mac80211: support A-MPDU status reporting

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>

2 files changed, 80 insertions, 15 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index d9cef31f4cbf..edc235c51a68 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 0cb4edee6af5..78bf6c7e80c8 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;
+        }
 }
 
 /*