Make homehost information appear in superblock.

When an array is created, if the homehost is know,
the superblock gets it, either in the uuid, (via sha1)
or in the name field.

Signed-off-by: Neil Brown <neilb@suse.de>

11 files changed, 721 insertions, 14 deletions

diff --git a/Create.c b/Create.c
index fe7a3ab..ed81122 100644
--- a/Create.c
+++ b/Create.c
@@ -33,7 +33,7 @@
 
 int Create(struct supertype *st, char *mddev, int mdfd,
 	   int chunk, int level, int layout, unsigned long long size, int raiddisks, int sparedisks,
-	   char *name,
+	   char *name, char *homehost,
 	   int subdevs, mddev_dev_t devlist,
 	   int runstop, int verbose, int force, int assume_clean,
 	   char *bitmap_file, int bitmap_chunk, int write_behind, int delay)
@@ -389,7 +389,7 @@ int Create(struct supertype *st, char *mddev, int mdfd,
 	array.chunk_size = chunk*1024;
 	array.major_version = st->ss->major;
 
-	if (!st->ss->init_super(st, &super, &array, size, name))
+	if (!st->ss->init_super(st, &super, &array, size, name, homehost))
 		return 1;
 
 	if (bitmap_file && vers < 9003) {
diff --git a/Kill.c b/Kill.c
index e411ff3..dc6baa1 100644
--- a/Kill.c
+++ b/Kill.c
@@ -67,7 +67,7 @@ int Kill(char *dev, int force, int quiet)
 		mdu_array_info_t info;
 		info.major_version = -1; /* zero superblock */
 		free(super);
-		st->ss->init_super(st, &super, &info, 0, "");
+		st->ss->init_super(st, &super, &info, 0, "", NULL);
 		if (st->ss->store_super(st, fd, super)) {
 			if (!quiet)
 				fprintf(stderr, Name ": Could not zero superblock on %s\n",
diff --git a/Makefile b/Makefile
index 8ddb997..dd710fd 100644
--- a/Makefile
+++ b/Makefile
@@ -32,6 +32,7 @@
 TCC = tcc
 UCLIBC_GCC = $(shell for nm in i386-uclibc-linux-gcc i386-uclibc-gcc; do which $$nm > /dev/null && { echo $$nm ; exit; } ; done; echo false No uclibc found )
 DIET_GCC = diet gcc
+LDLIBS=-lssl
 
 KLIBC=/home/src/klibc/klibc-0.77
 
@@ -84,11 +85,11 @@ everything: all mdadm.static mdadm.uclibc swap_super test_stripe  mdassemble mda
 # mdadm.tcc doesn't work..
 
 mdadm : rmconf $(OBJS)
-	$(CC) $(LDFLAGS) -o mdadm $(OBJS)
+	$(CC) $(LDFLAGS) -o mdadm $(OBJS) $(LDLIBS)
 
 mdadm.static : STATIC=-DSTATIC
 mdadm.static : rmconf $(OBJS)
-	$(CC) $(LDFLAGS) -DSTATIC -static -o mdadm.static $(OBJS)
+	$(CC) $(LDFLAGS) -DSTATIC -static -o mdadm.static $(OBJS) SHA1.o sha1.o
 rmconf:
 	rm -f config.o
 
