_BA_ATTR_TIMEOUT] = { .type = NLA_U16 },
+	[NL80211_SMD_CTX_BA_ATTR_EXT_NO_FRAG] = { .type = NLA_FLAG },
+	[NL80211_SMD_CTX_BA_ATTR_EXT_FRAG_LEVEL] = { .type = NLA_U8 },
+	[NL80211_SMD_CTX_BA_ATTR_EXT_BUFF_SIZE] = { .type = NLA_U16 },
+};
+
+static const struct nla_policy
+nl80211_smd_ctx_dl_policy[NL80211_SMD_CTX_DL_ATTR_MAX + 1] = {
+	[NL80211_SMD_CTX_DL_ATTR_VALID_TID_BITMAP] = { .type = NLA_U8 },
+	[NL80211_SMD_CTX_DL_ATTR_SN] = { .type = NLA_NESTED },
+	[NL80211_SMD_CTX_DL_ATTR_PN] = { .type = NLA_BINARY,
+					 .len = IEEE80211_SMD_CTX_MAX_PN_LEN },
+	[NL80211_SMD_CTX_DL_ATTR_BA_PARAMS] =
+		NLA_POLICY_NESTED_ARRAY(nl80211_smd_ctx_ba_policy),
+};
+
+static const struct nla_policy
+nl80211_smd_ctx_ul_policy[NL80211_SMD_CTX_UL_ATTR_MAX + 1] = {
+	[NL80211_SMD_CTX_UL_ATTR_VALID_TID_BITMAP] = { .type = NLA_U8 },
+	[NL80211_SMD_CTX_UL_ATTR_SN] = { .type = NLA_NESTED },
+	[NL80211_SMD_CTX_UL_ATTR_PN] = { .type = NLA_NESTED },
+	[NL80211_SMD_CTX_UL_ATTR_BA_PARAMS] =
+		NLA_POLICY_NESTED_ARRAY(nl80211_smd_ctx_ba_policy),
+};
+
+static const struct nla_policy
+nl80211_smd_ctx_policy[NL80211_SMD_CTX_ATTR_MAX + 1] = {
+	[NL80211_SMD_CTX_ATTR_DL] =
+		NLA_POLICY_NESTED(nl80211_smd_ctx_dl_policy),
+	[NL80211_SMD_CTX_ATTR_UL] =
+		NLA_POLICY_NESTED(nl80211_smd_ctx_ul_policy),
+	[NL80211_SMD_CTX_ATTR_DRV_DATA] =
+		NLA_POLICY_RANGE(NLA_BINARY,
+				 3, IEEE80211_MAX_DATA_LEN),
+};
+
 static const struct netlink_range_validation nl80211_punct_bitmap_range = {
 	.min = 0,
 	.max = 0xffff,
@@ -1118,6 +1159,9 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
 	[NL80211_ATTR_PEER_SMD_MAC_ADDR] = NLA_POLICY_ETH_ADDR,
 	[NL80211_ATTR_PEER_SMD_DL_DATA_FORWARDING] = { .type = NLA_FLAG },
 	[NL80211_ATTR_SMD_ROAM_STA] = { .type = NLA_FLAG },
+	[NL80211_ATTR_SMD_CTX] = NLA_POLICY_NESTED(nl80211_smd_ctx_policy),
+	[NL80211_ATTR_SMD_CTX_TYPE] =
+		NLA_POLICY_MAX(NLA_U8, NL80211_SMD_CTX_TYPE_MAX),
 };
 
 /* policy for the key attributes */

-- 
2.34.1