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/*
* Guillaume Cottenceau (gc@mandrakesoft.com)
*
* Copyright 2000 MandrakeSoft
*
* This software may be freely redistributed under the terms of the GNU
* public license.
*
* 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.
*
*/
/*
* mar - The Mandrake Archiver
*
* An archiver that supports compression (through zlib).
*
*/
/*
* This code should suffice for stage1 on-the-fly uncompression of kernel modules.
* (and it DOES perform tests and return values, blaaaah..)
*/
#include "mar.h"
void
gzerr(gzFile f) /* decrease code size */
{
fprintf(stderr, gzerror(f, &gz_errnum));
}
int
calc_integrity(struct mar_stream *s)
{
char buf[4096];
int current_crc = 0;
if (gzseek(s->mar_gzfile, sizeof(int), SEEK_SET) != sizeof(int))
{
gzerr(s->mar_gzfile);
return -1;
}
while (!gzeof(s->mar_gzfile))
{
int bytes = gzread(s->mar_gzfile, buf, sizeof(buf));
if (bytes == -1)
{
gzerr(s->mar_gzfile);
return -1;
}
DEBUG_MAR(printf("D: mar::calc_integrity more-bytes-to-handle-for-crc %d\n", bytes););
while (bytes > 0)
{
bytes--;
current_crc += buf[bytes];
}
}
DEBUG_MAR(printf("D: mar::calc_integrity computed-crc %d\n", current_crc););
return current_crc;
}
int
extract_file(struct mar_stream *s, char *filename, char *dest_dir)
{
struct mar_element * elem = s->first_element;
while (elem)
{
if (strcmp(elem->filename, filename) == 0)
{
char *buf;
char *dest_file;
int fd;
dest_file = (char *) alloca(strlen(dest_dir) + strlen(filename) + 1);
strcpy(dest_file, dest_dir);
strcat(dest_file, filename);
fd = creat(dest_file, 00660);
if (fd == -1)
{
perror(dest_file);
return -1;
}
buf = (char *) alloca(elem->file_length);
if (!buf)
{
perror(dest_file);
return -1;
}
if (gzseek(s->mar_gzfile, elem->data_offset, SEEK_SET) != elem->data_offset)
{
gzerr(s->mar_gzfile);
return -1;
}
if (gzread(s->mar_gzfile, buf, elem->file_length) != elem->file_length)
{
gzerr(s->mar_gzfile);
return -1;
}
if (write(fd, buf, elem->file_length) != elem->file_length)
{
perror(dest_file);
return -1;
}
close(fd); /* do not check return value for code size */
return 0;
}
elem = elem->next_element;
}
return 1; /* 1 for file_not_found_in_archive */
}
int
open_marfile(char *filename, struct mar_stream *s)
{
int end_filetable = 0;
struct mar_element * previous_element = NULL;
/* mar_gzfile */
s->mar_gzfile = gzopen(filename, "rb");
if (!s->mar_gzfile)
{
perror(filename);
return -1;
}
/* crc32 */
if (gzread(s->mar_gzfile, &(s->crc32), sizeof(int)) != sizeof(int))
{
gzerr(s->mar_gzfile);
return -1;
}
DEBUG_MAR(printf("D: mar::open_marfile crc-in-marfile %d\n", s->crc32););
/* verify integrity */
if (s->crc32 != calc_integrity(s))
{
fprintf(stderr, "E: mar::open_marfile CRC check failed\n");
return -1;
}
else
if (gzseek(s->mar_gzfile, sizeof(int), SEEK_SET) != sizeof(int))
{
gzerr(s->mar_gzfile);
return -1;
}
while (end_filetable == 0)
{
char buf[512];
int ptr = 0;
/* read filename */
do
{
if (gzread(s->mar_gzfile, &(buf[ptr]), sizeof(char)) != sizeof(char))
{
gzerr(s->mar_gzfile);
return -1;
}
ptr++;
} while ((buf[ptr-1] != 0) && (ptr < 512));
/* ptr == 1 when we arrive on the "char 0" of the end of the filetable */
if (ptr > 1)
{
struct mar_element * e = (struct mar_element *) malloc(sizeof(struct mar_element));
e->filename = strdup(buf);
DEBUG_MAR(printf("D: mar::open_marfile processing-file %s\n", e->filename););
/* read file_length */
if (gzread(s->mar_gzfile, &(e->file_length), sizeof(int)) != sizeof(int))
{
gzerr(s->mar_gzfile);
return -1;
}
/* read data_offset */
if (gzread(s->mar_gzfile, &(e->data_offset), sizeof(int)) != sizeof(int))
{
gzerr(s->mar_gzfile);
return -1;
}
/* write down chaining */
if (previous_element)
previous_element->next_element = e;
else
s->first_element = e;
previous_element = e;
}
else
end_filetable = 1;
}
/* chaining for last element */
previous_element->next_element = NULL;
return 0;
}
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