mac80211: add radiotap flag and handling for 5/10 MHz

Wireshark already defines radiotap channel flags for 5 and 10 MHz, so
just use them in Linux radiotap too. Furthermore, add rx status flags to
allow drivers to report when they received data on 5 or 10 MHz channels.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>

3 files changed, 20 insertions, 9 deletions

diff --git a/include/net/ieee80211_radiotap.h b/include/net/ieee80211_radiotap.h
index c6d07cb074bc..8b5b71433297 100644
--- a/include/net/ieee80211_radiotap.h
+++ b/include/net/ieee80211_radiotap.h
@@ -230,6 +230,10 @@ enum ieee80211_radiotap_type {
 #define IEEE80211_CHAN_PASSIVE  0x0200  /* Only passive scan allowed */
 #define IEEE80211_CHAN_DYN      0x0400  /* Dynamic CCK-OFDM channel */
 #define IEEE80211_CHAN_GFSK     0x0800  /* GFSK channel (FHSS PHY) */
+#define IEEE80211_CHAN_GSM      0x1000  /* GSM (900 MHz) */
+#define IEEE80211_CHAN_STURBO   0x2000  /* Static Turbo */
+#define IEEE80211_CHAN_HALF     0x4000  /* Half channel (10 MHz wide) */
+#define IEEE80211_CHAN_QUARTER  0x8000  /* Quarter channel (5 MHz wide) */
 
 /* For IEEE80211_RADIOTAP_FLAGS */
 #define IEEE80211_RADIOTAP_F_CFP        0x01    /* sent/received
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index fe5fee830aa8..3124036285eb 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -811,6 +811,8 @@ ieee80211_tx_info_clear_status(struct ieee80211_tx_info *info)
  * @RX_FLAG_AMPDU_DELIM_CRC_KNOWN: The delimiter CRC field is known (the CRC
  *      is stored in the @ampdu_delimiter_crc field)
  * @RX_FLAG_STBC_MASK: STBC 2 bit bitmask. 1 - Nss=1, 2 - Nss=2, 3 - Nss=3
+ * @RX_FLAG_10MHZ: 10 MHz (half channel) was used
+ * @RX_FLAG_5MHZ: 5 MHz (quarter channel) was used
  */
 enum mac80211_rx_flags {
         RX_FLAG_MMIC_ERROR              = BIT(0),
@@ -839,6 +841,8 @@ enum mac80211_rx_flags {
         RX_FLAG_80P80MHZ                = BIT(24),
         RX_FLAG_160MHZ                  = BIT(25),
         RX_FLAG_STBC_MASK               = BIT(26) | BIT(27),
+        RX_FLAG_10MHZ                   = BIT(28),
+        RX_FLAG_5MHZ                    = BIT(29),
 };
 
 #define RX_FLAG_STBC_SHIFT              26
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index c9f2ca43856a..deeeca1299bd 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -159,6 +159,7 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
         __le32 *it_present;
         u32 it_present_val;
         u16 rx_flags = 0;
+        u16 channel_flags = 0;
         int mpdulen, chain;
         unsigned long chains = status->chains;
 
@@ -243,20 +244,22 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
         /* IEEE80211_RADIOTAP_CHANNEL */
         put_unaligned_le16(status->freq, pos);
         pos += 2;
+        if (status->flag & RX_FLAG_10MHZ)
+                channel_flags |= IEEE80211_CHAN_HALF;
+        else if (status->flag & RX_FLAG_5MHZ)
+                channel_flags |= IEEE80211_CHAN_QUARTER;
+
         if (status->band == IEEE80211_BAND_5GHZ)
-                put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ,
-                                   pos);
+                channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ;
         else if (status->flag & (RX_FLAG_HT | RX_FLAG_VHT))
-                put_unaligned_le16(IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ,
-                                   pos);
+                channel_flags |= IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ;
         else if (rate && rate->flags & IEEE80211_RATE_ERP_G)
-                put_unaligned_le16(IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ,
-                                   pos);
+                channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ;
         else if (rate)
-                put_unaligned_le16(IEEE80211_CHAN_CCK | IEEE80211_CHAN_2GHZ,
-                                   pos);
+                channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ;
         else
-                put_unaligned_le16(IEEE80211_CHAN_2GHZ, pos);
+                channel_flags |= IEEE80211_CHAN_2GHZ;
+        put_unaligned_le16(channel_flags, pos);
         pos += 2;
 
         /* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */