libglusterfs: Add checksum functions.

gf_rsync_weak_checksum:   Calculates a simple 32-bit checksum.
gf_rsync_strong_checksum: Calculates the MD5 checksum.

The strong checksum function makes use of Christophe Devine's
MD5 implementation (adapted from the rsync source code,
version 3.0.6. <http://www.samba.org/ftp/rsync/>).

Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

5 files changed, 495 insertions, 2 deletions

diff --git a/libglusterfs/src/Makefile.am b/libglusterfs/src/Makefile.am
index a3fb923ca..05d124aee 100644
--- a/libglusterfs/src/Makefile.am
+++ b/libglusterfs/src/Makefile.am
@@ -6,9 +6,9 @@ libglusterfs_la_LIBADD = @LEXLIB@
 
 lib_LTLIBRARIES = libglusterfs.la
 
-libglusterfs_la_SOURCES = dict.c spec.lex.c y.tab.c xlator.c logging.c  hashfn.c defaults.c scheduler.c common-utils.c transport.c timer.c inode.c call-stub.c compat.c authenticate.c fd.c compat-errno.c event.c mem-pool.c gf-dirent.c syscall.c iobuf.c globals.c statedump.c stack.c
+libglusterfs_la_SOURCES = dict.c spec.lex.c y.tab.c xlator.c logging.c  hashfn.c defaults.c scheduler.c common-utils.c transport.c timer.c inode.c call-stub.c compat.c authenticate.c fd.c compat-errno.c event.c mem-pool.c gf-dirent.c syscall.c iobuf.c globals.c statedump.c stack.c checksum.c md5.c
 
-noinst_HEADERS = common-utils.h defaults.h dict.h glusterfs.h hashfn.h logging.h protocol.h scheduler.h xlator.h transport.h stack.h timer.h list.h inode.h call-stub.h compat.h authenticate.h fd.h revision.h compat-errno.h event.h mem-pool.h byte-order.h gf-dirent.h locking.h syscall.h iobuf.h globals.h statedump.h
+noinst_HEADERS = common-utils.h defaults.h dict.h glusterfs.h hashfn.h logging.h protocol.h scheduler.h xlator.h transport.h stack.h timer.h list.h inode.h call-stub.h compat.h authenticate.h fd.h revision.h compat-errno.h event.h mem-pool.h byte-order.h gf-dirent.h locking.h syscall.h iobuf.h globals.h statedump.h checksum.h md5.h
 
