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mac80211_hwsim: fix beacon timestamp and mactime

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Set the beacon timestamp once during "transmission" so the
monitor interface also gets a timestamped beacon.

Also use a common base between TX timestamp and RX
mactime. This eliminates "TX" path delay, which shows up
as a constant error in Toffset.

Get the global TSF once before iterating over all RX HWs,
so they all set a mactime with the same time base.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Thomas Pedersen 2013-01-07 14:48:07 -08:00 committed by John W. Linville
parent 29b7d9ad91
commit b66851c3c8
1 changed files with 39 additions and 18 deletions
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57
drivers/net/wireless/mac80211_hwsim.c
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@ -363,6 +363,8 @@ struct mac80211_hwsim_data {
/* difference between this hw's clock and the real clock, in usecs */
s64 tsf_offset;
s64 bcn_delta;
/* absolute beacon transmission time. Used to cover up "tx" delay. */
u64 abs_bcn_ts;
};
@ -410,15 +412,19 @@ static netdev_tx_t hwsim_mon_xmit(struct sk_buff *skb,
return NETDEV_TX_OK;
}
static inline u64 mac80211_hwsim_get_tsf_raw(void)
{
return ktime_to_us(ktime_get_real());
}
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;
u64 now = mac80211_hwsim_get_tsf_raw();
return cpu_to_le64(now + data->tsf_offset);
}
static u64 mac80211_hwsim_get_tsf(struct ieee80211_hw *hw,
struct ieee80211_vif *vif)
struct ieee80211_vif *vif)
{
struct mac80211_hwsim_data *data = hw->priv;
return le64_to_cpu(__mac80211_hwsim_get_tsf(data));
@ -705,7 +711,7 @@ static bool mac80211_hwsim_tx_frame_no_nl(struct ieee80211_hw *hw,
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct ieee80211_rx_status rx_status;
struct ieee80211_rate *txrate = ieee80211_get_tx_rate(hw, info);
u64 now;
memset(&rx_status, 0, sizeof(rx_status));
rx_status.flag |= RX_FLAG_MACTIME_START;
@ -731,11 +737,23 @@ static bool mac80211_hwsim_tx_frame_no_nl(struct ieee80211_hw *hw,
secpath_reset(skb);
nf_reset(skb);
/*
* Get absolute mactime here so all HWs RX at the "same time", and
* absolute TX time for beacon mactime so the timestamp matches.
* Giving beacons a different mactime than non-beacons looks messy, but
* it helps the Toffset be exact and a ~10us mactime discrepancy
* probably doesn't really matter.
*/
if (ieee80211_is_beacon(hdr->frame_control) ||
ieee80211_is_probe_resp(hdr->frame_control))
now = data->abs_bcn_ts;
else
now = mac80211_hwsim_get_tsf_raw();
/* Copy skb to all enabled radios that are on the current frequency */
spin_lock(&hwsim_radio_lock);
list_for_each_entry(data2, &hwsim_radios, list) {
struct sk_buff *nskb;
struct ieee80211_mgmt *mgmt;
struct tx_iter_data tx_iter_data = {
.receive = false,
.channel = chan,
@ -787,17 +805,7 @@ static bool mac80211_hwsim_tx_frame_no_nl(struct ieee80211_hw *hw,
if (mac80211_hwsim_addr_match(data2, hdr->addr1))
ack = true;
/* set bcn timestamp relative to receiver mactime */
rx_status.mactime =
le64_to_cpu(__mac80211_hwsim_get_tsf(data2));
mgmt = (struct ieee80211_mgmt *) nskb->data;
if (ieee80211_is_beacon(mgmt->frame_control) ||
ieee80211_is_probe_resp(mgmt->frame_control))
mgmt->u.beacon.timestamp = cpu_to_le64(
rx_status.mactime +
(data->tsf_offset - data2->tsf_offset) +
24 * 8 * 10 / txrate->bitrate);
rx_status.mactime = now + data2->tsf_offset;
#if 0
/*
* Don't enable this code by default as the OUI 00:00:00
@ -987,7 +995,11 @@ static void mac80211_hwsim_tx_frame(struct ieee80211_hw *hw,
static void mac80211_hwsim_beacon_tx(void *arg, u8 *mac,
struct ieee80211_vif *vif)
{
struct ieee80211_hw *hw = arg;
struct mac80211_hwsim_data *data = arg;
struct ieee80211_hw *hw = data->hw;
struct ieee80211_tx_info *info;
struct ieee80211_rate *txrate;
struct ieee80211_mgmt *mgmt;
struct sk_buff *skb;
hwsim_check_magic(vif);
@ -1000,6 +1012,15 @@ static void mac80211_hwsim_beacon_tx(void *arg, u8 *mac,
skb = ieee80211_beacon_get(hw, vif);
if (skb == NULL)
return;
info = IEEE80211_SKB_CB(skb);
txrate = ieee80211_get_tx_rate(hw, info);
mgmt = (struct ieee80211_mgmt *) skb->data;
/* fake header transmission time */
data->abs_bcn_ts = mac80211_hwsim_get_tsf_raw();
mgmt->u.beacon.timestamp = cpu_to_le64(data->abs_bcn_ts +
data->tsf_offset +
24 * 8 * 10 / txrate->bitrate);
mac80211_hwsim_tx_frame(hw, skb,
rcu_dereference(vif->chanctx_conf)->def.chan);
@ -1020,7 +1041,7 @@ mac80211_hwsim_beacon(struct hrtimer *timer)
ieee80211_iterate_active_interfaces_atomic(
hw, IEEE80211_IFACE_ITER_NORMAL,
mac80211_hwsim_beacon_tx, hw);
mac80211_hwsim_beacon_tx, data);
/* beacon at new TBTT + beacon interval */
if (data->bcn_delta) {