@@ -136,6 +137,11 @@ mdassemble.man : mdassemble.8
 
 $(OBJS) : mdadm.h bitmap.h
 
+sha1.o : sha1.c sha1.h md5.h
+	$(CC) $(CFLAGS) -DHAVE_STDINT_H -o sha1.o -c sha1.c
+SHA1.o : SHA1.c
+	$(CC) $(CFLAGS) -DHAVE_STDINT_H -o SHA1.o -c SHA1.c
+
 install : mdadm mdadm.8 md.4 mdadm.conf.5
 	$(INSTALL) -D $(STRIP) -m 755 mdadm $(DESTDIR)$(BINDIR)/mdadm
 	$(INSTALL) -D -m 644 mdadm.8 $(DESTDIR)$(MAN8DIR)/mdadm.8
diff --git a/SHA1.c b/SHA1.c
new file mode 100644
index 0000000..29e42ba
--- /dev/null
+++ b/SHA1.c
@@ -0,0 +1,19 @@
+
+/* Simple wrapper for code in sha1.c, to
+ * provide SHA1() interface as provided by opensll.
+ * I do this because I cannot get SHA1 when staticly linking.
+ *
+ * sha1.c sha1.h md5.h all copied from coreutils-5.94
+ */
+
+#include "sha1.h"
+
+unsigned char *SHA1(unsigned char *buf, int len, unsigned char *dest)
+{
+	static unsigned char defdest[20];
+	if (dest == NULL) dest = defdest;
+
+	return (unsigned char *)sha1_buffer((const char*)buf,
+					    len,
+					    (void*)dest);
+}
diff --git a/md5.h b/md5.h
new file mode 100644
index 0000000..1c29e67
--- /dev/null
+++ b/md5.h
@@ -0,0 +1,136 @@
+/* Declaration of functions and data types used for MD5 sum computing
+   library functions.
+   Copyright (C) 1995-1997,1999-2005 Free Software Foundation, Inc.
+
+   NOTE: The canonical source of this file is maintained with the GNU C
+   Library.  Bugs can be reported to bug-glibc@prep.ai.mit.edu.
+
+   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 2, 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, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef _MD5_H
+#define _MD5_H 1
+
+#include <stdio.h>
+
+#if HAVE_INTTYPES_H
+# include <inttypes.h>
+#endif
+#if HAVE_STDINT_H || _LIBC
+# include <stdint.h>
+#endif
+
+#ifndef __GNUC_PREREQ
+# if defined __GNUC__ && defined __GNUC_MINOR__
+#  define __GNUC_PREREQ(maj, min) \
+	((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
+# else
+#  define __GNUC_PREREQ(maj, min) 0
+# endif
+#endif
+
+#ifndef __THROW
+# if defined __cplusplus && __GNUC_PREREQ (2,8)
+#  define __THROW	throw ()
+# else
+#  define __THROW
+# endif
+#endif
+
+#ifndef __attribute__
+# if ! __GNUC_PREREQ (2,8) || __STRICT_ANSI__
+#  define __attribute__(x)
+# endif
+#endif
+
+#ifndef _LIBC
+# define __md5_buffer md5_buffer
+# define __md5_finish_ctx md5_finish_ctx
+# define __md5_init_ctx md5_init_ctx
+# define __md5_process_block md5_process_block
+# define __md5_process_bytes md5_process_bytes
+# define __md5_read_ctx md5_read_ctx
+# define __md5_stream md5_stream
+#endif
+
+typedef uint32_t md5_uint32;
+
+/* Structure to save state of computation between the single steps.  */
+struct md5_ctx
+{
+  md5_uint32 A;
+  md5_uint32 B;
+  md5_uint32 C;
+  md5_uint32 D;
+
+  md5_uint32 total[2];
+  md5_uint32 buflen;
+  char buffer[128] __attribute__ ((__aligned__ (__alignof__ (md5_uint32))));
+};
+
+/*
+ * The following three functions are build up the low level used in
+ * the functions `md5_stream' and `md5_buffer'.
+ */
+
+/* Initialize structure containing state of computation.
+   (RFC 1321, 3.3: Step 3)  */
+extern void __md5_init_ctx (struct md5_ctx *ctx) __THROW;
+
+/* Starting with the result of former calls of this function (or the
+   initialization function update the context for the next LEN bytes
+   starting at BUFFER.
+   It is necessary that LEN is a multiple of 64!!! */
+extern void __md5_process_block (const void *buffer, size_t len,
+				 struct md5_ctx *ctx) __THROW;
+
+/* Starting with the result of former calls of this function (or the
+   initialization function update the context for the next LEN bytes
+   starting at BUFFER.
+   It is NOT required that LEN is a multiple of 64.  */
+extern void __md5_process_bytes (const void *buffer, size_t len,
+				 struct md5_ctx *ctx) __THROW;
+
+/* Process the remaining bytes in the buffer and put result from CTX
+   in first 16 bytes following RESBUF.  The result is always in little
+   endian byte order, so that a byte-wise output yields to the wanted
+   ASCII representation of the message digest.
+
+   IMPORTANT: On some systems it is required that RESBUF be correctly
+   aligned for a 32 bits value.  */
+extern void *__md5_finish_ctx (struct md5_ctx *ctx, void *resbuf) __THROW;
+
+
+/* Put result from CTX in first 16 bytes following RESBUF.  The result is
+   always in little endian byte order, so that a byte-wise output yields
+   to the wanted ASCII representation of the message digest.
+
+   IMPORTANT: On some systems it is required that RESBUF is correctly
+   aligned for a 32 bits value.  */
+extern void *__md5_read_ctx (const struct md5_ctx *ctx, void *resbuf) __THROW;
+
+
+/* Compute MD5 message digest for bytes read from STREAM.  The
+   resulting message digest number will be written into the 16 bytes
+   beginning at RESBLOCK.  */
+extern int __md5_stream (FILE *stream, void *resblock) __THROW;
+
+/* Compute MD5 message digest for LEN bytes beginning at BUFFER.  The
+   result is always in little endian byte order, so that a byte-wise
+   output yields to the wanted ASCII representation of the message
+   digest.  */
+extern void *__md5_buffer (const char *buffer, size_t len,
+			   void *resblock) __THROW;
+
+#endif /* md5.h */
diff --git a/mdadm.c b/mdadm.c
index df8d904..d123e49 100644
--- a/mdadm.c
+++ b/mdadm.c
@@ -88,6 +88,7 @@ int main(int argc, char *argv[])
 	int autof = 0;
 
