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mac80211: add support for radiotap timestamp field

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Use the existing device timestamp from the RX status information
to add support for the new radiotap timestamp field. Currently
only 32-bit counters are supported, but we also add the radiotap
mactime where applicable. This new field allows more flexibility
in where the timestamp is taken etc. The non-timestamp data in
the field is taken from a new field in the hw struct.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Johannes Berg 2016-08-29 23:25:17 +03:00
parent 42bd20d998
commit 99ee7cae3b
4 changed files with 66 additions and 0 deletions
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21
include/net/ieee80211_radiotap.h
View File

@ -190,6 +190,10 @@ struct ieee80211_radiotap_header {
* IEEE80211_RADIOTAP_VHT u16, u8, u8, u8[4], u8, u8, u16
*
* Contains VHT information about this frame.
*
* IEEE80211_RADIOTAP_TIMESTAMP u64, u16, u8, u8 variable
*
* Contains timestamp information for this frame.
*/
enum ieee80211_radiotap_type {
IEEE80211_RADIOTAP_TSFT = 0,
@ -214,6 +218,7 @@ enum ieee80211_radiotap_type {
IEEE80211_RADIOTAP_MCS = 19,
IEEE80211_RADIOTAP_AMPDU_STATUS = 20,
IEEE80211_RADIOTAP_VHT = 21,
IEEE80211_RADIOTAP_TIMESTAMP = 22,
/* valid in every it_present bitmap, even vendor namespaces */
IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE = 29,
@ -321,6 +326,22 @@ enum ieee80211_radiotap_type {
#define IEEE80211_RADIOTAP_CODING_LDPC_USER2 0x04
#define IEEE80211_RADIOTAP_CODING_LDPC_USER3 0x08
/* For IEEE80211_RADIOTAP_TIMESTAMP */
#define IEEE80211_RADIOTAP_TIMESTAMP_UNIT_MASK 0x000F
#define IEEE80211_RADIOTAP_TIMESTAMP_UNIT_MS 0x0000
#define IEEE80211_RADIOTAP_TIMESTAMP_UNIT_US 0x0001
#define IEEE80211_RADIOTAP_TIMESTAMP_UNIT_NS 0x0003
#define IEEE80211_RADIOTAP_TIMESTAMP_SPOS_MASK 0x00F0
#define IEEE80211_RADIOTAP_TIMESTAMP_SPOS_BEGIN_MDPU 0x0000
#define IEEE80211_RADIOTAP_TIMESTAMP_SPOS_EO_MPDU 0x0010
#define IEEE80211_RADIOTAP_TIMESTAMP_SPOS_EO_PPDU 0x0020
#define IEEE80211_RADIOTAP_TIMESTAMP_SPOS_PLCP_SIG_ACQ 0x0030
#define IEEE80211_RADIOTAP_TIMESTAMP_SPOS_UNKNOWN 0x00F0
#define IEEE80211_RADIOTAP_TIMESTAMP_FLAG_64BIT 0x00
#define IEEE80211_RADIOTAP_TIMESTAMP_FLAG_32BIT 0x01
#define IEEE80211_RADIOTAP_TIMESTAMP_FLAG_ACCURACY 0x02
/* helpers */
static inline int ieee80211_get_radiotap_len(unsigned char *data)
{

12
include/net/mac80211.h
View File

@ -2145,6 +2145,14 @@ enum ieee80211_hw_flags {
* the default is _GI | _BANDWIDTH.
* Use the %IEEE80211_RADIOTAP_VHT_KNOWN_* values.
*
* @radiotap_timestamp: Information for the radiotap timestamp field; if the
* 'units_pos' member is set to a non-negative value it must be set to
* a combination of a IEEE80211_RADIOTAP_TIMESTAMP_UNIT_* and a
* IEEE80211_RADIOTAP_TIMESTAMP_SPOS_* value, and then the timestamp
* field will be added and populated from the &struct ieee80211_rx_status
* device_timestamp. If the 'accuracy' member is non-negative, it's put
* into the accuracy radiotap field and the accuracy known flag is set.
*
* @netdev_features: netdev features to be set in each netdev created
* from this HW. Note that not all features are usable with mac80211,
* other features will be rejected during HW registration.
@ -2188,6 +2196,10 @@ struct ieee80211_hw {
u8 offchannel_tx_hw_queue;
u8 radiotap_mcs_details;
u16 radiotap_vht_details;
struct {
int units_pos;
s16 accuracy;
} radiotap_timestamp;
netdev_features_t netdev_features;
u8 uapsd_queues;
u8 uapsd_max_sp_len;

3
net/mac80211/main.c
View File

@ -660,6 +660,9 @@ struct ieee80211_hw *ieee80211_alloc_hw_nm(size_t priv_data_len,
ieee80211_roc_setup(local);
local->hw.radiotap_timestamp.units_pos = -1;
local->hw.radiotap_timestamp.accuracy = -1;
return &local->hw;
err_free:
wiphy_free(wiphy);

30
net/mac80211/rx.c
View File

@ -180,6 +180,11 @@ ieee80211_rx_radiotap_hdrlen(struct ieee80211_local *local,
len += 12;
}
if (local->hw.radiotap_timestamp.units_pos >= 0) {
len = ALIGN(len, 8);
len += 12;
}
if (status->chains) {
/* antenna and antenna signal fields */
len += 2 * hweight8(status->chains);
@ -447,6 +452,31 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
pos += 2;
}
if (local->hw.radiotap_timestamp.units_pos >= 0) {
u16 accuracy = 0;
u8 flags = IEEE80211_RADIOTAP_TIMESTAMP_FLAG_32BIT;
rthdr->it_present |=
cpu_to_le32(1 << IEEE80211_RADIOTAP_TIMESTAMP);
/* ensure 8 byte alignment */
while ((pos - (u8 *)rthdr) & 7)
pos++;
put_unaligned_le64(status->device_timestamp, pos);
pos += sizeof(u64);
if (local->hw.radiotap_timestamp.accuracy >= 0) {
accuracy = local->hw.radiotap_timestamp.accuracy;
flags |= IEEE80211_RADIOTAP_TIMESTAMP_FLAG_ACCURACY;
}
put_unaligned_le16(accuracy, pos);
pos += sizeof(u16);
*pos++ = local->hw.radiotap_timestamp.units_pos;
*pos++ = flags;
}
for_each_set_bit(chain, &chains, IEEE80211_MAX_CHAINS) {
*pos++ = status->chain_signal[chain];
*pos++ = chain;