[PATCH 0/3] A-MPDU status reporting

[PATCH 0/3] A-MPDU status reporting

[Johannes Berg]

We just added A-MPDU status reporting in radiotap, this
implements it in mac80211 and iwlwifi. The changes will
be adopted formally next week so I'll merge the patches
then (into the different trees.)

johannes

[PATCH 1/3] wireless: add radiotap A-MPDU status field

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

Define the A-MPDU status field in radiotap, also
update the radiotap parser for it and the MCS field
that was apparently missed last time.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 include/net/ieee80211_radiotap.h |   11 +++++++++++
 net/wireless/radiotap.c          |    2 ++
 2 files changed, 13 insertions(+)

diff --git a/include/net/ieee80211_radiotap.h b/include/net/ieee80211_radiotap.h
index 7139254..b273c5b 100644
--- a/include/net/ieee80211_radiotap.h
+++ b/include/net/ieee80211_radiotap.h
@@ -183,6 +183,9 @@ struct ieee80211_radiotap_header {
  *     Contains a bitmap of known fields/flags, the flags, and
  *     the MCS index.
  *
+ * IEEE80211_RADIOTAP_AMPDU_STATUS	u32, u16, u8, u8	unitlesss
+ *
+ *	Contains the AMPDU information for the subframe.
  */
 enum ieee80211_radiotap_type {
 	IEEE80211_RADIOTAP_TSFT = 0,
@@ -205,6 +208,7 @@ enum ieee80211_radiotap_type {
 	IEEE80211_RADIOTAP_DATA_RETRIES = 17,
 
 	IEEE80211_RADIOTAP_MCS = 19,
+	IEEE80211_RADIOTAP_AMPDU_STATUS = 20,
 
 	/* valid in every it_present bitmap, even vendor namespaces */
 	IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE = 29,
@@ -270,6 +274,13 @@ enum ieee80211_radiotap_type {
 #define IEEE80211_RADIOTAP_MCS_FMT_GF		0x08
 #define IEEE80211_RADIOTAP_MCS_FEC_LDPC		0x10
 
+/* For IEEE80211_RADIOTAP_AMPDU_STATUS */
+#define IEEE80211_RADIOTAP_AMPDU_REPORT_ZEROLEN		0x0001
+#define IEEE80211_RADIOTAP_AMPDU_IS_ZEROLEN		0x0002
+#define IEEE80211_RADIOTAP_AMPDU_LAST_KNOWN		0x0004
+#define IEEE80211_RADIOTAP_AMPDU_IS_LAST		0x0008
+#define IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_ERR		0x0010
+#define IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_KNOWN	0x0020
 
 /* helpers */
 static inline int ieee80211_get_radiotap_len(unsigned char *data)
diff --git a/net/wireless/radiotap.c b/net/wireless/radiotap.c
index c4ad795..7d604c0 100644
--- a/net/wireless/radiotap.c
+++ b/net/wireless/radiotap.c
@@ -41,6 +41,8 @@ static const struct radiotap_align_size rtap_namespace_sizes[] = {
 	[IEEE80211_RADIOTAP_TX_FLAGS] = { .align = 2, .size = 2, },
 	[IEEE80211_RADIOTAP_RTS_RETRIES] = { .align = 1, .size = 1, },
 	[IEEE80211_RADIOTAP_DATA_RETRIES] = { .align = 1, .size = 1, },
+	[IEEE80211_RADIOTAP_MCS] = { .align = 1, .size = 3, },
+	[IEEE80211_RADIOTAP_AMPDU_STATUS] = { .align = 4, .size = 8, },
 	/*
 	 * add more here as they are defined in radiotap.h
 	 */
-- 
1.7.10.4

[PATCH 2/3] mac80211: support A-MPDU status reporting

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

Support getting A-MPDU status information from the
drivers and reporting it to userspace via radiotap
in the standard fields.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 include/net/mac80211.h |   53 +++++++++++++++++++++++++++++++++++-------------
 net/mac80211/rx.c      |   42 +++++++++++++++++++++++++++++++++++++-
 2 files changed, 80 insertions(+), 15 deletions(-)