 	char *homehost = NULL;
+	char sys_hostname[256];
 	char *mailaddr = NULL;
 	char *program = NULL;
 	int delay = 0;
@@ -900,6 +901,12 @@ int main(int argc, char *argv[])
 
 	if (homehost == NULL)
 		homehost = conf_get_homehost(configfile);
+	if (homehost && strcmp(homehost, "<system>")==0) {
+		if (gethostname(sys_hostname, sizeof(sys_hostname)) == 0) {
+			sys_hostname[sizeof(sys_hostname)-1] = 0;
+			homehost = sys_hostname;
+		}
+	}
 
 	rv = 0;
 	switch(mode) {
@@ -1030,7 +1037,7 @@ int main(int argc, char *argv[])
 		}
 
 		rv = Create(ss, devlist->devname, mdfd, chunk, level, layout, size<0 ? 0 : size,
-			    raiddisks, sparedisks, ident.name,
+			    raiddisks, sparedisks, ident.name, homehost,
 			    devs_found-1, devlist->next, runstop, verbose-quiet, force, assume_clean,
 			    bitmap_file, bitmap_chunk, write_behind, delay);
 		break;
diff --git a/mdadm.h b/mdadm.h
index 991dc8e..7bfd8cb 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -280,7 +280,7 @@ extern struct superswitch {
 	void (*getinfo_super)(struct mdinfo *info, void *sbv);
 	int (*update_super)(struct mdinfo *info, void *sbv, char *update, char *devname, int verbose);
 	__u64 (*event_super)(void *sbv);
-	int (*init_super)(struct supertype *st, void **sbp, mdu_array_info_t *info, unsigned long long size, char *name);
+	int (*init_super)(struct supertype *st, void **sbp, mdu_array_info_t *info, unsigned long long size, char *name, char *homehost);
 	void (*add_to_super)(void *sbv, mdu_disk_info_t *dinfo);
 	int (*store_super)(struct supertype *st, int fd, void *sbv);
 	int (*write_init_super)(struct supertype *st, void *sbv, mdu_disk_info_t *dinfo, char *devname);
@@ -353,7 +353,7 @@ extern int Build(char *mddev, int mdfd, int chunk, int level, int layout,
 