 EXTRA_DIST = spec.l spec.y
 
diff --git a/libglusterfs/src/checksum.c b/libglusterfs/src/checksum.c
new file mode 100644
index 000000000..2040fe73b
--- /dev/null
+++ b/libglusterfs/src/checksum.c
@@ -0,0 +1,78 @@
+/*
+   Copyright (c) 2009 Z RESEARCH, Inc. <http://www.zresearch.com>
+   This file is part of GlusterFS.
+
+   GlusterFS is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published
+   by the Free Software Foundation; either version 3 of the License,
+   or (at your option) any later version.
+
+   GlusterFS is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see
+   <http://www.gnu.org/licenses/>.
+*/
+
+#include <inttypes.h>
+
+#include "glusterfs.h"
+#include "md5.h"
+#include "checksum.h"
+
+
+/*
+ * The "weak" checksum required for the rsync algorithm,
+ * adapted from the rsync source code. The following comment
+ * appears there:
+ *
+ * "a simple 32 bit checksum that can be upadted from either end
+ *  (inspired by Mark Adler's Adler-32 checksum)"
+ */
+
+uint32_t
+gf_rsync_weak_checksum (char *buf1, int32_t len)
+{
+        int32_t i;
+        uint32_t s1, s2;
+
+        signed char *buf = (signed char *) buf1;
+        uint32_t csum;
+
+        s1 = s2 = 0;
+        for (i = 0; i < (len-4); i+=4) {
+                s2 += 4*(s1 + buf[i]) + 3*buf[i+1] + 2*buf[i+2] + buf[i+3];
+
+                s1 += buf[i+0] + buf[i+1] + buf[i+2] + buf[i+3];
+        }
+
+        for (; i < len; i++) {
+                s1 += buf[i];
+                s2 += s1;
+        }
+
+        csum = (s1 & 0xffff) + (s2 << 16);
+
+        return csum;
+}
+
+
+/*
+ * The "strong" checksum required for the rsync algorithm,
+ * adapted from the rsync source code.
+ */
+
+void
+gf_rsync_strong_checksum (char *buf, int32_t len, uint8_t *sum)
+{
+        md_context m;
+
+        md5_begin (&m);
+        md5_update (&m, (unsigned char *) buf, len);
+        md5_result (&m, (unsigned char *) sum);
+
+        return;
+}
diff --git a/libglusterfs/src/checksum.h b/libglusterfs/src/checksum.h
new file mode 100644
index 000000000..e79340904
--- /dev/null
+++ b/libglusterfs/src/checksum.h
@@ -0,0 +1,29 @@
+/*
+   Copyright (c) 2009 Z RESEARCH, Inc. <http://www.zresearch.com>
+   This file is part of GlusterFS.
+
+   GlusterFS is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published
+   by the Free Software Foundation; either version 3 of the License,
+   or (at your option) any later version.
+
+   GlusterFS is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see
+   <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __CHECKSUM_H__
+#define __CHECKSUM_H__
+
+uint32_t
+gf_rsync_weak_checksum (char *buf, int32_t len);
+
+void
+gf_rsync_strong_checksum (char *buf, int32_t len, uint8_t *sum);
+
+#endif /* __CHECKSUM_H__ */
diff --git a/libglusterfs/src/md5.c b/libglusterfs/src/md5.c
new file mode 100644
index 000000000..6fd6ecbf7
--- /dev/null
+++ b/libglusterfs/src/md5.c
@@ -0,0 +1,308 @@
+/*
+ * RFC 1321 compliant MD5 implementation
+ *
