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mac80211: simplify code in util.c

PATCH In review Harvey Harrison 3 participants 4 messages Apr 21, 2008 mac80211

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Harvey Harrison

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#0 lore raw

PATCH 1/1 mac80211: simplify code in util.c

Signed-off-by Harvey Harrison <[email protected]>
---
 net/mac80211/util.c |   11 ++++-------
 1 files changed, 4 insertions(+), 7 deletions(-)
net/mac80211/util.c +4 -7
index cc9f715..9960372 100644
@@ -101,16 +101,13 @@ int ieee80211_get_hdrlen(u16 fc)
 	switch (fc & IEEE80211_FCTL_FTYPE) {
 	case IEEE80211_FTYPE_DATA:
 		if ((fc & IEEE80211_FCTL_FROMDS) && (fc & IEEE80211_FCTL_TODS))
-			hdrlen = 30; /* Addr4 */
+			hdrlen += ETH_ALEN; /* Addr4 */
 		/*
 		 * The QoS Control field is two bytes and its presence is
-		 * indicated by the IEEE80211_STYPE_QOS_DATA bit. Add 2 to
-		 * hdrlen if that bit is set.
-		 * This works by masking out the bit and shifting it to
-		 * bit position 1 so the result has the value 0 or 2.
+		 * indicated by the IEEE80211_STYPE_QOS_DATA bit.
 		 */
-		hdrlen += (fc & IEEE80211_STYPE_QOS_DATA)
-				>> (ilog2(IEEE80211_STYPE_QOS_DATA)-1);
+		if (fc & IEEE80211_STYPE_QOS_DATA)
+			hdrlen += 2;
 		break;
 	case IEEE80211_FTYPE_CTL:
 		/*
Signature · 1 line
1.5.5.144.g3e42
#1 lore raw

net/mac80211/util.c int ieee80211_get_hdrlen(u16 fc) · line 110

Quoted 4 lines · Harvey Harrison
net/mac80211/util.c +2 -2
-		hdrlen += (fc & IEEE80211_STYPE_QOS_DATA)
-				>> (ilog2(IEEE80211_STYPE_QOS_DATA)-1);
+		if (fc & IEEE80211_STYPE_QOS_DATA)
+			hdrlen += 2;

You need also take other QoS types (i.e QOS_NULLFUNC) into consideration. Please take a look at WLAN_FC_IS_QOS_DATA macro.

Thanks,
-yi

author
#2 lore raw
Quoted 9 lines · Zhu Yi

net/mac80211/util.c int ieee80211_get_hdrlen(u16 fc) · line 110

Quoted 4 lines · Harvey Harrison
net/mac80211/util.c +2 -2
-		hdrlen += (fc & IEEE80211_STYPE_QOS_DATA)
-				>> (ilog2(IEEE80211_STYPE_QOS_DATA)-1);
+		if (fc & IEEE80211_STYPE_QOS_DATA)
+			hdrlen += 2;

You need also take other QoS types (i.e QOS_NULLFUNC) into consideration. Please take a look at WLAN_FC_IS_QOS_DATA macro.

Well, that would be a change from what's there now, I've just got a few pure cleanup patches I've done while making some changes in wpa.c I'm going to submit the cleanup patches on their own first, then patches with more substance.

Cheers,

Harvey

maintainer
#3 lore raw
In reply to Harvey Harrison
Quoted 7 lines · Harvey Harrison
Signed-off-by Harvey Harrison <[email protected]>
net/mac80211/util.c +1 -1
 		if ((fc & IEEE80211_FCTL_FROMDS) && (fc & IEEE80211_FCTL_TODS))
-			hdrlen = 30; /* Addr4 */
+			hdrlen += ETH_ALEN; /* Addr4 */
 		/*
 		 * The QoS Control field is two bytes and its presence is

net/mac80211/util.c int ieee80211_get_hdrlen(u16 fc) · line 110

Quoted 10 lines
net/mac80211/util.c +3 -6
-		 * indicated by the IEEE80211_STYPE_QOS_DATA bit. Add 2 to
-		 * hdrlen if that bit is set.
-		 * This works by masking out the bit and shifting it to
-		 * bit position 1 so the result has the value 0 or 2.
+		 * indicated by the IEEE80211_STYPE_QOS_DATA bit.
 		 */
-		hdrlen += (fc & IEEE80211_STYPE_QOS_DATA)
-				>> (ilog2(IEEE80211_STYPE_QOS_DATA)-1);
+		if (fc & IEEE80211_STYPE_QOS_DATA)
+			hdrlen += 2;

Have you checked the generated code? Last time I checked it was better with what we had there.

johannes