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 8114f59..3762636 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -676,21 +676,41 @@ ieee80211_tx_info_clear_status(struct ieee80211_tx_info *info)
  * @RX_FLAG_HT_GF: This frame was received in a HT-greenfield transmission, if
  *	the driver fills this value it should add %IEEE80211_RADIOTAP_MCS_HAVE_FMT
  *	to hw.radiotap_mcs_details to advertise that fact
+ * @RX_FLAG_AMPDU_DETAILS: A-MPDU details are known, in particular the reference
+ *	number (@ampdu_reference) must be populated and be a distinct number for
+ *	each A-MPDU
+ * @RX_FLAG_AMPDU_REPORT_ZEROLEN: driver reports 0-length subframes
+ * @RX_FLAG_AMPDU_IS_ZEROLEN: This is a zero-length subframe, for
+ *	monitoring purposes only
+ * @RX_FLAG_AMPDU_LAST_KNOWN: last subframe is known, should be set on all
+ *	subframes of a single A-MPDU
+ * @RX_FLAG_AMPDU_IS_LAST: this subframe is the last subframe of the A-MPDU
+ * @RX_FLAG_AMPDU_DELIM_CRC_ERROR: A delimiter CRC error has been detected
+ *	on this subframe
+ * @RX_FLAG_AMPDU_DELIM_CRC_KNOWN: The delimiter CRC field is known (the CRC
+ *	is stored in the @ampdu_delimiter_crc field)
  */
 enum mac80211_rx_flags {
-	RX_FLAG_MMIC_ERROR	= 1<<0,
-	RX_FLAG_DECRYPTED	= 1<<1,
-	RX_FLAG_MMIC_STRIPPED	= 1<<3,
-	RX_FLAG_IV_STRIPPED	= 1<<4,
-	RX_FLAG_FAILED_FCS_CRC	= 1<<5,
-	RX_FLAG_FAILED_PLCP_CRC = 1<<6,
-	RX_FLAG_MACTIME_MPDU	= 1<<7,
-	RX_FLAG_SHORTPRE	= 1<<8,
-	RX_FLAG_HT		= 1<<9,
-	RX_FLAG_40MHZ		= 1<<10,
-	RX_FLAG_SHORT_GI	= 1<<11,
-	RX_FLAG_NO_SIGNAL_VAL	= 1<<12,
-	RX_FLAG_HT_GF		= 1<<13,
+	RX_FLAG_MMIC_ERROR		= BIT(0),
+	RX_FLAG_DECRYPTED		= BIT(1),
+	RX_FLAG_MMIC_STRIPPED		= BIT(3),
+	RX_FLAG_IV_STRIPPED		= BIT(4),
+	RX_FLAG_FAILED_FCS_CRC		= BIT(5),
+	RX_FLAG_FAILED_PLCP_CRC 	= BIT(6),
+	RX_FLAG_MACTIME_MPDU		= BIT(7),
+	RX_FLAG_SHORTPRE		= BIT(8),
+	RX_FLAG_HT			= BIT(9),
+	RX_FLAG_40MHZ			= BIT(10),
+	RX_FLAG_SHORT_GI		= BIT(11),
+	RX_FLAG_NO_SIGNAL_VAL		= BIT(12),
+	RX_FLAG_HT_GF			= BIT(13),
+	RX_FLAG_AMPDU_DETAILS		= BIT(14),
+	RX_FLAG_AMPDU_REPORT_ZEROLEN	= BIT(15),
+	RX_FLAG_AMPDU_IS_ZEROLEN	= BIT(16),
+	RX_FLAG_AMPDU_LAST_KNOWN	= BIT(17),
+	RX_FLAG_AMPDU_IS_LAST		= BIT(18),
+	RX_FLAG_AMPDU_DELIM_CRC_ERROR	= BIT(19),
+	RX_FLAG_AMPDU_DELIM_CRC_KNOWN	= BIT(20),
 };
 
 /**
@@ -714,17 +734,22 @@ enum mac80211_rx_flags {
  *	HT rates are use (RX_FLAG_HT)
  * @flag: %RX_FLAG_*
  * @rx_flags: internal RX flags for mac80211
+ * @ampdu_reference: A-MPDU reference number, must be a different value for
+ *	each A-MPDU but the same for each subframe within one A-MPDU
+ * @ampdu_delimiter_crc: A-MPDU delimiter CRC
  */
 struct ieee80211_rx_status {
 	u64 mactime;
 	u32 device_timestamp;
-	u16 flag;
+	u32 ampdu_reference;
+	u32 flag;
 	u16 freq;
 	u8 rate_idx;
 	u8 rx_flags;
 	u8 band;
 	u8 antenna;
 	s8 signal;
+	u8 ampdu_delimiter_crc;
 };
 
