1 files changed, 399 insertions, 0 deletions

diff --git a/bzip2recover.c b/bzip2recover.c
new file mode 100644
index 0000000..efdfb3c
--- /dev/null
+++ b/bzip2recover.c
@@ -0,0 +1,399 @@
+
+/*-----------------------------------------------------------*/
+/*--- Block recoverer program for bzip2                   ---*/
+/*---                                      bzip2recover.c ---*/
+/*-----------------------------------------------------------*/
+
+/*--
+  This program is bzip2recover, a program to attempt data 
+  salvage from damaged files created by the accompanying
+  bzip2 program.
+
+  Copyright (C) 1996, 1997 by Julian Seward.
+     Guildford, Surrey, UK
+     email: jseward@acm.org
+
+  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 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, write to the Free Software
+  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+  The GNU General Public License is contained in the file LICENSE.
+--*/
+
+
+#include <stdio.h>
+#include <errno.h>
+#include <malloc.h>
+#include <stdlib.h>
+#include <strings.h>  /*-- or try string.h --*/
+
+#define UInt32  unsigned int
+#define Int32   int
+#define UChar   unsigned char
+#define Char    char
+#define Bool    unsigned char
+#define True    1
+#define False   0
+
+
+Char inFileName[2000];
+Char outFileName[2000];
+Char progName[2000];
+
+UInt32 bytesOut = 0;
+UInt32 bytesIn  = 0;
+
+
+/*---------------------------------------------------*/
+/*--- I/O errors                                  ---*/
+/*---------------------------------------------------*/
+
+/*---------------------------------------------*/
+void readError ( void )
+{
+   fprintf ( stderr,
+             "%s: I/O error reading `%s', possible reason follows.\n",
+            progName, inFileName );
+   perror ( progName );
+   fprintf ( stderr, "%s: warning: output file(s) may be incomplete.\n",
+             progName );
+   exit ( 1 );
+}
+
+
+/*---------------------------------------------*/
+void writeError ( void )
+{
+   fprintf ( stderr,
+             "%s: I/O error reading `%s', possible reason follows.\n",
+            progName, inFileName );
+   perror ( progName );
+   fprintf ( stderr, "%s: warning: output file(s) may be incomplete.\n",
+             progName );
+   exit ( 1 );
+}
+
+
+/*---------------------------------------------*/
+void mallocFail ( Int32 n )
+{
+   fprintf ( stderr,
+             "%s: malloc failed on request for %d bytes.\n",
+            progName, n );
+   fprintf ( stderr, "%s: warning: output file(s) may be incomplete.\n",
+             progName );
+   exit ( 1 );
+}
+
+
+/*---------------------------------------------------*/
+/*--- Bit stream I/O                              ---*/
+/*---------------------------------------------------*/
+
+typedef
+   struct {
+      FILE*  handle;
+      Int32  buffer;
+      Int32  buffLive;
+      Char   mode;
+   }
+   BitStream;
+
+
+/*---------------------------------------------*/
+BitStream* bsOpenReadStream ( FILE* stream )
+{
+   BitStream *bs = malloc ( sizeof(BitStream) );
+   if (bs == NULL) mallocFail ( sizeof(BitStream) );
+   bs->handle = stream;
+   bs->buffer = 0;
+   bs->buffLive = 0;
+   bs->mode = 'r';
+   return bs;
+}
+
+
+/*---------------------------------------------*/
+BitStream* bsOpenWriteStream ( FILE* stream )
+{
+   BitStream *bs = malloc ( sizeof(BitStream) );
+   if (bs == NULL) mallocFail ( sizeof(BitStream) );
+   bs->handle = stream;
+   bs->buffer = 0;
+   bs->buffLive = 0;
+   bs->mode = 'w';
+   return bs;
+}
+
+
+/*---------------------------------------------*/
+void bsPutBit ( BitStream* bs, Int32 bit )
+{
+   if (bs->buffLive == 8) {
+      Int32 retVal = putc ( (UChar) bs->buffer, bs->handle );
+      if (retVal == EOF) writeError();
+      bytesOut++;
+      bs->buffLive = 1;
+      bs->buffer = bit & 0x1;
+   } else {
+      bs->buffer = ( (bs->buffer << 1) | (bit & 0x1) );
+      bs->buffLive++;
+   };
+}
+
+
+/*---------------------------------------------*/
+/*--
+   Returns 0 or 1, or 2 to indicate EOF.
