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>

1 files changed, 23 insertions, 22 deletions

diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index e9b9340a97dc..152617034d19 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -1534,37 +1534,38 @@ static void mac80211_hwsim_add_vendor_rtap(struct sk_buff *skb)
 	 * the values accordingly.
 	 */
 #ifdef HWSIM_RADIOTAP_OUI
-	struct ieee80211_vendor_radiotap *rtap;
+	struct ieee80211_radiotap_vendor_tlv *rtap;
+	static const char vendor_data[8] = "ABCDEFGH";
+
+	// Make sure no padding is needed
+	BUILD_BUG_ON(sizeof(vendor_data) % 4);
+	/* this is last radiotap info before the mac header, so
+	 * skb_reset_mac_header for mac8022 to know the end of
+	 * the radiotap TLV/beginning of the 802.11 header
+	 */
+	skb_reset_mac_header(skb);
 
 	/*
 	 * Note that this code requires the headroom in the SKB
 	 * that was allocated earlier.
 	 */
-	rtap = skb_push(skb, sizeof(*rtap) + 8 + 4);
+	rtap = skb_push(skb, sizeof(*rtap) + sizeof(vendor_data));
+
+	rtap->len = cpu_to_le16(sizeof(*rtap) -
+				sizeof(struct ieee80211_radiotap_tlv) +
+				sizeof(vendor_data));
+	rtap->type = cpu_to_le16(IEEE80211_RADIOTAP_VENDOR_NAMESPACE);
+
 	rtap->oui[0] = HWSIM_RADIOTAP_OUI[0];
 	rtap->oui[1] = HWSIM_RADIOTAP_OUI[1];
 	rtap->oui[2] = HWSIM_RADIOTAP_OUI[2];
-	rtap->subns = 127;
+	rtap->oui_subtype = 127;
+	/* clear reserved field */
+	rtap->reserved = 0;
+	rtap->vendor_type = 0;
+	memcpy(rtap->data, vendor_data, sizeof(vendor_data));
 
-	/*
-	 * Radiotap vendor namespaces can (and should) also be
-	 * split into fields by using the standard radiotap
-	 * presence bitmap mechanism. Use just BIT(0) here for
-	 * the presence bitmap.
-	 */
-	rtap->present = BIT(0);
-	/* We have 8 bytes of (dummy) data */
-	rtap->len = 8;
-	/* For testing, also require it to be aligned */
-	rtap->align = 8;
-	/* And also test that padding works, 4 bytes */
-	rtap->pad = 4;
-	/* push the data */
-	memcpy(rtap->data, "ABCDEFGH", 8);
-	/* make sure to clear padding, mac80211 doesn't */
-	memset(rtap->data + 8, 0, 4);
-
-	IEEE80211_SKB_RXCB(skb)->flag |= RX_FLAG_RADIOTAP_VENDOR_DATA;
+	IEEE80211_SKB_RXCB(skb)->flag |= RX_FLAG_RADIOTAP_TLV_AT_END;
 #endif
 }