 /**
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 090d417..6284e86 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -60,7 +60,9 @@ static inline int should_drop_frame(struct sk_buff *skb,
 	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
 
-	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
+	if (status->flag & (RX_FLAG_FAILED_FCS_CRC |
+			    RX_FLAG_FAILED_PLCP_CRC |
+			    RX_FLAG_AMPDU_IS_ZEROLEN))
 		return 1;
 	if (unlikely(skb->len < 16 + present_fcs_len))
 		return 1;
@@ -91,6 +93,13 @@ ieee80211_rx_radiotap_len(struct ieee80211_local *local,
 	if (status->flag & RX_FLAG_HT) /* HT info */
 		len += 3;
 
+	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
+		/* padding */
+		while (len & 3)
+			len++;
+		len += 8;
+	}
+
 	return len;
 }
 
@@ -215,6 +224,37 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
 		pos++;
 		*pos++ = status->rate_idx;
 	}
+
+	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
+		u16 flags = 0;
+
+		/* ensure 4 byte alignment */
+		while ((pos - (u8 *)rthdr) & 3)
+			pos++;
+		rthdr->it_present |=
+			cpu_to_le32(1 << IEEE80211_RADIOTAP_AMPDU_STATUS);
+		put_unaligned_le32(status->ampdu_reference, pos);
+		pos += 4;
+		if (status->flag & RX_FLAG_AMPDU_REPORT_ZEROLEN)
+			flags |= IEEE80211_RADIOTAP_AMPDU_REPORT_ZEROLEN;
+		if (status->flag & RX_FLAG_AMPDU_IS_ZEROLEN)
+			flags |= IEEE80211_RADIOTAP_AMPDU_IS_ZEROLEN;
+		if (status->flag & RX_FLAG_AMPDU_LAST_KNOWN)
+			flags |= IEEE80211_RADIOTAP_AMPDU_LAST_KNOWN;
+		if (status->flag & RX_FLAG_AMPDU_IS_LAST)
+			flags |= IEEE80211_RADIOTAP_AMPDU_IS_LAST;
+		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_ERROR)
+			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_ERR;
+		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
+			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_KNOWN;
+		put_unaligned_le16(flags, pos);
+		pos += 2;
+		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
+			*pos++ = status->ampdu_delimiter_crc;
+		else
+			*pos++ = 0;
+		*pos++ = 0;
+	}
 }
 
 /*
-- 
1.7.10.4

[PATCH 3/3] iwlwifi: report A-MPDU status

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

Since the firmware will give us an A-MPDU bit and
only a single PHY information packet for all the
subframes in an A-MPDU, we can easily report the
minimal A-MPDU information for radiotap.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 drivers/net/wireless/iwlwifi/dvm/commands.h |    1 +
 drivers/net/wireless/iwlwifi/dvm/dev.h      |    1 +
 drivers/net/wireless/iwlwifi/dvm/rx.c       |   11 +++++++++++
 3 files changed, 13 insertions(+)

diff --git a/drivers/net/wireless/iwlwifi/dvm/commands.h b/drivers/net/wireless/iwlwifi/dvm/commands.h
index 4a361c5..c5d4490 100644
--- a/drivers/net/wireless/iwlwifi/dvm/commands.h
+++ b/drivers/net/wireless/iwlwifi/dvm/commands.h
@@ -1055,6 +1055,7 @@ struct iwl_wep_cmd {
 #define RX_RES_PHY_FLAGS_MOD_CCK_MSK		cpu_to_le16(1 << 1)
 #define RX_RES_PHY_FLAGS_SHORT_PREAMBLE_MSK	cpu_to_le16(1 << 2)
 #define RX_RES_PHY_FLAGS_NARROW_BAND_MSK	cpu_to_le16(1 << 3)
+#define RX_RES_PHY_FLAGS_AGG_MSK		cpu_to_le16(1 << 7)
 #define RX_RES_PHY_FLAGS_ANTENNA_MSK		0xf0
 #define RX_RES_PHY_FLAGS_ANTENNA_POS		4
 
diff --git a/drivers/net/wireless/iwlwifi/dvm/dev.h b/drivers/net/wireless/iwlwifi/dvm/dev.h
index 054f728..8141f91 100644
--- a/drivers/net/wireless/iwlwifi/dvm/dev.h
+++ b/drivers/net/wireless/iwlwifi/dvm/dev.h
@@ -771,6 +771,7 @@ struct iwl_priv {
 	u8 agg_tids_count;
 
 	struct iwl_rx_phy_res last_phy_res;
+	u32 ampdu_ref;
 	bool last_phy_res_valid;
 