+--*/
+Int32 bsGetBit ( BitStream* bs )
+{
+   if (bs->buffLive > 0) {
+      bs->buffLive --;
+      return ( ((bs->buffer) >> (bs->buffLive)) & 0x1 );
+   } else {
+      Int32 retVal = getc ( bs->handle );
+      if ( retVal == EOF ) {
+         if (errno != 0) readError();
+         return 2;
+      }
+      bs->buffLive = 7;
+      bs->buffer = retVal;
+      return ( ((bs->buffer) >> 7) & 0x1 );
+   }
+}
+
+
+/*---------------------------------------------*/
+void bsClose ( BitStream* bs )
+{
+   Int32 retVal;
+
+   if ( bs->mode == 'w' ) {
+      while ( bs->buffLive < 8 ) {
+         bs->buffLive++;
+         bs->buffer <<= 1;
+      };
+      retVal = putc ( (UChar) (bs->buffer), bs->handle );
+      if (retVal == EOF) writeError();
+      bytesOut++;
+      retVal = fflush ( bs->handle );
+      if (retVal == EOF) writeError();
+   }
+   retVal = fclose ( bs->handle );
+   if (retVal == EOF)
+      if (bs->mode == 'w') writeError(); else readError();
+   free ( bs );
+}
+
+
+/*---------------------------------------------*/
+void bsPutUChar ( BitStream* bs, UChar c )
+{
+   Int32 i;
+   for (i = 7; i >= 0; i--)
+      bsPutBit ( bs, (((UInt32) c) >> i) & 0x1 );
+}
+
+
+/*---------------------------------------------*/
+void bsPutUInt32 ( BitStream* bs, UInt32 c )
+{
+   Int32 i;
+
+   for (i = 31; i >= 0; i--)
+      bsPutBit ( bs, (c >> i) & 0x1 );
+}
+
+
+/*---------------------------------------------*/
+Bool endsInBz2 ( Char* name )
+{
+   Int32 n = strlen ( name );
+   if (n <= 4) return False;
+   return
+      (name[n-4] == '.' &&
+       name[n-3] == 'b' &&
+       name[n-2] == 'z' &&
+       name[n-1] == '2');
+}
+
+
+/*---------------------------------------------------*/
+/*---                                             ---*/
+/*---------------------------------------------------*/
+
+#define BLOCK_HEADER_HI  0x00003141UL
+#define BLOCK_HEADER_LO  0x59265359UL
+
+#define BLOCK_ENDMARK_HI 0x00001772UL
+#define BLOCK_ENDMARK_LO 0x45385090UL
+
+Int32 main ( Int32 argc, Char** argv )
+{
+   FILE*       inFile;
+   FILE*       outFile;
+   BitStream*  bsIn, *bsWr;
+   Int32       currBlock, b, wrBlock;
+   UInt32      bitsRead;
+   UInt32      bStart[20000];
+   UInt32      bEnd[20000];
+   UInt32      buffHi, buffLo, blockCRC;
+   Char*       p;
+
+   strcpy ( progName, argv[0] );
+   inFileName[0] = outFileName[0] = 0;
+
+   fprintf ( stderr, "bzip2recover: extracts blocks from damaged .bz2 files.\n" );
+
+   if (argc != 2) {
+      fprintf ( stderr, "%s: usage is `%s damaged_file_name'.\n",
+                        progName, progName );
+      exit(1);
+   }
+
+   strcpy ( inFileName, argv[1] );
+
+   inFile = fopen ( inFileName, "rb" );
+   if (inFile == NULL) {
+      fprintf ( stderr, "%s: can't read `%s'\n", progName, inFileName );
+      exit(1);
+   }
+
+   bsIn = bsOpenReadStream ( inFile );
+   fprintf ( stderr, "%s: searching for block boundaries ...\n", progName );
+
+   bitsRead = 0;
+   buffHi = buffLo = 0;
+   currBlock = 0;
+   bStart[currBlock] = 0;
+
+   while (True) {
+      b = bsGetBit ( bsIn );
+      bitsRead++;
+      if (b == 2) {
+         if (bitsRead >= bStart[currBlock] &&
+            (bitsRead - bStart[currBlock]) >= 40) {
+            bEnd[currBlock] = bitsRead-1;
+            if (currBlock > 0)
+               fprintf ( stderr, "   block %d runs from %d to %d (incomplete)\n",
+                         currBlock,  bStart[currBlock], bEnd[currBlock] );
+         } else
+            currBlock--;
+         break;
+      }