+ * Copyright (C) 2001-2003 Christophe Devine
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, visit the http://fsf.org website.
+ */
+
+
+#include <inttypes.h>
+#include <string.h>
+
+#include "md5.h"
+
+void md5_begin(md_context *ctx)
+{
+	ctx->A = 0x67452301;
+	ctx->B = 0xEFCDAB89;
+	ctx->C = 0x98BADCFE;
+	ctx->D = 0x10325476;
+
+	ctx->totalN = ctx->totalN2 = 0;
+}
+
+static void md5_process(md_context *ctx, const uint8_t data[CSUM_CHUNK])
+{
+	uint32_t X[16], A, B, C, D;
+
+	A = ctx->A;
+	B = ctx->B;
+	C = ctx->C;
+	D = ctx->D;
+
+	X[0] = IVAL(data, 0);
+	X[1] = IVAL(data, 4);
+	X[2] = IVAL(data, 8);
+	X[3] = IVAL(data, 12);
+	X[4] = IVAL(data, 16);
+	X[5] = IVAL(data, 20);
+	X[6] = IVAL(data, 24);
+	X[7] = IVAL(data, 28);
+	X[8] = IVAL(data, 32);
+	X[9] = IVAL(data, 36);
+	X[10] = IVAL(data, 40);
+	X[11] = IVAL(data, 44);
+	X[12] = IVAL(data, 48);
+	X[13] = IVAL(data, 52);
+	X[14] = IVAL(data, 56);
+	X[15] = IVAL(data, 60);
+
+#define S(x,n) ((x << n) | ((x & 0xFFFFFFFF) >> (32 - n)))
+
+#define P(a,b,c,d,k,s,t) a += F(b,c,d) + X[k] + t, a = S(a,s) + b
+
+#define F(x,y,z) (z ^ (x & (y ^ z)))
+
+	P(A, B, C, D,  0,  7, 0xD76AA478);
+	P(D, A, B, C,  1, 12, 0xE8C7B756);
+	P(C, D, A, B,  2, 17, 0x242070DB);
+	P(B, C, D, A,  3, 22, 0xC1BDCEEE);
+	P(A, B, C, D,  4,  7, 0xF57C0FAF);
+	P(D, A, B, C,  5, 12, 0x4787C62A);
+	P(C, D, A, B,  6, 17, 0xA8304613);
+	P(B, C, D, A,  7, 22, 0xFD469501);
+	P(A, B, C, D,  8,  7, 0x698098D8);
+	P(D, A, B, C,  9, 12, 0x8B44F7AF);
+	P(C, D, A, B, 10, 17, 0xFFFF5BB1);
+	P(B, C, D, A, 11, 22, 0x895CD7BE);
+	P(A, B, C, D, 12,  7, 0x6B901122);
+	P(D, A, B, C, 13, 12, 0xFD987193);
+	P(C, D, A, B, 14, 17, 0xA679438E);
+	P(B, C, D, A, 15, 22, 0x49B40821);
+
+#undef F
+#define F(x,y,z) (y ^ (z & (x ^ y)))
+
+	P(A, B, C, D,  1,  5, 0xF61E2562);
+	P(D, A, B, C,  6,  9, 0xC040B340);
+	P(C, D, A, B, 11, 14, 0x265E5A51);
+	P(B, C, D, A,  0, 20, 0xE9B6C7AA);
+	P(A, B, C, D,  5,  5, 0xD62F105D);
+	P(D, A, B, C, 10,  9, 0x02441453);
+	P(C, D, A, B, 15, 14, 0xD8A1E681);
+	P(B, C, D, A,  4, 20, 0xE7D3FBC8);
+	P(A, B, C, D,  9,  5, 0x21E1CDE6);
+	P(D, A, B, C, 14,  9, 0xC33707D6);
+	P(C, D, A, B,  3, 14, 0xF4D50D87);
+	P(B, C, D, A,  8, 20, 0x455A14ED);
+	P(A, B, C, D, 13,  5, 0xA9E3E905);
+	P(D, A, B, C,  2,  9, 0xFCEFA3F8);
+	P(C, D, A, B,  7, 14, 0x676F02D9);
+	P(B, C, D, A, 12, 20, 0x8D2A4C8A);
+
+#undef F
+#define F(x,y,z) (x ^ y ^ z)
+
+	P(A, B, C, D,  5,  4, 0xFFFA3942);
+	P(D, A, B, C,  8, 11, 0x8771F681);
+	P(C, D, A, B, 11, 16, 0x6D9D6122);
+	P(B, C, D, A, 14, 23, 0xFDE5380C);
+	P(A, B, C, D,  1,  4, 0xA4BEEA44);
+	P(D, A, B, C,  4, 11, 0x4BDECFA9);
+	P(C, D, A, B,  7, 16, 0xF6BB4B60);
+	P(B, C, D, A, 10, 23, 0xBEBFBC70);
+	P(A, B, C, D, 13,  4, 0x289B7EC6);
+	P(D, A, B, C,  0, 11, 0xEAA127FA);
+	P(C, D, A, B,  3, 16, 0xD4EF3085);
+	P(B, C, D, A,  6, 23, 0x04881D05);
+	P(A, B, C, D,  9,  4, 0xD9D4D039);
+	P(D, A, B, C, 12, 11, 0xE6DB99E5);
+	P(C, D, A, B, 15, 16, 0x1FA27CF8);
+	P(B, C, D, A,  2, 23, 0xC4AC5665);
+
+#undef F
+#define F(x,y,z) (y ^ (x | ~z))
