mac80211_hwsim: Add tsf to beacons, probe responses and radiotap header.

Generate a tsf from internal kernel clock.  Prepare the path for having
different tsf offsets on each phy.  This will be useful for testing
mesh synchronization algorithms.
Signed-off-by: Javier Cardona <javier@cozybit.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/mac80211_hwsim.c

@@ -27,6 +27,7 @@
 #include <linux/etherdevice.h>
 #include <linux/debugfs.h>
 #include <linux/module.h>
+#include <linux/ktime.h>
 #include <net/genetlink.h>
 #include "mac80211_hwsim.h"
 
@@ -321,11 +322,15 @@ struct mac80211_hwsim_data {
 	struct dentry *debugfs_group;
 
 	int power_level;
+
+	/* difference between this hw's clock and the real clock, in usecs */
+	u64 tsf_offset;
 };
 
 
 struct hwsim_radiotap_hdr {
 	struct ieee80211_radiotap_header hdr;
+	__le64 rt_tsft;
 	u8 rt_flags;
 	u8 rt_rate;
 	__le16 rt_channel;
@@ -367,6 +372,12 @@ static netdev_tx_t hwsim_mon_xmit(struct sk_buff *skb,
 	return NETDEV_TX_OK;
 }
 
+static __le64 __mac80211_hwsim_get_tsf(struct mac80211_hwsim_data *data)
+{
+	struct timeval tv = ktime_to_timeval(ktime_get_real());
+	u64 now = tv.tv_sec * USEC_PER_SEC + tv.tv_usec;
+	return cpu_to_le64(now + data->tsf_offset);
+}
 
 static void mac80211_hwsim_monitor_rx(struct ieee80211_hw *hw,
 				      struct sk_buff *tx_skb)
@@ -391,7 +402,9 @@ static void mac80211_hwsim_monitor_rx(struct ieee80211_hw *hw,
 	hdr->hdr.it_len = cpu_to_le16(sizeof(*hdr));
 	hdr->hdr.it_present = cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
 					  (1 << IEEE80211_RADIOTAP_RATE) |
+					  (1 << IEEE80211_RADIOTAP_TSFT) |
 					  (1 << IEEE80211_RADIOTAP_CHANNEL));
+	hdr->rt_tsft = __mac80211_hwsim_get_tsf(data);
 	hdr->rt_flags = 0;
 	hdr->rt_rate = txrate->bitrate / 5;
 	hdr->rt_channel = cpu_to_le16(data->channel->center_freq);
@@ -610,7 +623,8 @@ static bool mac80211_hwsim_tx_frame_no_nl(struct ieee80211_hw *hw,
 	}
 
 	memset(&rx_status, 0, sizeof(rx_status));
-	/* TODO: set mactime */
+	rx_status.mactime = le64_to_cpu(__mac80211_hwsim_get_tsf(data));
+	rx_status.flag |= RX_FLAG_MACTIME_MPDU;
 	rx_status.freq = data->channel->center_freq;
 	rx_status.band = data->channel->band;
 	rx_status.rate_idx = info->control.rates[0].idx;
@@ -667,6 +681,12 @@ static void mac80211_hwsim_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 	bool ack;
 	struct ieee80211_tx_info *txi;
 	u32 _pid;
+	struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *) skb->data;
+	struct mac80211_hwsim_data *data = hw->priv;
+
+	if (ieee80211_is_beacon(mgmt->frame_control) ||
+	    ieee80211_is_probe_resp(mgmt->frame_control))
+		mgmt->u.beacon.timestamp = __mac80211_hwsim_get_tsf(data);
 
 	mac80211_hwsim_monitor_rx(hw, skb);
 
@@ -763,9 +783,11 @@ static void mac80211_hwsim_beacon_tx(void *arg, u8 *mac,
 				     struct ieee80211_vif *vif)
 {
 	struct ieee80211_hw *hw = arg;
+	struct mac80211_hwsim_data *data = hw->priv;
 	struct sk_buff *skb;
 	struct ieee80211_tx_info *info;
 	u32 _pid;
+	struct ieee80211_mgmt *mgmt;
 
 	hwsim_check_magic(vif);
 
@@ -779,6 +801,9 @@ static void mac80211_hwsim_beacon_tx(void *arg, u8 *mac,
 		return;
 	info = IEEE80211_SKB_CB(skb);
 
+	mgmt = (struct ieee80211_mgmt *) skb->data;
+	mgmt->u.beacon.timestamp = __mac80211_hwsim_get_tsf(data);
+
 	mac80211_hwsim_monitor_rx(hw, skb);
 
 	/* wmediumd mode check */