diff options
Diffstat (limited to 'bzlib-src/bzip2recover.c')
| -rw-r--r-- | bzlib-src/bzip2recover.c | 514 |
1 files changed, 514 insertions, 0 deletions
diff --git a/bzlib-src/bzip2recover.c b/bzlib-src/bzip2recover.c new file mode 100644 index 0000000..f9de049 --- /dev/null +++ b/bzlib-src/bzip2recover.c @@ -0,0 +1,514 @@ +/*-----------------------------------------------------------*/ +/*--- Block recoverer program for bzip2 ---*/ +/*--- bzip2recover.c ---*/ +/*-----------------------------------------------------------*/ + +/* ------------------------------------------------------------------ + This file is part of bzip2/libbzip2, a program and library for + lossless, block-sorting data compression. + + bzip2/libbzip2 version 1.0.6 of 6 September 2010 + Copyright (C) 1996-2010 Julian Seward <jseward@bzip.org> + + Please read the WARNING, DISCLAIMER and PATENTS sections in the + README file. + + This program is released under the terms of the license contained + in the file LICENSE. + ------------------------------------------------------------------ */ + +/* This program is a complete hack and should be rewritten properly. + It isn't very complicated. */ + +#include <stdio.h> +#include <errno.h> +#include <stdlib.h> +#include <string.h> + + +/* This program records bit locations in the file to be recovered. + That means that if 64-bit ints are not supported, we will not + be able to recover .bz2 files over 512MB (2^32 bits) long. + On GNU supported platforms, we take advantage of the 64-bit + int support to circumvent this problem. Ditto MSVC. + + This change occurred in version 1.0.2; all prior versions have + the 512MB limitation. +*/ +#ifdef __GNUC__ + typedef unsigned long long int MaybeUInt64; +# define MaybeUInt64_FMT "%Lu" +#else +#ifdef _MSC_VER + typedef unsigned __int64 MaybeUInt64; +# define MaybeUInt64_FMT "%I64u" +#else + typedef unsigned int MaybeUInt64; +# define MaybeUInt64_FMT "%u" +#endif +#endif + +typedef unsigned int UInt32; +typedef int Int32; +typedef unsigned char UChar; +typedef char Char; +typedef unsigned char Bool; +#define True ((Bool)1) +#define False ((Bool)0) + + +#define BZ_MAX_FILENAME 2000 + +Char inFileName[BZ_MAX_FILENAME]; +Char outFileName[BZ_MAX_FILENAME]; +Char progName[BZ_MAX_FILENAME]; + +MaybeUInt64 bytesOut = 0; +MaybeUInt64 bytesIn = 0; + + +/*---------------------------------------------------*/ +/*--- Header bytes ---*/ +/*---------------------------------------------------*/ + +#define BZ_HDR_B 0x42 /* 'B' */ +#define BZ_HDR_Z 0x5a /* 'Z' */ +#define BZ_HDR_h 0x68 /* 'h' */ +#define BZ_HDR_0 0x30 /* '0' */ + + +/*---------------------------------------------------*/ +/*--- I/O errors ---*/ +/*---------------------------------------------------*/ + +/*---------------------------------------------*/ +static 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 ); +} + + +/*---------------------------------------------*/ +static 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 ); +} + + +/*---------------------------------------------*/ +static 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 ); +} + + +/*---------------------------------------------*/ +static void tooManyBlocks ( Int32 max_handled_blocks ) +{ + fprintf ( stderr, + "%s: `%s' appears to contain more than %d blocks\n", + progName, inFileName, max_handled_blocks ); + fprintf ( stderr, + "%s: and cannot be handled. To fix, increase\n", + progName ); + fprintf ( stderr, + "%s: BZ_MAX_HANDLED_BLOCKS in bzip2recover.c, and recompile.\n", + progName ); + exit ( 1 ); +} + + + +/*---------------------------------------------------*/ +/*--- Bit stream I/O ---*/ +/*---------------------------------------------------*/ + +typedef + struct { + FILE* handle; + Int32 buffer; + Int32 buffLive; + Char mode; + } + BitStream; + + +/*---------------------------------------------*/ +static 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; +} + + +/*---------------------------------------------*/ +static 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; +} + + +/*---------------------------------------------*/ +static 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. +--*/ +static 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 ); + } +} + + +/*---------------------------------------------*/ +static 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 ); +} + + +/*---------------------------------------------*/ +static void bsPutUChar ( BitStream* bs, UChar c ) +{ + Int32 i; + for (i = 7; i >= 0; i--) + bsPutBit ( bs, (((UInt32) c) >> i) & 0x1 ); +} + + +/*---------------------------------------------*/ +static void bsPutUInt32 ( BitStream* bs, UInt32 c ) +{ + Int32 i; + + for (i = 31; i >= 0; i--) + bsPutBit ( bs, (c >> i) & 0x1 ); +} + + +/*---------------------------------------------*/ +static 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'); +} + + +/*---------------------------------------------------*/ +/*--- ---*/ +/*---------------------------------------------------*/ + +/* This logic isn't really right when it comes to Cygwin. */ +#ifdef _WIN32 +# define BZ_SPLIT_SYM '\\' /* path splitter on Windows platform */ +#else +# define BZ_SPLIT_SYM '/' /* path splitter on Unix platform */ +#endif + +#define BLOCK_HEADER_HI 0x00003141UL +#define BLOCK_HEADER_LO 0x59265359UL + +#define BLOCK_ENDMARK_HI 0x00001772UL +#define BLOCK_ENDMARK_LO 0x45385090UL + +/* Increase if necessary. However, a .bz2 file with > 50000 blocks + would have an uncompressed size of at least 40GB, so the chances + are low you'll need to up this. +*/ +#define BZ_MAX_HANDLED_BLOCKS 50000 + +MaybeUInt64 bStart [BZ_MAX_HANDLED_BLOCKS]; +MaybeUInt64 bEnd [BZ_MAX_HANDLED_BLOCKS]; +MaybeUInt64 rbStart[BZ_MAX_HANDLED_BLOCKS]; +MaybeUInt64 rbEnd [BZ_MAX_HANDLED_BLOCKS]; + +Int32 main ( Int32 argc, Char** argv ) +{ + FILE* inFile; + FILE* outFile; + BitStream* bsIn, *bsWr; + Int32 b, wrBlock, currBlock, rbCtr; + MaybeUInt64 bitsRead; + + UInt32 buffHi, buffLo, blockCRC; + Char* p; + + strcpy ( progName, argv[0] ); + inFileName[0] = outFileName[0] = 0; + + fprintf ( stderr, + "bzip2recover 1.0.6: extracts blocks from damaged .bz2 files.\n" ); + + if (argc != 2) { + fprintf ( stderr, "%s: usage is `%s damaged_file_name'.\n", + progName, progName ); + switch (sizeof(MaybeUInt64)) { + case 8: + fprintf(stderr, + "\trestrictions on size of recovered file: None\n"); + break; + case 4: + fprintf(stderr, + "\trestrictions on size of recovered file: 512 MB\n"); + fprintf(stderr, + "\tto circumvent, recompile with MaybeUInt64 as an\n" + "\tunsigned 64-bit int.\n"); + break; + default: + fprintf(stderr, + "\tsizeof(MaybeUInt64) is not 4 or 8 -- " + "configuration error.\n"); + break; + } + exit(1); + } + + if (strlen(argv[1]) >= BZ_MAX_FILENAME-20) { + fprintf ( stderr, + "%s: supplied filename is suspiciously (>= %d chars) long. Bye!\n", + progName, (int)strlen(argv[1]) ); + 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; + + rbCtr = 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 " MaybeUInt64_FMT + " to " MaybeUInt64_FMT " (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 && + (bEnd[currBlock] - bStart[currBlock]) >= 130) { + fprintf ( stderr, " block %d runs from " MaybeUInt64_FMT + " to " MaybeUInt64_FMT "\n", + rbCtr+1, bStart[currBlock], bEnd[currBlock] ); + rbStart[rbCtr] = bStart[currBlock]; + rbEnd[rbCtr] = bEnd[currBlock]; + rbCtr++; + } + if (currBlock >= BZ_MAX_HANDLED_BLOCKS) + tooManyBlocks(BZ_MAX_HANDLED_BLOCKS); + currBlock++; + + bStart[currBlock] = bitsRead; + } + } + + bsClose ( bsIn ); + + /*-- identified blocks run from 1 to rbCtr inclusive. --*/ + + if (rbCtr < 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 = 0; + while (True) { + b = bsGetBit(bsIn); + if (b == 2) break; + buffHi = (buffHi << 1) | (buffLo >> 31); + buffLo = (buffLo << 1) | (b & 1); + if (bitsRead == 47+rbStart[wrBlock]) + blockCRC = (buffHi << 16) | (buffLo >> 16); + + if (outFile != NULL && bitsRead >= rbStart[wrBlock] + && bitsRead <= rbEnd[wrBlock]) { + bsPutBit ( bsWr, b ); + } + + bitsRead++; + + if (bitsRead == rbEnd[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 >= rbCtr) break; + wrBlock++; + } else + if (bitsRead == rbStart[wrBlock]) { + /* Create the output file name, correctly handling leading paths. + (31.10.2001 by Sergey E. Kusikov) */ + Char* split; + Int32 ofs, k; + for (k = 0; k < BZ_MAX_FILENAME; k++) + outFileName[k] = 0; + strcpy (outFileName, inFileName); + split = strrchr (outFileName, BZ_SPLIT_SYM); + if (split == NULL) { + split = outFileName; + } else { + ++split; + } + /* Now split points to the start of the basename. */ + ofs = split - outFileName; + sprintf (split, "rec%5d", wrBlock+1); + for (p = split; *p != 0; p++) if (*p == ' ') *p = '0'; + strcat (outFileName, inFileName + ofs); + + if ( !endsInBz2(outFileName)) strcat ( outFileName, ".bz2" ); + + fprintf ( stderr, " writing block %d to `%s' ...\n", + wrBlock+1, 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, BZ_HDR_B ); + bsPutUChar ( bsWr, BZ_HDR_Z ); + bsPutUChar ( bsWr, BZ_HDR_h ); + bsPutUChar ( bsWr, BZ_HDR_0 + 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 ---*/ +/*-----------------------------------------------------------*/ |