+      buffHi = (buffHi << 1) | (buffLo >> 31);
+      buffLo = (buffLo << 1) | (b & 1);
+      if ( ( (buffHi & 0x0000ffff) == BLOCK_HEADER_HI 
+             && buffLo == BLOCK_HEADER_LO)
+           || 
+           ( (buffHi & 0x0000ffff) == BLOCK_ENDMARK_HI 
+             && buffLo == BLOCK_ENDMARK_LO)
+         ) {
+         if (bitsRead > 49)
+            bEnd[currBlock] = bitsRead-49; else
+            bEnd[currBlock] = 0;
+         if (currBlock > 0)
+            fprintf ( stderr, "   block %d runs from %d to %d\n",
+                      currBlock,  bStart[currBlock], bEnd[currBlock] );
+         currBlock++;
+         bStart[currBlock] = bitsRead;
+      }
+   }
+
+   bsClose ( bsIn );
+
+   /*-- identified blocks run from 1 to currBlock inclusive. --*/
+
+   if (currBlock < 1) {
+      fprintf ( stderr,
+                "%s: sorry, I couldn't find any block boundaries.\n",
+                progName );
+      exit(1);
+   };
+
+   fprintf ( stderr, "%s: splitting into blocks\n", progName );
+
+   inFile = fopen ( inFileName, "rb" );
+   if (inFile == NULL) {
+      fprintf ( stderr, "%s: can't open `%s'\n", progName, inFileName );
+      exit(1);
+   }
+   bsIn = bsOpenReadStream ( inFile );
+
+   /*-- placate gcc's dataflow analyser --*/
+   blockCRC = 0; bsWr = 0;
+
+   bitsRead = 0;
+   outFile = NULL;
+   wrBlock = 1;
+   while (True) {
+      b = bsGetBit(bsIn);
+      if (b == 2) break;
+      buffHi = (buffHi << 1) | (buffLo >> 31);
+      buffLo = (buffLo << 1) | (b & 1);
+      if (bitsRead == 47+bStart[wrBlock]) 
+         blockCRC = (buffHi << 16) | (buffLo >> 16);
+
+      if (outFile != NULL && bitsRead >= bStart[wrBlock]
+                          && bitsRead <= bEnd[wrBlock]) {
+         bsPutBit ( bsWr, b );
+      }
+
+      bitsRead++;
+
+      if (bitsRead == bEnd[wrBlock]+1) {
+         if (outFile != NULL) {
+            bsPutUChar ( bsWr, 0x17 ); bsPutUChar ( bsWr, 0x72 );
+            bsPutUChar ( bsWr, 0x45 ); bsPutUChar ( bsWr, 0x38 );
+            bsPutUChar ( bsWr, 0x50 ); bsPutUChar ( bsWr, 0x90 );
+            bsPutUInt32 ( bsWr, blockCRC );
+            bsClose ( bsWr );
+         }
+         if (wrBlock >= currBlock) break;
+         wrBlock++;
+      } else
+      if (bitsRead == bStart[wrBlock]) {
+         outFileName[0] = 0;
+         sprintf ( outFileName, "rec%4d", wrBlock );
+         for (p = outFileName; *p != 0; p++) if (*p == ' ') *p = '0';
+         strcat ( outFileName, inFileName );
+         if ( !endsInBz2(outFileName)) strcat ( outFileName, ".bz2" );
+
+         fprintf ( stderr, "   writing block %d to `%s' ...\n",
+                           wrBlock, outFileName );
+
+         outFile = fopen ( outFileName, "wb" );
+         if (outFile == NULL) {
+            fprintf ( stderr, "%s: can't write `%s'\n",
+                      progName, outFileName );
+            exit(1);
+         }
+         bsWr = bsOpenWriteStream ( outFile );
+         bsPutUChar ( bsWr, 'B' ); bsPutUChar ( bsWr, 'Z' );
+         bsPutUChar ( bsWr, 'h' ); bsPutUChar ( bsWr, '9' );
+         bsPutUChar ( bsWr, 0x31 ); bsPutUChar ( bsWr, 0x41 );
+         bsPutUChar ( bsWr, 0x59 ); bsPutUChar ( bsWr, 0x26 );
+         bsPutUChar ( bsWr, 0x53 ); bsPutUChar ( bsWr, 0x59 );
+      }
+   }
+
+   fprintf ( stderr, "%s: finished\n", progName );
+   return 0;
+}
+
+
+
+/*-----------------------------------------------------------*/
+/*--- end                                  bzip2recover.c ---*/
+/*-----------------------------------------------------------*/