 	/*
diff --git a/drivers/net/wireless/iwlwifi/dvm/rx.c b/drivers/net/wireless/iwlwifi/dvm/rx.c
index fee5cff..5a9c325 100644
--- a/drivers/net/wireless/iwlwifi/dvm/rx.c
+++ b/drivers/net/wireless/iwlwifi/dvm/rx.c
@@ -667,6 +667,7 @@ static int iwlagn_rx_reply_rx_phy(struct iwl_priv *priv,
 	struct iwl_rx_packet *pkt = rxb_addr(rxb);
 
 	priv->last_phy_res_valid = true;
+	priv->ampdu_ref++;
 	memcpy(&priv->last_phy_res, pkt->data,
 	       sizeof(struct iwl_rx_phy_res));
 	return 0;
@@ -981,6 +982,16 @@ static int iwlagn_rx_reply_rx(struct iwl_priv *priv,
 	if (phy_res->phy_flags & RX_RES_PHY_FLAGS_SHORT_PREAMBLE_MSK)
 		rx_status.flag |= RX_FLAG_SHORTPRE;
 
+	if (phy_res->phy_flags & RX_RES_PHY_FLAGS_AGG_MSK) {
+		/*
+		 * We know which subframes of an A-MPDU belong
+		 * together since we get a single PHY response
+		 * from the firmware for all of them
+		 */
+		rx_status.flag |= RX_FLAG_AMPDU_DETAILS;
+		rx_status.ampdu_reference = priv->ampdu_ref;
+	}
+
 	/* Set up the HT phy flags */
 	if (rate_n_flags & RATE_MCS_HT_MSK)
 		rx_status.flag |= RX_FLAG_HT;
-- 
1.7.10.4

Re: [PATCH 1/3] wireless: add radiotap A-MPDU status field

[Gertjan van Wingerde]

Hi Johannes,

On 31 jul. 2012, at 13:35, Johannes Berg <johannes@sipsolutions.net> wrote:

> From: Johannes Berg <johannes.berg@intel.com>
> 
> Define the A-MPDU status field in radiotap, also
> update the radiotap parser for it and the MCS field
> that was apparently missed last time.
> 
> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
> ---
> include/net/ieee80211_radiotap.h |   11 +++++++++++
> net/wireless/radiotap.c          |    2 ++
> 2 files changed, 13 insertions(+)
> 
> diff --git a/include/net/ieee80211_radiotap.h b/include/net/ieee80211_radiotap.h
> index 7139254..b273c5b 100644
> --- a/include/net/ieee80211_radiotap.h
> +++ b/include/net/ieee80211_radiotap.h
> @@ -183,6 +183,9 @@ struct ieee80211_radiotap_header {
>  *     Contains a bitmap of known fields/flags, the flags, and
>  *     the MCS index.
>  *
> + * IEEE80211_RADIOTAP_AMPDU_STATUS    u32, u16, u8, u8    unitlesss

Just a minor nit, but there seems to be an 's' too many in unitlesss above.

---
Gertjan

Re: [PATCH 1/3] wireless: add radiotap A-MPDU status field

[Johannes Berg]

On Tue, 2012-07-31 at 19:00 +0200, Gertjan van Wingerde wrote:

> > + * IEEE80211_RADIOTAP_AMPDU_STATUS    u32, u16, u8, u8    unitlesss
> 
> Just a minor nit, but there seems to be an 's' too many in unitlesss above.

Good catch, thanks. I fixed it, but I'm not going to repost the patches
for it :-)

johannes

[PATCH] carl9170: report A-MPDU status

[Christian Lamparter]

Because the hardware reports whenever an frame
was either at the start, in the middle or at
the end of a A-MPDU, we can easily report the
information for radiotap.

