void csArchive::ReadZipDirectory (FILE *infile)
{
ZIP_end_central_dir_record ecdr;
ZIP_central_directory_file_header cdfh;
char buff[1024]; /* Read ZIPfile from end in 1K chunks */
size_t cur_offs, min_offs, central_directory_offset;
size_t step = ZIP_END_CENTRAL_DIR_RECORD_SIZE + sizeof (hdr_endcentral);
if (!infile)
return; /* File not open */
if (fseek (infile, 0, SEEK_END))
return; /* Seek error */
if ((long) (cur_offs = ftell (infile)) == -1)
return; /* Can't get file position */
if (cur_offs >= (65535 + ZIP_END_CENTRAL_DIR_RECORD_SIZE + sizeof (hdr_endcentral)))
min_offs = cur_offs - (65535 + ZIP_END_CENTRAL_DIR_RECORD_SIZE + sizeof (hdr_endcentral));
else
min_offs = 0;
/* Try to find ZIPfile central directory structure */
/* For this we have to search from end of file the signature "PK" */
/* after which follows a two-byte END_CENTRAL_SIG */
while (cur_offs > min_offs)
{
UInt search_pos;
if (cur_offs >= sizeof (buff) - step)
cur_offs -= sizeof (buff) - step;
else
cur_offs = 0;
fseek (infile, cur_offs, SEEK_SET);
search_pos = fread (buff, 1, sizeof (buff), infile);
if (search_pos >= step)
{
register char *search_ptr;
for (search_ptr = &buff[search_pos - step]; search_ptr > buff; search_ptr--)
if ((*search_ptr == 'P') &&
(memcmp (search_ptr, hdr_endcentral, sizeof (hdr_endcentral)) == 0))
{
/* Central directory structure found */
central_directory_offset = cur_offs + (ULong) search_ptr - (ULong)buff;
LoadECDR (ecdr, &search_ptr[sizeof (hdr_endcentral)]);
if (fseek (infile, central_directory_offset + sizeof (hdr_endcentral) + ZIP_END_CENTRAL_DIR_RECORD_SIZE, SEEK_SET)
|| !ReadArchiveComment (infile, ecdr.zipfile_comment_length)
|| fseek (infile, ecdr.offset_start_central_directory, SEEK_SET))
goto rebuild_cdr; /* Broken central directory */
/* Now read central directory structure */
for (;;)
{
if ((fread (buff, 1, sizeof (hdr_central), infile) < sizeof (hdr_central))
|| (memcmp (buff, hdr_central, sizeof (hdr_central)) != 0))
{
if (dir.Length ())
return; /* Finished reading central directory */
else
goto rebuild_cdr; /* Broken central directory */
}
if ((!ReadCDFH (cdfh, infile))
|| (cdfh.filename_length > sizeof (buff))
|| (fread (buff, 1, cdfh.filename_length, infile) < cdfh.filename_length))
return; /* Broken zipfile? */
buff[cdfh.filename_length] = 0;
if ((buff[cdfh.filename_length - 1] == PATH_SEPARATOR)
|| (buff[cdfh.filename_length - 1] == PATH_SEPARATOR_2))
{
if (fseek (infile, cdfh.extra_field_length + cdfh.file_comment_length, SEEK_CUR))
return; /* Broken zipfile? */
continue;
} /* endif */
ArchiveEntry *curentry = InsertEntry (buff, cdfh);
if (!curentry->ReadExtraField (infile, cdfh.extra_field_length)
|| !curentry->ReadFileComment (infile, cdfh.file_comment_length))
return; /* Broken zipfile? */
} /* endfor */
} /* endif */
} /* endif */
} /* endwhile */
rebuild_cdr:
/* If we are here, we did not succeeded to read central directory */
/* If so, we have to rebuild it by reading each ZIPfile member separately */
if (fseek (infile, 0, SEEK_SET))
return;
ReadZipEntries (infile);
}
