wireless: update radiotap parser

Upstream radiotap has adopted the namespace
proposal David Young made and I then took care
of, for which I had adapted the radiotap parser
as a library outside the kernel. This brings
the in-kernel parser up to speed.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

include/net/cfg80211.h

@@ -1561,37 +1561,82 @@ ieee80211_get_response_rate(struct ieee80211_supported_band *sband,
  * Documentation in Documentation/networking/radiotap-headers.txt
  */
 
+struct radiotap_align_size {
+	uint8_t align:4, size:4;
+};
+
+struct ieee80211_radiotap_namespace {
+	const struct radiotap_align_size *align_size;
+	int n_bits;
+	uint32_t oui;
+	uint8_t subns;
+};
+
+struct ieee80211_radiotap_vendor_namespaces {
+	const struct ieee80211_radiotap_namespace *ns;
+	int n_ns;
+};
+
 /**
  * struct ieee80211_radiotap_iterator - tracks walk thru present radiotap args
- * @rtheader: pointer to the radiotap header we are walking through
- * @max_length: length of radiotap header in cpu byte ordering
- * @this_arg_index: IEEE80211_RADIOTAP_... index of current arg
- * @this_arg: pointer to current radiotap arg
- * @arg_index: internal next argument index
- * @arg: internal next argument pointer
- * @next_bitmap: internal pointer to next present u32
- * @bitmap_shifter: internal shifter for curr u32 bitmap, b0 set == arg present
+ * @this_arg_index: index of current arg, valid after each successful call
+ *	to ieee80211_radiotap_iterator_next()
+ * @this_arg: pointer to current radiotap arg; it is valid after each
+ *	call to ieee80211_radiotap_iterator_next() but also after
+ *	ieee80211_radiotap_iterator_init() where it will point to
+ *	the beginning of the actual data portion
+ * @this_arg_size: length of the current arg, for convenience
+ * @current_namespace: pointer to the current namespace definition
+ *	(or internally %NULL if the current namespace is unknown)
+ * @is_radiotap_ns: indicates whether the current namespace is the default
+ *	radiotap namespace or not
+ *
+ * @overrides: override standard radiotap fields
+ * @n_overrides: number of overrides
+ *
+ * @_rtheader: pointer to the radiotap header we are walking through
+ * @_max_length: length of radiotap header in cpu byte ordering
+ * @_arg_index: next argument index
+ * @_arg: next argument pointer
+ * @_next_bitmap: internal pointer to next present u32
+ * @_bitmap_shifter: internal shifter for curr u32 bitmap, b0 set == arg present
+ * @_vns: vendor namespace definitions
+ * @_next_ns_data: beginning of the next namespace's data
+ * @_reset_on_ext: internal; reset the arg index to 0 when going to the
+ *	next bitmap word
+ *
+ * Describes the radiotap parser state. Fields prefixed with an underscore
+ * must not be used by users of the parser, only by the parser internally.
  */
 
 struct ieee80211_radiotap_iterator {
-	struct ieee80211_radiotap_header *rtheader;
-	int max_length;
+	struct ieee80211_radiotap_header *_rtheader;
+	const struct ieee80211_radiotap_vendor_namespaces *_vns;
+	const struct ieee80211_radiotap_namespace *current_namespace;
+
+	unsigned char *_arg, *_next_ns_data;
+	uint32_t *_next_bitmap;
+
+	unsigned char *this_arg;
 	int this_arg_index;
-	u8 *this_arg;
+	int this_arg_size;
 
-	int arg_index;
-	u8 *arg;
-	__le32 *next_bitmap;
-	u32 bitmap_shifter;
+	int is_radiotap_ns;
+
+	int _max_length;
+	int _arg_index;
+	uint32_t _bitmap_shifter;
+	int _reset_on_ext;
 };
 
 extern int ieee80211_radiotap_iterator_init(
-   struct ieee80211_radiotap_iterator *iterator,
-   struct ieee80211_radiotap_header *radiotap_header,
-   int max_length);
+	struct ieee80211_radiotap_iterator *iterator,
+	struct ieee80211_radiotap_header *radiotap_header,
+	int max_length, const struct ieee80211_radiotap_vendor_namespaces *vns);
 
 extern int ieee80211_radiotap_iterator_next(
-   struct ieee80211_radiotap_iterator *iterator);
+	struct ieee80211_radiotap_iterator *iterator);
+
 
 extern const unsigned char rfc1042_header[6];
 extern const unsigned char bridge_tunnel_header[6];

include/net/ieee80211_radiotap.h

@@ -198,6 +198,10 @@ enum ieee80211_radiotap_type {
 	IEEE80211_RADIOTAP_TX_FLAGS = 15,
 	IEEE80211_RADIOTAP_RTS_RETRIES = 16,
 	IEEE80211_RADIOTAP_DATA_RETRIES = 17,
+
+	/* valid in every it_present bitmap, even vendor namespaces */
+	IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE = 29,
+	IEEE80211_RADIOTAP_VENDOR_NAMESPACE = 30,
 	IEEE80211_RADIOTAP_EXT = 31
 };
 

net/mac80211/tx.c

@@ -1010,7 +1010,8 @@ static bool __ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
 		(struct ieee80211_radiotap_header *) skb->data;
 	struct ieee80211_supported_band *sband;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
-	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len);
+	int ret = ieee80211_radiotap_iterator_init(&iterator, rthdr, skb->len,
+						   NULL);
 
 	sband = tx->local->hw.wiphy->bands[tx->channel->band];
 
@@ -1046,7 +1047,7 @@ static bool __ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
 				 * because it will be recomputed and added
 				 * on transmission
 				 */
-				if (skb->len < (iterator.max_length + FCS_LEN))
+				if (skb->len < (iterator._max_length + FCS_LEN))
 					return false;
 
 				skb_trim(skb, skb->len - FCS_LEN);
@@ -1073,10 +1074,10 @@ static bool __ieee80211_parse_tx_radiotap(struct ieee80211_tx_data *tx,
 
 	/*
 	 * remove the radiotap header
-	 * iterator->max_length was sanity-checked against
+	 * iterator->_max_length was sanity-checked against
 	 * skb->len by iterator init
 	 */
-	skb_pull(skb, iterator.max_length);
+	skb_pull(skb, iterator._max_length);
 
 	return true;
 }