+
+	P(A, B, C, D,  0,  6, 0xF4292244);
+	P(D, A, B, C,  7, 10, 0x432AFF97);
+	P(C, D, A, B, 14, 15, 0xAB9423A7);
+	P(B, C, D, A,  5, 21, 0xFC93A039);
+	P(A, B, C, D, 12,  6, 0x655B59C3);
+	P(D, A, B, C,  3, 10, 0x8F0CCC92);
+	P(C, D, A, B, 10, 15, 0xFFEFF47D);
+	P(B, C, D, A,  1, 21, 0x85845DD1);
+	P(A, B, C, D,  8,  6, 0x6FA87E4F);
+	P(D, A, B, C, 15, 10, 0xFE2CE6E0);
+	P(C, D, A, B,  6, 15, 0xA3014314);
+	P(B, C, D, A, 13, 21, 0x4E0811A1);
+	P(A, B, C, D,  4,  6, 0xF7537E82);
+	P(D, A, B, C, 11, 10, 0xBD3AF235);
+	P(C, D, A, B,  2, 15, 0x2AD7D2BB);
+	P(B, C, D, A,  9, 21, 0xEB86D391);
+
+#undef F
+
+	ctx->A += A;
+	ctx->B += B;
+	ctx->C += C;
+	ctx->D += D;
+}
+
+void md5_update(md_context *ctx, const uint8_t *input, uint32_t length)
+{
+	uint32_t left, fill;
+
+	if (!length)
+		return;
+
+	left = ctx->totalN & 0x3F;
+	fill = CSUM_CHUNK - left;
+
+	ctx->totalN += length;
+	ctx->totalN &= 0xFFFFFFFF;
+
+	if (ctx->totalN < length)
+		ctx->totalN2++;
+
+	if (left && length >= fill) {
+		memcpy(ctx->buffer + left, input, fill);
+		md5_process(ctx, ctx->buffer);
+		length -= fill;
+		input  += fill;
+		left = 0;
+	}
+
+	while (length >= CSUM_CHUNK) {
+		md5_process(ctx, input);
+		length -= CSUM_CHUNK;
+		input  += CSUM_CHUNK;
+	}
+
+	if (length)
+		memcpy(ctx->buffer + left, input, length);
+}
+
+static uint8_t md5_padding[CSUM_CHUNK] = { 0x80 };
+
+void md5_result(md_context *ctx, uint8_t digest[MD5_DIGEST_LEN])
+{
+	uint32_t last, padn;
+	uint32_t high, low;
+	uint8_t msglen[8];
+
+	high = (ctx->totalN >> 29)
+	     | (ctx->totalN2 <<  3);
+	low  = (ctx->totalN <<  3);
+
+	SIVAL(msglen, 0, low);
+	SIVAL(msglen, 4, high);
+
+	last = ctx->totalN & 0x3F;
+	padn = last < 56 ? 56 - last : 120 - last;
+
+	md5_update(ctx, md5_padding, padn);
+	md5_update(ctx, msglen, 8);
+
+	SIVAL(digest, 0, ctx->A);
+	SIVAL(digest, 4, ctx->B);
+	SIVAL(digest, 8, ctx->C);
+	SIVAL(digest, 12, ctx->D);
+}
+
+void get_md5(uint8_t *out, const uint8_t *input, int n)
+{
+	md_context ctx;
+	md5_begin(&ctx);
+	md5_update(&ctx, input, n);
+	md5_result(&ctx, out);
+}
+
+#ifdef TEST_MD5
+
+#include <stdlib.h>
+#include <stdio.h>
+
+/*
+ * those are the standard RFC 1321 test vectors
+ */
+
+static struct {
+    char *str, *md5;
+} tests[] = {
+ { "",
+   "d41d8cd98f00b204e9800998ecf8427e" },
+ { "a",
+   "0cc175b9c0f1b6a831c399e269772661" },
+ { "abc",
+   "900150983cd24fb0d6963f7d28e17f72" },
+ { "message digest",
+   "f96b697d7cb7938d525a2f31aaf161d0" },
+ { "abcdefghijklmnopqrstuvwxyz",
+   "c3fcd3d76192e4007dfb496cca67e13b" },
+ { "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789",
+   "d174ab98d277d9f5a5611c2c9f419d9f" },
+ { "12345678901234567890123456789012345678901234567890123456789012345678901234567890",
+   "57edf4a22be3c955ac49da2e2107b67a" },
+ { NULL, NULL }
+};
+
+int main(int argc, char *argv[])
+{
+	FILE *f;
+	int i, j;
+	char output[33];
+	md_context ctx;
+	uint8_t buf[1000];
+	uint8_t md5sum[MD5_DIGEST_LEN];
+
+	if (argc < 2) {
+		printf("\nMD5 Validation Tests:\n\n");
