2008-03-08 09:23:02

by Harvey Harrison

[permalink] [raw]
Subject: [PATCH 1/5] mac80211: use kernel-provided bit rotation/byteordering

Signed-off-by: Harvey Harrison <[email protected]>
---
Perhaps a bit too fine-grained of a patch series, but each one should
be pretty easily reviewable.

include/linux/bitops.h | 40 ++++++++++++++++++++++++++++++++++++++++
net/mac80211/michael.c | 28 ++++++----------------------
net/mac80211/tkip.c | 20 ++++++--------------
3 files changed, 52 insertions(+), 36 deletions(-)

diff --git a/include/linux/bitops.h b/include/linux/bitops.h
index 69c1edb..40d5473 100644
--- a/include/linux/bitops.h
+++ b/include/linux/bitops.h
@@ -65,6 +65,46 @@ static inline __u32 ror32(__u32 word, unsigned int shift)
return (word >> shift) | (word << (32 - shift));
}

+/**
+ * rol16 - rotate a 16-bit value left
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u16 rol16(__u16 word, unsigned int shift)
+{
+ return (word << shift) | (word >> (16 - shift));
+}
+
+/**
+ * ror16 - rotate a 16-bit value right
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u16 ror16(__u16 word, unsigned int shift)
+{
+ return (word >> shift) | (word << (16 - shift));
+}
+
+/**
+ * rol8 - rotate an 8-bit value left
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u8 rol8(__u8 word, unsigned int shift)
+{
+ return (word << shift) | (word >> (8 - shift));
+}
+
+/**
+ * ror8 - rotate an 8-bit value right
+ * @word: value to rotate
+ * @shift: bits to roll
+ */
+static inline __u8 ror8(__u8 word, unsigned int shift)
+{
+ return (word >> shift) | (word << (8 - shift));
+}
+
static inline unsigned fls_long(unsigned long l)
{
if (sizeof(l) == 4)
diff --git a/net/mac80211/michael.c b/net/mac80211/michael.c
index 0f844f7..1a1871f 100644
--- a/net/mac80211/michael.c
+++ b/net/mac80211/michael.c
@@ -7,53 +7,37 @@
* published by the Free Software Foundation.
*/

-#include <linux/types.h>
+#include <linux/kernel.h>

#include "michael.h"

-static inline u32 rotr(u32 val, int bits)
-{
- return (val >> bits) | (val << (32 - bits));
-}
-
-
-static inline u32 rotl(u32 val, int bits)
-{
- return (val << bits) | (val >> (32 - bits));
-}
-
-
static inline u32 xswap(u32 val)
{
return ((val & 0xff00ff00) >> 8) | ((val & 0x00ff00ff) << 8);
}

-
#define michael_block(l, r) \
do { \
- r ^= rotl(l, 17); \
+ r ^= rol32(l, 17); \
l += r; \
r ^= xswap(l); \
l += r; \
- r ^= rotl(l, 3); \
+ r ^= rol32(l, 3); \
l += r; \
- r ^= rotr(l, 2); \
+ r ^= ror32(l, 2); \
l += r; \
} while (0)


static inline u32 michael_get32(u8 *data)
{
- return data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
+ return le32_to_cpup((__le32 *)data);
}


static inline void michael_put32(u32 val, u8 *data)
{
- data[0] = val & 0xff;
- data[1] = (val >> 8) & 0xff;
- data[2] = (val >> 16) & 0xff;
- data[3] = (val >> 24) & 0xff;
+ *((u32 *)data) = cpu_to_le32(val);
}


diff --git a/net/mac80211/tkip.c b/net/mac80211/tkip.c
index 3abe194..229b4b4 100644
--- a/net/mac80211/tkip.c
+++ b/net/mac80211/tkip.c
@@ -8,7 +8,6 @@
*/

#include <linux/kernel.h>
-#include <linux/types.h>
#include <linux/netdevice.h>

#include <net/mac80211.h>
@@ -91,13 +90,6 @@ static inline u16 Lo16(u32 v)
return v & 0xffff;
}

-
-static inline u16 RotR1(u16 v)
-{
- return (v >> 1) | ((v & 0x0001) << 15);
-}
-
-
static inline u16 tkip_S(u16 val)
{
u16 a = tkip_sbox[Hi8(val)];
@@ -154,12 +146,12 @@ static void tkip_mixing_phase2(const u16 *p1k, const u8 *tk, u16 tsc_IV16,
ppk[3] += tkip_S(ppk[2] ^ Mk16(tk[ 7], tk[ 6]));
ppk[4] += tkip_S(ppk[3] ^ Mk16(tk[ 9], tk[ 8]));
ppk[5] += tkip_S(ppk[4] ^ Mk16(tk[11], tk[10]));
- ppk[0] += RotR1(ppk[5] ^ Mk16(tk[13], tk[12]));
- ppk[1] += RotR1(ppk[0] ^ Mk16(tk[15], tk[14]));
- ppk[2] += RotR1(ppk[1]);
- ppk[3] += RotR1(ppk[2]);
- ppk[4] += RotR1(ppk[3]);
- ppk[5] += RotR1(ppk[4]);
+ ppk[0] += ror16(ppk[5] ^ Mk16(tk[13], tk[12]), 1);
+ ppk[1] += ror16(ppk[0] ^ Mk16(tk[15], tk[14]), 1);
+ ppk[2] += ror16(ppk[1], 1);
+ ppk[3] += ror16(ppk[2], 1);
+ ppk[4] += ror16(ppk[3], 1);
+ ppk[5] += ror16(ppk[4], 1);

rc4key[0] = Hi8(tsc_IV16);
rc4key[1] = (Hi8(tsc_IV16) | 0x20) & 0x7f;
--
1.5.4.GIT




2008-03-11 16:47:26

by Harvey Harrison

[permalink] [raw]
Subject: Re: [PATCH 1/5] mac80211: use kernel-provided bit rotation/byteordering

On Tue, 2008-03-11 at 17:11 +0100, Johannes Berg wrote:
> > include/linux/bitops.h | 40 ++++++++++++++++++++++++++++++++++++++++
>
> > +++ b/include/linux/bitops.h
> > @@ -65,6 +65,46 @@ static inline __u32 ror32(__u32 word, unsigned int shift)
> > return (word >> shift) | (word << (32 - shift));
> > }
> >
> > +/**
> > + * rol16 - rotate a 16-bit value left
> > + * @word: value to rotate
> > + * @shift: bits to roll
> > + */
> > +static inline __u16 rol16(__u16 word, unsigned int shift)
>
> I don't think we can take that via wireless, and I think architectures
> should be able to override this if they can optimise it (though the
> compiler might be good enough...)

OK, I'll get the common parts through Andrew and once that's in I'll
resubmit the wireless parts.

Harvey


2008-03-11 16:12:11

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH 1/5] mac80211: use kernel-provided bit rotation/byteordering


> include/linux/bitops.h | 40 ++++++++++++++++++++++++++++++++++++++++

> +++ b/include/linux/bitops.h
> @@ -65,6 +65,46 @@ static inline __u32 ror32(__u32 word, unsigned int shift)
> return (word >> shift) | (word << (32 - shift));
> }
>
> +/**
> + * rol16 - rotate a 16-bit value left
> + * @word: value to rotate
> + * @shift: bits to roll
> + */
> +static inline __u16 rol16(__u16 word, unsigned int shift)

I don't think we can take that via wireless, and I think architectures
should be able to override this if they can optimise it (though the
compiler might be good enough...)

johannes


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