nl80211: MBSSID and EMA support in AP mode

Add new attributes to configure support for multiple BSSID
and advanced multi-BSSID advertisements (EMA) in AP mode.

- NL80211_ATTR_MBSSID_CONFIG used for per interface configuration.
- NL80211_ATTR_MBSSID_ELEMS used to MBSSID elements for beacons.

Memory for the elements is allocated dynamically. This change frees
the memory in existing functions which call nl80211_parse_beacon(),
a comment is added to indicate the new references to do the same.

Signed-off-by: John Crispin <john@phrozen.org>
Co-developed-by: Aloka Dixit <alokad@codeaurora.org>
Signed-off-by: Aloka Dixit <alokad@codeaurora.org>
Link: https://lore.kernel.org/r/20210916025437.29138-2-alokad@codeaurora.org
[don't leave ERR_PTR hanging around]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 75 insertions, 1 deletions

diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index e89bbf856228..eda608b1eb09 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -360,7 +360,10 @@
  * @NL80211_CMD_DEL_INTERFACE: Virtual interface was deleted, has attributes
  *	%NL80211_ATTR_IFINDEX and %NL80211_ATTR_WIPHY. Can also be sent from
  *	userspace to request deletion of a virtual interface, then requires
- *	attribute %NL80211_ATTR_IFINDEX.
+ *	attribute %NL80211_ATTR_IFINDEX. If multiple BSSID advertisements are
+ *	enabled using %NL80211_ATTR_MBSSID_CONFIG, %NL80211_ATTR_MBSSID_ELEMS,
+ *	and if this command is used for the transmitting interface, then all
+ *	the non-transmitting interfaces are deleted as well.
  *
  * @NL80211_CMD_GET_KEY: Get sequence counter information for a key specified
  *	by %NL80211_ATTR_KEY_IDX and/or %NL80211_ATTR_MAC.
@@ -2624,6 +2627,18 @@ enum nl80211_commands {
  * @NL80211_ATTR_COLOR_CHANGE_ELEMS: Nested set of attributes containing the IE
  *	information for the time while performing a color switch.
  *
+ * @NL80211_ATTR_MBSSID_CONFIG: Nested attribute for multiple BSSID
+ *	advertisements (MBSSID) parameters in AP mode.
+ *	Kernel uses this attribute to indicate the driver's support for MBSSID
+ *	and enhanced multi-BSSID advertisements (EMA AP) to the userspace.
+ *	Userspace should use this attribute to configure per interface MBSSID
+ *	parameters.
+ *	See &enum nl80211_mbssid_config_attributes for details.
+ *
+ * @NL80211_ATTR_MBSSID_ELEMS: Nested parameter to pass multiple BSSID elements.
+ *	Mandatory parameter for the transmitting interface to enable MBSSID.
+ *	Optional for the non-transmitting interfaces.
+ *
  * @NUM_NL80211_ATTR: total number of nl80211_attrs available
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
@@ -3127,6 +3142,9 @@ enum nl80211_attrs {
 	NL80211_ATTR_COLOR_CHANGE_COLOR,
 	NL80211_ATTR_COLOR_CHANGE_ELEMS,
 
+	NL80211_ATTR_MBSSID_CONFIG,
+	NL80211_ATTR_MBSSID_ELEMS,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,
@@ -7386,4 +7404,60 @@ enum nl80211_sar_specs_attrs {
 	NL80211_SAR_ATTR_SPECS_MAX = __NL80211_SAR_ATTR_SPECS_LAST - 1,
 };
 
+/**
+ * enum nl80211_mbssid_config_attributes - multiple BSSID (MBSSID) and enhanced
+ * multi-BSSID advertisements (EMA) in AP mode.
+ * Kernel uses some of these attributes to advertise driver's support for
+ * MBSSID and EMA.
+ * Remaining attributes should be used by the userspace to configure the
+ * features.
+ *
+ * @__NL80211_MBSSID_CONFIG_ATTR_INVALID: Invalid
+ *
+ * @NL80211_MBSSID_CONFIG_ATTR_MAX_INTERFACES: Used by the kernel to advertise
+ *	the maximum number of MBSSID interfaces supported by the driver.
+ *	Driver should indicate MBSSID support by setting
+ *	wiphy->mbssid_max_interfaces to a value more than or equal to 2.
+ *
+ * @NL80211_MBSSID_CONFIG_ATTR_MAX_EMA_PROFILE_PERIODICITY: Used by the kernel
+ *	to advertise the maximum profile periodicity supported by the driver
+ *	if EMA is enabled. Driver should indicate EMA support to the userspace
+ *	by setting wiphy->mbssid_max_ema_profile_periodicity to
+ *	a non-zero value.
+ *
+ * @NL80211_MBSSID_CONFIG_ATTR_INDEX: Mandatory parameter to pass the index of
+ *	this BSS (u8) in the multiple BSSID set.
+ *	Value must be set to 0 for the transmitting interface and non-zero for
+ *	all non-transmitting interfaces. The userspace will be responsible
+ *	for using unique indices for the interfaces.
+ *	Range: 0 to wiphy->mbssid_max_interfaces-1.
+ *
+ * @NL80211_MBSSID_CONFIG_ATTR_TX_IFINDEX: Mandatory parameter for
+ *	a non-transmitted profile which provides the interface index (u32) of
+ *	the transmitted profile. The value must match one of the interface
+ *	indices advertised by the kernel. Optional if the interface being set up
+ *	is the transmitting one, however, if provided then the value must match
+ *	the interface index of the same.
+ *
+ * @NL80211_MBSSID_CONFIG_ATTR_EMA: Flag used to enable EMA AP feature.
+ *	Setting this flag is permitted only if the driver advertises EMA support
+ *	by setting wiphy->mbssid_max_ema_profile_periodicity to non-zero.
+ *
+ * @__NL80211_MBSSID_CONFIG_ATTR_LAST: Internal
+ * @NL80211_MBSSID_CONFIG_ATTR_MAX: highest attribute
+ */
+enum nl80211_mbssid_config_attributes {
+	__NL80211_MBSSID_CONFIG_ATTR_INVALID,
+
+	NL80211_MBSSID_CONFIG_ATTR_MAX_INTERFACES,
+	NL80211_MBSSID_CONFIG_ATTR_MAX_EMA_PROFILE_PERIODICITY,
+	NL80211_MBSSID_CONFIG_ATTR_INDEX,
+	NL80211_MBSSID_CONFIG_ATTR_TX_IFINDEX,
+	NL80211_MBSSID_CONFIG_ATTR_EMA,
+
+	/* keep last */
+	__NL80211_MBSSID_CONFIG_ATTR_LAST,
+	NL80211_MBSSID_CONFIG_ATTR_MAX = __NL80211_MBSSID_CONFIG_ATTR_LAST - 1,
+};
+
 #endif /* __LINUX_NL80211_H */