+
+		for (i = 0; tests[i].str; i++) {
+			char *str = tests[i].str;
+			char *chk = tests[i].md5;
+
+			printf("  Test %d ", i + 1);
+
+			get_md5(md5sum, str, strlen(str));
+
+			for (j = 0; j < MD5_DIGEST_LEN; j++)
+				sprintf(output + j * 2, "%02x", md5sum[j]);
+
+			if (memcmp(output, chk, 32)) {
+				printf("failed!\n");
+				return 1;
+			}
+
+			printf("passed.\n");
+		}
+
+		printf("\n");
+		return 0;
+	}
+
+	while (--argc) {
+		if (!(f = fopen(*++argv, "rb"))) {
+			perror("fopen");
+			return 1;
+		}
+
+		md5_begin(&ctx);
+
+		while ((i = fread(buf, 1, sizeof buf, f)) > 0)
+			md5_update(&ctx, buf, i);
+
+		md5_result(&ctx, md5sum);
+
+		for (j = 0; j < MD5_DIGEST_LEN; j++)
+			printf("%02x", md5sum[j]);
+
+		printf("  %s\n", *argv);
+	}
+
+	return 0;
+}
+
+#endif
diff --git a/libglusterfs/src/md5.h b/libglusterfs/src/md5.h
new file mode 100644
index 000000000..ba8f08dbc
--- /dev/null
+++ b/libglusterfs/src/md5.h
@@ -0,0 +1,78 @@
+/* rsync-3.0.6/byteorder.h */
+
+/*
+ * Simple byteorder handling.
+ *
+ * Copyright (C) 1992-1995 Andrew Tridgell
+ * Copyright (C) 2007-2008 Wayne Davison
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, visit the http://fsf.org website.
+ */
+
+#undef CAREFUL_ALIGNMENT
+
+/* We know that the x86 can handle misalignment and has the same
+ * byte order (LSB-first) as the 32-bit numbers we transmit. */
+
+#ifdef __i386__
+#define CAREFUL_ALIGNMENT 0
+#endif
+
+#ifndef CAREFUL_ALIGNMENT
+#define CAREFUL_ALIGNMENT 1
+#endif
+
+#define CVAL(buf,pos) (((unsigned char *)(buf))[pos])
+#define UVAL(buf,pos) ((uint32_t)CVAL(buf,pos))
+#define SCVAL(buf,pos,val) (CVAL(buf,pos) = (val))
+
+#if CAREFUL_ALIGNMENT
+#define PVAL(buf,pos) (UVAL(buf,pos)|UVAL(buf,(pos)+1)<<8)
+#define IVAL(buf,pos) (PVAL(buf,pos)|PVAL(buf,(pos)+2)<<16)
+#define SSVALX(buf,pos,val) (CVAL(buf,pos)=(val)&0xFF,CVAL(buf,pos+1)=(val)>>8)
+#define SIVALX(buf,pos,val) (SSVALX(buf,pos,val&0xFFFF),SSVALX(buf,pos+2,val>>16))
+#define SIVAL(buf,pos,val) SIVALX((buf),(pos),((uint32_t)(val)))
+#else
+
+/* this handles things for architectures like the 386 that can handle
+   alignment errors */
+
+/*
+   WARNING: This section is dependent on the length of int32
+   being correct. set CAREFUL_ALIGNMENT if it is not.
+*/
+
+#define IVAL(buf,pos) (*(uint32_t *)((char *)(buf) + (pos)))
+#define SIVAL(buf,pos,val) IVAL(buf,pos)=((uint32_t)(val))
+#endif
+
+/* The include file for both the MD4 and MD5 routines. */
+
+#define MD5_DIGEST_LEN 16
+#define MAX_DIGEST_LEN MD5_DIGEST_LEN
+
+#define CSUM_CHUNK 64
+
+typedef struct {
+	uint32_t A, B, C, D;
+	uint32_t totalN;          /* bit count, lower 32 bits */
+	uint32_t totalN2;         /* bit count, upper 32 bits */
+	uint8_t buffer[CSUM_CHUNK];
+} md_context;
+
+void md5_begin(md_context *ctx);
+void md5_update(md_context *ctx, const uint8_t *input, uint32_t length);
+void md5_result(md_context *ctx, uint8_t digest[MD5_DIGEST_LEN]);
+
+void get_md5(uint8_t digest[MD5_DIGEST_LEN], const uint8_t *input, int n);