ZipFile.cpp

   1 /*
   2  * This file is part of NumptyPhysics
   3  * Copyright (C) 2008 Tim Edmonds
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation; either version 3 of the
   8  * License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  */
  16
  17 #include "ZipFile.h"
  18 #include <string>
  19 #include <cstring>
  20 #include <cstdio>
  21 #include <fcntl.h>
  22 #include <sys/stat.h>
  23 #include <sys/mman.h>
  24 #include <unistd.h>
  25 #include <zlib.h>
  26
  27 //zip file structs and uncompress_int below lifted from navit project (GPL).
  28 struct zip_lfh {
  29         int ziplocsig;
  30         short zipver;
  31         short zipgenfld;
  32         short zipmthd;
  33         short ziptime;
  34         short zipdate;
  35         int zipcrc;
  36         unsigned int zipsize;
  37         unsigned int zipuncmp;
  38         unsigned short zipfnln;
  39         unsigned short zipxtraln;
  40         char zipname[0];
  41 } __attribute__ ((packed));
  42
  43 struct zip_cd {
  44         int zipcensig;
  45         char zipcver;
  46         char zipcos;
  47         char zipcvxt;
  48         char zipcexos;
  49         short zipcflg;
  50         short zipcmthd;
  51         short ziptim;
  52         short zipdat;
  53         int zipccrc;
  54         unsigned int zipcsiz;
  55         unsigned int zipcunc;
  56         unsigned short zipcfnl;
  57         unsigned short zipcxtl;
  58         unsigned short zipccml;
  59         unsigned short zipdsk;
  60         unsigned short zipint;
  61         unsigned int zipext;
  62         unsigned int zipofst;
  63         char zipcfn[0];
  64 } __attribute__ ((packed));
  65
  66 struct zip_eoc {
  67         int zipesig;
  68         unsigned short zipedsk;
  69         unsigned short zipecen;
  70         unsigned short zipenum;
  71         unsigned short zipecenn;
  72         unsigned int zipecsz;
  73         unsigned int zipeofst;
  74         short zipecoml;
  75         char zipecom[0];
  76 } __attribute__ ((packed));
  77
  78 int uncompress_int(unsigned char *dest, int *destLen,
  79                    const unsigned char *source, int sourceLen)
  80 {
  81   z_stream stream;
  82   int err;
  83
  84   stream.next_in = (Bytef*)source;
  85   stream.avail_in = (uInt)sourceLen;
  86   stream.next_out = dest;
  87   stream.avail_out = (uInt)*destLen;
  88
  89   stream.zalloc = (alloc_func)0;
  90   stream.zfree = (free_func)0;
  91
  92   err = inflateInit2(&stream, -MAX_WBITS);
  93   if (err != Z_OK) return err;
  94
  95   err = inflate(&stream, Z_FINISH);
  96   if (err != Z_STREAM_END) {
  97     inflateEnd(&stream);
  98     if (err == Z_NEED_DICT || (err == Z_BUF_ERROR && stream.avail_in == 0))
  99       return Z_DATA_ERROR;
 100     return err;
 101     }
 102   *destLen = stream.total_out;
 103
 104   err = inflateEnd(&stream);
 105   return err;
 106 }
 107
 108
 109
 110 ZipFile::ZipFile(const std::string& fn)
 111 {
 112   m_temp = NULL;
 113   m_fd=open(fn.c_str(), O_RDONLY);
 114   struct stat stat;
 115   fstat(m_fd, &stat);
 116   m_dataLen = stat.st_size;
 117   // TODO - win32
 118   m_data = (unsigned char*)mmap(NULL,m_dataLen,PROT_READ,MAP_PRIVATE, m_fd, 0);
 119   if ( !m_data ) throw "mmap failed";
 120   if ( *(int*)&m_data[0] != 0x04034b50 ) throw "bad zip magic";
 121   m_eoc = (zip_eoc*)&m_data[m_dataLen-sizeof(zip_eoc)];
 122   m_firstcd = (zip_cd*)&m_data[m_eoc->zipeofst];
 123   if ( m_eoc && m_firstcd ) {
 124     m_entries = m_eoc->zipenum;
 125   } else {
 126     m_entries = 0;
 127   }
 128 }
 129
 130
 131 ZipFile::~ZipFile()
 132 {
 133   delete[] m_temp;
 134   if ( m_data ) munmap( m_data, m_dataLen );
 135   if ( m_fd ) close( m_fd );
 136 }
 137
 138
 139 std::string ZipFile::entryName( int n )
 140 {
 141   if ( n < 0 || n >= m_entries ) return std::string();
 142   zip_cd* cd = m_firstcd;
 143   for ( int count=0; cd < (zip_cd*)m_eoc && count < n; count++ ) {
 144     cd = (zip_cd*)(((char*)cd) + sizeof(zip_cd) + cd->zipcfnl + cd->zipcxtl + cd->zipccml);
 145   }
 146   zip_lfh* lfh = (zip_lfh*)&m_data[cd->zipofst];
 147
 148   if ( lfh ) {
 149     return std::string(lfh->zipname,lfh->zipfnln);
 150   }
 151   return std::string();
 152 }
 153
 154 unsigned char* ZipFile::extract( int n, int *l )
 155 {
 156   if ( n < 0 || n >= m_entries ) return NULL;
 157   zip_cd* cd = m_firstcd;
 158   for ( int count=0; cd < (zip_cd*)m_eoc && count < n; count++ ) {
 159     cd = (zip_cd*)(((char*)cd) + sizeof(zip_cd) + cd->zipcfnl + cd->zipcxtl + cd->zipccml);
 160   }
 161   zip_lfh* lfh = (zip_lfh*)&m_data[cd->zipofst];
 162
 163   if ( lfh ) {
 164     *l = lfh->zipuncmp;
 165     unsigned char* zdat = (unsigned char*)lfh + sizeof(*lfh) + lfh->zipfnln + lfh->zipxtraln;
 166     switch (lfh->zipmthd) {
 167     case 0:
 168       return zdat;
 169     case 8:
 170       delete[] m_temp;
 171       m_temp = new unsigned char[*l];
 172       if ( uncompress_int(m_temp, l, zdat, lfh->zipsize) == Z_OK) {
 173         return m_temp;
 174       }
 175     }
 176   }
 177   return NULL;
 178 }
 179
 180
 181
 182