Commit 99ee7cae authored by Johannes Berg's avatar Johannes Berg
Browse files

mac80211: add support for radiotap timestamp field 



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: default avatarJohannes Berg <johannes.berg@intel.com>
parent 42bd20d9

include/net/ieee80211_radiotap.h

+21 −0
Original line number Diff line number Diff line
@@ -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)

{

include/net/mac80211.h

+12 −0
Original line number Diff line number Diff line
@@ -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;

net/mac80211/main.c

+3 −0
Original line number Diff line number Diff line
@@ -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);

net/mac80211/rx.c

+30 −0
Original line number Diff line number Diff line
@@ -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;