mac80211: add back support for radiotap vendor namespace data

Radiotap vendor namespace data might still be useful, but we
reverted it because it used too much space in the RX status.
Put it back, but address the space problem by using a single
bit only and putting everything else into the skb->data.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 50 insertions, 0 deletions

diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index 209db62..58f11bb 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -984,6 +984,53 @@ static void mac80211_hwsim_tx_iter(void *_data, u8 *addr,
 	data->receive = true;
 }
 
+static void mac80211_hwsim_add_vendor_rtap(struct sk_buff *skb)
+{
+	/*
+	 * To enable this code, #define the HWSIM_RADIOTAP_OUI,
+	 * e.g. like this:
+	 * #define HWSIM_RADIOTAP_OUI "\x02\x00\x00"
+	 * (but you should use a valid OUI, not that)
+	 *
+	 * If anyone wants to 'donate' a radiotap OUI/subns code
+	 * please send a patch removing this #ifdef and changing
+	 * the values accordingly.
+	 */
+#ifdef HWSIM_RADIOTAP_OUI
+	struct ieee80211_vendor_radiotap *rtap;
+
+	/*
+	 * Note that this code requires the headroom in the SKB
+	 * that was allocated earlier.
+	 */
+	rtap = (void *)skb_push(skb, sizeof(*rtap) + 8 + 4);
+	rtap->oui[0] = HWSIM_RADIOTAP_OUI[0];
+	rtap->oui[1] = HWSIM_RADIOTAP_OUI[1];
+	rtap->oui[2] = HWSIM_RADIOTAP_OUI[2];
+	rtap->subns = 127;
+
+	/*
+	 * 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;
+#endif
+}
+
 static bool mac80211_hwsim_tx_frame_no_nl(struct ieee80211_hw *hw,
 					  struct sk_buff *skb,
 					  struct ieee80211_channel *chan)
@@ -1098,6 +1145,9 @@ static bool mac80211_hwsim_tx_frame_no_nl(struct ieee80211_hw *hw,
 		rx_status.mactime = now + data2->tsf_offset;
 
 		memcpy(IEEE80211_SKB_RXCB(nskb), &rx_status, sizeof(rx_status));
+
+		mac80211_hwsim_add_vendor_rtap(nskb);
+
 		data2->rx_pkts++;
 		data2->rx_bytes += nskb->len;
 		ieee80211_rx_irqsafe(data2->hw, nskb);