urarlib.c

一个解RAR文件的开发库源码

    sprintf(DebugMsg, "Extracted %u Bytes.", (unsigned int)*size);
  }
  debug_log(DebugMsg);
#else
  }
#endif
  *(DWORD*)output=(DWORD)temp_output_buffer;/* return pointer for unpacked*/
                                            /* data                       */
  
  return retcode;
}


int urarlib_list(void *rarfile, ArchiveList_struct *list)
{
  ArchiveList_struct *tmp_List = NULL;
  int NoOfFilesInArchive       = 0;         /* number of files in archive   */

#ifdef _DEBUG_LOG
  if(debug_log_first_start)
  {
    debug_log_first_start=FALSE;            /* only create a new log file   */
    debug_init(_DEBUG_LOG_FILE);            /* on startup                   */
  }
#endif

  InitCRC();                                /* init some vars               */

#ifdef _USE_MEMORY_TO_MEMORY_DECOMPRESSION
  MemRARFile         = rarfile;             /* assign pointer to RAR file   */
  MemRARFile->offset = 0;
  if (!IsArchive())
  {
    debug_log("Not a RAR file");
    return NoOfFilesInArchive;              /* error => exit!               */
  } 
#else
  /* open and identify archive                                              */
  if ((ArcPtr=fopen(rarfile,READBINARY))!=NULL)
  {
    if (!IsArchive())
    {
      debug_log("Not a RAR file");
      fclose(ArcPtr);
      ArcPtr = NULL;
      return NoOfFilesInArchive;            /* error => exit!               */
    }
  }
  else {
    debug_log("Error opening file.");
    return NoOfFilesInArchive;
  }
#endif

  if ((UnpMemory=malloc(UNP_MEMORY))==NULL)
  {
    debug_log("Can't allocate memory for decompression!");
    return NoOfFilesInArchive;
  }

#ifdef _USE_MEMORY_TO_MEMORY_DECOMPRESSION
  MemRARFile->offset+=NewMhd.HeadSize-MainHeadSize;
#else
  tseek(ArcPtr,NewMhd.HeadSize-MainHeadSize,SEEK_CUR);
#endif
  (void*)(*(DWORD*)list) = NULL;            /* init file list               */
  /* do while file is not extracted and there's no error                    */
  while (TRUE)
  {
    if (ReadBlock(FILE_HEAD | READSUBBLOCK) <= 0) /* read name of the next  */
    {                                       /* file within the RAR archive  */
      debug_log("Couldn't read next filename from archive (I/O error).");
      break;                                /* error, file not found in     */
    }                                       /* archive or I/O error         */
    if (BlockHead.HeadType==SUB_HEAD)
    {
      debug_log("Sorry, sub-headers not supported.");
      break;                                /* error => exit                */
    }

    if((void*)(*(DWORD*)list) == NULL)      /* first entry                  */
    {
      tmp_List = malloc(sizeof(ArchiveList_struct));
      tmp_List->next = NULL;

      (void*)(*(DWORD*)list) = tmp_List;
 
    } else                                  /* add entry                    */
    {
      tmp_List->next = malloc(sizeof(ArchiveList_struct));
      tmp_List = (ArchiveList_struct*) tmp_List->next;
      tmp_List->next = NULL;
    }

    tmp_List->item.Name = malloc(NewLhd.NameSize + 1);
    strcpy(tmp_List->item.Name, ArcFileName);
    tmp_List->item.NameSize = NewLhd.NameSize;
    tmp_List->item.PackSize = NewLhd.PackSize;
    tmp_List->item.UnpSize = NewLhd.UnpSize;
    tmp_List->item.HostOS = NewLhd.HostOS;
    tmp_List->item.FileCRC = NewLhd.FileCRC;
    tmp_List->item.FileTime = NewLhd.FileTime;
    tmp_List->item.UnpVer = NewLhd.UnpVer;
    tmp_List->item.Method = NewLhd.Method;
    tmp_List->item.FileAttr = NewLhd.FileAttr;

