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mac80211: introduce struct michael_mic_ctx and static helpers

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Replace the existing macro with a static function, significantly shrinks the
size of the produced object file.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Harvey Harrison 2008-05-14 16:26:17 -07:00 committed by John W. Linville
parent 1bd3dff549
commit 1b19ca3966
2 changed files with 44 additions and 35 deletions
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75
net/mac80211/michael.c
View File

@ -13,46 +13,52 @@
#include "michael.h"
#define michael_block(l, r) \
do { \
r ^= rol32(l, 17); \
l += r; \
r ^= ((l & 0xff00ff00) >> 8) | ((l & 0x00ff00ff) << 8); \
l += r; \
r ^= rol32(l, 3); \
l += r; \
r ^= ror32(l, 2); \
l += r; \
} while (0)
static void michael_block(struct michael_mic_ctx *mctx, u32 val)
{
mctx->l ^= val;
mctx->r ^= rol32(mctx->l, 17);
mctx->l += mctx->r;
mctx->r ^= ((mctx->l & 0xff00ff00) >> 8) |
((mctx->l & 0x00ff00ff) << 8);
mctx->l += mctx->r;
mctx->r ^= rol32(mctx->l, 3);
mctx->l += mctx->r;
mctx->r ^= ror32(mctx->l, 2);
mctx->l += mctx->r;
}
static void michael_mic_hdr(struct michael_mic_ctx *mctx,
u8 *key, u8 *da, u8 *sa, u8 priority)
{
mctx->l = get_unaligned_le32(key);
mctx->r = get_unaligned_le32(key + 4);
/*
* A pseudo header (DA, SA, Priority, 0, 0, 0) is used in Michael MIC
* calculation, but it is _not_ transmitted
*/
michael_block(mctx, get_unaligned_le32(da));
michael_block(mctx, get_unaligned_le16(&da[4]) |
(get_unaligned_le16(sa) << 16));
michael_block(mctx, get_unaligned_le32(&sa[2]));
michael_block(mctx, priority);
}
void michael_mic(u8 *key, u8 *da, u8 *sa, u8 priority,
u8 *data, size_t data_len, u8 *mic)
{
u32 l, r, val;
u32 val;
size_t block, blocks, left;
struct michael_mic_ctx mctx;
l = get_unaligned_le32(key);
r = get_unaligned_le32(key + 4);
/* A pseudo header (DA, SA, Priority, 0, 0, 0) is used in Michael MIC
* calculation, but it is _not_ transmitted */
l ^= get_unaligned_le32(da);
michael_block(l, r);
l ^= get_unaligned_le16(&da[4]) | (get_unaligned_le16(sa) << 16);
michael_block(l, r);
l ^= get_unaligned_le32(&sa[2]);
michael_block(l, r);
l ^= priority;
michael_block(l, r);
michael_mic_hdr(&mctx, key, da, sa, priority);
/* Real data */
blocks = data_len / 4;
left = data_len % 4;
for (block = 0; block < blocks; block++) {
l ^= get_unaligned_le32(&data[block * 4]);
michael_block(l, r);
}
for (block = 0; block < blocks; block++)
michael_block(&mctx, get_unaligned_le32(&data[block * 4]));
/* Partial block of 0..3 bytes and padding: 0x5a + 4..7 zeros to make
* total length a multiple of 4. */
@ -62,11 +68,10 @@ void michael_mic(u8 *key, u8 *da, u8 *sa, u8 priority,
left--;
val |= data[blocks * 4 + left];
}
l ^= val;
michael_block(l, r);
/* last block is zero, so l ^ 0 = l */
michael_block(l, r);
put_unaligned_le32(l, mic);
put_unaligned_le32(r, mic + 4);
michael_block(&mctx, val);
michael_block(&mctx, 0);
put_unaligned_le32(mctx.l, mic);
put_unaligned_le32(mctx.r, mic + 4);
}

4
net/mac80211/michael.h
View File

@ -14,6 +14,10 @@
#define MICHAEL_MIC_LEN 8
struct michael_mic_ctx {
u32 l, r;
};
void michael_mic(u8 *key, u8 *da, u8 *sa, u8 priority,
u8 *data, size_t data_len, u8 *mic);