 extern int Create(struct supertype *st, char *mddev, int mdfd,
 		  int chunk, int level, int layout, unsigned long long size, int raiddisks, int sparedisks,
-		  char *name,
+		  char *name, char *homehost,
 		  int subdevs, mddev_dev_t devlist,
 		  int runstop, int verbose, int force, int assume_clean,
 		  char *bitmap_file, int bitmap_chunk, int write_behind, int delay);
diff --git a/sha1.c b/sha1.c
new file mode 100644
index 0000000..556d9ca
--- /dev/null
+++ b/sha1.c
@@ -0,0 +1,423 @@
+/* sha1.c - Functions to compute SHA1 message digest of files or
+   memory blocks according to the NIST specification FIPS-180-1.
+
+   Copyright (C) 2000, 2001, 2003, 2004, 2005 Free Software Foundation, Inc.
+
+   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 2, 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, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Scott G. Miller
+   Credits:
+      Robert Klep <robert@ilse.nl>  -- Expansion function fix
+*/
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "sha1.h"
+
+#include <stddef.h>
+#include <string.h>
+
+#if USE_UNLOCKED_IO
+# include "unlocked-io.h"
+#endif
+
+/* SWAP does an endian swap on architectures that are little-endian,
+   as SHA1 needs some data in a big-endian form.  */
+
+#ifdef WORDS_BIGENDIAN
+# define SWAP(n) (n)
+#else
+# define SWAP(n) \
+    (((n) << 24) | (((n) & 0xff00) << 8) | (((n) >> 8) & 0xff00) | ((n) >> 24))
+#endif
+
+#define BLOCKSIZE 4096
+#if BLOCKSIZE % 64 != 0
+# error "invalid BLOCKSIZE"
+#endif
+
+/* This array contains the bytes used to pad the buffer to the next
+   64-byte boundary.  (RFC 1321, 3.1: Step 1)  */
+static const unsigned char fillbuf[64] = { 0x80, 0 /* , 0, 0, ...  */ };
+
+
+/*
+  Takes a pointer to a 160 bit block of data (five 32 bit ints) and
+  intializes it to the start constants of the SHA1 algorithm.  This
+  must be called before using hash in the call to sha1_hash.
+*/
+void
+sha1_init_ctx (struct sha1_ctx *ctx)
+{
+  ctx->A = 0x67452301;
+  ctx->B = 0xefcdab89;
+  ctx->C = 0x98badcfe;
+  ctx->D = 0x10325476;
+  ctx->E = 0xc3d2e1f0;
+
+  ctx->total[0] = ctx->total[1] = 0;
+  ctx->buflen = 0;
+}
+
+/* Put result from CTX in first 20 bytes following RESBUF.  The result
+   must be in little endian byte order.
+
+   IMPORTANT: On some systems it is required that RESBUF is correctly
+   aligned for a 32 bits value.  */
+void *
+sha1_read_ctx (const struct sha1_ctx *ctx, void *resbuf)
+{
+  ((md5_uint32 *) resbuf)[0] = SWAP (ctx->A);
+  ((md5_uint32 *) resbuf)[1] = SWAP (ctx->B);
+  ((md5_uint32 *) resbuf)[2] = SWAP (ctx->C);
+  ((md5_uint32 *) resbuf)[3] = SWAP (ctx->D);
+  ((md5_uint32 *) resbuf)[4] = SWAP (ctx->E);
+
+  return resbuf;
+}
+
+/* Process the remaining bytes in the internal buffer and the usual
+   prolog according to the standard and write the result to RESBUF.
+
+   IMPORTANT: On some systems it is required that RESBUF is correctly
+   aligned for a 32 bits value.  */
+void *
+sha1_finish_ctx (struct sha1_ctx *ctx, void *resbuf)
+{
+  /* Take yet unprocessed bytes into account.  */
+  md5_uint32 bytes = ctx->buflen;
+  size_t pad;
+
+  /* Now count remaining bytes.  */
+  ctx->total[0] += bytes;
+  if (ctx->total[0] < bytes)
+    ++ctx->total[1];
+
+  pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes;
+  memcpy (&ctx->buffer[bytes], fillbuf, pad);
+
+  /* Put the 64-bit file length in *bits* at the end of the buffer.  */
+  *(md5_uint32 *) &ctx->buffer[bytes + pad + 4] = SWAP (ctx->total[0] << 3);
+  *(md5_uint32 *) &ctx->buffer[bytes + pad] = SWAP ((ctx->total[1] << 3) |
+						    (ctx->total[0] >> 29));
+
+  /* Process last bytes.  */
+  sha1_process_block (ctx->buffer, bytes + pad + 8, ctx);
+
+  return sha1_read_ctx (ctx, resbuf);
+}
+
+/* Compute SHA1 message digest for bytes read from STREAM.  The
+   resulting message digest number will be written into the 16 bytes
+   beginning at RESBLOCK.  */
+int
+sha1_stream (FILE *stream, void *resblock)
+{
+  struct sha1_ctx ctx;
+  char buffer[BLOCKSIZE + 72];
+  size_t sum;
