* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
+#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "unarchive.h"
#include "libbb.h"
-#define ZIP_FILEHEADER_MAGIC 0x04034b50
-#define ZIP_CDS_MAGIC 0x02014b50
-#define ZIP_CDS_END_MAGIC 0x06054b50
-#define ZIP_DD_MAGIC 0x8074b50
+#define ZIP_FILEHEADER_MAGIC 0x04034b50
+#define ZIP_CDS_MAGIC 0x02014b50
+#define ZIP_CDS_END_MAGIC 0x06054b50
+#define ZIP_DD_MAGIC 0x08074b50
+
+
+enum {
+ zh_version,
+ zh_flags,
+ zh_method,
+ zh_modtime,
+ zh_moddate,
+ zh_crc32,
+ zh_cmpsize,
+ zh_ucmpsize,
+ zh_filename_len,
+ zh_extra_len
+};
+
+static const char fail_msg[] = "Invalid file or read error";
+
+static int le_read_int(FILE *fp, int n)
+{
+ int r = 0;
+ int s = 1;
+ int c;
+
+ archive_offset += n;
+
+ do {
+ if ((c = fgetc(fp)) == EOF) {
+ error_msg_and_die(fail_msg);
+ }
+ r += s * c;
+ s <<= 8;
+ } while (--n);
+
+ return r;
+}
+
+static void read_header(FILE *fp, int *zh)
+{
+ static const char s[] = { 2, 2, 2, 2, 2, 4, 4, 4, 2, 2, 0 };
+ int i = 0;
+
+ do {
+ zh[i] = le_read_int(fp, s[i]);
+ } while (s[++i]);
+}
file_header_t *get_header_zip(FILE *zip_stream)
{
- struct {
- short version __attribute__ ((packed));
- short flags __attribute__ ((packed));
- short method __attribute__ ((packed));
- short modtime __attribute__ ((packed));
- short moddate __attribute__ ((packed));
- int crc32 __attribute__ ((packed));
- int cmpsize __attribute__ ((packed));
- int ucmpsize __attribute__ ((packed));
- short filename_len __attribute__ ((packed));
- short extra_len __attribute__ ((packed));
- } zip_header;
+ int zip_header[10];
file_header_t *zip_entry = NULL;
- int magic;
- static int dd_ahead = 0; // If this is true, the we didn't know how long the last extraced file was
+ int magic, tmpmagic;
+ /* If dd_ahead is true, we didn't know the last extracted file's length. */
+ static int dd_ahead = 0;
- fread (&magic, 4, 1, zip_stream);
- archive_offset += 4;
+ magic = le_read_int(zip_stream, 4);
- if (feof(zip_stream)) return(NULL);
-checkmagic:
+ checkmagic:
switch (magic) {
case ZIP_FILEHEADER_MAGIC:
zip_entry = xcalloc(1, sizeof(file_header_t));
- fread (&zip_header, sizeof(zip_header), 1, zip_stream);
- archive_offset += sizeof(zip_header);
- if (!(zip_header.method == 8 || zip_header.method == 0)) { printf("Unsupported compression method %d\n", zip_header.method); return(NULL); }
- zip_entry->name = calloc(zip_header.filename_len + 1, sizeof(char));
- fread (zip_entry->name, sizeof(char), zip_header.filename_len, zip_stream);
- archive_offset += zip_header.filename_len;
- seek_sub_file(zip_stream, zip_header.extra_len);
- zip_entry->size = zip_header.cmpsize;
- if (zip_header.method == 8) zip_entry->extract_func = &inflate;
+
+ read_header(zip_stream, zip_header);
+
+ if (zip_header[zh_method] == 8) {
+ zip_entry->extract_func = &inflate;
+ } else if (zip_header[zh_method] != 0) {
+ error_msg_and_die("Unsupported compression method %d\n",
+ zip_header[zh_method]);
+ }
+
+ zip_entry->name = xmalloc(zip_header[zh_filename_len] + 1);
+ if (!fread(zip_entry->name, zip_header[zh_filename_len], 1, zip_stream)) {
+ error_msg_and_die(fail_msg);
+ }
+ archive_offset += zip_header[zh_filename_len];
+
+ seek_sub_file(zip_stream, zip_header[zh_extra_len]);
+
+ zip_entry->size = zip_header[zh_cmpsize];
+
zip_entry->mode = S_IFREG | 0777;
- // Time/Date?
