mac80211: dont use interface indices in drivers

This patch gets rid of the if_id stuff where possible in favour of
a new per-virtual-interface structure "struct ieee80211_vif". This
structure is located at the end of the per-interface structure and
contains a variable length driver-use data area.

This has two advantages:
 * removes the need to look up interfaces by if_id, this is better
   for working with network namespaces and performance
 * allows drivers to store and retrieve per-interface data without
   having to allocate own lists/hash tables

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index be2a383..24a8ad3 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -280,6 +280,7 @@
  * the hardware to use given values (depending on what is supported). */
 
 struct ieee80211_tx_control {
+	struct ieee80211_vif *vif;
 	int tx_rate; /* Transmit rate, given as the hw specific value for the
 		      * rate (from struct ieee80211_rate) */
 	int rts_cts_rate; /* Transmit rate for RTS/CTS frame, given as the hw
@@ -332,7 +333,6 @@
 			     * packet dropping when probing higher rates, if hw
 			     * supports multiple retry rates. -1 = not used */
 	int type;	/* internal */
-	int ifindex;	/* internal */
 };
 
 
@@ -530,13 +530,25 @@
 };
 
 /**
+ * struct ieee80211_vif - per-interface data
+ *
+ * Data in this structure is continually present for driver
+ * use during the life of a virtual interface.
+ *
+ * @drv_priv: data area for driver use, will always be aligned to
+ *	sizeof(void *).
+ */
+struct ieee80211_vif {
+	/* must be last */
+	u8 drv_priv[0] __attribute__((__aligned__(sizeof(void *))));
+};
+
+/**
  * struct ieee80211_if_init_conf - initial configuration of an interface
  *
- * @if_id: internal interface ID. This number has no particular meaning to
- *	drivers and the only allowed usage is to pass it to
- *	ieee80211_beacon_get() and ieee80211_get_buffered_bc() functions.
- *	This field is not valid for monitor interfaces
- *	(interfaces of %IEEE80211_IF_TYPE_MNTR type).
+ * @vif: pointer to a driver-use per-interface structure. The pointer
+ *	itself is also used for various functions including
+ *	ieee80211_beacon_get() and ieee80211_get_buffered_bc().
  * @type: one of &enum ieee80211_if_types constants. Determines the type of
  *	added/removed interface.
  * @mac_addr: pointer to MAC address of the interface. This pointer is valid
@@ -553,8 +565,8 @@
  * in pure monitor mode.
  */
 struct ieee80211_if_init_conf {
-	int if_id;
 	enum ieee80211_if_types type;
+	struct ieee80211_vif *vif;
 	void *mac_addr;
 };
 
@@ -757,6 +769,9 @@
  * @rate_control_algorithm: rate control algorithm for this hardware.
  *	If unset (NULL), the default algorithm will be used. Must be
  *	set before calling ieee80211_register_hw().
+ *
+ * @vif_data_size: size (in bytes) of the drv_priv data area
+ *	within &struct ieee80211_vif.
  */
 struct ieee80211_hw {
 	struct ieee80211_conf conf;
@@ -767,6 +782,7 @@
 	u32 flags;
 	unsigned int extra_tx_headroom;
 	int channel_change_time;
+	int vif_data_size;
 	u8 queues;
 	s8 max_rssi;
 	s8 max_signal;
@@ -1076,7 +1092,8 @@
 				 struct ieee80211_if_init_conf *conf);
 	int (*config)(struct ieee80211_hw *hw, struct ieee80211_conf *conf);
 	int (*config_interface)(struct ieee80211_hw *hw,
-				int if_id, struct ieee80211_if_conf *conf);
+				struct ieee80211_vif *vif,
+				struct ieee80211_if_conf *conf);
 	void (*configure_filter)(struct ieee80211_hw *hw,
 				 unsigned int changed_flags,
 				 unsigned int *total_flags,
@@ -1094,7 +1111,7 @@
 	int (*set_frag_threshold)(struct ieee80211_hw *hw, u32 value);
 	int (*set_retry_limit)(struct ieee80211_hw *hw,
 			       u32 short_retry, u32 long_retr);
-	void (*sta_notify)(struct ieee80211_hw *hw, int if_id,
+	void (*sta_notify)(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 			enum sta_notify_cmd, const u8 *addr);
 	void (*erp_ie_changed)(struct ieee80211_hw *hw, u8 changes,
 			       int cts_protection, int preamble);
@@ -1309,7 +1326,7 @@
 /**
  * ieee80211_beacon_get - beacon generation function
  * @hw: pointer obtained from ieee80211_alloc_hw().
- * @if_id: interface ID from &struct ieee80211_if_init_conf.
+ * @vif: &struct ieee80211_vif pointer from &struct ieee80211_if_init_conf.
  * @control: will be filled with information needed to send this beacon.
  *
  * If the beacon frames are generated by the host system (i.e., not in
@@ -1320,13 +1337,13 @@
  * is responsible of freeing it.
  */
 struct sk_buff *ieee80211_beacon_get(struct ieee80211_hw *hw,
-				     int if_id,
+				     struct ieee80211_vif *vif,
 				     struct ieee80211_tx_control *control);
 