+
+  /* Initialize the computation context.  */
+  sha1_init_ctx (&ctx);
+
+  /* Iterate over full file contents.  */
+  while (1)
+    {
+      /* We read the file in blocks of BLOCKSIZE bytes.  One call of the
+	 computation function processes the whole buffer so that with the
+	 next round of the loop another block can be read.  */
+      size_t n;
+      sum = 0;
+
+      /* Read block.  Take care for partial reads.  */
+      while (1)
+	{
+	  n = fread (buffer + sum, 1, BLOCKSIZE - sum, stream);
+
+	  sum += n;
+
+	  if (sum == BLOCKSIZE)
+	    break;
+
+	  if (n == 0)
+	    {
+	      /* Check for the error flag IFF N == 0, so that we don't
+		 exit the loop after a partial read due to e.g., EAGAIN
+		 or EWOULDBLOCK.  */
+	      if (ferror (stream))
+		return 1;
+	      goto process_partial_block;
+	    }
+
+	  /* We've read at least one byte, so ignore errors.  But always
+	     check for EOF, since feof may be true even though N > 0.
+	     Otherwise, we could end up calling fread after EOF.  */
+	  if (feof (stream))
+	    goto process_partial_block;
+	}
+
+      /* Process buffer with BLOCKSIZE bytes.  Note that
+			BLOCKSIZE % 64 == 0
+       */
+      sha1_process_block (buffer, BLOCKSIZE, &ctx);
+    }
+
+ process_partial_block:;
+
+  /* Process any remaining bytes.  */
+  if (sum > 0)
+    sha1_process_bytes (buffer, sum, &ctx);
+
+  /* Construct result in desired memory.  */
+  sha1_finish_ctx (&ctx, resblock);
+  return 0;
+}
+
+/* Compute MD5 message digest for LEN bytes beginning at BUFFER.  The
+   result is always in little endian byte order, so that a byte-wise
+   output yields to the wanted ASCII representation of the message
+   digest.  */
+void *
+sha1_buffer (const char *buffer, size_t len, void *resblock)
+{
+  struct sha1_ctx ctx;
+
+  /* Initialize the computation context.  */
+  sha1_init_ctx (&ctx);
+
+  /* Process whole buffer but last len % 64 bytes.  */
+  sha1_process_bytes (buffer, len, &ctx);
+
+  /* Put result in desired memory area.  */
+  return sha1_finish_ctx (&ctx, resblock);
+}
+
+void
+sha1_process_bytes (const void *buffer, size_t len, struct sha1_ctx *ctx)
+{
+  /* When we already have some bits in our internal buffer concatenate
+     both inputs first.  */
+  if (ctx->buflen != 0)
+    {
+      size_t left_over = ctx->buflen;
+      size_t add = 128 - left_over > len ? len : 128 - left_over;
+
+      memcpy (&ctx->buffer[left_over], buffer, add);
+      ctx->buflen += add;
+
+      if (ctx->buflen > 64)
+	{
+	  sha1_process_block (ctx->buffer, ctx->buflen & ~63, ctx);
+
+	  ctx->buflen &= 63;
+	  /* The regions in the following copy operation cannot overlap.  */
+	  memcpy (ctx->buffer, &ctx->buffer[(left_over + add) & ~63],
+		  ctx->buflen);
+	}
+
+      buffer = (const char *) buffer + add;
+      len -= add;
+    }
+
+  /* Process available complete blocks.  */
+  if (len >= 64)
+    {
+#if !_STRING_ARCH_unaligned
+# define alignof(type) offsetof (struct { char c; type x; }, x)
+# define UNALIGNED_P(p) (((size_t) p) % alignof (md5_uint32) != 0)
+      if (UNALIGNED_P (buffer))
+	while (len > 64)
+	  {
+	    sha1_process_block (memcpy (ctx->buffer, buffer, 64), 64, ctx);
+	    buffer = (const char *) buffer + 64;
+	    len -= 64;
+	  }
+      else
+#endif
+	{
+	  sha1_process_block (buffer, len & ~63, ctx);
+	  buffer = (const char *) buffer + (len & ~63);
+	  len &= 63;
+	}
+    }
+
+  /* Move remaining bytes in internal buffer.  */
+  if (len > 0)
+    {
+      size_t left_over = ctx->buflen;
+
+      memcpy (&ctx->buffer[left_over], buffer, len);
+      left_over += len;
+      if (left_over >= 64)
+	{
+	  sha1_process_block (ctx->buffer, 64, ctx);
+	  left_over -= 64;
+	  memcpy (ctx->buffer, &ctx->buffer[64], left_over);
+	}
+      ctx->buflen = left_over;
+    }
+}
+
+/* --- Code below is the primary difference between md5.c and sha1.c --- */
+
+/* SHA1 round constants */
+#define K1 0x5a827999L
+#define K2 0x6ed9eba1L
+#define K3 0x8f1bbcdcL
+#define K4 0xca62c1d6L
+
+/* Round functions.  Note that F2 is the same as F4.  */
