1 files changed, 182 insertions, 0 deletions
diff --git a/fs/reiserfs/hashes.c b/fs/reiserfs/hashes.c
new file mode 100644
index 00000000..6471c670
--- /dev/null
+++ b/fs/reiserfs/hashes.c
@@ -0,0 +1,182 @@
+
+/*
+ * Keyed 32-bit hash function using TEA in a Davis-Meyer function
+ *   H0 = Key
+ *   Hi = E Mi(Hi-1) + Hi-1
+ *
+ * (see Applied Cryptography, 2nd edition, p448).
+ *
+ * Jeremy Fitzhardinge <jeremy@zip.com.au> 1998
+ *
+ * Jeremy has agreed to the contents of reiserfs/README. -Hans
+ * Yura's function is added (04/07/2000)
+ */
+
+//
+// keyed_hash
+// yura_hash
+// r5_hash
+//
+
+#include <linux/kernel.h>
+#include <linux/reiserfs_fs.h>
+#include <asm/types.h>
+
+#define DELTA 0x9E3779B9
+#define FULLROUNDS 10		/* 32 is overkill, 16 is strong crypto */
+#define PARTROUNDS 6		/* 6 gets complete mixing */
+
+/* a, b, c, d - data; h0, h1 - accumulated hash */
+#define TEACORE(rounds)							\
+	do {								\
+		u32 sum = 0;						\
+		int n = rounds;						\
+		u32 b0, b1;						\
+									\
+		b0 = h0;						\
+		b1 = h1;						\
+									\
+		do							\
+		{							\
+			sum += DELTA;					\
+			b0 += ((b1 << 4)+a) ^ (b1+sum) ^ ((b1 >> 5)+b);	\
+			b1 += ((b0 << 4)+c) ^ (b0+sum) ^ ((b0 >> 5)+d);	\
+		} while(--n);						\
+									\
+		h0 += b0;						\
+		h1 += b1;						\
+	} while(0)
+
+u32 keyed_hash(const signed char *msg, int len)
+{
+	u32 k[] = { 0x9464a485, 0x542e1a94, 0x3e846bff, 0xb75bcfc3 };
+
+	u32 h0 = k[0], h1 = k[1];
+	u32 a, b, c, d;
+	u32 pad;
+	int i;
+
+	//      assert(len >= 0 && len < 256);
+
+	pad = (u32) len | ((u32) len << 8);
+	pad |= pad << 16;
+
+	while (len >= 16) {
+		a = (u32) msg[0] |
+		    (u32) msg[1] << 8 | (u32) msg[2] << 16 | (u32) msg[3] << 24;
+		b = (u32) msg[4] |
+		    (u32) msg[5] << 8 | (u32) msg[6] << 16 | (u32) msg[7] << 24;
+		c = (u32) msg[8] |
+		    (u32) msg[9] << 8 |
+		    (u32) msg[10] << 16 | (u32) msg[11] << 24;
+		d = (u32) msg[12] |
+		    (u32) msg[13] << 8 |
+		    (u32) msg[14] << 16 | (u32) msg[15] << 24;
+
+		TEACORE(PARTROUNDS);
+
+		len -= 16;
+		msg += 16;
+	}
+
+	if (len >= 12) {
+		a = (u32) msg[0] |
+		    (u32) msg[1] << 8 | (u32) msg[2] << 16 | (u32) msg[3] << 24;
+		b = (u32) msg[4] |
+		    (u32) msg[5] << 8 | (u32) msg[6] << 16 | (u32) msg[7] << 24;
+		c = (u32) msg[8] |
+		    (u32) msg[9] << 8 |
+		    (u32) msg[10] << 16 | (u32) msg[11] << 24;
+
+		d = pad;
+		for (i = 12; i < len; i++) {
+			d <<= 8;
+			d |= msg[i];
+		}
+	} else if (len >= 8) {
+		a = (u32) msg[0] |
+		    (u32) msg[1] << 8 | (u32) msg[2] << 16 | (u32) msg[3] << 24;
+		b = (u32) msg[4] |
+		    (u32) msg[5] << 8 | (u32) msg[6] << 16 | (u32) msg[7] << 24;
+
+		c = d = pad;
+		for (i = 8; i < len; i++) {
+			c <<= 8;
+			c |= msg[i];
+		}
+	} else if (len >= 4) {
+		a = (u32) msg[0] |
+		    (u32) msg[1] << 8 | (u32) msg[2] << 16 | (u32) msg[3] << 24;
+
+		b = c = d = pad;
+		for (i = 4; i < len; i++) {
+			b <<= 8;
+			b |= msg[i];
+		}
+	} else {
+		a = b = c = d = pad;
+		for (i = 0; i < len; i++) {
+			a <<= 8;
+			a |= msg[i];
+		}
+	}
+
+	TEACORE(FULLROUNDS);
+
+/*	return 0;*/
+	return h0 ^ h1;
+}
+
+/* What follows in this file is copyright 2000 by Hans Reiser, and the
+ * licensing of what follows is governed by reiserfs/README */
+
+u32 yura_hash(const signed char *msg, int len)
+{
+	int j, pow;
+	u32 a, c;
+	int i;
+
+	for (pow = 1, i = 1; i < len; i++)
+		pow = pow * 10;
+
+	if (len == 1)
+		a = msg[0] - 48;
+	else
+		a = (msg[0] - 48) * pow;
+
+	for (i = 1; i < len; i++) {
+		c = msg[i] - 48;
+		for (pow = 1, j = i; j < len - 1; j++)
+			pow = pow * 10;
+		a = a + c * pow;
+	}
+
+	for (; i < 40; i++) {
+		c = '0' - 48;
+		for (pow = 1, j = i; j < len - 1; j++)
+			pow = pow * 10;
+		a = a + c * pow;
+	}
+
+	for (; i < 256; i++) {
+		c = i;
+		for (pow = 1, j = i; j < len - 1; j++)
+			pow = pow * 10;
+		a = a + c * pow;
+	}
+
+	a = a << 7;
+	return a;
+}
+
+u32 r5_hash(const signed char *msg, int len)
+{
+	u32 a = 0;
+	while (*msg) {
+		a += *msg << 4;
+		a += *msg >> 4;
+		a *= 11;
+		msg++;
+	}
+	return a;
+}