    NoOfFilesInArchive++;                   /* count files                  */

#ifdef _USE_MEMORY_TO_MEMORY_DECOMPRESSION
    MemRARFile->offset = NextBlockPos;
#else
    if (ArcPtr!=NULL) tseek(ArcPtr,NextBlockPos,SEEK_SET);
#endif

  }; 

  /* free memory, clear password and close archive                          */
  memset(Password,0,sizeof(Password));      /* clear password               */
#ifndef _USE_MEMORY_TO_MEMORY_DECOMPRESSION
  if (ArcPtr!=NULL){
      fclose(ArcPtr);
      ArcPtr = NULL;
  }
#endif

  free(UnpMemory);                          /* free memory                  */
  free(TempMemory);
  free(CommMemory);
  UnpMemory=NULL;
  TempMemory=NULL;
  CommMemory=NULL;
 
  return NoOfFilesInArchive;
}

/* ------------------------------------------------------------------------ */

















/****************************************************************************
 ****************************************************************************
 ****************************************************************************
 ****************************************************************************
 *******                                                              *******
 *******                                                              *******
 *******                                                              *******
 *******                    B L O C K   I / O                         *******
 *******                                                              *******
 *******                                                              *******
 *******                                                              *******
 ****************************************************************************
 ****************************************************************************
 ****************************************************************************
 ****************************************************************************/



#define GetHeaderByte(N) Header[N]

#define GetHeaderWord(N) (Header[N]+((UWORD)Header[N+1]<<8))

#define GetHeaderDword(N) (Header[N]+((UWORD)Header[N+1]<<8)+\
                          ((UDWORD)Header[N+2]<<16)+\
                          ((UDWORD)Header[N+3]<<24))


int ReadBlock(int BlockType)
{
  struct NewFileHeader SaveFileHead;
  int Size=0,ReadSubBlock=0;
  static int LastBlock;
  memcpy(&SaveFileHead,&NewLhd,sizeof(SaveFileHead));
  if (BlockType & READSUBBLOCK)
    ReadSubBlock=1;
  BlockType &= 0xff;
  {
    while (1)
    {
#ifdef _USE_MEMORY_TO_MEMORY_DECOMPRESSION
      CurBlockPos=MemRARFile->offset;       /* get offset of mem-file       */
#else
      CurBlockPos=ftell(ArcPtr);
#endif
      Size=ReadHeader(FILE_HEAD);
      if (Size!=0)
      {
        if (NewLhd.HeadSize<SIZEOF_SHORTBLOCKHEAD)
          return(0);
        NextBlockPos=CurBlockPos+NewLhd.HeadSize;
        if (NewLhd.Flags & LONG_BLOCK)
          NextBlockPos+=NewLhd.PackSize;
        if (NextBlockPos<=CurBlockPos)
          return(0);
      }

      if (Size > 0 && BlockType!=SUB_HEAD)
        LastBlock=BlockType;
      if (Size==0 || BlockType==ALL_HEAD || NewLhd.HeadType==BlockType ||
          (NewLhd.HeadType==SUB_HEAD && ReadSubBlock && LastBlock==BlockType))
        break;
#ifdef _USE_MEMORY_TO_MEMORY_DECOMPRESSION
      MemRARFile->offset = NextBlockPos;
#else
      tseek(ArcPtr, NextBlockPos, SEEK_SET);
#endif
    }
  }

  BlockHead.HeadCRC=NewLhd.HeadCRC;
  BlockHead.HeadType=NewLhd.HeadType;
  BlockHead.Flags=NewLhd.Flags;
  BlockHead.HeadSize=NewLhd.HeadSize;
  BlockHead.DataSize=NewLhd.PackSize;

  if (BlockType!=NewLhd.HeadType) BlockType=ALL_HEAD;