+#define F1(B,C,D) ( D ^ ( B & ( C ^ D ) ) )
+#define F2(B,C,D) (B ^ C ^ D)
+#define F3(B,C,D) ( ( B & C ) | ( D & ( B | C ) ) )
+#define F4(B,C,D) (B ^ C ^ D)
+
+/* Process LEN bytes of BUFFER, accumulating context into CTX.
+   It is assumed that LEN % 64 == 0.
+   Most of this code comes from GnuPG's cipher/sha1.c.  */
+
+void
+sha1_process_block (const void *buffer, size_t len, struct sha1_ctx *ctx)
+{
+  const md5_uint32 *words = buffer;
+  size_t nwords = len / sizeof (md5_uint32);
+  const md5_uint32 *endp = words + nwords;
+  md5_uint32 x[16];
+  md5_uint32 a = ctx->A;
+  md5_uint32 b = ctx->B;
+  md5_uint32 c = ctx->C;
+  md5_uint32 d = ctx->D;
+  md5_uint32 e = ctx->E;
+
+  /* First increment the byte count.  RFC 1321 specifies the possible
+     length of the file up to 2^64 bits.  Here we only compute the
+     number of bytes.  Do a double word increment.  */
+  ctx->total[0] += len;
+  if (ctx->total[0] < len)
+    ++ctx->total[1];
+
+#define rol(x, n) (((x) << (n)) | ((x) >> (32 - (n))))
+
+#define M(I) ( tm =   x[I&0x0f] ^ x[(I-14)&0x0f] \
+		    ^ x[(I-8)&0x0f] ^ x[(I-3)&0x0f] \
+	       , (x[I&0x0f] = rol(tm, 1)) )
+
+#define R(A,B,C,D,E,F,K,M)  do { E += rol( A, 5 )     \
+				      + F( B, C, D )  \
+				      + K	      \
+				      + M;	      \
+				 B = rol( B, 30 );    \
+			       } while(0)
+
+  while (words < endp)
+    {
+      md5_uint32 tm;
+      int t;
+      for (t = 0; t < 16; t++)
+	{
+	  x[t] = SWAP (*words);
+	  words++;
+	}
+
+      R( a, b, c, d, e, F1, K1, x[ 0] );
+      R( e, a, b, c, d, F1, K1, x[ 1] );
+      R( d, e, a, b, c, F1, K1, x[ 2] );
+      R( c, d, e, a, b, F1, K1, x[ 3] );
+      R( b, c, d, e, a, F1, K1, x[ 4] );
+      R( a, b, c, d, e, F1, K1, x[ 5] );
+      R( e, a, b, c, d, F1, K1, x[ 6] );
+      R( d, e, a, b, c, F1, K1, x[ 7] );
+      R( c, d, e, a, b, F1, K1, x[ 8] );
+      R( b, c, d, e, a, F1, K1, x[ 9] );
+      R( a, b, c, d, e, F1, K1, x[10] );
+      R( e, a, b, c, d, F1, K1, x[11] );
+      R( d, e, a, b, c, F1, K1, x[12] );
+      R( c, d, e, a, b, F1, K1, x[13] );
+      R( b, c, d, e, a, F1, K1, x[14] );
+      R( a, b, c, d, e, F1, K1, x[15] );
+      R( e, a, b, c, d, F1, K1, M(16) );
+      R( d, e, a, b, c, F1, K1, M(17) );
+      R( c, d, e, a, b, F1, K1, M(18) );
+      R( b, c, d, e, a, F1, K1, M(19) );
+      R( a, b, c, d, e, F2, K2, M(20) );
+      R( e, a, b, c, d, F2, K2, M(21) );
+      R( d, e, a, b, c, F2, K2, M(22) );
+      R( c, d, e, a, b, F2, K2, M(23) );
+      R( b, c, d, e, a, F2, K2, M(24) );
+      R( a, b, c, d, e, F2, K2, M(25) );
+      R( e, a, b, c, d, F2, K2, M(26) );
+      R( d, e, a, b, c, F2, K2, M(27) );
+      R( c, d, e, a, b, F2, K2, M(28) );
+      R( b, c, d, e, a, F2, K2, M(29) );
+      R( a, b, c, d, e, F2, K2, M(30) );
+      R( e, a, b, c, d, F2, K2, M(31) );
+      R( d, e, a, b, c, F2, K2, M(32) );
+      R( c, d, e, a, b, F2, K2, M(33) );
+      R( b, c, d, e, a, F2, K2, M(34) );
+      R( a, b, c, d, e, F2, K2, M(35) );
+      R( e, a, b, c, d, F2, K2, M(36) );
+      R( d, e, a, b, c, F2, K2, M(37) );
+      R( c, d, e, a, b, F2, K2, M(38) );
+      R( b, c, d, e, a, F2, K2, M(39) );
+      R( a, b, c, d, e, F3, K3, M(40) );
+      R( e, a, b, c, d, F3, K3, M(41) );
+      R( d, e, a, b, c, F3, K3, M(42) );
+      R( c, d, e, a, b, F3, K3, M(43) );
+      R( b, c, d, e, a, F3, K3, M(44) );
+      R( a, b, c, d, e, F3, K3, M(45) );
+      R( e, a, b, c, d, F3, K3, M(46) );
+      R( d, e, a, b, c, F3, K3, M(47) );
+      R( c, d, e, a, b, F3, K3, M(48) );
+      R( b, c, d, e, a, F3, K3, M(49) );
+      R( a, b, c, d, e, F3, K3, M(50) );
+      R( e, a, b, c, d, F3, K3, M(51) );
+      R( d, e, a, b, c, F3, K3, M(52) );
+      R( c, d, e, a, b, F3, K3, M(53) );
+      R( b, c, d, e, a, F3, K3, M(54) );
+      R( a, b, c, d, e, F3, K3, M(55) );
+      R( e, a, b, c, d, F3, K3, M(56) );
+      R( d, e, a, b, c, F3, K3, M(57) );
+      R( c, d, e, a, b, F3, K3, M(58) );
+      R( b, c, d, e, a, F3, K3, M(59) );
