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authorHarvey Harrison <harvey.harrison@gmail.com>2008-06-11 14:21:57 -0700
committerJohn W. Linville <linville@tuxdriver.com>2008-06-14 12:18:13 -0400
commit6693be7124cb8e4f15f0d80ed6e3e50678771737 (patch)
treeaadddb7a21250d1e7b76e0f4ba2ca124288515e3 /net/mac80211
parentc9c6950c14ffc0e30e592fec1ebcb203ad3dff10 (diff)
mac80211: add utility function to get header length
Take a __le16 directly rather than a host-endian value. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/mac80211')
-rw-r--r--net/mac80211/util.c32
1 files changed, 32 insertions, 0 deletions
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index f3c30d00b21..9f365a3af96 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -133,6 +133,38 @@ int ieee80211_get_hdrlen(u16 fc)
}
EXPORT_SYMBOL(ieee80211_get_hdrlen);
+unsigned int ieee80211_hdrlen(__le16 fc)
+{
+ unsigned int hdrlen = 24;
+
+ if (ieee80211_is_data(fc)) {
+ if (ieee80211_has_a4(fc))
+ hdrlen = 30;
+ if (ieee80211_is_data_qos(fc))
+ hdrlen += IEEE80211_QOS_CTL_LEN;
+ goto out;
+ }
+
+ if (ieee80211_is_ctl(fc)) {
+ /*
+ * ACK and CTS are 10 bytes, all others 16. To see how
+ * to get this condition consider
+ * subtype mask: 0b0000000011110000 (0x00F0)
+ * ACK subtype: 0b0000000011010000 (0x00D0)
+ * CTS subtype: 0b0000000011000000 (0x00C0)
+ * bits that matter: ^^^ (0x00E0)
+ * value of those: 0b0000000011000000 (0x00C0)
+ */
+ if ((fc & cpu_to_le16(0x00E0)) == cpu_to_le16(0x00C0))
+ hdrlen = 10;
+ else
+ hdrlen = 16;
+ }
+out:
+ return hdrlen;
+}
+EXPORT_SYMBOL(ieee80211_hdrlen);
+
unsigned int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb)
{
const struct ieee80211_hdr *hdr = (const struct ieee80211_hdr *)skb->data;