  if((FILE_HEAD == BlockType) && (Size>0))
  {
    NewLhd.NameSize=Min(NewLhd.NameSize,sizeof(ArcFileName)-1);
#ifdef _USE_MEMORY_TO_MEMORY_DECOMPRESSION
    tread(MemRARFile, ArcFileName, NewLhd.NameSize);
#else
    tread(ArcPtr,ArcFileName,NewLhd.NameSize);
#endif
    ArcFileName[NewLhd.NameSize]=0;
#ifdef _DEBUG_LOG
    if (NewLhd.HeadCRC!=(UWORD)~CalcCRC32(HeaderCRC,(UBYTE*)&ArcFileName[0],
                                          NewLhd.NameSize))
    {
      debug_log("file header broken");
    }
#endif
    Size+=NewLhd.NameSize;      
  } else
  { 
    memcpy(&NewLhd,&SaveFileHead,sizeof(NewLhd));
#ifdef _USE_MEMORY_TO_MEMORY_DECOMPRESSION
    MemRARFile->offset = CurBlockPos;
#else
    tseek(ArcPtr,CurBlockPos,SEEK_SET);
#endif
  }


  return(Size);
}


int ReadHeader(int BlockType)
{
  int Size = 0;            
  unsigned char Header[64];
  switch(BlockType)
  {
    case MAIN_HEAD:
#ifdef _USE_MEMORY_TO_MEMORY_DECOMPRESSION
        Size=tread(MemRARFile, Header, SIZEOF_NEWMHD);
#else
        Size=tread(ArcPtr,Header,SIZEOF_NEWMHD);
#endif
        NewMhd.HeadCRC=(unsigned short)GetHeaderWord(0);
        NewMhd.HeadType=GetHeaderByte(2);
        NewMhd.Flags=(unsigned short)GetHeaderWord(3);
        NewMhd.HeadSize=(unsigned short)GetHeaderWord(5);
        NewMhd.Reserved=(unsigned short)GetHeaderWord(7);
        NewMhd.Reserved1=GetHeaderDword(9);
        HeaderCRC=CalcCRC32(0xFFFFFFFFL,&Header[2],SIZEOF_NEWMHD-2);
      break;
    case FILE_HEAD:
#ifdef _USE_MEMORY_TO_MEMORY_DECOMPRESSION
        Size=tread(MemRARFile, Header, SIZEOF_NEWLHD);
#else
        Size=tread(ArcPtr,Header,SIZEOF_NEWLHD);
#endif
        NewLhd.HeadCRC=(unsigned short)GetHeaderWord(0);
        NewLhd.HeadType=GetHeaderByte(2);
        NewLhd.Flags=(unsigned short)GetHeaderWord(3);
        NewLhd.HeadSize=(unsigned short)GetHeaderWord(5);
        NewLhd.PackSize=GetHeaderDword(7);
        NewLhd.UnpSize=GetHeaderDword(11);
        NewLhd.HostOS=GetHeaderByte(15);
        NewLhd.FileCRC=GetHeaderDword(16);
        NewLhd.FileTime=GetHeaderDword(20);
        NewLhd.UnpVer=GetHeaderByte(24);
        NewLhd.Method=GetHeaderByte(25);
        NewLhd.NameSize=(unsigned short)GetHeaderWord(26);
        NewLhd.FileAttr=GetHeaderDword(28);
        HeaderCRC=CalcCRC32(0xFFFFFFFFL,&Header[2],SIZEOF_NEWLHD-2);
      break;

#ifdef _DEBUG_LOG
  case COMM_HEAD:                           /* log errors in case of debug  */
        debug_log("Comment headers not supported! "\
                  "Please create archives without comments.");
      break;
  case PROTECT_HEAD:
        debug_log("Protected headers not supported!");
      break;
  case ALL_HEAD:
        debug_log("ShortBlockHeader not supported!");
      break;
  default:
        debug_log("Unknown//unsupported !");
#else
  default:                                  /* else do nothing              */
        break;
#endif
  }
  return(Size);
}

/* **************************************************************************
 ****************************************************************************
 ****************************************************************************
 ************************************************************************** */

















