[PATCH] wireless networking: move frame inline functions to generic header

These inlines are generally useful, not just with mac80211.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Michael Wu <flamingice@sourmilk.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 272f8c8..30621c2 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -16,6 +16,7 @@
 #define IEEE80211_H
 
 #include <linux/types.h>
+#include <asm/byteorder.h>
 
 #define FCS_LEN 4
 
@@ -350,4 +351,64 @@
 
 #define WLAN_MAX_KEY_LEN		32
 
+/**
+ * ieee80211_get_SA - get pointer to SA
+ *
+ * Given an 802.11 frame, this function returns the offset
+ * to the source address (SA). It does not verify that the
+ * header is long enough to contain the address, and the
+ * header must be long enough to contain the frame control
+ * field.
+ *
+ * @hdr: the frame
+ */
+static inline u8 *ieee80211_get_SA(struct ieee80211_hdr *hdr)
+{
+	u8 *raw = (u8 *) hdr;
+	u8 tofrom = (*(raw+1)) & 3; /* get the TODS and FROMDS bits */
+
+	switch (tofrom) {
+		case 2:
+			return hdr->addr3;
+		case 3:
+			return hdr->addr4;
+	}
+	return hdr->addr2;
+}
+
+/**
+ * ieee80211_get_DA - get pointer to DA
+ *
+ * Given an 802.11 frame, this function returns the offset
+ * to the destination address (DA). It does not verify that
+ * the header is long enough to contain the address, and the
+ * header must be long enough to contain the frame control
+ * field.
+ *
+ * @hdr: the frame
+ */
+static inline u8 *ieee80211_get_DA(struct ieee80211_hdr *hdr)
+{
+	u8 *raw = (u8 *) hdr;
+	u8 to_ds = (*(raw+1)) & 1; /* get the TODS bit */
+
+	if (to_ds)
+		return hdr->addr3;
+	return hdr->addr1;
+}
+
+/**
+ * ieee80211_get_morefrag - determine whether the MOREFRAGS bit is set
+ *
+ * This function determines whether the "more fragments" bit is set
+ * in the frame.
+ *
+ * @hdr: the frame
+ */
+static inline int ieee80211_get_morefrag(struct ieee80211_hdr *hdr)
+{
+	return (le16_to_cpu(hdr->frame_control) &
+		IEEE80211_FCTL_MOREFRAGS) != 0;
+}
+
 #endif /* IEEE80211_H */