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Commit 1b19ca39 authored by Harvey Harrison's avatar Harvey Harrison Committed by John W. Linville
Browse files

mac80211: introduce struct michael_mic_ctx and static helpers 



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

Signed-off-by: default avatarHarvey Harrison <harvey.harrison@gmail.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 1bd3dff5

net/mac80211/michael.c

+40 −35
Original line number Diff line number Diff line
@@ -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);

}

net/mac80211/michael.h

+4 −0
Original line number Diff line number Diff line
@@ -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);