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
---
 drivers/net/wireless/ath/carl9170/carl9170.h |    1 +
 drivers/net/wireless/ath/carl9170/rx.c       |   15 +++++++++++----
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/carl9170/carl9170.h b/drivers/net/wireless/ath/carl9170/carl9170.h
index 376be11..58b73a0 100644
--- a/drivers/net/wireless/ath/carl9170/carl9170.h
+++ b/drivers/net/wireless/ath/carl9170/carl9170.h
@@ -425,6 +425,7 @@ struct ar9170 {
 	bool rx_has_plcp;
 	struct sk_buff *rx_failover;
 	int rx_failover_missing;
+	u32 ampdu_ref;
 
 	/* FIFO for collecting outstanding BlockAckRequest */
 	struct list_head bar_list[__AR9170_NUM_TXQ];
diff --git a/drivers/net/wireless/ath/carl9170/rx.c b/drivers/net/wireless/ath/carl9170/rx.c
index 25910a1..a57e44e 100644
--- a/drivers/net/wireless/ath/carl9170/rx.c
+++ b/drivers/net/wireless/ath/carl9170/rx.c
@@ -623,7 +623,8 @@ static void carl9170_ba_check(struct ar9170 *ar, void *data, unsigned int len)
 #undef TID_CHECK
 }
 
-static bool carl9170_ampdu_check(struct ar9170 *ar, u8 *buf, u8 ms)
+static bool carl9170_ampdu_check(struct ar9170 *ar, u8 *buf, u8 ms,
+				 struct ieee80211_rx_status *rx_status)
 {
 	__le16 fc;
 
@@ -636,6 +637,9 @@ static bool carl9170_ampdu_check(struct ar9170 *ar, u8 *buf, u8 ms)
 		return true;
 	}
 
+	rx_status->flag |= RX_FLAG_AMPDU_DETAILS | RX_FLAG_AMPDU_LAST_KNOWN;
+	rx_status->ampdu_reference = ar->ampdu_ref;
+
 	/*
 	 * "802.11n - 7.4a.3 A-MPDU contents" describes in which contexts
 	 * certain frame types can be part of an aMPDU.
@@ -684,12 +688,15 @@ static void carl9170_handle_mpdu(struct ar9170 *ar, u8 *buf, int len)
 	if (unlikely(len < sizeof(*mac)))
 		goto drop;
 
+	memset(&status, 0, sizeof(status));
+
 	mpdu_len = len - sizeof(*mac);
 
 	mac = (void *)(buf + mpdu_len);
 	mac_status = mac->status;
 	switch (mac_status & AR9170_RX_STATUS_MPDU) {
 	case AR9170_RX_STATUS_MPDU_FIRST:
+		ar->ampdu_ref++;
 		/* Aggregated MPDUs start with an PLCP header */
 		if (likely(mpdu_len >= sizeof(struct ar9170_rx_head))) {
 			head = (void *) buf;
@@ -720,12 +727,13 @@ static void carl9170_handle_mpdu(struct ar9170 *ar, u8 *buf, int len)
 		break;
 
 	case AR9170_RX_STATUS_MPDU_LAST:
+		status.flag |= RX_FLAG_AMPDU_IS_LAST;
+
 		/*
 		 * The last frame of an A-MPDU has an extra tail
 		 * which does contain the phy status of the whole
 		 * aggregate.
 		 */
-
 		if (likely(mpdu_len >= sizeof(struct ar9170_rx_phystatus))) {
 			mpdu_len -= sizeof(struct ar9170_rx_phystatus);
 			phy = (void *)(buf + mpdu_len);
@@ -773,11 +781,10 @@ static void carl9170_handle_mpdu(struct ar9170 *ar, u8 *buf, int len)
 	if (unlikely(mpdu_len < (2 + 2 + ETH_ALEN + FCS_LEN)))
 		goto drop;
 
-	memset(&status, 0, sizeof(status));
 	if (unlikely(carl9170_rx_mac_status(ar, head, mac, &status)))
 		goto drop;
 
-	if (!carl9170_ampdu_check(ar, buf, mac_status))
+	if (!carl9170_ampdu_check(ar, buf, mac_status, &status))
 		goto drop;
 
 	if (phy)
-- 
1.7.10.4

Re: [PATCH 0/3] A-MPDU status reporting

[Johannes Berg]

On Tue, 2012-07-31 at 13:35 +0200, Johannes Berg wrote:
> We just added A-MPDU status reporting in radiotap, this
> implements it in mac80211 and iwlwifi. The changes will
> be adopted formally next week so I'll merge the patches
> then (into the different trees.)

Applied the wrieless/mac80211 changes.

johannes

Re: [PATCH] carl9170: report A-MPDU status

[Johannes Berg]

On Tue, 2012-07-31 at 23:12 +0200, Christian Lamparter wrote:
> Because the hardware reports whenever an frame
> was either at the start, in the middle or at
> the end of a A-MPDU, we can easily report the
> information for radiotap.

John, you can pick this up after you pull from me, I've included the
prerequisite patches now.

johannes