/* **************************************************************************
 ****************************************************************************
 ****************************************************************************
 ****************************************************************************
 *******                                                              *******
 *******                                                              *******
 *******                                                              *******
 *******                  E X T R A C T   L O O P                     *******
 *******                                                              *******
 *******                                                              *******
 *******                                                              *******
 ****************************************************************************
 ****************************************************************************
 ****************************************************************************
 ************************************************************************** */


int IsArchive(void)
{
#ifdef _DEBUG_LOG
  int  str_offs;                            /* used for debug-strings       */
  char DebugMsg[500];                       /* used to compose debug msg    */
#endif

#ifdef _USE_MEMORY_TO_MEMORY_DECOMPRESSION
  if (tread(MemRARFile, MarkHead.Mark, SIZEOF_MARKHEAD) != SIZEOF_MARKHEAD)
    return(FALSE);
#else
  if (tread(ArcPtr,MarkHead.Mark,SIZEOF_MARKHEAD)!=SIZEOF_MARKHEAD)
    return(FALSE);
#endif
  /* Old archive => error                                                   */
  if (MarkHead.Mark[0]==0x52 && MarkHead.Mark[1]==0x45 &&
      MarkHead.Mark[2]==0x7e && MarkHead.Mark[3]==0x5e)
  {
    debug_log("Attention: format as OLD detected! Can't handel archive!");
  }
  else
      /* original RAR v2.0                                                  */
      if ((MarkHead.Mark[0]==0x52 && MarkHead.Mark[1]==0x61 && /* original  */
           MarkHead.Mark[2]==0x72 && MarkHead.Mark[3]==0x21 && /* RAR header*/
           MarkHead.Mark[4]==0x1a && MarkHead.Mark[5]==0x07 &&
           MarkHead.Mark[6]==0x00) ||
     /* "UniquE!" - header                                                  */
          (MarkHead.Mark[0]=='U' && MarkHead.Mark[1]=='n' &&   /* "UniquE!" */
           MarkHead.Mark[2]=='i' && MarkHead.Mark[3]=='q' &&   /* header    */
           MarkHead.Mark[4]=='u' && MarkHead.Mark[5]=='E' &&
           MarkHead.Mark[6]=='!'))

    {
      if (ReadHeader(MAIN_HEAD)!=SIZEOF_NEWMHD)
        return(FALSE);
    } else
    {

#ifdef _DEBUG_LOG
     /* sorry for this ugly code, but older SunOS gcc compilers don't       */
     /* support white spaces within strings                                 */
     str_offs  = sprintf(DebugMsg, "unknown archive type (only plain RAR ");
     str_offs += sprintf(DebugMsg + str_offs, "supported (normal and solid ");
     str_offs += sprintf(DebugMsg + str_offs, "archives), SFX and Volumes ");
     str_offs += sprintf(DebugMsg + str_offs, "are NOT supported!)");

     debug_log(DebugMsg);
#endif
                
    }


  MainHeadSize=SIZEOF_NEWMHD;
 
  return(TRUE);
}


BOOL ExtrFile(void)
{
  BOOL ReturnCode=TRUE;
  FileFound=FALSE;                          /* no file found by default     */

#ifdef  _USE_MEMORY_TO_MEMORY_DECOMPRESSION
  MemRARFile->offset = 0;                   /* start reading from offset 0  */
  if (!IsArchive())
  {
    debug_log("Not a RAR file");
    return FALSE;                           /* error => exit!               */
  }

#else
  /* open and identify archive                                              */
  if ((ArcPtr=fopen(ArcName,READBINARY))!=NULL)
  {
    if (!IsArchive())
    {
      debug_log("Not a RAR file");
      fclose(ArcPtr);
      ArcPtr = NULL;
      return FALSE;                         /* error => exit!               */
    }
  } else
  {
    debug_log("Error opening file.");
    return FALSE;                 
  }
#endif


  if ((UnpMemory=malloc(UNP_MEMORY))==NULL)
  {
    debug_log("Can't allocate memory for decompression!");
    return FALSE;                 
  }

#ifdef _USE_MEMORY_TO_MEMORY_DECOMPRESSION
  MemRARFile->offset+=NewMhd.HeadSize-MainHeadSize;
#else