wifi: mac80211: add support for driver adding radiotap TLVs

The new TLV format enables adding TLVs after the fixed
fields in radiotap, as part of the radiotap header.
Support this and move vendor data to the TLV format,
allowing a reuse of the RX_FLAG_RADIOTAP_VENDOR_DATA as
the new RX_FLAG_RADIOTAP_TLV_AT_END flag.

Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230301115906.b18fd5da8477.I576400ec40a7b35ef97a3b09a99b3a49e9174786@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

2 files changed, 27 insertions, 37 deletions

diff --git a/include/net/ieee80211_radiotap.h b/include/net/ieee80211_radiotap.h
index 0fc2667a9a5d..95436686d3fe 100644
--- a/include/net/ieee80211_radiotap.h
+++ b/include/net/ieee80211_radiotap.h
@@ -369,6 +369,26 @@ struct ieee80211_radiotap_tlv {
 	u8 data[];
 } __packed;
 
+/**
+ * struct ieee80211_radiotap_vendor_tlv - vendor radiotap data information
+ * @type: should always be set to IEEE80211_RADIOTAP_VENDOR_NAMESPACE
+ * @len: length of data
+ * @oui: radiotap vendor namespace OUI
+ * @oui_subtype: radiotap vendor sub namespace
+ * @vendor_type: radiotap vendor type
+ * @reserved: should always be set to zero (to avoid leaking memory)
+ * @data: the actual vendor namespace data
+ */
+struct ieee80211_radiotap_vendor_tlv {
+	__le16 type; /* IEEE80211_RADIOTAP_VENDOR_NAMESPACE */
+	__le16 len;
+	u8 oui[3];
+	u8 oui_subtype;
+	__le16 vendor_type;
+	__le16 reserved;
+	u8 data[];
+} __packed;
+
 /* ieee80211_radiotap_eht_usig - content of U-SIG tlv (type 33)
  * see www.radiotap.org/fields/U-SIG.html for details
  */
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 5df9eb828a58..3a43ce5fd4ec 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1375,9 +1375,12 @@ ieee80211_tx_info_clear_status(struct ieee80211_tx_info *info)
  *	subframes share the same sequence number. Reported subframes can be
  *	either regular MSDU or singly A-MSDUs. Subframes must not be
  *	interleaved with other frames.
- * @RX_FLAG_RADIOTAP_VENDOR_DATA: This frame contains vendor-specific
- *	radiotap data in the skb->data (before the frame) as described by
- *	the &struct ieee80211_vendor_radiotap.
+ * @RX_FLAG_RADIOTAP_TLV_AT_END: This frame contains radiotap TLVs in the
+ *	skb->data (before the 802.11 header).
+ *	If used, the SKB's mac_header pointer must be set to point
+ *	to the 802.11 header after the TLVs, and any padding added after TLV
+ *	data to align to 4 must be cleared by the driver putting the TLVs
+ *	in the skb.
  * @RX_FLAG_ALLOW_SAME_PN: Allow the same PN as same packet before.
  *	This is used for AMSDU subframes which can have the same PN as
  *	the first subframe.
@@ -1429,7 +1432,7 @@ enum mac80211_rx_flags {
 	RX_FLAG_ONLY_MONITOR		= BIT(17),
 	RX_FLAG_SKIP_MONITOR		= BIT(18),
 	RX_FLAG_AMSDU_MORE		= BIT(19),
-	RX_FLAG_RADIOTAP_VENDOR_DATA	= BIT(20),
+	RX_FLAG_RADIOTAP_TLV_AT_END	= BIT(20),
 	RX_FLAG_MIC_STRIPPED		= BIT(21),
 	RX_FLAG_ALLOW_SAME_PN		= BIT(22),
 	RX_FLAG_ICV_STRIPPED		= BIT(23),
@@ -1570,39 +1573,6 @@ ieee80211_rx_status_to_khz(struct ieee80211_rx_status *rx_status)
 }
 
 /**
- * struct ieee80211_vendor_radiotap - vendor radiotap data information
- * @present: presence bitmap for this vendor namespace
- *	(this could be extended in the future if any vendor needs more
- *	 bits, the radiotap spec does allow for that)
- * @align: radiotap vendor namespace alignment. This defines the needed
- *	alignment for the @data field below, not for the vendor namespace
- *	description itself (which has a fixed 2-byte alignment)
- *	Must be a power of two, and be set to at least 1!
- * @oui: radiotap vendor namespace OUI
- * @subns: radiotap vendor sub namespace
- * @len: radiotap vendor sub namespace skip length, if alignment is done
- *	then that's added to this, i.e. this is only the length of the
- *	@data field.
- * @pad: number of bytes of padding after the @data, this exists so that
- *	the skb data alignment can be preserved even if the data has odd
- *	length
- * @data: the actual vendor namespace data
- *
- * This struct, including the vendor data, goes into the skb->data before
- * the 802.11 header. It's split up in mac80211 using the align/oui/subns
- * data.
- */
-struct ieee80211_vendor_radiotap {
-	u32 present;
-	u8 align;
-	u8 oui[3];
-	u8 subns;
-	u8 pad;
-	u16 len;
-	u8 data[];
-} __packed;
-
-/**
  * enum ieee80211_conf_flags - configuration flags
  *
  * Flags to define PHY configuration options