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Modified so that it "works" for archs other than i386... arm in particular.

Browse Source 
Also tried to clean up the logic a little, and ensure that read errors
or invalid archives resulted in error returns.  This could use a lot more
work... Volunteers?
This commit is contained in:
Manuel Novoa III 2002-09-17 21:02:16 +00:00
parent 60943c5d5c
commit 6c32a8add4
1 changed files with 108 additions and 47 deletions
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147
archival/libunarchive/get_header_zip.c
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@ -19,6 +19,7 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/ */
#include <stddef.h>
#include <stdio.h> #include <stdio.h>
#include <stdlib.h> #include <stdlib.h>
#include <string.h> #include <string.h>
@ -28,83 +29,143 @@
#define ZIP_FILEHEADER_MAGIC 0x04034b50 #define ZIP_FILEHEADER_MAGIC 0x04034b50
#define ZIP_CDS_MAGIC 0x02014b50 #define ZIP_CDS_MAGIC 0x02014b50
#define ZIP_CDS_END_MAGIC 0x06054b50 #define ZIP_CDS_END_MAGIC 0x06054b50
#define ZIP_DD_MAGIC 0x8074b50 #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) file_header_t *get_header_zip(FILE *zip_stream)
{ {
struct { int zip_header[10];
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;
file_header_t *zip_entry = NULL; file_header_t *zip_entry = NULL;
int magic; int magic, tmpmagic;
static int dd_ahead = 0; // If this is true, the we didn't know how long the last extraced file was /* 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); magic = le_read_int(zip_stream, 4);
archive_offset += 4;
if (feof(zip_stream)) return(NULL);
checkmagic: checkmagic:
switch (magic) { switch (magic) {
case ZIP_FILEHEADER_MAGIC: case ZIP_FILEHEADER_MAGIC:
zip_entry = xcalloc(1, sizeof(file_header_t)); zip_entry = xcalloc(1, sizeof(file_header_t));
fread (&zip_header, sizeof(zip_header), 1, zip_stream);
archive_offset += sizeof(zip_header); read_header(zip_stream, 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)); if (zip_header[zh_method] == 8) {
fread (zip_entry->name, sizeof(char), zip_header.filename_len, zip_stream); zip_entry->extract_func = &inflate;
archive_offset += zip_header.filename_len; } else if (zip_header[zh_method] != 0) {
seek_sub_file(zip_stream, zip_header.extra_len); error_msg_and_die("Unsupported compression method %d\n",
zip_entry->size = zip_header.cmpsize; zip_header[zh_method]);
if (zip_header.method == 8) zip_entry->extract_func = &inflate; }
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; 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_IFREG;
zip_entry->mode |= S_IFDIR; 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[zh_flags] & 0x8) {
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 /* crc32, and sizes are in the data description _after_ the file */
if (zip_header.ucmpsize != 0) dd_ahead = 2; // Humm... we would otherwise skip this twice - not good! 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; break;
case ZIP_CDS_MAGIC: /* FALLTHRU */ case ZIP_CDS_MAGIC: /* FALLTHRU */
case ZIP_CDS_END_MAGIC: case ZIP_CDS_END_MAGIC:
return(NULL); return(NULL);
break; break;
case ZIP_DD_MAGIC: { case ZIP_DD_MAGIC: {
int cmpsize; int cmpsize;
seek_sub_file(zip_stream, 4); // Skip crc32 seek_sub_file(zip_stream, 4); // Skip crc32
fread(&cmpsize, 4, 1, zip_stream); cmpsize = le_read_int(zip_stream, 4);
archive_offset += 4;
if (dd_ahead == 1) archive_offset += cmpsize; if (dd_ahead == 1) archive_offset += cmpsize;
seek_sub_file(zip_stream, 4); // Skip uncompressed size seek_sub_file(zip_stream, 4); // Skip uncompressed size
dd_ahead = 0; dd_ahead = 0;
return (get_header_zip(zip_stream)); return (get_header_zip(zip_stream));
break; } break; }
default: default:
if (!dd_ahead) error_msg("Invalid magic (%#x): Trying to skip junk", magic); if (!dd_ahead) error_msg("Invalid magic (%#x): Trying to skip junk", magic);
dd_ahead = 0; dd_ahead = 0;
while (!feof(zip_stream)) { while ((tmpmagic = fgetc(zip_stream)) != EOF) {
int tmpmagic;
tmpmagic = fgetc(zip_stream);
archive_offset++; archive_offset++;
magic = ((magic >> 8) & 0x00ffffff) | ((tmpmagic << 24) & 0xff000000); 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);
} }
//if (archive_offset != ftell(zip_stream)) printf("Archive offset out of sync (%d,%d)\n", (int) archive_offset, (int) ftell(zip_stream)); error_msg_and_die(fail_msg);
}
return(zip_entry); return(zip_entry);
} }