[MAC80211]: improved short preamble handling

Similarly to CTS protection, whether short preambles are used for 802.11b
transmissions should be a per-subif setting, not device global.

For STAs, this patch makes short preamble handling automatic based on the ERP
IE. For APs, hostapd still uses the prism ioctls, but the write ioctl has been
restricted to AP-only subifs.

ieee80211_txrx_data.short_preamble (an unused field) was removed.

Unfortunately, some API changes were required for the following functions:
 - ieee80211_generic_frame_duration
 - ieee80211_rts_duration
 - ieee80211_ctstoself_duration
 - ieee80211_rts_get
 - ieee80211_ctstoself_get
Affected drivers were updated accordingly.

Signed-off-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 10 insertions, 5 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 91cee0f0aa71..3282038a1510 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -835,6 +835,7 @@ struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
 /**
  * ieee80211_rts_get - RTS frame generation function
  * @hw: pointer obtained from ieee80211_alloc_hw().
+ * @if_id: interface ID from &struct ieee80211_if_init_conf.
  * @frame: pointer to the frame that is going to be protected by the RTS.
  * @frame_len: the frame length (in octets).
  * @frame_txctl: &struct ieee80211_tx_control of the frame.
@@ -845,7 +846,7 @@ struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
  * the next RTS frame from the 802.11 code. The low-level is responsible
  * for calling this function before and RTS frame is needed.
  */
-void ieee80211_rts_get(struct ieee80211_hw *hw,
+void ieee80211_rts_get(struct ieee80211_hw *hw, int if_id,
                        const void *frame, size_t frame_len,
                        const struct ieee80211_tx_control *frame_txctl,
                        struct ieee80211_rts *rts);
@@ -853,6 +854,7 @@ void ieee80211_rts_get(struct ieee80211_hw *hw,
 /**
  * ieee80211_rts_duration - Get the duration field for an RTS frame
  * @hw: pointer obtained from ieee80211_alloc_hw().
+ * @if_id: interface ID from &struct ieee80211_if_init_conf.
  * @frame_len: the length of the frame that is going to be protected by the RTS.
  * @frame_txctl: &struct ieee80211_tx_control of the frame.
  *
@@ -860,13 +862,14 @@ void ieee80211_rts_get(struct ieee80211_hw *hw,
  * the duration field, the low-level driver uses this function to receive
  * the duration field value in little-endian byteorder.
  */
-__le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
+__le16 ieee80211_rts_duration(struct ieee80211_hw *hw, int if_id,
                               size_t frame_len,
                               const struct ieee80211_tx_control *frame_txctl);
 
 /**
  * ieee80211_ctstoself_get - CTS-to-self frame generation function
  * @hw: pointer obtained from ieee80211_alloc_hw().
+ * @if_id: interface ID from &struct ieee80211_if_init_conf.
  * @frame: pointer to the frame that is going to be protected by the CTS-to-self.
  * @frame_len: the frame length (in octets).
  * @frame_txctl: &struct ieee80211_tx_control of the frame.
@@ -877,7 +880,7 @@ __le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
  * the next CTS-to-self frame from the 802.11 code. The low-level is responsible
  * for calling this function before and CTS-to-self frame is needed.
  */
-void ieee80211_ctstoself_get(struct ieee80211_hw *hw,
+void ieee80211_ctstoself_get(struct ieee80211_hw *hw, int if_id,
                              const void *frame, size_t frame_len,
                              const struct ieee80211_tx_control *frame_txctl,
                              struct ieee80211_cts *cts);
@@ -885,6 +888,7 @@ void ieee80211_ctstoself_get(struct ieee80211_hw *hw,
 /**
  * ieee80211_ctstoself_duration - Get the duration field for a CTS-to-self frame
  * @hw: pointer obtained from ieee80211_alloc_hw().
+ * @if_id: interface ID from &struct ieee80211_if_init_conf.
  * @frame_len: the length of the frame that is going to be protected by the CTS-to-self.
  * @frame_txctl: &struct ieee80211_tx_control of the frame.
  *
@@ -892,20 +896,21 @@ void ieee80211_ctstoself_get(struct ieee80211_hw *hw,
  * the duration field, the low-level driver uses this function to receive
  * the duration field value in little-endian byteorder.
  */
-__le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
+__le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw, int if_id,
                                     size_t frame_len,
                                     const struct ieee80211_tx_control *frame_txctl);
 
 /**
  * ieee80211_generic_frame_duration - Calculate the duration field for a frame
  * @hw: pointer obtained from ieee80211_alloc_hw().
+ * @if_id: interface ID from &struct ieee80211_if_init_conf.
  * @frame_len: the length of the frame.
  * @rate: the rate (in 100kbps) at which the frame is going to be transmitted.
  *
  * Calculate the duration field of some generic frame, given its
  * length and transmission rate (in 100kbps).
  */
-__le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw,
+__le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw, int if_id,
                                         size_t frame_len,
                                         int rate);