+      R( a, b, c, d, e, F4, K4, M(60) );
+      R( e, a, b, c, d, F4, K4, M(61) );
+      R( d, e, a, b, c, F4, K4, M(62) );
+      R( c, d, e, a, b, F4, K4, M(63) );
+      R( b, c, d, e, a, F4, K4, M(64) );
+      R( a, b, c, d, e, F4, K4, M(65) );
+      R( e, a, b, c, d, F4, K4, M(66) );
+      R( d, e, a, b, c, F4, K4, M(67) );
+      R( c, d, e, a, b, F4, K4, M(68) );
+      R( b, c, d, e, a, F4, K4, M(69) );
+      R( a, b, c, d, e, F4, K4, M(70) );
+      R( e, a, b, c, d, F4, K4, M(71) );
+      R( d, e, a, b, c, F4, K4, M(72) );
+      R( c, d, e, a, b, F4, K4, M(73) );
+      R( b, c, d, e, a, F4, K4, M(74) );
+      R( a, b, c, d, e, F4, K4, M(75) );
+      R( e, a, b, c, d, F4, K4, M(76) );
+      R( d, e, a, b, c, F4, K4, M(77) );
+      R( c, d, e, a, b, F4, K4, M(78) );
+      R( b, c, d, e, a, F4, K4, M(79) );
+
+      a = ctx->A += a;
+      b = ctx->B += b;
+      c = ctx->C += c;
+      d = ctx->D += d;
+      e = ctx->E += e;
+    }
+}
diff --git a/sha1.h b/sha1.h
new file mode 100644
index 0000000..bb48855
--- /dev/null
+++ b/sha1.h
@@ -0,0 +1,87 @@
+/* Declarations of functions and data types used for SHA1 sum
+   library functions.
+   Copyright (C) 2000, 2001, 2003, 2005 Free Software Foundation, Inc.
+
+   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 2, 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, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+#ifndef SHA1_H
+# define SHA1_H 1
+
+# include <stdio.h>
+# include "md5.h"
+
+/* Structure to save state of computation between the single steps.  */
+struct sha1_ctx
+{
+  md5_uint32 A;
+  md5_uint32 B;
+  md5_uint32 C;
+  md5_uint32 D;
+  md5_uint32 E;
+
+  md5_uint32 total[2];
+  md5_uint32 buflen;
+  char buffer[128] __attribute__ ((__aligned__ (__alignof__ (md5_uint32))));
+};
+
+
+/* Initialize structure containing state of computation. */
+extern void sha1_init_ctx (struct sha1_ctx *ctx);
+
+/* Starting with the result of former calls of this function (or the
+   initialization function update the context for the next LEN bytes
+   starting at BUFFER.
+   It is necessary that LEN is a multiple of 64!!! */
+extern void sha1_process_block (const void *buffer, size_t len,
+				struct sha1_ctx *ctx);
+
+/* Starting with the result of former calls of this function (or the
+   initialization function update the context for the next LEN bytes
+   starting at BUFFER.
+   It is NOT required that LEN is a multiple of 64.  */
+extern void sha1_process_bytes (const void *buffer, size_t len,
+				struct sha1_ctx *ctx);
+
+/* Process the remaining bytes in the buffer and put result from CTX
+   in first 20 bytes following RESBUF.  The result is always in little
+   endian byte order, so that a byte-wise output yields to the wanted
+   ASCII representation of the message digest.
+
+   IMPORTANT: On some systems it is required that RESBUF be correctly
+   aligned for a 32 bits value.  */
+extern void *sha1_finish_ctx (struct sha1_ctx *ctx, void *resbuf);
+
+
+/* Put result from CTX in first 20 bytes following RESBUF.  The result is
+   always in little endian byte order, so that a byte-wise output yields
+   to the wanted ASCII representation of the message digest.
+
+   IMPORTANT: On some systems it is required that RESBUF is correctly
+   aligned for a 32 bits value.  */
+extern void *sha1_read_ctx (const struct sha1_ctx *ctx, void *resbuf);
+
+
+/* Compute SHA1 message digest for bytes read from STREAM.  The
+   resulting message digest number will be written into the 20 bytes
+   beginning at RESBLOCK.  */
+extern int sha1_stream (FILE *stream, void *resblock);
+
+/* Compute SHA1 message digest for LEN bytes beginning at BUFFER.  The
+   result is always in little endian byte order, so that a byte-wise
+   output yields to the wanted ASCII representation of the message
+   digest.  */
+extern void *sha1_buffer (const char *buffer, size_t len, void *resblock);
+
+#endif
diff --git a/super0.c b/super0.c
index 0bf38ed..7fe2336 100644
--- a/super0.c
+++ b/super0.c
@@ -28,7 +28,7 @@
  */
 
