2 files changed, 44 insertions, 35 deletions

diff --git a/net/mac80211/michael.c b/net/mac80211/michael.c
index c1e5897fcf7..4e151e0caeb 100644
--- a/net/mac80211/michael.c
+++ b/net/mac80211/michael.c
@@ -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);
 }
diff --git a/net/mac80211/michael.h b/net/mac80211/michael.h
index 2e6aebabeea..7d5707bf884 100644
--- a/net/mac80211/michael.h
+++ b/net/mac80211/michael.h
@@ -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);