 /**
  * ieee80211_rts_get - RTS frame generation function
  * @hw: pointer obtained from ieee80211_alloc_hw().
- * @if_id: interface ID from &struct ieee80211_if_init_conf.
+ * @vif: &struct ieee80211_vif pointer 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.
@@ -1337,7 +1354,7 @@
  * 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, int if_id,
+void ieee80211_rts_get(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 		       const void *frame, size_t frame_len,
 		       const struct ieee80211_tx_control *frame_txctl,
 		       struct ieee80211_rts *rts);
@@ -1345,7 +1362,7 @@
 /**
  * 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.
+ * @vif: &struct ieee80211_vif pointer 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.
  *
@@ -1353,14 +1370,14 @@
  * 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, int if_id,
-			      size_t frame_len,
+__le16 ieee80211_rts_duration(struct ieee80211_hw *hw,
+			      struct ieee80211_vif *vif, 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.
+ * @vif: &struct ieee80211_vif pointer 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.
@@ -1371,7 +1388,8 @@
  * 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, int if_id,
+void ieee80211_ctstoself_get(struct ieee80211_hw *hw,
+			     struct ieee80211_vif *vif,
 			     const void *frame, size_t frame_len,
 			     const struct ieee80211_tx_control *frame_txctl,
 			     struct ieee80211_cts *cts);
@@ -1379,7 +1397,7 @@
 /**
  * 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.
+ * @vif: &struct ieee80211_vif pointer 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.
  *
@@ -1387,28 +1405,30 @@
  * 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, int if_id,
+__le16 ieee80211_ctstoself_duration(struct ieee80211_hw *hw,
+				    struct ieee80211_vif *vif,
 				    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.
+ * @vif: &struct ieee80211_vif pointer 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, int if_id,
+__le16 ieee80211_generic_frame_duration(struct ieee80211_hw *hw,
+					struct ieee80211_vif *vif,
 					size_t frame_len,
 					int rate);
 
 /**
  * ieee80211_get_buffered_bc - accessing buffered broadcast and multicast frames
  * @hw: pointer as obtained from ieee80211_alloc_hw().
- * @if_id: interface ID from &struct ieee80211_if_init_conf.
+ * @vif: &struct ieee80211_vif pointer from &struct ieee80211_if_init_conf.
  * @control: will be filled with information needed to send returned frame.
  *
  * Function for accessing buffered broadcast and multicast frames. If
@@ -1427,7 +1447,7 @@
  * use common code for all beacons.
  */
 struct sk_buff *
-ieee80211_get_buffered_bc(struct ieee80211_hw *hw, int if_id,
+ieee80211_get_buffered_bc(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 			  struct ieee80211_tx_control *control);
 
 /**
@@ -1517,7 +1537,7 @@
  */
 void ieee80211_iterate_active_interfaces(struct ieee80211_hw *hw,
 					 void (*iterator)(void *data, u8 *mac,
-							  int if_id),
+						struct ieee80211_vif *vif),
 					 void *data);
 
 #endif /* MAC80211_H */