 #include "mdadm.h"
-
+#include <openssl/sha.h> /* for SHA1 */
 /*
  * All handling for the 0.90.0 version superblock is in
  * this file.
@@ -449,9 +449,17 @@ static __u64 event_super0(void *sbv)
 	return md_event(sb);
 }
 
+/*
+ * For verion-0 superblock, the homehost is 'stored' in the
+ * uuid.  8 bytes for a hash of the host leaving 8 bytes
+ * of random material.
+ * We use the first 8 bytes (64bits) of the sha1 of the
+ * host name
+ */
 
 
-static int init_super0(struct supertype *st, void **sbp, mdu_array_info_t *info, unsigned long long size, char *ignored_name)
+static int init_super0(struct supertype *st, void **sbp, mdu_array_info_t *info,
+		       unsigned long long size, char *ignored_name, char *homehost)
 {
 	mdp_super_t *sb = malloc(MD_SB_BYTES + sizeof(bitmap_super_t));
 	int spares;
@@ -460,6 +468,7 @@ static int init_super0(struct supertype *st, void **sbp, mdu_array_info_t *info,
 
 	if (info->major_version == -1) {
 		/* zeroing the superblock */
+		*sbp = sb;
 		return 0;
 	}
 
@@ -494,6 +503,12 @@ static int init_super0(struct supertype *st, void **sbp, mdu_array_info_t *info,
 	}
 	if (rfd >= 0)
 		close(rfd);
+	if (homehost) {
+		unsigned char *hash = SHA1((unsigned char*)homehost,
+					   strlen(homehost),
+					   NULL);
+		memcpy(&sb->set_uuid2, hash, 8);
+	}
 
 	sb->utime = sb->ctime;
 	sb->state = info->state;
diff --git a/super1.c b/super1.c
index cc0a5e3..a29795a 100644
--- a/super1.c
+++ b/super1.c
@@ -498,16 +498,20 @@ static __u64 event_super1(void *sbv)
 	return __le64_to_cpu(sb->events);
 }
 
-static int init_super1(struct supertype *st, void **sbp, mdu_array_info_t *info, unsigned long long size, char *name)
+static int init_super1(struct supertype *st, void **sbp, mdu_array_info_t *info,
+		       unsigned long long size, char *name, char *homehost)
 {
 	struct mdp_superblock_1 *sb = malloc(1024 + sizeof(bitmap_super_t));
 	int spares;
 	int rfd;
+	char defname[10];
 	memset(sb, 0, 1024);
 
-	if (info->major_version == -1)
+	if (info->major_version == -1) {
 		/* zeroing superblock */
+		*sbp = sb;
 		return 0;
+	}
 
 	spares = info->working_disks - info->active_disks;
 	if (info->raid_disks + spares  > 384) {
@@ -516,7 +520,6 @@ static int init_super1(struct supertype *st, void **sbp, mdu_array_info_t *info,
 		return 0;
 	}
 
-
 	sb->magic = __cpu_to_le32(MD_SB_MAGIC);
 	sb->major_version = __cpu_to_le32(1);
 	sb->feature_map = 0;
@@ -531,8 +534,19 @@ static int init_super1(struct supertype *st, void **sbp, mdu_array_info_t *info,
 	}
 	if (rfd >= 0) close(rfd);
 
+	if (name == NULL || *name == 0) {
+		sprintf(defname, "%d", info->md_minor);
+		name = defname;
+	}
 	memset(sb->set_name, 0, 32);
-	strcpy(sb->set_name, name);
+	if (homehost &&
+	    strchr(name, ':')== NULL &&
+	    strlen(homehost)+1+strlen(name) < 32) {
+		strcpy(sb->set_name, homehost);
+		strcat(sb->set_name, ":");
+		strcat(sb->set_name, name);
+	} else
+		strcpy(sb->set_name, name);
 
 	sb->ctime = __cpu_to_le64((unsigned long long)time(0));
 	sb->level = __cpu_to_le32(info->level);