- if (*(zip_entry->name + strlen(zip_entry->name) - 1) == '/') { // Files that end in a / are directories
+
+ /* Time/Date? */
+
+ zip_entry->name[zip_header[zh_filename_len]] = 0;
+ if (*(zip_entry->name + zip_header[zh_filename_len] - 1) == '/') {
+ /* Files that end in a / are directories */
+ /* Remove trailing / so unarchive doesn't get confused */
+ *(zip_entry->name + zip_header[zh_filename_len] - 1) = '\0';
zip_entry->mode ^= S_IFREG;
zip_entry->mode |= S_IFDIR;
- *(zip_entry->name + strlen(zip_entry->name) - 1) = '\0'; // Remove trailing / so unarchive doesn't get confused
}
- //printf("cmpsize: %d, ucmpsize: %d, method: %d\n", zip_header.cmpsize, zip_header.ucmpsize, zip_header.method);
- if (zip_header.flags & 0x8) { // crc32, and sizes are in the data description _after_ the file
- if (zip_header.cmpsize == 0) dd_ahead = 1; // As we don't know how long this file it is difficult to skip! but it is compressed, so normally its ok
- if (zip_header.ucmpsize != 0) dd_ahead = 2; // Humm... we would otherwise skip this twice - not good!
+
+ if (zip_header[zh_flags] & 0x8) {
+ /* crc32, and sizes are in the data description _after_ the file */
+ if (zip_header[zh_cmpsize] == 0) {
+ /* As we don't know how long this file it is difficult to skip!
+ * but it is compressed, so normally its ok */
+ dd_ahead = 1;
+ }
+ if (zip_header[zh_ucmpsize] != 0) {
+ /* Humm... we would otherwise skip this twice - not good! */
+ dd_ahead = 2;
+ }
}
break;
+
case ZIP_CDS_MAGIC: /* FALLTHRU */
case ZIP_CDS_END_MAGIC:
return(NULL);
break;
+
case ZIP_DD_MAGIC: {
int cmpsize;
seek_sub_file(zip_stream, 4); // Skip crc32
- fread(&cmpsize, 4, 1, zip_stream);
- archive_offset += 4;
+ cmpsize = le_read_int(zip_stream, 4);
if (dd_ahead == 1) archive_offset += cmpsize;
seek_sub_file(zip_stream, 4); // Skip uncompressed size
dd_ahead = 0;
return (get_header_zip(zip_stream));
break; }
+
default:
if (!dd_ahead) error_msg("Invalid magic (%#x): Trying to skip junk", magic);
dd_ahead = 0;
- while (!feof(zip_stream)) {
- int tmpmagic;
- tmpmagic = fgetc(zip_stream);
+ while ((tmpmagic = fgetc(zip_stream)) != EOF) {
archive_offset++;
magic = ((magic >> 8) & 0x00ffffff) | ((tmpmagic << 24) & 0xff000000);
- if (magic == ZIP_FILEHEADER_MAGIC || magic == ZIP_CDS_MAGIC || magic == ZIP_CDS_END_MAGIC) goto checkmagic;
+ if (magic == ZIP_FILEHEADER_MAGIC
+ || magic == ZIP_CDS_MAGIC
+ || magic == ZIP_CDS_END_MAGIC) {
+ goto checkmagic;
+ }
}
- error_msg("End of archive reached: Bad archive");
- return(NULL);
+ error_msg_and_die(fail_msg);
}
- //if (archive_offset != ftell(zip_stream)) printf("Archive offset out of sync (%d,%d)\n", (int) archive_offset, (int) ftell(zip_stream));
+
return(zip_entry);
}
projects / oweals / busybox.git / commitdiff